# Global Perspective of Plant-Based Cosmetic Industry and Possible Contribution of Sri Lanka to the Development of Herbal Cosmetics

Authors: Dehel Gamage Nadeeshani Dilhara Gamage; Rathnayaka Mudiyanselage Dharmadasa; Don Chandana Abeysinghe; Rathnayaka Gamlathge Saman Wijesekara; Gamika A. Prathapasinghe; Takao Someya
Journal: Evidence-Based Complementary and Alternative Medicine
 (2022)

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## Abstract

The global consumption of plant-based cosmetics has shown spectacular growth in recent years because of rising consumer awareness regarding the long-term health benefits of natural ingredients. As the global demand for herbal cosmetics increases, there are ample opportunities for Sri Lanka as a tropical Asian country to expand its productions and global exports along with its unique biodiversity and inherited traditional knowledge. Therefore, the present review attempts to give an overview of the widely used medicinal plants in the global herbal cosmetic industry and strengths, challenges, and possible solutions for the development of the herbal cosmetic industry of Sri Lanka. Information was collected using electronic search (using Pub Med, Science Direct, Web of Science, Google Scholar, TEEAL, and Scopus) for articles published in peer-reviewed journals, industrial reports, market surveys, and library search for local books on ethnobotany. Important plant-derived ingredients used in the global herbal cosmetic industry are essential oils, colorants, oils, fats, and waxes. The traditional usage of 108 medicinal plant species (belonging to 58 families) in cosmetic treatments was identified from the local books of Sri Lanka. Of these, 49 plant species were reported as new ingredients for the herbal cosmetic industry. However, the lack of ethnobotanical and ethnopharmacological surveys to identify the cosmetic potential plants, insufficient or absence of continuous supply of raw materials for production in line with the existing demand, the lack of quality control of raw materials and finished cosmetic products, improper systematic cultivation systems for medicinal plants, poor postharvest practices, and the lack of innovations are major challenges encountered in Sri Lanka for the development of the herbal cosmetic industry. In conclusion, addressing these vital knowledge gaps is a timely requirement of the country for the sustainable development of the herbal cosmetic industry in Sri Lanka. Furthermore, assembling of the multidisciplinary cooperation of botanists, chemists, toxicologists, researchers, and biologists is crucial to analyze the interesting functional properties, efficacy, and effectiveness of documented medicinal plants with cosmetic potential.


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## Body

## 1. Introduction

In today’s world, being presentable and looking great have become necessary for everyone [1]. The growing consumer demand for cosmetics is mainly driven by the aspiring young population who want to invest in grooming while maintaining their health [2]. Nonetheless, most individuals in different age groups use cosmetics in various forms [3]. With its huge profitability, it is a challenge for a manufacturer to provide a good quality product at a low cost that is simultaneously environmentally friendly [4]. Although cosmetic products are not generally associated with serious health risks, there are possibilities of adverse long-term effects of extensive usage of cosmetics [5]. For instance, cosmetics and toiletries may contain several hazardous ingredients: allergens, carcinogens, and endocrine disruptors. The various harmful allergens present in cosmetics may be grouped under phthalates, parabens, metals, chlorofluorocarbon propellants, and dioxanes. The bioaccumulation of these harmful chemicals and metals in the body over time has been associated with cancers, reproductive and developmental disorders, contact dermatitis, hair loss, lung damage, aging, allergies, and skin diseases [5, 6].With the increasing awareness about the fewer side effects of herbal products [7], consumer demand for herbal cosmetics is becoming a rapidly growing segment globally [8]. The global natural and organic personal care products market is valued approximately at US$ 11 billion in 2016 and is expected to reach US$ 22 billion by 2022 [9]. North America is the major market for natural and organic personal care products, followed by Europe and Asia-Pacific. China and India are the specific countries that play a significant role in the global herbal cosmetics market. Natural and organic skin care maintains top billing in the global organic beauty market and is expected to emerge as the most attractive segment with a 30.9% share by 2024, followed by hair care [10].Cosmeceuticals, which are cosmetic products containing naturally derived ingredients and fully organic cosmetic products, have become a trend at present. Consumer attraction for these products in the future is anticipated to grow significantly. Thus, the global demand for herbal cosmetics results in a huge trade from the local to the international level. At present, the majority of the developed countries’ cosmetic manufacturers are continuously probing for new products and ingredients that are of tropical origin as their raw materials often have interesting properties because of varied climatic and topographical conditions [11]. Unfortunately, the plant-based cosmetic industry is still at its early stages in some tropical Asian countries, such as Sri Lanka, Vietnam, Indonesia, and Thailand. For the successful development of the herbal cosmetic industry in those countries, several challenges must be addressed. This review aims to give an overview of these points while providing widely used medicinal plants in the global herbal cosmetic industry. Furthermore, this review will highlight the possible contribution of Sri Lanka as a tropical Asian country to the development of herbal cosmetics.


## 2. Methodology

The process of bibliographic research was conducted from January 2020 to August 2020, comprehending works from 1999 to 2019. This review was mainly focused to address the following research questions:(1)
What is the present status of the global herbal cosmetic industry, including market annual growth, leading cosmetic product categories, and the pioneers of the herbal cosmetic industry by geographical zones and countries?(2)
What are the widely used specialty plant materials in global herbal cosmetic production and their functions?(3)
What is the present status of the herbal cosmetic industry of Sri Lanka?(4)
What are the strengths, challenges, and possible solutions for the development of the herbal cosmetic industry of Sri Lanka as a tropical Asian country?The research was organized in two phases. Data extraction was done by two investigators (D.G.N.D. Gamage and R.M. Dharmadasa) independently at each phase. Any inconsistencies between the investigators were resolved by consensus with a third investigator (D.C. Abeysinghe). Information was gathered by adopting databases, such as Pub Med, Science Direct, Web of Science, Google Scholar, TEEAL, Wiley Online Library (Wiley), and Scopus.During the first phase, information was collected on the global herbal cosmetic industry. Extensive bibliographic research was performed using keywords and syntax, such as “herbal cosmetics,” “global herbal cosmetic industry,” “medicinal plants with cosmetic potential,” “specialty plant materials used for cosmetic production and their functions,” “essential oils,” “plant-based dye and colorants,” “plant oils used in cosmetics,” “fat and waxes for cosmetics,” “herbal cosmetic industry in China,” “herbal cosmetic industry in India,” “medicinal plants used in cosmetics in China,” “Cosmetic treatments and traditional Chinese medicine,” and “medicinal plants used in skin care/hair care/oral care in India.” Furthermore, references listed in relevant journals were also screened. 218 journals were identified using databases, whereas 20 web resources, 13 industrial reports, 01 book, and 03 book chapters were identified using “Google” search. However, 93 journals, 14 web resources, 10 industrial reports, 01 book (International Cosmetic Ingredient Dictionary and Handbook, published by Personal Care Products Council, Washington), and 03 book chapters (The Therapeutic Benefits of Essential Oils, Chinese Topical Herbal Treatments and Essential Oil Protocols and Cosmetics’ Quality Control) were utilized for writing on the global herbal cosmetic industry after excluding repeated records, suspected plagiarisms, non-peer reviewed journals, incomplete data or obvious errors of information (e.g., errors in scientific, vernacular, or English names of medicinal plants), and records in different languages. Materials in the English language alone were chosen during this phase. Furthermore, peer-reviewed journals and books, market analysis done by reputed research organizations (e.g., Future Market Insights/FMI), industry reports developed by governments or recognized non-governmental associations (e.g., Basic Chemicals, Cosmetics and Dyes Export Promotion Council, India/CHEMEXCIL, The Associated Chambers of Commerce and Industry of India/ASSOCHAM), ethnobotanical and ethnopharmacological surveys with minimum sample size andin vitro bioactivity studies of medicinal plants with a minimum number of replications were considered to be eligibility materials for writing in this phase. Moreover, extracted data from the publications on medicinal plants with cosmetic potential in China were compared with the “Inventory of Existing Cosmetic Ingredients in China (IECIC)-2015” issued by the National Medical Products Administration, China to confirm the usage of identified plant materials in the cosmetic industry. Cross-checking was performed by two investigators (D. G. N. D. Gamage and R. G. S. Wijesekara). However, no inventories or dictionaries of cosmetic ingredients were found for data comparison in India.During the second phase, information on the herbal cosmetic industry of Sri Lanka, the traditional usage of medicinal plants in cosmetic treatments, strengths, and challenges for the development of the herbal cosmetic industry of Sri Lanka was accumulated. The bibliographic research was performed using keywords and syntax, such as “herbal cosmetics of Sri Lanka,” “herbal cosmetic industry of Sri Lanka,” “medicinal plants used for cosmetic treatments in Sri Lanka,” “medicinal plants and bioactivity studies in Sri Lanka,” and “medicinal plants used in skin care/hair care/oral care in Sri Lanka.” The numbers of records identified using databases and “Google” searching were 95 and 17, respectively. After applying the same inclusion and exclusion criteria, only 14 publications and 2 conference proceedings (Current scenario on the import of plant-based Ayurvedic raw materials in Sri Lanka and Current scenario of herbal medicine in Sri Lanka) were accepted for writing in this phase. Because of the lack of relevant publications available in databases, data extraction was focused by searching local books from the libraries of Industrial Technology Institute, National Science Foundation and Institute of Indigenous Medicine, University of Colombo in Sri Lanka. Therefore, both English and Sinhala languages were considered during the search of libraries. Four Ayurveda authentic books, namely the “Compendium of medicinal plants-Sri Lankan study, volumes I, II, III, and IV,” published by the Ayurveda Department of Sri Lanka and the book called “A collection of medicinal plants in Sri Lanka,” published by Nature’s Beauty Creations Limited, Sri Lanka, were selected to identify potential medicinal plants for cosmetic productions. The current usage of identified medicinal plants with cosmetic potential through books was compared with the survey conducted on identifying medicinal plants used in the herbal cosmetic industry of Sri Lanka [12] to recognize new plant materials for the Sri Lankan herbal cosmetic industry.In total, 107 peer-reviewed journal articles, 14 web resources, 10 industrial reports, 6 books, 2 conference papers from proceedings, and 3 book chapters were employed for writing this review. Figure1 illustrates the schematic diagram of the employed methodology. The results were summarized in a narrative manner using tables. The scientific names of documented plants were validated based on the collections listed on the homepages http://www.theplantlist.org and http://www.worldfloraonline.org. In addition, important links have been given where all details cannot be provided.Figure 1
Flowchart of the study selection process.


## 3. Results and Discussion

### 3.1. Global Perspective of the Plant-Based Cosmetic Industry

#### 3.1.1. Specialty Plant Materials for Herbal Cosmetic Production

In line with the U.S. Food and Drug Administration (FDA), the law defines cosmetics as “articles intended to be rubbed, poured, sprinkled, sprayed on, introduced into, or otherwise applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance” [3]. However, products that are formulated using various permissible cosmetic ingredients to form the base in which one or more herbal ingredients are used to provide defined cosmetic benefits, e.g., influencing the functions of the skin and providing nutrients necessary for healthy skin or healthy hair, can be described as “herbal cosmetics” [13, 14]. Free-radical scavenging, anti-inflammatory, antiaging, sun protection, the reduction of hyperpigmentation, and antimicrobial effects are some of the functional benefits [15]. In the formulation of herbal cosmetics, plants are used in three ways: a total extract, a single molecule obtained from the purification of extracts, or a selective extract [16]. Some important plant-derived ingredients used in cosmetics are oils, fats, waxes, essential oils, plant extracts, and colorants. These ingredients have numerous roles in the final cosmetic products, such as coloring, scenting, moisturizing, thickening, and stabilizing [15]. The usage amount of these specialty plant materials or their extracts in herbal cosmetic products is varied according to the product category, plant materials used, national, regional (e.g., EU cosmetics regulations), and international (e.g., The International Organization for Standardization (ISO), Food and Drug Administration (FDA)) rules and regulations. For instance, the allowable level of Citrus bergamia Risso (Bergamot oil) in cosmetics is 0.1 ppm in Austria. Furthermore, in line with the EU Cosmetics Regulation, the permissible concentration of essential oil in shower gels and baths (rinse-off products) is 0.01%, while the permissible concentration of essential oil in body oils, massage oils, and creams is 0.001% [17]. However, information on the acceptable concentrations of these individual specialty plant materials in cosmetics is scarce.(1) Essential Oils. People have been using aromatic plants and oils for thousands of years in incense, perfumes, cosmetics, medicinal, and culinary applications [15]. Essential oils are highly concentrated, volatile, hydrophobic mixtures of chemicals extracted from plants. It is estimated that more than 3000 essential oils are of commercial importance and are used in flavor and cosmetic industries [18]. The largest consumer of essential oils is the United States of America, followed by western European countries, namely France, Germany, and the United Kingdom. At present, the United States and developing countries are dominant in the production of the most important essential oils. Essential oils are primarily used for their fragrance properties in cosmetic products. However, certain essential oils possess other interesting properties, such as antibacterial or antifungal, conditioning hair, and improving skin elasticity. Because of the unique functional properties and fragrances of plant-derived essential oils, the cosmetic industry uses them profoundly in a wide range of cosmetic products [11]. Table 1 lists the examples of plant-derived essential oils used in cosmetic products.Table 1
Examples for plant-derived essential oils used in cosmetic products.
Vernacular nameScientific nameFunctional property/propertiesReference(s)BasilOcimum basilicum L.Fragrance[11]Antimicrobial propertiesBayLaurus nobilis L.Fragrance[11]Bergamot oilCitrus bergamia RissoFragrance[19]CalamusAcorus calamus L.Use in aromatherapy[11]CarawayCarum carvi L.Fragrance flavouring agent (mouth washes, toothpastes)[11]CardamomElettaria cardamomum (L.) MatonUse in aromatherapy[11]Carrot seedDaucus carota L.Use in aromatherapy[11]CitronCitrus medica L.Fragrance[11]Antimicrobial propertiesCitronella oilCymbopogon winterianus Jowitt ex BorFragrance[11, 19]Clary sageSalvia sclarea L.Fragrance[11]Garden sageSalvia officinalis L.Spanish sageSalvia lavandulifolia VahlCloveSyzygium aromaticum (L.) Merr. & L.M.PerryAntimicrobial properties[11, 20]German chamomileMatricaria chamomilla L.Herbaceous odour[17, 20]Anti-inflammatory and antiseptic propertiesImmortelleHelichrysum italicum (Roth) G. DonFragrance[17]Stimulates blood circulation in the skin and regenerates the skinAntiwrinkle propertiesJasmine oilJasminum officinale L.Flowery fragrance[19]LavenderLavandula angustifolia Mill.Sweet floral aroma[11, 17, 20, 21]Anti-inflammatory, carminative, and sedativeHeadache-relieving propertiesSkin-healing propertiesLemonCitrus limon (L.) OsbeckAntimicrobial properties[11, 20]Mint oilMentha × piperita L.Fragrance[11, 19, 20]NeroliCitrus × aurantium L.Antimicrobial properties and antidepressant properties[11, 17]Antiseptic propertiesCarminativeSedative propertiesPatchouli oilPogostemon cablin (Blanco) Benth.Fragrance[11, 19]Rose oilRosa × damascena Herrm.[17, 19]Antimicrobial, anti-inflammatory, and antioxidant properties, and moisturizing dry skinCleansing propertiesRosemary oilRosmarinus officinalis L.Fragrance (is widely used for hair care), nourishes the hair[17, 19]Promotes hair growthAntidandruff propertiesPrevents hair lossSandal oilSantalum album L.Fragrance[11, 19]Spike lavenderLavandula latifolia Medik.Antibacterial propertiesAntiviral properties,Anti-inflammatory, and nourishing propertiesSri Lanka cinnamonCinnamomum zeylanicum BlumeFragrance[11]Antimicrobial propertiesStar aniseIllicium verum Hook.f.Fragrance[11]Sweet orangeCitrus sinensis (L.) OsbeckAntiseptic properties[11, 20]SedativeCarminativeTonicTea tree oilMelaleuca alternifolia (Maiden & Betche) CheelFragrance[17, 20]Melaleuca linariifolia Sm.Antiseptic propertiesMelaleuca dissitiflora F.Muell.Antifungal propertiesAnti-inflammatoryVetiver oilChrysopogon zizanioides (L.) RobertyFragrance[11, 19](2) Dye and Colorants. Currently, the market for natural colors in cosmetics continues to grow throughout the world. Manufacturers seek natural plant-based coloring materials that offer health benefits, such as antioxidant, antimicrobial, anti-inflammatory, antiaging, and UV protection properties, beyond their coloring properties alone [22–25]. At present, the main exporting countries of natural dyes are China, Peru, and India [11]. Plant colorants and pigments are used in a whole range of cosmetic products, such as creams, soaps, lotions, hair dyes, and make-up products [15, 26]. Table 2 lists various plant origin colorants and dyes used in the cosmetic industry.Table 2
Plants containing natural dye/colorant compounds used in the cosmetic industry.
English nameSource plantChemical classColorReference(s)AlkanetAlkanna tinctoria (L.) TauschAlkanninRed/purple[24, 25]AnnattoBixa orellana L.Norbixin, bixinOrange/red[11, 22, 27]Butterfly peaClitoria ternatea L.DelphinidinPurple/blue[24, 25]CalendulaCalendula officinalis L.FlavoxanthinOrange[24, 25]CarrotDaucus carota L.Beta-caroteneOrange[27]CatechuSenegalia catechu (L. f.) P.J.H. Hurter & Mabb.CatechinRed[25]ChamomileMatricaria recutita L.ChamazuleneBlue[24, 25]Dyer’s woadIsatis tinctoria L.AlkaloidBlue (indigo)[11]European barberryBerberis vulgaris L.AlkaloidYellow-brown[11]French marigoldTagetes patula L.FlavonoidsYellow[11, 22, 27]Grape vineVitis vinifera L.AnthocyaninRed/blue[11]HennaLawsonia inermis L.NaphthoquinoneRed[11, 22, 27]HibiscusHibiscus rosa-sinensis L.Cyanidin-3-sophoroside, cyanidin-3-sambubioside, delphinidin-3-sambubiosideRed/pink[27]IndigoIndigofera tinctoria L.IndigotinBlue[22]IrisIris × germanica L.Mangiferin, delphinidinPurple/blue/green[24, 25]MadderRubia tinctorum L.Alizarin, purpurinRed/purple[11, 27]PaprikaCapsicum annuum L.CarotenoidsOrange/red[11, 22]Persian walnutJuglans regia L.NaphthoquinoneBrown[11]PomegranatePunica granatum L.PunicalaginRed/purple[22]Red beetBeta vulgaris L.BetaninPink/red[11]Red cabbageBrassica oleracea L.Cyanidin-3-glucoside and delphinidin-3-glucosidePink/purple[25]Red sandalwoodPterocarpus santalinus L.f.SantalinRed[22]RosehipRosa canina L.Lycopene, beta-caroteneRed/orangeSafflowerCarthamus tinctorius L.FlavonoidYellow/red[11, 22]SaffronCrocus sativus L.Crocin, crocetin, picrocrocin, riboflavinYellow[22, 27]SappanwoodCaesalpinia sappan L.AnthocyaninRed[24, 25]SpinachSpinacia oleracea L.ChlorophyllGreen[25]TomatoSolanum lycopersicum L.LycopeneRed/orange[22]TurmericCurcuma longa L.PolyphenolBright yellow[11, 22, 27](3) Oils. Oils are rich sources of fatty acids. Plant-derived oils from edible vegetables, fruits, seeds, plant seedlings, groundnuts, and trees have been safely consumed by humans for millennia. Various oils have been used on the skin since ancient times for cosmetic purposes. Oils are used as the base in a wide variety of cosmetic products, such as creams, emulsions, cosmetic milk, creams, ointments, hair conditioners, brilliantine, cosmetic masks, protective lipstick, bath fluids, nail varnish, and nail cleaners, along with their conditioning, occlusive, emollient, and moisturizing properties [28, 29]. As highlighted by Lubbe and Verpoorte [11], Zielinska and Nowak [29], and Athar and Nasir [30], Table 3 summarizes some commonly used plant-derived oils in cosmetic products.Table 3
Some commonly used plant-derived oils in cosmetic products.
OilSource plantPropertiesReference(s)Almond oilPrunus dulcis (Mill.) D.A.WebbReduces hypertrophic scarring, smoothing, rejuvenating, emollient, improving complexion and skin tone, anti-inflammatory, immunity-boosting[31, 32]Apricot kernel oilPrunus armeniaca L.Nourishing, revitalizing, emollient[33]Avocado oilPersea americana Mill.Hydrating, regenerating, antiaging, antiwrinkle, stimulating hair growth, having extraordinary transepidermal penetration capacity[34]Brazil nut oilBertholletia excelsa Bonpl.Antioxidative[35]Camellia oilCamellia sinensis (L.) KuntzeAntimicrobial, antioxidative, antiallergic, antiviral, skin healing properties, antiwrinkle[36]Carrot oilDaucus carota L.Antiaging, antioxidant, suntan accelerator, photo protection, hair colour protection, emollient[37]Cashew nut oilAnacardium occidentale L.Antiaging, restoring moisture, smoothing[38]Castor oilRicinus communis L.Emollient, lubricant, nourishing[39, 40]Coconut oilCocos nucifera L.Emollient, hydrating, lubricating, cooling, soothing[32]Corn oilZea mays L.Antioxidative, nourishing, antiaging, regenerating damaged cell membranesCotton seed oilGossypium hirsutum L.Emollient, cleansing, antioxidative, anti-inflammatory, soothing[41]Hyptis oilHyptis suaveolens (L.) Poit.Emollient, antimicrobial[42]Jojoba oilSimmondsia chinensis (Link) C.K. Schneid.Soothing, healing, immune booster, antiacne, antibacterial[32]Linseed oilLinum usitatissimum L.Antiseptic, astringent[43]Marula oilSclerocarya birrea (A.Rich.) Hochst.Moisturizing, occlusive[44]Neem oilAzadirachta indica A.Juss.Emollient, antiacne, immunostimulatory, antimicrobial, anti- inflammatory[45]Peanut oilArachis hypogaea L.Emollient, anti-inflammatory[32, 46]Pine nut oilPinus pinea L.Nourishing, curative, antiaging[47]Pumpkin seed oilCucurbita pepo L.Antibacterial, antioxidative, anti-inflammatory[48]Rice bran oilOryza sativa L.Antioxidative, antiaging[49, 50]Sesame oilSesamum indicum L.Antioxidative, antiaging, healing effect[32]Soybean oilGlycine max (L.) Merr.Anti-inflammatory, skin lightening, antioxidative, antiaging, photoprotective[51]Starflower oilBorago officinalis L.Skin barrier repair effect, anti-inflammatory[32]Sunflower seed oilHelianthus annuus L.Emollient, moisturizing, nourishing, conditioning, antioxidative, antimicrobial[32]Walnut oilJuglans regia L.Antioxidative, moisturizing, antimicrobial, nourishing[52, 53]Watermelon seed oilCitrullus lanatus (Thunb.) Matsum. & NakaiNourishing, soothing, skin lightening, moisturizing[54](4) Fat and Waxes. Fats and waxes form an important group of ingredients for the manufacture of personal care products and decorative cosmetics. These are harder substances and very resistant to moisture, oxidation, and microbial attack. Waxes are widely used in a large variety of cosmetic products, such as creams, lotions, balms, ointments, lipsticks, mascara, foundations, and eye shadows for their emollient, moisturizing, thickening, and emulsifying properties. Kokum butter (Garcinia indica (Thouars) Choisy), Sal butter (Shorea robusta Gaertn.), Illipe butter (Shorea stenoptera Burck), avocado butter (Persea americana Mill.), cocoa butter (Theobroma cacao L.), carnauba wax (Copernicia prunifera (Mill.) H.E.Moore), candelilla wax (Euphorbia spp.), berry wax (Rhus verniciflua Stokes), sunflower wax (Helianthus annuus L.), and rice bran wax (Oryza sativa L.) are the most commonly used plant-derived fats and waxes used in cosmetic industry [11, 30, 55].


#### 3.1.2. China and India as Premier Exporters of Herbal Cosmetics

As CHEMEXCIL (Basic Chemicals, Cosmetics, and Dyes Export Promotion Council), set up by the Ministry of Commerce and Industry, Government of India, and Singh [56] highlight, China is the largest exporter of herbal cosmetics. Traditional Chinese medicine (TCM) has a deep history of herbal cosmetics production. There are plentiful instances where herbal skincare therapies have been popularly used in TCM. Most cosmetic products belong to the two categories called “antiaging products” and “moisturizer products.” Herbal drugs utilized in TCMs for medicinal purposes are used in cosmetics and personal care products. Therefore, the use of TCM compounds in the production of cosmetic products is very much derived from the medicinal and pharmaceutical applications of TCM [57]. TCM uses approximately 5000 plant species in a wide variety of herbal products [58]. Table 4 indicates some commonly used medicinal plants in TCM for cosmetic treatments [104].Table 4
Some commonly used medicinal plants in TCM for cosmetic treatments.
Source plantEnglish namePlant partFunction and usageReference/sAchyranthes bidentata BlumeOx kneeRootAnti-inflammatory, antioxidant, antiaging properties[59]Adenophora stricta Miq.Lady bellRootHumectant and skin conditioning[60]∗Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav.Chinese angelicaRootAngelica sinensis (Oliv.) DielsFemale ginsengRootAnti-inflammatory and antioxidant properties[61]∗Asarum sieboldii Miq.Chinese wild gingerWhole plant∗Asarum heterotropoides F.SchmidtChinese wild gingerWhole plant∗Astragalus propinquus SchischkinMongolian milkvetchRootPlatycladus orientalis (L.) FrancoChinese arborvitaeShootAnti-inflammatory properties[62]Bletilla striata (Thunb.) Rchb.f.Chinese ground orchidRhizomeAntimicrobial, antioxidant, antiaging properties[63]Bupleurum falcatum L.Chinese thoroughwaxRootAnti-inflammatory and antioxidant properties[64]Calendula officinalis L.Scotch marigoldFlower, leavesCleansing and antimicrobial properties[65]Used in numerous cosmetic formulations, i.e., creams, lotions, shampooCamellia sinensis (L.) KuntzeTeaLeavesAnti-inflammatory, antimicrobial, antiviral, antioxidant properties[66]Relieving skin damage and promoting wound healingCentella asiatica (L.) Urb.Asiatic pennywortLeavesWound healing, anti-inflammatory, antiviral, antibacterial, antifungal, and antioxidant properties[67]Chrysanthemum indicum L.ChrysanthemumStem, flowerAnti-inflammatory properties[68]Cimicifuga dahurica (Turcz. ex Fisch. & C.A.Mey.) Maxim.SilberkerzeRootAnti-inflammatory, antiviral and antioxidant properties[69]Coptis chinensis Franch.GoldthreadRhizomeAntimicrobial properties[70]Eucommia ulmoides Oliv.EucommiaBarkAntioxidant, anti-inflammatory, antimicrobial, and antiaging properties[71]∗Evodia ruticarpa (A.Juss.) Hook.f. & ThomsonEvodiaFruitForsythia suspensa (Thunb.) VahlWeeping forsythiaFruitAnti-inflammatory, antioxidant, antiviral, antibacterial properties[72]Ginkgo Biloba L.Maidenhair treeLeavesAntiaging properties[73]Glycyrrhiza glabra L.European liquoriceRootAntiaging, anti-inflammatory, and antioxidant properties[74]Glycyrrhiza uralensis Fisch.Chinese liquoriceRootSkin conditioning, antioxidant, and anti-inflammatory properties[75, 76]∗Hippophae rhamnoides L.Sea buckthornFruit∗Saccharina japonica (J.E.Areschoug) C.E.Lane, C.Mayes, Druehl & G.W.SaundersBrown algaeWhole plant∗Lavandula angustifolia Mill.Common lavenderFlower, leavesLentinus edodes (Berk.) SingerShiitake mushroomMushroomAntimicrobial, anti-inflammatory, and antioxidant properties[77]Faster skin renewal and increasing skin elasticityLeonurus japonicus Houtt.Chinese motherwortFruitMoisturizing, antiaging, and antioxidant properties[78]∗Ligusticum striatum DC.Szechwan lovageRootLigusticum sinense Oliv.Chinese lovage rootRhizomeAntimelanogenic and moisturizing properties[79]Ligustrum lucidum W.T. AitonChinese privetRootPromoting growth and darkening of hair, reducing facial dark spots[80]Lycium chinense Mill.WolfberryFruitAntiaging, anti-inflammatory, and antioxidant properties[81]Magnolia biondii Pamp.Chinese willow leaves magnoliaBarkAnti-inflammatory and antimicrobial properties[82]Magnolia officinalis Rehder & E.H.WilsonHoupu magnoliaFlowerAntioxidant and anti-inflammatory properties[83]∗Matricaria reticulata L.Scented mayweedFlower, seedMorus alba L.MulberryFruitAntioxidant, anti-inflammatory, antimicrobial, and antiviral properties[84]Tyrosinase inhibitors activityNelumbo nucifera Gaertn.LotusLeavesReduction of hyperpigmentation and antiwrinkling properties[85]Paeonia × suffruticosa AndrewsPeonyLeaves, rootAntioxidant, anti-inflammatory, and antiaging properties[86]Panax ginseng C.A. Mey.Asian ginsengLeavesAntiaging and antiwrinkling properties[87]Phellodendron amurense Rupr.Amur cork treeBarkUsed to treat acne[88]∗Pinus tabuliformis CarrièreChinese red pineWood, leavesPolygonatum officinale All.Solomon’s sealRootAnti-inflammatory and healing properties[89]Polygonum cuspidatum Siebold & Zucc.Japanese knotweedRootPotent tyrosinase inhibition, anti-inflammatory, antimicrobial, antiviral properties[90]Polygonum multiflorum Thunb.Chinese knotweedLeaves, root tuber, rhizomesTonic and antiaging agents[91, 92]Used for promoting hair growth and treating early hair greying (blackening).Prunus armeniaca L.ApricotSeedAntiaging, antioxidant, anti-inflammatory, antimicrobial, and radioprotective properties[93, 94]Rehmannia glutinosa (Gaertn.) DC.RehmanniaRootUsed to treat premature aging, greying hair, and wrinkles[95]Rhodiola rosea L.Golden rootRhizomeAntiaging and anti-inflammatory properties[96]Salvia miltiorrhiza BungeChinese sageRootAnti-inflammatory and antioxidant properties[97]Scutellaria baicalensis GeorgiChinese skullcapRootAntibacterial, antioxidation, and UV protection effects, and it can be used as a skin-whitening ingredient in the beauty industry because of its ability to inhibit melanin synthesis[98]Silybum marianum (L.) Gaertn.Milk thistleSeedAntioxidant and UV B-protective properties[99]Slowing down skin (photo) aging.Sophora flavescens AitonKorean cream peaRootReduction of skin hyperpigmentation[100]Tribulus terrestris L.Land caltropsFruitAntiaging, anti-inflammatory, and antioxidant properties[101]Vitis vinifera L.GrapeFruit, seedAntioxidant and skin conditioning properties[102]Zanthoxylum alatum Roxb.Prickly ashBarkAntifungal, anti-inflammatory, and antioxidant properties[103]Used for scouring teeth∗The plants that were not included in the “Inventory of Existing Cosmetic Ingredients in China (IECIC)-2015.”However,Angelica dahurica Fisch.ex Hoffm., Asarum sieboldii Miq., Asarum heterotropoides F.Schmidt, Astragalus propinquus Schischkin, Evodia ruticarpa (A.Juss.) Hook.f. & Thomson, Hippophae rhamnoides L., Saccharina japonica (J.E.Areschoug) C.E.Lane, C.Mayes, Druehl & G.W.Saunders, Lavandula angustifolia Mill., Ligusticum striatum DC. (Benth. & Hook.fil.) Franch., Matricaria reticulata L., and Pinus tabuliformis Carrière, which were listed in Table 4, are no longer considered cosmetic ingredients according to the IECIC 2015.IECIC 2015 was the latest version issued by the China Food and Drug Administration (CFDA) in 2015. It is a list of existing cosmetic ingredients that have already been used in cosmetics in China. According to IECIC [105], 8783 cosmetic ingredients are allowed to be used in China. Approximately, one-third of these ingredients are classified as “botanical extracts.” However, many of these ingredients are various formulations of the same plant material [104]. Cosmetic ingredients that are not listed are regarded as new cosmetic ingredients. Therefore, new cosmetic ingredients, including botanicals, must be approved by CFDA first before they can be used in cosmetics in China. Furthermore, more information about the approved cosmetic plant ingredients can be found from this link (http://www.cirs-reach.com/China_Chemical_Regulation/SFDA_Registration_of_New_Cosmetic_Ingredient_in_China.html).In India, traditional medicine literature like the Ayurveda has proved the concept of using herbs for beautification in the past. The cosmetic preparations were used for worship and sensual enjoyment. Moreover, herbal extracts have been used for various skin and hair ailments and for enhancing the overall appearance over centuries. Over the last couple of decades, the Indian cosmetics industry has witnessed rapid and strong growth. Today, it is recognized as one of the emerging industries with immense growth potential [106]. Next to China, India is the largest producer of medicinal plants, and India owns more than 40% of global diversity [16]. According to the research report [107], India is one of the 12 mega biodiverse countries around the world. In India, nearly 45,000 plants are used in the Indian system of medicine, while 9,500 plant species are used by tribals in their daily requirements. Out of these 9500 species, 7,500 plants have direct medicinal use, while 950 are giving new leads and claims that require scientific scrutiny [108]. Furthermore, in India, more than 70% of the population uses herbal cosmetics for health care [109]. However, as indicated in the “International cosmetic ingredient dictionary and handbook” issued in 2016, India has not been included as the country that recognizes the need for uniformity in cosmetic ingredient nomenclature and has not formally identified dictionary (potential cosmetic ingredients) in its regulations [110]. Table 5 lists the most common herbal plants used for cosmetics and toiletries in India.Table 5
Most common herbal plants used for cosmetics and toiletries in India.
CategorySource plantEnglish namePlant partFunction and usageReference(s)Skin careMangifera indica L.MangoPlantAntioxidant properties[109, 111]Juniperus communis L.JuniperWhole plantRejuvenation properties[109, 111]Cuscuta reflexa Roxb.DodderPlantAntimicrobial properties[109, 111]Phyllanthus emblica L.Indian gooseberryFruitAntioxidant properties[109, 111–113]Withania somnifera (L.) DunalWinter cherryWhole plantAntioxidant properties[109, 111]Cullen corylifolium (L.) Medik.PsoraleaSeedsAntimicrobial properties[109, 111]Matricaria chamomilla L.ChamomileLeavesAntiacne properties, skin fairness properties[109, 111]Prunus dulcis (Mill.) D.A.WebbAlmondKernelAntiacne properties[109, 113]Skin fairness propertiesLagerstroemia speciosa (L.) Pers.Giant crape-myrtleLeavesAntiaging properties[109]Cydonia oblonga Mill.QuinceSeedsBeautification and skin protection[109, 111]GenusArctiumBurdockRootDeep cleaning the pores and purifying the surface of the skin[109]Jasminum grandiflorum L.Spanish JasmineFlowersControlling skin diseases, protecting from sunburn[109, 111]Santalum album L.SandalwoodHardwoodAntioxidant properties and beautification[109, 111]Salvia hispanica L.ChiaSeedsAntiaging properties[109]Euphorbia thymifolia L.Milk wortPlantAntimicrobial properties[109, 111]Cucumis sativus L.CucumberPeelCooling, toning, and skin-tightening properties[109, 111]Butea monosperma (Lam.) Taub.Bastard teakLeaves and seedsAntifungal properties[109, 111]Allium sativum L.GarlicClovesControlling sores, pimples, and acne[109, 111]Aloe vera (L.) Burm.f.AloeLeavesImproving skin smoothness, healing, controlling skin burn[109, 111]GenusVitisGrapeSeedsProtecting skin elasticity[109, 113]Curcuma longa L.TurmericRhizomeAnti-inflammatory and antioxidant properties[109, 111–113]Leucas aspera (Willd.) LinkThumbaiLeavesControlling scabies, skin psoriasis, chronic skin, skin eruption, and eczema[109, 111]Mallotus philippensis (Lam.) Müll.Arg.Monkey face treeFlowersControlling scabies ringworm, leprous eruption[109, 111]Mimosa pudica L.Humble plantHerbControlling itching[109]Rosa × damascena Herrm.Damask roseFlowersFor beautification, smoothness, and protection from sunburns[109, 111, 113]Lavandula vera DC.LavenderInflorescenceAntiacne properties[109, 111]Lepidium meyenii Walp.MacaRootPromoting elasticity and maintaining the suppleness of the skin[109]Ailanthus excelsa Roxb.Tree of heavenLeavesChecking skin eruption[109, 111]Zea mays L.MaizeStigmaRejuvenation properties[109, 111]Cocos nucifera L.CoconutKernelFor skin itching and rashes[109, 111, 113]Azadirachta indica A.Juss.NeemBark, seeds, fruits and leavesAntioxidant properties[109, 111–113]Citrus limon (L.) OsbeckLemonFruitReducing skin itching and nourishing the skin[109, 111]Senna tora (L.) Roxb.Sickle sennaLeaves and seedAntimicrobial properties[109, 111]Carica papaya L.PapayaLeaves and seedImproving skin softness and removing blemishes[109, 111]Plukenetia volubilis L.Mountain peanutPromoting skin elasticity[109]GenusHippophaeSea buckthornNourishing the skin[109]GenusHelianthusSunflowerEnhancing the brightness of the skin[109, 113]Sesamum indicum L.SesameSeedsRejuvenation properties[109, 111]Ocimum basilicum L.BasilLeavesProtecting from skin infections and rejuvenation properties[109, 111]Pistia stratiotes L.Water lettuceLeavesControlling chronic skin disorders[109, 111]Justicia adhatoda L.Malabar nutLeavesProtecting skin and controlling scabies[109, 111]Hair careJuglans regia L.WalnutLeaves and hullHair dyeing[109, 113]Aloe vera (L.) Burm.f.AloeGelDissolving the dead skin cells and excessive sebum that can clog hair follicles[109, 113]Phyllanthus emblica L.Indian gooseberryFruitPromoting hair growth[109, 111, 114]Ocimum basilicum L.BasilAnti-inflammatory properties, strengthening hair against breakage, and improving circulation in the hair follicles, which helps to stimulate growth[109]Eclipta prostrata (L.) L.False daisyHerbEncouraging hair growth[109, 111, 112]Thymus serpyllum L.Wild thymeHerbUseful for preparing hair tonics[109, 111]Ficus racemosa L.Cluster figAerial rootChecking falling hairs[109, 111]Terminalia bellirica (Gaertn.) Roxb.Belleric myrobalansSeedsUse for hair dyingpreparation[109, 111]Betula pendula RothBirchLeavesAntidandruff properties[109, 111]Centella asiatica (L.) Urb.PennywortWhole plantImproving circulation and promoting stronger hair growth[109, 111, 114]Terminalia chebula Retz.GingerSeedsUse in hair care formulations[109, 111]Lawsonia inermis L.HennaLeavesUse for hair dyeing and nourishment[109, 111–114]Nardostachys jatamansi (D.Don) DC.SpikenardRhizomeUse in hair tonics for growth[109, 111, 112, 114]Lavandula angustifolia Mill.LavenderInflorescenceStimulating circulation in the scalp, strengthening new hair growth, and helping balance the natural oil production of the scalp[109]Calendula officinalis L.MarigoldFlowersSmoothening effect of hair[109, 111]Brassica spp.MustardSeedsNourishing the hair[109, 111]Cocos nucifera L.CoconutKernelUse for preparing hair oils and tonics[109, 111, 113, 114]Mentha × piperita L.PeppermintUse as a healing scalp treatment[109]Sapindus mukorossi Gaertn.Soap nutFruit coatNatural shampoo and cleansing hair[109, 111]Carthamus tinctorius L.SafflowerUse in hair tonics[109, 111]Salvia officinalis L.SageUse as a hair conditioner[109, 111]Acacia concinna (Willd.) DC.Soap podPodsUse as hair cleanser and for control of dandruff[109, 111, 112, 114]Sesamum indicum L.SesameSeedsMajor source of hair oils and use for preparing specific hair oils[109, 111, 114]Nasturtium officinale R.Br.WatercressSupporting the stronger hair growth[109]Oral careAchyranthes aspera L.Prickly chaff flowerRootUse as a toothbrush, good for dental caries[115]Argemone mexicana L.Mexican pricklypoppySeedsGood for gum troubles[115]Azadirachta indica A.Juss.NeemTwigsUse to clean teeth and is considered good for dental caries and gum infection[113, 115]Berberis lycium RoyleIndian lyciumPeeled stemConsidered good for scouring teeth[115]Calotropis procera (Aiton) Dryand.SodomLatexUsed for toothache[115]Capsicum annuum L.PaprikaFruitsGood for toothache[115]Senna occidentalis (L.) LinkCoffee sennaLeavesUse for scouring teeth[115]Cinnamomum tamala (Buch.-Ham.) T.Nees & Eberm.Bay leafLeavesUse for scouring teeth[115]Good for gum inflammationCitrus limon (L.) OsbeckLemonLeavesUse for scouring teeth[115]Good as a mouth freshenerCitrus medica L.CitronLeaves and rind of fruitsGood for scouring teeth[115]Curcuma angustifolia Roxb.East Indian arrowrootRhizomeAppling on gums for pyorrhoea[115]Ficus hispida L.f.Hairy figLatexUse for toothache[115]Ipomoea carnea Jacq.Bush morning gloryLeavesGood for toothache[115]Jatropha curcas L.Physic nutTwigsUse as a toothbrush[115]Good against dental cariesJuglans regia L.WalnutBark and leavesUse for scouring teeth[115]Mangifera indica L.MangoLeavesUse for scouring teeth[115]Murraya koenigii (L.) Spreng.Curry leafStemUse for scouring teeth and for healthy gums[115]Carya illinoinensis (Wangenh.) K.KochPecanLeavesUsed for scouring teeth[115]Good for gumsPlumbago zeylanica L.Ceylon leadwortStemGood for scouring teeth[115]Prunus cerasoides Buch.-Ham. ex D.DonWild Himalayan cherryTwigsUse for scouring teeth[115]Psidium guajava L.GuavaLeaves and stemUse for scouring teeth[115]Robinia pseudoacacia L.Black locustBarkGood for toothache[115]Vitex negundo L.Chinese chaste treeTwigsGood for cleaning teeth[115]Good for pyorrhoea, gum inflammation, dental cariesZanthoxylum armatum DC.Winged prickly ashTwigsUse for scouring teeth[115]


### 3.2. Sri Lanka as an Example for Tropical Asian Country: Possible Contribution to the Development of Herbal Cosmetics

Sri Lanka, formerly known as Ceylon, is an island with an area of approximately 65,610 km2. Despite its relatively small size, Sri Lanka possesses a high level of biodiversity because of its varied climate and topographical conditions. In view of that, it is recognized as a biodiversity hotspot of global and national importance. Sri Lanka has a traditional system of medicine, which is as ancient as the civilization of the island and practiced from generation to generation [116]. Natural resources, including herbal, mineral, and animal products, are the key resources of the Ayurveda and indigenous systems of medicine in Sri Lanka. Since time immemorial, plants have been playing a vital role in the healthcare system of Sri Lankans’ livelihoods [117].As specified in the literature, Sri Lanka has rich traditional systems of medicine, such as Ayurveda, Siddha, Unani, and Deshiya Chikitsa. It plays a pivotal role by fulfilling 60% to 70% of the rural populations’ primary health care needs [118]. Sri Lanka is one of the most biologically diverse countries in Asia and currently possesses 29.7% of forest cover [119]. There are 3,771 flowering plant species, out of which about 927 (24%) are endemic to the country [120]. According to Sugathadasa et al. [121], 1,430 species representing 181 families and 838 genera can be considered medicinal plants. Out of the total number of species, 174 (12%) are endemic to Sri Lanka. About 250 species of medicinal plants are commonly used in traditional medicine, of which 50 species are heavily used [122]. The study conducted by Kankanamalage et al. [123] reveals the sources of medicinal plant materials that are obtained for numerous medicinal plant-based trades. Approximately 71.13% of these medicinal plants/herbal materials are obtained from local sources, and 26% are imported. Moreover, it reveals that 80% of the fresh and dry plant materials contribute to the herbal industry. Thus, it implies the importance of medicinal plants in different systems of medicine in Sri Lanka. Moreover, the study conducted by Dissanayake [124] on “Medicinal plant research in Sri Lanka: A scientometric study based on Scopus database” highlights the research studies of 190 plants, including 22 endemic plants. It reveals that most of the conducted studies were activity-based studies, such as toxicity, antibacterial, antifungal, hypoglycemic, antioxidant, anti-inflammatory, and diuretic activities. It was followed by general studies, such as physicochemical, chemical, postharvest, horticultural, and propagation studies of plants. This study shows the largely unexplored knowledge gap of medicinal plants in Sri Lanka.However, considering the herbal cosmetics in Sri Lanka, the available data on herbal cosmetics’ production and cosmetic potential medicinal plants are very scarce. Although the herbal cosmetic industry has exponentially increased throughout the world, the supply of potential cosmetic herbal products from Sri Lanka is still very limited. As Napagoda et al. [125] stated, only a handful of scientific evidence is available on the bioactivity studies of medicinal plants in Sri Lanka that could lead to the development of herbal cosmetics. Apart from the study on “cosmetic perspective of ethnobotany in the northern part of Sri Lanka,” [126] there has been hardly any ethnobotany report on the cosmetic potential of Sri Lankan medicinal plants. A total of 62 plant species belonging to 36 families have been identified based on the traditional knowledge and practices of the local community through this study. The identified plants are used for beautifying purposes, such as skin care, hair care, nail care, lip care, and eye care. However, the assembling of the multidisciplinary cooperation of botanists, chemists, toxicologists, researchers, and biologists is crucial to analyze interesting functional properties, efficacy, and effectiveness of documented cosmetic potential medicinal plants. Furthermore, Napagoda et al. [125] highlighted the probable usage of Atalantia ceylanica (Arn.) Oliv., Hibiscus furcatus Mullend., Leucas zeylanica (L.) W.T.Aiton, Mollugo cerviana (L.) Ser., Olax zeylanica L., and Ophiorrhiza mungos L. for the development of photoprotective cosmetic products by analyzing the antioxidant activity and the sun protection factor (SPF). Moreover, the research study conducted by Liyanaarachchi et al. [9] reveals the possible usage of Artocarpus nobilis Thwaites, Artocarpus altilis (Parkinson ex F.A.Zorn) Fosberg, Elaeocarpus serratus Heyne, Curcuma aromatica, and Artocarpus heterophyllus Lam. in the treatment of various skin disorders, such as hyperpigmentation, wrinkling, premature aging, and biological aging by analyzing tyrosinase, elastase, and hyaluronidase enzyme inhibitory and antioxidant activities.Furthermore, Dissanayake [124] reports that most of the medicinal plant-related studies in Sri Lanka are still on the laboratory scale. Thus, investigating the cosmetic potential medicinal plants, isolation of active compounds, and bioactivity studies of medicinal plants has become necessary for Sri Lanka to support herbal cosmetic productions and innovations.


#### 3.2.1. Strengths of Sri Lanka as a Tropical Asian Country for the Development of Herbal Cosmetic Industry

Medicinal plants have played a pivotal role in many ancient traditional systems of medicine in Asia, such as the Ayurvedic and Unani systems of India and the traditional Chinese medicine and their derivatives in most Asian countries. Tropical Asian countries are unique among the geographical regions of the world because of high biological diversity, high cultural diversity, diverse ancient civilizations, and abundant raw materials. Because of their widely diversified ecological conditions, particularly in tropical rain forests, they have relatively high biological diversity that is the greatest of all world regions. This high diversity of the region is reflected by the number of species of plants and animals, including medicinal plants. The areas of high biological diversity are among the most culturally disparate, with large numbers of distinct communities inhabiting adjacent areas, each with its own language, culture, and system of traditional medicine. A wealth of traditional knowledge about medicinal plants to cure illnesses has been accumulated over a long period and has been handed down from generation to generation until the present time [127].Medicinal plants have been used for centuries in medicinal, therapeutic, and beauty applications in Sri Lanka by different traditional systems of medicine, which have a documented history of over 2,500 years. Many formulae of medicinal preparations in the Sri Lankan traditional system of medicine are handed down from generation to generation. Some formulae are found only in the scripts of old “ola leaf” books treasured by traditional and Ayurvedic practitioners [128]. Table 6 lists the traditional usage of medicinal plants in Sri Lanka for cosmetic treatments.Table 6
Traditional usage of medicinal plants in cosmetic treatments of Sri Lanka.
NoFamilyScientific nameEnglish nameVernacular nameTraditional usesReference/s1AcanthaceaeBarleria prionitis L.∗CrossandraKatu karanduThe juice of the crushed leaves is applied to promote skin and scalp health[116, 129]Prevent early grey or white hair2Justicia adhatoda L.Malabar nutAdhatodaHerbal toothpaste formulated with other plants is effective for oral hygiene[116]3AcoraceaeAcorus calamus L.∗Sweet flagWada-kahaGround rhizome is applied for pediculosis and to improve skin complexion[116, 130]4AmaranthaceaeAlternanthera sessilis (L.) R.Br. ex DC.Sessile joyweedMukunuwennaLeaf juice promotes healthy hair and is used for manufacturing shampoos[116, 130]5AmaryllidaceaeAllium sativum L.∗GarlicSudulunuGround garlic mixed with honey or mixed with turmeric and honey is applied for curing pimples[130]6AnnonaceaeAnnona muricata L.∗Prickly custard appleKatu-anodaThe juice of crushed young leaves is applied for pediculosis[116, 129]7ApiaceaeCentella asiatica (L.) Urb.Indian pennywortGotukolaThe crushed leaves are used for damaged hair treatments and skin healing[116, 131]8ApocynaceaeHemidesmus indicus(L.) R. Br. ex Schult.Indian sarsaparillaIramusuThe juice of the crushed leaves is applied to reduce hair loss and to improve skin complexion[116, 129]9Holarrhena pubescens Wall. ex G.Don∗KurchiKelindaThe decoction of the bark is used as a mouth wash[131]10ArecaceaeAreca catechu L.∗Areca nutPuwakThe decoction of the flowers is used as a mouth wash and is used in toothpaste manufacturing[116, 131]11Caryota urens L.∗Wine palmKithulThe bark and tender flowers improve hair growth[116]12Cocos nucifera L.King coconut/PolThambili/CoconutKernel oil promotes hair growth[116]13AsparagaceaeAsparagus racemosus Willd.Wild asparagusHathawariyaThe juice of the crushed leaves is applied to improve hair colour, promote hair growth, and prevent hair loss and early grey hair or white hair[130]Possesses antiaging propertiesThe juice of the crushed leaves is applied to improve skin complexion and to remove skin freckles14AsphodelaceaeAloe vera (L.) Burm.f.Aloe plantKomarikaSustaining youthful appearance, leaf gel is used to remove dead cells around the eye, freckles, and for curing pimples,[116, 131]Leaf gel is applied to prevent hair loss and leaf gel with passion fruit (Passiflora edulis Sims) is applied to treat dandruff15AsteraceaeEclipta prostrata (L.) L.False daisyKeekirindiyaLeaf oil promotes hair growth[116, 131]The juice of the crushed leaves is used to treat skin discolorations, and it possesses antiaging properties16Baccharoides anthelmintica (L.) Moench∗Purple fleabaneSanninayamCrushed seeds are applied to treat freckles[132]Crushed seeds with lime juice is applied for pediculosis17BerberidaceaeBerberis aristata DC.∗Indian barberryDaruharidraThe decoction of the bark is used as a mouth wash[131]18BombacaceaeBombax ceiba L.∗Red silk cotton treeImbulCrushed thrones are applied to improve the skin complexion, to remove freckles, and for curing pimples[129]Seed oil is used for manufacturing soaps19BrassicaceaeBrassica juncea (L.) Czern.∗Indian mustardAbaSeed oil is applied on the hands and legs to soften the skin and improve the complexion[129]20CalophyllaceaeMesua ferrea L.Iron woodNaThe crushed flower stamens mixed with khas-khas powder is applied on the body to remove the malodors of the body, remove freckles, and improve complexion by frequent application[116]21CannabaceaeCeltis timorensis Span.∗StinkwoodGurenda/BurendaWood powder mixed with gingelly oil is applied on the skin for dryness to improve complexion[116]22CaricaceaeCarica papaya L.PapayaGaslabuThe ripe fruit is used to remove freckles[116]23CelastraceaeKokoona zeylanica ThwaitesKokunSoaps made from the crushed bark with water have been used for bathing by men and women since ancient times[132]The bark powder is used to treat pimples and to improve skin complexion24ClusiaceaeGarcinia × mangostana L.∗MangosteenMangusThe decoction of the bark is used as a mouth wash for healthy gums and teeth[116]25Garcinia quaesita PierreRed mangoGorakaIt is used for manufacturing toothpastes[131]26CombretaceaeTerminalia arjuna (Roxb. ex DC.) Wight & Arn.∗Arjuna myrobalanKumbukThe bark powder mixed with honey is applied on pimples, and the bark is used for manufacturing toothpaste[131]27Terminalia bellirica (Gaertn.) Roxb.Beleric myrobalanBuluApplying the seeds’ oil improves the black colour of hair and controls hair loss[131]28Terminalia chebula Retz.MyrabalansAraluThe infusion of the powdered, dried, young fruit is used as a mouthwash[116, 129]Possesses antiaging properties and is used to manufacture yellow colour dye29ConvolvulaceaeArgyreia populifolia Choisy∗Sri Lankan elephant creeperGiritillaThe juice of the young shoots is applied on the gums for sanitation[116]30Cuscuta chinensis Lam.∗DodderAgamula nathi walConcentrated plant extract with gingelly oil upon boiling is applied to improve the black color of hair and prevent hair loss, and it is used to treat dandruff[132]31Evolvulus alsinoides(L.)L.∗Slender dwarf morning- gloryVishnukranthiPlant extracted oil is applied to promote healthy hair growth[130]32Ipomoea pes-caprae (L.) R. Br.∗Goats foot creeperBinthamburuThe decoction of the leaves is used for foot health[131]33CostaceaeCheilocostus speciosus (J.Koenig) C.D.Specht∗Crape gingerThebuThe bark is used to remove freckles, especially those that occurred during chicken pox[132]34CucurbitaceaeCucumis melo L.∗Bitter cucumberGon kakiriThe crushed fruit mixed with the nux-vomica tree (Strychnos nux-vomica L.) seeds is used to treat pimples[131]35Cucumis sativus L.CucumberPipingnaFruit slices are used to treat darkness under the eyes and are used for skin cooling, soothing, and healing[116]36Trichosanthes cucumerina L.∗Wild snake gourdDummallaThe decoction of leaves is used to control early grey or white hair[131]37CyperaceaeCyperus rotundus L.NutgrassKalanduruCrushed tubers are used to treat acne[129]38DilleniaceaeDillenia retusa Thunb.GodaparaThe fruit pulp is used to cleanse the scalp and promote healthy hair growth[116, 131]39EbenaceaeDiospyros malabarica (Desr.) Kostel.∗Riber ebonyTimbiriThe decoction of unripe fruit slices is used as a mouthwash or gargle for mouth sanitation[116]40ElaeocarpaceaeElaeocarpus serratus L.Wild oliveWeraluThe leaves are boiled with true lime slices to clean the scalp and hair[116]41EuphorbiaceaeJatropha curcas L.Purging nutRata endaruThe decoction of the bark is used for mouth sanitation[116]42FabaceaeAbrus precatorius L.∗Wild liquoriceOlindaGrounded seeds with true lime are used to treat acne[116]43Caesalpinia bonduc (L.) Roxb.∗Molucca beanKumburuSeeds’ oil is applied to cure pimples, and fried seeds’ powder is used for brushing the teeth[131]44Crotalaria verrucosa L.∗Blue rattle weedNil-adanahiriyaGargling and the infusion of young shoots and leaves promote mouth sanitation[116]45Entada rheedii Spreng.∗Elephant creepes mackayPus wellSeed kernel powder mixed with white sandalwood powder in true lime juice is used to treat pimples[116, 132]The ground seeds, stem, and bark, along with water, are used to clean the scalp and hair46Indigofera tinctoria L.IndigoNilawariMedicated oil prepared with fresh leaf juice and king coconut oil is applied to improve skin complexion[116]Ground with false daisy, turmeric, and kurchi, it is applied to control hair loss, and the oil extracted from the leaves promotes hair growth47Mimosa pudica L.∗Sensitive plantNidikumbaThe ground aerial parts with gingelly oil are applied on the skin because of healing properties, and a decoction of the roots is used as a mouth wash to improve mouth hygiene[116]48Pongamia pinnata (L.) PierreIndian beechKarandaSeed oil is used in soap manufacturing because of its antimicrobial properties[130]49Pterocarpus marsupium Roxb.∗Indian kino treeGammaluDissolved dried gum in warm water is used as a mouthwash for healthy gums and teeth[116, 131]50Pterocarpus santalinus L.f.Red sandalwoodRath-handunCrushed heartwood mixed with turmeric powder and milk is used to treat pimples and is used in soap manufacturing[116, 130]51Senna alata (L.) Roxb.Candle bushEththoraThe leaves are used in antiseptic soap manufacturing because of antimicrobial properties[116, 129]52Senna auriculata (L.) Roxb.∗Tanner’s cassiaRanawaraCrushed flowers are applied to the skin to improve complexion[130]53Tephrosia purpurea (L.) Pers.Purple tephrosiaKathurupilaThe roots are used for mouth sanitation and are used in manufacturing toothpastes[116, 131]54Trigonella foenum-graecum L.FenugreekUluhalBoiled with unripe true limes to treat dandruff[131]55HypoxidaceaeCurculigo orchioides Gaertn.∗Black musaleBinthalThe crushed tuber has been used to improve the beauty of the face by men and women since ancient times[131]56LamiaceaeOcimum tenuiflorum L.Holy basilHeen maduruthalaThe extracted leaf oil is used as a fragrant agent, and the juice of the crushed leaves is used to treat pimples and freckles[130]57Pogostemon heyneanus Benth.∗PatchouliGas-kollankolaInfusion of fresh or dried leaves is used as a mouthwash for healthy gums and teeth[116]58Premna obtusifolia R.Br.∗Heen midiLeaves mixed with coconut oil are used to clean the scalp and hair[130]59Tectona grandis L.f.∗TeakThekkaDried fruit powder promotes hair growth[116]60LauraceaeCinnamomum verum J.PreslCeylon cinnamonKurunduThe dried inner bark is used as a mouth wash for gum and teeth sanitation[116]Cinnamon powder mixed with honey is applied to treat pimples61LecythidaceaeBarringtonia acutangula (L.) Gaertn.∗Indian oakMidellaThe decoction of the leaf, bark, and flower is used as a mouth wash for healthy, strong gums[130]62Careya arborea Rroxb.∗Patana oakKahataBark gum is used to soften the skin[132]63Couroupita guianensis Aubl.∗Cannon ball treeSalLeaves stimulate the dermal fibroblast proliferation[116]64LythraceaeLawsonia inermis L.HennaMarathondiLeaves are boiled in water with true lime fruit pieces are used to treat grey or white hair, and the leaves stimulate hair growth and are used to colour nails[116]65Punica granatum L.PomegranateDelumThe decoction of the roots and fruit rind is used as a mouth wash, and the decoction of the leaves is good for the eyes[116, 131]66MalvaceaeAbutilon indicum (L.) Sweet∗Country mallowBehethanodaCrushed leaves are used as a mouth wash[131]67Gossypium arboreum L.∗CottonKapuLeaves stimulate dermal fibroblast proliferation[116]68Abelmoschus moschatus Medik.Musk mallowKapukinissaSeeds’ paste is applied for skin itching, and chewing the seeds removes the malodors of the mouth[116, 129]69Hibiscus rosa-sinensis L.Shoe flowerPokuru wadaOil prepared by boiling the leaves and flowers with coconut oil or gingelly oil is applied to promote healthy hair growth, prevent early grey or white hair, hair loss, and dandruff[116]Crushed flowers and leaves are applied to remove suntan, to cure pimples, and to remove freckles on the skin70Theobroma cacao L.CocoKokovaPossesses emollient properties and is used to soften and treat dry skin and chapped lips[116]71MeliaceaeAzadirachta indica A.Juss.NeemKohombaCrushed leaves mixed with true lime juice are applied on pimples, and a decoction of the roots is used as a mouth wash and is used in manufacturing soaps and toothpastes[131]72MenispermaceaeCoscinium fenestratum (Goetgh.) Colebr.Calumba woodWeniwelStem powder mixed with honey is used to exfoliate the skin, and it possess antiacne properties[116, 130]73MoraceaeFicus racemosa L.Country figAttikkaCrushed leaves are used to treat freckles and skin discoloration[129]74MyristicaceaeMyristica fragrans Houtt.NutmegSadhikkaThe seed extracted oil is used in soap and toothpaste manufacturing, the herbal shampoo is prepared for pediculosis, it is used to clean the scalp and hair, and it is used to protect skin keratinocytes from UV B- induced damage[116, 130]75MyrtaceaeMelaleuca leucadendra (L.) L.Cajuput treeLothsumbuluImproves skin complexion, and the bark acts as a stimulant and tonic[116]76Syzygium aromaticum (L.) Merr. & L.M.PerryCloveKarabuIt is used in toothpaste manufacturing[116, 129]77Syzygium cumini (L.) Skeels∗Indian black berryMadanThe bark is used to prepare mouth washes for healthy gums and teeth used in manufacturing toothpastes[116, 130]78NymphaeaceaeNymphaea nouchali Burm.f.Blue water lilyNil manelThe flowers are mixed with cow milk and stored in a covered clay pot approximately a month to colour grey or white hair into black[130]79OleaceaeJasminum grandiflorum L.JasmineSamanpichchaGround roots and flowers improve skin discoloration, used to treat skin discolorations, plant-extracted oil is applied to cool the scalp[116, 130]80Jasminum multiflorum (Burm.f.) Andrews∗Sambac JasmineGeta pichchaPaste made by grinding the flower buds is applied on the skin for improved complexion[116]81OxalidaceaeAverrhoa bilimbi L.∗BilimbiBilinLeaf juice is applied to cure pimples, herbal shampoo prepared from the plant is effective for pediculosis[116]82PedaliaceaeSesamum indicum L.GingellyThel-thalaLiniments to promote hair growth, possesses healing properties[116]83PhyllanthaceaePhyllanthus emblica L.Emblic myrobalanNelliImproves skin complexion, prevents hair loss and early grey or white hair[131]Used in manufacturing herbal hair oil, shampoo, conditioner, and skin care products84PlantaginaceaeBacopa monnieri (L.) Wettst.Thyme leaved gratiolaLunuwilaPossesses antiaging properties and antidandruff properties[116]85PoaceaeCymbopogon citratus (DC.) StapfLemon grassSeraShampoo containing essential oil is effective for pediculosis and dandruff[116, 130]86Chrysopogon zizanioides (L.) RobertyKhas-khasSawandaraRoot-extracted oil is used in the perfume industry and soap manufacturing and is used as a fragrant agent, and the crushed roots are applied on the skin[116, 130]87PonterderiaceaeMonochoria vaginalis (Burm.f.) C.PreslOval leafed pondweedDiyahabaralaRoot infusion is used as a mouthwash for mouth inflammations[116]88RubiaceaeMorinda citrifolia L.∗Indian mulberryAhuThe juice of the fruits in salt water is used as a mouthwash for healthy gums, and the crushed leaves are used to exfoliate the skin and for dermal fibroblast proliferation[116, 129]89Rubia cordifolia L.Heart leaved madderVelmadataCrushed roots mixed with honey are used to remove freckles and skin discolorations[130]90RutaceaeAcronychia pedunculata (L.) Miq.Claw flowered laurelAnkendaCrushed leaves are used to treat pimples[116]91Aegle marmelos (L.) CorrêaBael fruit treeBeliRipe fruit mixed with green gram powder is applied to improve skin complexion and can be used as an eye lotion[116, 131]92Citrus aurantiifolia (Christm.) SwingleTrue limeDehiActs as a cleanser, unripe fruits are boiled with fenugreek to treat dandruff, fruits are ground with lotus leaves to treat pediculosis[131]93Citrus hystrix DC.∗Kaffir limeGada dehiFruit juice is used to treat dandruff and is used in aromatic baths and as a shampoo[116]94Melicope lunu-ankenda (Gaertn.) T.G. Hartley∗Lunu-ankendaCrushed leaves are used to improve complexion[116]95Murraya koenigii (L.) Spreng.∗Curry leafKarapinchaThe juice of the crushed leaves is used to promote healthy hair growth[129]96Ruta graveolens L.Garden rueArudaHerbal oil prepared with fresh leaves and pure coconut oil is applied for healthy hair[129]97SantalaceaeSantalum album L.SandalwoodSudu handunHeartwood powder mixed with lime juice is applied gently on pimples to improve skin complexion, the powder mixed with cow milk is used to treat freckles, and it possesses antiaging properties[116, 130]98SapindaceaeSchleichera oleosa (Lour.) Merr.Ceylon oakKonSeed oil is applied to promote healthy hair[116]99SapotaceaeMimusops elengi L.Bullet wood treeMunamalThe decoction of the mature bark is used as a mouthwash for healthy gums and teeth, herbal toothpaste formulated with other plants is effective for oral hygiene[116, 130]100SolanaceaeDatura metel L.∗DaturaAttanaThe root powder is applied on the gums for mouth sanitation[116]101SymplocaceaeSymplocos cochinchinensis (Lour.) S. Moore∗BombuBark decoction is used as a mouthwash for healthy gums[116]102TheaceaeCamellia sinensis (L.) KuntzeTeaThaePossesses antiwrinkle properties[116]103VitaceaeLeea indica (Burm. f.) Merr.∗Bandicoot berryGurullaCrushed leaves are applied on skin patches to improve skin complexion[130]104ZingiberaceaAlpinia malaccensis (Burm.f.) RoscoeRankihiriyaFlower bud juice in lukewarm water is used as a mouth wash for healthy gums and teeth[116]105Curcuma longa L.TurmericAth kahaThe crushed rhizome is used to improve skin complexion, prevents UV B-induced skin aging[116]106Curcuma zedoaria (Christm.) RoscoeZedoaryHaran kahaCrushed rhizome improves skin complexion, and it is used as a fragrant agent[130]107Kaempferia galanga L.∗Java galangaIngurupiyaliDried sliced rhizome infusion is used as a mouth wash, powdered rhizome with coconut oil on the skin to improves skin complexion, improves lustrous of hair, possesses antidandruff properties and skin whitening properties[116, 129]108Zingiber officinale RoscoeGingerInguruJuice-extracted ginger pulp is applied on pimples, and it is used to improve skin complexion[129]∗The plant species that are currently not used in the herbal cosmetic industry of Sri Lanka (in comparison with the survey conducted on “Emerging herbal cosmetic production in Sri Lanka: Identifying the possible interventions for the development of herbal cosmetic industry” [12]).As listed in Table6, a total of 108 different plant species belonging to 58 families were identified from the books, “Compendium of medicinal plants, Sri Lankan study, Volume I to IV” and “A collection of medicinal plants in Sri Lanka.” The most dominant family was the family Fabaceae (13 plant species). A wide range of plant parts has been used for traditional cosmetic treatments. Based on the remedies, the identified plant parts were the leaves, bark, seeds, fruits, roots, flowers, rhizome, stem, heartwood, flower buds, tuber, gum, fruit rind, shoots, bulb, flower stamens, fruit kernel, inner bark, leaf gel, thorns, and wood. Medicinal plants are used in cosmetic treatments for various reasons, such as skin care, hair care, and oral care. Myristica fragrans Houtt. (Sadhikka) and Kaempferia galanga L. (Ingurupiyali) are reported in all three cosmetic treatment categories. Furthermore, 04 plants, namely Ocimum tenuiflorum L. (Heen Maduruthala), Chrysopogon zizanioides (L.) Roberty (Sawandara), Citrus hystrix DC. (Gada dehi), and Curcuma zedoaria (Christm.) Roscoe (Haran Kaha) are fragrant agents that have possible usage in the perfume industry.The recent survey conducted by Gamage et al. [12] discloses the current usage of 115 plant species in herbal cosmetic productions in Sri Lanka. Furthermore, this study highlights the lack of proper cultivation systems of medicinal plants with cosmetic potential within the country for continuous herbal cosmetic productions. Although established cultivation systems are available for some highly used plants in the herbal cosmetic industry of Sri Lanka, such as Aloe vera (L.) Burm.f., most of the other medicinal plant materials are obtained either from the wild or through importation. Consequently, harvesting restrictions were imposed by the government for some wild species, such as Coscinium fenestratum (Goetgh.) Colebr. The adulteration of medicinal plant materials, lack of growers, declining suppliers, and lack of proper cultivation systems are major hindrances to the success of the herbal cosmetic industry in Sri Lanka. However, a comparison between the plant list identified through this survey and the plant list identified from the local books shows the possible usage of 49 plant species in the herbal cosmetic industry as new ingredients. Thus, these findings can be utilized for inventing new products in the future. As global demand for herbal cosmetics increases, there are ample opportunities for Sri Lanka to expand global export with its unique biodiversity and a rich base of traditional knowledge. It will lead to the upliftment of people’s livelihoods and the county’s economic development.


#### 3.2.2. Major Challenges and Possible Solutions for Sri Lanka to Develop Plant-Based Cosmetic Productions

At present, most developed countries’ cosmetic manufacturers are continuously probing for new products and ingredients of tropical origin because their raw materials often have interesting properties. The interesting properties of tropical origin ingredients could vary based on climatic and topographical conditions [11]. However, the Association of Southeast Asian Nations (ASEAN) integration report issued in 2015 clearly indicates that developing cosmetic products and cosmetic product markets based on indigenous ingredients is one of the major challenges [133]. The lack of ethnobotanical and ethnopharmacological surveys to identify the cosmetic potential plants, insufficient or absence of continuous supply of raw materials for production in line with the existing demand, lack of quality control of raw materials and finished cosmetic products, improper systematic cultivation systems for medicinal plants, poor postharvest practices, lack of innovations, and the lack of efficacy tests (in vivo and in vitro) to ensure the safety are the major challenges found in Sri Lanka for the development of the herbal cosmetic industry [12, 104, 123, 124, 134].To overcome the aforementioned challenges, collecting information on medicinal plants, traditional drugs, ethnobotany, and ethnopharmacology related to cosmetic treatments with traditional practitioners, Ayurveda physicians, and local communities in each country is required. As most of the traditional knowledge on medicinal plants and treatments in Sri Lanka is passed from generation to generation within families, conducting ethnobotanical and ethnopharmacological surveys will aid to identify cosmetic potential plants, important plant parts, remedies while preserving the traditional knowledge. Furthermore, information gathered through surveys could ultimately be utilized to develop the herbal cosmetic industry by the isolation and characterization of bioactive compounds from identified plants. Cosmetic companies work with a wide range of suppliers to obtain botanical raw materials. These suppliers purchase plant biomass from a wide array of sources ranging from large to small scale. However, harvesting plants from the wild is still popular for many medicinal herbs among local suppliers. Consequently, overharvesting can reduce plant populations to the point where the species’ biodiversity is threatened, some species even to their extinction. Therefore, establishing proper systematic cultivation systems for identified medicinal plants is paramount. Furthermore, future research must be focused on nursery techniques, field establishments, and the harvest management of medicinal plants. Cultivated plant materials are preferred for the cosmetic industry as it is easier to control the whole supply chain and chemical variations. With the use of cultivated plants, problems such as adulteration and misidentification of material are mostly eliminated. It is also easier to adhere to quality standards and has less batch-to-batch variation as the plants are grown under controlled conditions. Furthermore, the utilization of biotechnology techniques, such as tissue culture, will benefit from preserving biodiversity by utilizing the endangered or unavailable plants using conventional production or wildcrafting. Product development and innovation are other key factors to succeed in the herbal cosmetic industry in Sri Lanka. The process to bring a medicinal plant from field to finished good can be quite complicated with many challenges along the way. Stability testing on raw materials to anticipate any issues with color change, odor, viscosity, precipitation, separation, or degradation of actives must be carried out routinely by cosmetic manufacturers. The characteristics of cosmetic products can be affected by environmental factors, such as temperature, pH, light, air, and humidity, which impact their stability contributing to severe damage to the constituents of the product [135]. Because of the wide variety of cosmetic products and their inherent complexity, it is hard to find standard stability tests that can be applied to a vast range of products. However, generally used stability tests can be categorized into several categories namely stability and physical integrity of cosmetic products (under appropriate conditions of storage, transport, and use), chemical stability, microbiological stability, and the compatibility between the contents and the container. For example, the organoleptic characteristics of cosmetic preparations, such as color, smell, texture, and consistency, can be evaluated by visual inspection. Additionally, several physicochemical analyses can be performed, such as centrifugation, mechanical vibration, light tests, pH, density, viscosity determination, and spectrophotometric assays, besides accelerated and microbial stability tests [136]. Quality control testing must be performed and continuously monitored to ensure its physical and analytical characteristics are up to standard. Some current techniques used by the cosmetic industry can be applied to the evaluation of cosmetic’s quality control in an efficient manner, such as sensory analysis, rheology, and small-angle X-ray scattering [137]. Efficacy/safety tests should be performed on medicinal plant ingredients as well. For instance, cosmetics companies can perform in vitro testing to screen for cell damage in skin cell cultures or irritation in skin construct models and animal testing to avoid adverse events. However, the European Commission Cosmetics Directive has executed an animal testing ban on finished cosmetic products and ingredients. In such situations, cosmetic manufacturers have to find an alternative method to ensure product safety. At present, many alternatives to animal testing have been developed and validated for the safety and efficacy testing of cosmetic products and cosmetic ingredients. For example, 2D cell culture models derived from the human skin for evaluating anti-inflammatory properties, or predicting skin sensitization potential and 3D human skin equivalent models for evaluating skin irritation potential and excised human skin are being currently used as the gold standard for evaluating dermal absorption [138]. If a medicinal plant ingredient is safe and stable, it can move on to the formulation phase, where it is added to a cosmetic formula and retested for the same parameters, safety, and stability. With careful management, cosmetic companies can offer innovative beauty products that enhance living standards while conserving natural resources, promoting economic development for the poor, and protecting the environmental resources of Sri Lanka [11, 104, 108, 124, 127, 139, 140].In addition, the cosmetics industry must employ scientists from the discovery stage to product development. Universities can play an active role in medicinal plant research in Sri Lanka. Universities can initiate transferring technology to industries for product development using active natural compounds. In the discovery stage, many different strategies should be used, including monitoring consumer trends, evaluating scientific advances in developed countries for possible technology transfer opportunities, monitoring scientific publications, and press reports. Furthermore, external collaborations with universities, institutes, or non-governmental organizations will secure the supply chains of raw materials, gain certification of their raw materials, or find higher quality and more sustainable plant-based raw materials. For instance, collaborative research studies on medicinal plants between different faculties in the Wayamba University of Sri Lanka, faculty of agriculture and plantation management, faculty of technology, faculty of medicine, and the pioneer semigovernmental research organization, Industrial Technology Institute in Sri Lanka would be ideal for new discoveries in herbal cosmetics discipline by sharing knowledge and utilizing available facilities to a maximum extent in these two entities. Through these partnerships, the companies not only increase cosmetic manufacturers’ scientific knowledge and acquire innovative raw materials but also contribute positively to society [104, 124].


## 3.1. Global Perspective of the Plant-Based Cosmetic Industry

### 3.1.1. Specialty Plant Materials for Herbal Cosmetic Production

In line with the U.S. Food and Drug Administration (FDA), the law defines cosmetics as “articles intended to be rubbed, poured, sprinkled, sprayed on, introduced into, or otherwise applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance” [3]. However, products that are formulated using various permissible cosmetic ingredients to form the base in which one or more herbal ingredients are used to provide defined cosmetic benefits, e.g., influencing the functions of the skin and providing nutrients necessary for healthy skin or healthy hair, can be described as “herbal cosmetics” [13, 14]. Free-radical scavenging, anti-inflammatory, antiaging, sun protection, the reduction of hyperpigmentation, and antimicrobial effects are some of the functional benefits [15]. In the formulation of herbal cosmetics, plants are used in three ways: a total extract, a single molecule obtained from the purification of extracts, or a selective extract [16]. Some important plant-derived ingredients used in cosmetics are oils, fats, waxes, essential oils, plant extracts, and colorants. These ingredients have numerous roles in the final cosmetic products, such as coloring, scenting, moisturizing, thickening, and stabilizing [15]. The usage amount of these specialty plant materials or their extracts in herbal cosmetic products is varied according to the product category, plant materials used, national, regional (e.g., EU cosmetics regulations), and international (e.g., The International Organization for Standardization (ISO), Food and Drug Administration (FDA)) rules and regulations. For instance, the allowable level of Citrus bergamia Risso (Bergamot oil) in cosmetics is 0.1 ppm in Austria. Furthermore, in line with the EU Cosmetics Regulation, the permissible concentration of essential oil in shower gels and baths (rinse-off products) is 0.01%, while the permissible concentration of essential oil in body oils, massage oils, and creams is 0.001% [17]. However, information on the acceptable concentrations of these individual specialty plant materials in cosmetics is scarce.(1) Essential Oils. People have been using aromatic plants and oils for thousands of years in incense, perfumes, cosmetics, medicinal, and culinary applications [15]. Essential oils are highly concentrated, volatile, hydrophobic mixtures of chemicals extracted from plants. It is estimated that more than 3000 essential oils are of commercial importance and are used in flavor and cosmetic industries [18]. The largest consumer of essential oils is the United States of America, followed by western European countries, namely France, Germany, and the United Kingdom. At present, the United States and developing countries are dominant in the production of the most important essential oils. Essential oils are primarily used for their fragrance properties in cosmetic products. However, certain essential oils possess other interesting properties, such as antibacterial or antifungal, conditioning hair, and improving skin elasticity. Because of the unique functional properties and fragrances of plant-derived essential oils, the cosmetic industry uses them profoundly in a wide range of cosmetic products [11]. Table 1 lists the examples of plant-derived essential oils used in cosmetic products.Table 1
Examples for plant-derived essential oils used in cosmetic products.
Vernacular nameScientific nameFunctional property/propertiesReference(s)BasilOcimum basilicum L.Fragrance[11]Antimicrobial propertiesBayLaurus nobilis L.Fragrance[11]Bergamot oilCitrus bergamia RissoFragrance[19]CalamusAcorus calamus L.Use in aromatherapy[11]CarawayCarum carvi L.Fragrance flavouring agent (mouth washes, toothpastes)[11]CardamomElettaria cardamomum (L.) MatonUse in aromatherapy[11]Carrot seedDaucus carota L.Use in aromatherapy[11]CitronCitrus medica L.Fragrance[11]Antimicrobial propertiesCitronella oilCymbopogon winterianus Jowitt ex BorFragrance[11, 19]Clary sageSalvia sclarea L.Fragrance[11]Garden sageSalvia officinalis L.Spanish sageSalvia lavandulifolia VahlCloveSyzygium aromaticum (L.) Merr. & L.M.PerryAntimicrobial properties[11, 20]German chamomileMatricaria chamomilla L.Herbaceous odour[17, 20]Anti-inflammatory and antiseptic propertiesImmortelleHelichrysum italicum (Roth) G. DonFragrance[17]Stimulates blood circulation in the skin and regenerates the skinAntiwrinkle propertiesJasmine oilJasminum officinale L.Flowery fragrance[19]LavenderLavandula angustifolia Mill.Sweet floral aroma[11, 17, 20, 21]Anti-inflammatory, carminative, and sedativeHeadache-relieving propertiesSkin-healing propertiesLemonCitrus limon (L.) OsbeckAntimicrobial properties[11, 20]Mint oilMentha × piperita L.Fragrance[11, 19, 20]NeroliCitrus × aurantium L.Antimicrobial properties and antidepressant properties[11, 17]Antiseptic propertiesCarminativeSedative propertiesPatchouli oilPogostemon cablin (Blanco) Benth.Fragrance[11, 19]Rose oilRosa × damascena Herrm.[17, 19]Antimicrobial, anti-inflammatory, and antioxidant properties, and moisturizing dry skinCleansing propertiesRosemary oilRosmarinus officinalis L.Fragrance (is widely used for hair care), nourishes the hair[17, 19]Promotes hair growthAntidandruff propertiesPrevents hair lossSandal oilSantalum album L.Fragrance[11, 19]Spike lavenderLavandula latifolia Medik.Antibacterial propertiesAntiviral properties,Anti-inflammatory, and nourishing propertiesSri Lanka cinnamonCinnamomum zeylanicum BlumeFragrance[11]Antimicrobial propertiesStar aniseIllicium verum Hook.f.Fragrance[11]Sweet orangeCitrus sinensis (L.) OsbeckAntiseptic properties[11, 20]SedativeCarminativeTonicTea tree oilMelaleuca alternifolia (Maiden & Betche) CheelFragrance[17, 20]Melaleuca linariifolia Sm.Antiseptic propertiesMelaleuca dissitiflora F.Muell.Antifungal propertiesAnti-inflammatoryVetiver oilChrysopogon zizanioides (L.) RobertyFragrance[11, 19](2) Dye and Colorants. Currently, the market for natural colors in cosmetics continues to grow throughout the world. Manufacturers seek natural plant-based coloring materials that offer health benefits, such as antioxidant, antimicrobial, anti-inflammatory, antiaging, and UV protection properties, beyond their coloring properties alone [22–25]. At present, the main exporting countries of natural dyes are China, Peru, and India [11]. Plant colorants and pigments are used in a whole range of cosmetic products, such as creams, soaps, lotions, hair dyes, and make-up products [15, 26]. Table 2 lists various plant origin colorants and dyes used in the cosmetic industry.Table 2
Plants containing natural dye/colorant compounds used in the cosmetic industry.
English nameSource plantChemical classColorReference(s)AlkanetAlkanna tinctoria (L.) TauschAlkanninRed/purple[24, 25]AnnattoBixa orellana L.Norbixin, bixinOrange/red[11, 22, 27]Butterfly peaClitoria ternatea L.DelphinidinPurple/blue[24, 25]CalendulaCalendula officinalis L.FlavoxanthinOrange[24, 25]CarrotDaucus carota L.Beta-caroteneOrange[27]CatechuSenegalia catechu (L. f.) P.J.H. Hurter & Mabb.CatechinRed[25]ChamomileMatricaria recutita L.ChamazuleneBlue[24, 25]Dyer’s woadIsatis tinctoria L.AlkaloidBlue (indigo)[11]European barberryBerberis vulgaris L.AlkaloidYellow-brown[11]French marigoldTagetes patula L.FlavonoidsYellow[11, 22, 27]Grape vineVitis vinifera L.AnthocyaninRed/blue[11]HennaLawsonia inermis L.NaphthoquinoneRed[11, 22, 27]HibiscusHibiscus rosa-sinensis L.Cyanidin-3-sophoroside, cyanidin-3-sambubioside, delphinidin-3-sambubiosideRed/pink[27]IndigoIndigofera tinctoria L.IndigotinBlue[22]IrisIris × germanica L.Mangiferin, delphinidinPurple/blue/green[24, 25]MadderRubia tinctorum L.Alizarin, purpurinRed/purple[11, 27]PaprikaCapsicum annuum L.CarotenoidsOrange/red[11, 22]Persian walnutJuglans regia L.NaphthoquinoneBrown[11]PomegranatePunica granatum L.PunicalaginRed/purple[22]Red beetBeta vulgaris L.BetaninPink/red[11]Red cabbageBrassica oleracea L.Cyanidin-3-glucoside and delphinidin-3-glucosidePink/purple[25]Red sandalwoodPterocarpus santalinus L.f.SantalinRed[22]RosehipRosa canina L.Lycopene, beta-caroteneRed/orangeSafflowerCarthamus tinctorius L.FlavonoidYellow/red[11, 22]SaffronCrocus sativus L.Crocin, crocetin, picrocrocin, riboflavinYellow[22, 27]SappanwoodCaesalpinia sappan L.AnthocyaninRed[24, 25]SpinachSpinacia oleracea L.ChlorophyllGreen[25]TomatoSolanum lycopersicum L.LycopeneRed/orange[22]TurmericCurcuma longa L.PolyphenolBright yellow[11, 22, 27](3) Oils. Oils are rich sources of fatty acids. Plant-derived oils from edible vegetables, fruits, seeds, plant seedlings, groundnuts, and trees have been safely consumed by humans for millennia. Various oils have been used on the skin since ancient times for cosmetic purposes. Oils are used as the base in a wide variety of cosmetic products, such as creams, emulsions, cosmetic milk, creams, ointments, hair conditioners, brilliantine, cosmetic masks, protective lipstick, bath fluids, nail varnish, and nail cleaners, along with their conditioning, occlusive, emollient, and moisturizing properties [28, 29]. As highlighted by Lubbe and Verpoorte [11], Zielinska and Nowak [29], and Athar and Nasir [30], Table 3 summarizes some commonly used plant-derived oils in cosmetic products.Table 3
Some commonly used plant-derived oils in cosmetic products.
OilSource plantPropertiesReference(s)Almond oilPrunus dulcis (Mill.) D.A.WebbReduces hypertrophic scarring, smoothing, rejuvenating, emollient, improving complexion and skin tone, anti-inflammatory, immunity-boosting[31, 32]Apricot kernel oilPrunus armeniaca L.Nourishing, revitalizing, emollient[33]Avocado oilPersea americana Mill.Hydrating, regenerating, antiaging, antiwrinkle, stimulating hair growth, having extraordinary transepidermal penetration capacity[34]Brazil nut oilBertholletia excelsa Bonpl.Antioxidative[35]Camellia oilCamellia sinensis (L.) KuntzeAntimicrobial, antioxidative, antiallergic, antiviral, skin healing properties, antiwrinkle[36]Carrot oilDaucus carota L.Antiaging, antioxidant, suntan accelerator, photo protection, hair colour protection, emollient[37]Cashew nut oilAnacardium occidentale L.Antiaging, restoring moisture, smoothing[38]Castor oilRicinus communis L.Emollient, lubricant, nourishing[39, 40]Coconut oilCocos nucifera L.Emollient, hydrating, lubricating, cooling, soothing[32]Corn oilZea mays L.Antioxidative, nourishing, antiaging, regenerating damaged cell membranesCotton seed oilGossypium hirsutum L.Emollient, cleansing, antioxidative, anti-inflammatory, soothing[41]Hyptis oilHyptis suaveolens (L.) Poit.Emollient, antimicrobial[42]Jojoba oilSimmondsia chinensis (Link) C.K. Schneid.Soothing, healing, immune booster, antiacne, antibacterial[32]Linseed oilLinum usitatissimum L.Antiseptic, astringent[43]Marula oilSclerocarya birrea (A.Rich.) Hochst.Moisturizing, occlusive[44]Neem oilAzadirachta indica A.Juss.Emollient, antiacne, immunostimulatory, antimicrobial, anti- inflammatory[45]Peanut oilArachis hypogaea L.Emollient, anti-inflammatory[32, 46]Pine nut oilPinus pinea L.Nourishing, curative, antiaging[47]Pumpkin seed oilCucurbita pepo L.Antibacterial, antioxidative, anti-inflammatory[48]Rice bran oilOryza sativa L.Antioxidative, antiaging[49, 50]Sesame oilSesamum indicum L.Antioxidative, antiaging, healing effect[32]Soybean oilGlycine max (L.) Merr.Anti-inflammatory, skin lightening, antioxidative, antiaging, photoprotective[51]Starflower oilBorago officinalis L.Skin barrier repair effect, anti-inflammatory[32]Sunflower seed oilHelianthus annuus L.Emollient, moisturizing, nourishing, conditioning, antioxidative, antimicrobial[32]Walnut oilJuglans regia L.Antioxidative, moisturizing, antimicrobial, nourishing[52, 53]Watermelon seed oilCitrullus lanatus (Thunb.) Matsum. & NakaiNourishing, soothing, skin lightening, moisturizing[54](4) Fat and Waxes. Fats and waxes form an important group of ingredients for the manufacture of personal care products and decorative cosmetics. These are harder substances and very resistant to moisture, oxidation, and microbial attack. Waxes are widely used in a large variety of cosmetic products, such as creams, lotions, balms, ointments, lipsticks, mascara, foundations, and eye shadows for their emollient, moisturizing, thickening, and emulsifying properties. Kokum butter (Garcinia indica (Thouars) Choisy), Sal butter (Shorea robusta Gaertn.), Illipe butter (Shorea stenoptera Burck), avocado butter (Persea americana Mill.), cocoa butter (Theobroma cacao L.), carnauba wax (Copernicia prunifera (Mill.) H.E.Moore), candelilla wax (Euphorbia spp.), berry wax (Rhus verniciflua Stokes), sunflower wax (Helianthus annuus L.), and rice bran wax (Oryza sativa L.) are the most commonly used plant-derived fats and waxes used in cosmetic industry [11, 30, 55].


### 3.1.2. China and India as Premier Exporters of Herbal Cosmetics

As CHEMEXCIL (Basic Chemicals, Cosmetics, and Dyes Export Promotion Council), set up by the Ministry of Commerce and Industry, Government of India, and Singh [56] highlight, China is the largest exporter of herbal cosmetics. Traditional Chinese medicine (TCM) has a deep history of herbal cosmetics production. There are plentiful instances where herbal skincare therapies have been popularly used in TCM. Most cosmetic products belong to the two categories called “antiaging products” and “moisturizer products.” Herbal drugs utilized in TCMs for medicinal purposes are used in cosmetics and personal care products. Therefore, the use of TCM compounds in the production of cosmetic products is very much derived from the medicinal and pharmaceutical applications of TCM [57]. TCM uses approximately 5000 plant species in a wide variety of herbal products [58]. Table 4 indicates some commonly used medicinal plants in TCM for cosmetic treatments [104].Table 4
Some commonly used medicinal plants in TCM for cosmetic treatments.
Source plantEnglish namePlant partFunction and usageReference/sAchyranthes bidentata BlumeOx kneeRootAnti-inflammatory, antioxidant, antiaging properties[59]Adenophora stricta Miq.Lady bellRootHumectant and skin conditioning[60]∗Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav.Chinese angelicaRootAngelica sinensis (Oliv.) DielsFemale ginsengRootAnti-inflammatory and antioxidant properties[61]∗Asarum sieboldii Miq.Chinese wild gingerWhole plant∗Asarum heterotropoides F.SchmidtChinese wild gingerWhole plant∗Astragalus propinquus SchischkinMongolian milkvetchRootPlatycladus orientalis (L.) FrancoChinese arborvitaeShootAnti-inflammatory properties[62]Bletilla striata (Thunb.) Rchb.f.Chinese ground orchidRhizomeAntimicrobial, antioxidant, antiaging properties[63]Bupleurum falcatum L.Chinese thoroughwaxRootAnti-inflammatory and antioxidant properties[64]Calendula officinalis L.Scotch marigoldFlower, leavesCleansing and antimicrobial properties[65]Used in numerous cosmetic formulations, i.e., creams, lotions, shampooCamellia sinensis (L.) KuntzeTeaLeavesAnti-inflammatory, antimicrobial, antiviral, antioxidant properties[66]Relieving skin damage and promoting wound healingCentella asiatica (L.) Urb.Asiatic pennywortLeavesWound healing, anti-inflammatory, antiviral, antibacterial, antifungal, and antioxidant properties[67]Chrysanthemum indicum L.ChrysanthemumStem, flowerAnti-inflammatory properties[68]Cimicifuga dahurica (Turcz. ex Fisch. & C.A.Mey.) Maxim.SilberkerzeRootAnti-inflammatory, antiviral and antioxidant properties[69]Coptis chinensis Franch.GoldthreadRhizomeAntimicrobial properties[70]Eucommia ulmoides Oliv.EucommiaBarkAntioxidant, anti-inflammatory, antimicrobial, and antiaging properties[71]∗Evodia ruticarpa (A.Juss.) Hook.f. & ThomsonEvodiaFruitForsythia suspensa (Thunb.) VahlWeeping forsythiaFruitAnti-inflammatory, antioxidant, antiviral, antibacterial properties[72]Ginkgo Biloba L.Maidenhair treeLeavesAntiaging properties[73]Glycyrrhiza glabra L.European liquoriceRootAntiaging, anti-inflammatory, and antioxidant properties[74]Glycyrrhiza uralensis Fisch.Chinese liquoriceRootSkin conditioning, antioxidant, and anti-inflammatory properties[75, 76]∗Hippophae rhamnoides L.Sea buckthornFruit∗Saccharina japonica (J.E.Areschoug) C.E.Lane, C.Mayes, Druehl & G.W.SaundersBrown algaeWhole plant∗Lavandula angustifolia Mill.Common lavenderFlower, leavesLentinus edodes (Berk.) SingerShiitake mushroomMushroomAntimicrobial, anti-inflammatory, and antioxidant properties[77]Faster skin renewal and increasing skin elasticityLeonurus japonicus Houtt.Chinese motherwortFruitMoisturizing, antiaging, and antioxidant properties[78]∗Ligusticum striatum DC.Szechwan lovageRootLigusticum sinense Oliv.Chinese lovage rootRhizomeAntimelanogenic and moisturizing properties[79]Ligustrum lucidum W.T. AitonChinese privetRootPromoting growth and darkening of hair, reducing facial dark spots[80]Lycium chinense Mill.WolfberryFruitAntiaging, anti-inflammatory, and antioxidant properties[81]Magnolia biondii Pamp.Chinese willow leaves magnoliaBarkAnti-inflammatory and antimicrobial properties[82]Magnolia officinalis Rehder & E.H.WilsonHoupu magnoliaFlowerAntioxidant and anti-inflammatory properties[83]∗Matricaria reticulata L.Scented mayweedFlower, seedMorus alba L.MulberryFruitAntioxidant, anti-inflammatory, antimicrobial, and antiviral properties[84]Tyrosinase inhibitors activityNelumbo nucifera Gaertn.LotusLeavesReduction of hyperpigmentation and antiwrinkling properties[85]Paeonia × suffruticosa AndrewsPeonyLeaves, rootAntioxidant, anti-inflammatory, and antiaging properties[86]Panax ginseng C.A. Mey.Asian ginsengLeavesAntiaging and antiwrinkling properties[87]Phellodendron amurense Rupr.Amur cork treeBarkUsed to treat acne[88]∗Pinus tabuliformis CarrièreChinese red pineWood, leavesPolygonatum officinale All.Solomon’s sealRootAnti-inflammatory and healing properties[89]Polygonum cuspidatum Siebold & Zucc.Japanese knotweedRootPotent tyrosinase inhibition, anti-inflammatory, antimicrobial, antiviral properties[90]Polygonum multiflorum Thunb.Chinese knotweedLeaves, root tuber, rhizomesTonic and antiaging agents[91, 92]Used for promoting hair growth and treating early hair greying (blackening).Prunus armeniaca L.ApricotSeedAntiaging, antioxidant, anti-inflammatory, antimicrobial, and radioprotective properties[93, 94]Rehmannia glutinosa (Gaertn.) DC.RehmanniaRootUsed to treat premature aging, greying hair, and wrinkles[95]Rhodiola rosea L.Golden rootRhizomeAntiaging and anti-inflammatory properties[96]Salvia miltiorrhiza BungeChinese sageRootAnti-inflammatory and antioxidant properties[97]Scutellaria baicalensis GeorgiChinese skullcapRootAntibacterial, antioxidation, and UV protection effects, and it can be used as a skin-whitening ingredient in the beauty industry because of its ability to inhibit melanin synthesis[98]Silybum marianum (L.) Gaertn.Milk thistleSeedAntioxidant and UV B-protective properties[99]Slowing down skin (photo) aging.Sophora flavescens AitonKorean cream peaRootReduction of skin hyperpigmentation[100]Tribulus terrestris L.Land caltropsFruitAntiaging, anti-inflammatory, and antioxidant properties[101]Vitis vinifera L.GrapeFruit, seedAntioxidant and skin conditioning properties[102]Zanthoxylum alatum Roxb.Prickly ashBarkAntifungal, anti-inflammatory, and antioxidant properties[103]Used for scouring teeth∗The plants that were not included in the “Inventory of Existing Cosmetic Ingredients in China (IECIC)-2015.”However,Angelica dahurica Fisch.ex Hoffm., Asarum sieboldii Miq., Asarum heterotropoides F.Schmidt, Astragalus propinquus Schischkin, Evodia ruticarpa (A.Juss.) Hook.f. & Thomson, Hippophae rhamnoides L., Saccharina japonica (J.E.Areschoug) C.E.Lane, C.Mayes, Druehl & G.W.Saunders, Lavandula angustifolia Mill., Ligusticum striatum DC. (Benth. & Hook.fil.) Franch., Matricaria reticulata L., and Pinus tabuliformis Carrière, which were listed in Table 4, are no longer considered cosmetic ingredients according to the IECIC 2015.IECIC 2015 was the latest version issued by the China Food and Drug Administration (CFDA) in 2015. It is a list of existing cosmetic ingredients that have already been used in cosmetics in China. According to IECIC [105], 8783 cosmetic ingredients are allowed to be used in China. Approximately, one-third of these ingredients are classified as “botanical extracts.” However, many of these ingredients are various formulations of the same plant material [104]. Cosmetic ingredients that are not listed are regarded as new cosmetic ingredients. Therefore, new cosmetic ingredients, including botanicals, must be approved by CFDA first before they can be used in cosmetics in China. Furthermore, more information about the approved cosmetic plant ingredients can be found from this link (http://www.cirs-reach.com/China_Chemical_Regulation/SFDA_Registration_of_New_Cosmetic_Ingredient_in_China.html).In India, traditional medicine literature like the Ayurveda has proved the concept of using herbs for beautification in the past. The cosmetic preparations were used for worship and sensual enjoyment. Moreover, herbal extracts have been used for various skin and hair ailments and for enhancing the overall appearance over centuries. Over the last couple of decades, the Indian cosmetics industry has witnessed rapid and strong growth. Today, it is recognized as one of the emerging industries with immense growth potential [106]. Next to China, India is the largest producer of medicinal plants, and India owns more than 40% of global diversity [16]. According to the research report [107], India is one of the 12 mega biodiverse countries around the world. In India, nearly 45,000 plants are used in the Indian system of medicine, while 9,500 plant species are used by tribals in their daily requirements. Out of these 9500 species, 7,500 plants have direct medicinal use, while 950 are giving new leads and claims that require scientific scrutiny [108]. Furthermore, in India, more than 70% of the population uses herbal cosmetics for health care [109]. However, as indicated in the “International cosmetic ingredient dictionary and handbook” issued in 2016, India has not been included as the country that recognizes the need for uniformity in cosmetic ingredient nomenclature and has not formally identified dictionary (potential cosmetic ingredients) in its regulations [110]. Table 5 lists the most common herbal plants used for cosmetics and toiletries in India.Table 5
Most common herbal plants used for cosmetics and toiletries in India.
CategorySource plantEnglish namePlant partFunction and usageReference(s)Skin careMangifera indica L.MangoPlantAntioxidant properties[109, 111]Juniperus communis L.JuniperWhole plantRejuvenation properties[109, 111]Cuscuta reflexa Roxb.DodderPlantAntimicrobial properties[109, 111]Phyllanthus emblica L.Indian gooseberryFruitAntioxidant properties[109, 111–113]Withania somnifera (L.) DunalWinter cherryWhole plantAntioxidant properties[109, 111]Cullen corylifolium (L.) Medik.PsoraleaSeedsAntimicrobial properties[109, 111]Matricaria chamomilla L.ChamomileLeavesAntiacne properties, skin fairness properties[109, 111]Prunus dulcis (Mill.) D.A.WebbAlmondKernelAntiacne properties[109, 113]Skin fairness propertiesLagerstroemia speciosa (L.) Pers.Giant crape-myrtleLeavesAntiaging properties[109]Cydonia oblonga Mill.QuinceSeedsBeautification and skin protection[109, 111]GenusArctiumBurdockRootDeep cleaning the pores and purifying the surface of the skin[109]Jasminum grandiflorum L.Spanish JasmineFlowersControlling skin diseases, protecting from sunburn[109, 111]Santalum album L.SandalwoodHardwoodAntioxidant properties and beautification[109, 111]Salvia hispanica L.ChiaSeedsAntiaging properties[109]Euphorbia thymifolia L.Milk wortPlantAntimicrobial properties[109, 111]Cucumis sativus L.CucumberPeelCooling, toning, and skin-tightening properties[109, 111]Butea monosperma (Lam.) Taub.Bastard teakLeaves and seedsAntifungal properties[109, 111]Allium sativum L.GarlicClovesControlling sores, pimples, and acne[109, 111]Aloe vera (L.) Burm.f.AloeLeavesImproving skin smoothness, healing, controlling skin burn[109, 111]GenusVitisGrapeSeedsProtecting skin elasticity[109, 113]Curcuma longa L.TurmericRhizomeAnti-inflammatory and antioxidant properties[109, 111–113]Leucas aspera (Willd.) LinkThumbaiLeavesControlling scabies, skin psoriasis, chronic skin, skin eruption, and eczema[109, 111]Mallotus philippensis (Lam.) Müll.Arg.Monkey face treeFlowersControlling scabies ringworm, leprous eruption[109, 111]Mimosa pudica L.Humble plantHerbControlling itching[109]Rosa × damascena Herrm.Damask roseFlowersFor beautification, smoothness, and protection from sunburns[109, 111, 113]Lavandula vera DC.LavenderInflorescenceAntiacne properties[109, 111]Lepidium meyenii Walp.MacaRootPromoting elasticity and maintaining the suppleness of the skin[109]Ailanthus excelsa Roxb.Tree of heavenLeavesChecking skin eruption[109, 111]Zea mays L.MaizeStigmaRejuvenation properties[109, 111]Cocos nucifera L.CoconutKernelFor skin itching and rashes[109, 111, 113]Azadirachta indica A.Juss.NeemBark, seeds, fruits and leavesAntioxidant properties[109, 111–113]Citrus limon (L.) OsbeckLemonFruitReducing skin itching and nourishing the skin[109, 111]Senna tora (L.) Roxb.Sickle sennaLeaves and seedAntimicrobial properties[109, 111]Carica papaya L.PapayaLeaves and seedImproving skin softness and removing blemishes[109, 111]Plukenetia volubilis L.Mountain peanutPromoting skin elasticity[109]GenusHippophaeSea buckthornNourishing the skin[109]GenusHelianthusSunflowerEnhancing the brightness of the skin[109, 113]Sesamum indicum L.SesameSeedsRejuvenation properties[109, 111]Ocimum basilicum L.BasilLeavesProtecting from skin infections and rejuvenation properties[109, 111]Pistia stratiotes L.Water lettuceLeavesControlling chronic skin disorders[109, 111]Justicia adhatoda L.Malabar nutLeavesProtecting skin and controlling scabies[109, 111]Hair careJuglans regia L.WalnutLeaves and hullHair dyeing[109, 113]Aloe vera (L.) Burm.f.AloeGelDissolving the dead skin cells and excessive sebum that can clog hair follicles[109, 113]Phyllanthus emblica L.Indian gooseberryFruitPromoting hair growth[109, 111, 114]Ocimum basilicum L.BasilAnti-inflammatory properties, strengthening hair against breakage, and improving circulation in the hair follicles, which helps to stimulate growth[109]Eclipta prostrata (L.) L.False daisyHerbEncouraging hair growth[109, 111, 112]Thymus serpyllum L.Wild thymeHerbUseful for preparing hair tonics[109, 111]Ficus racemosa L.Cluster figAerial rootChecking falling hairs[109, 111]Terminalia bellirica (Gaertn.) Roxb.Belleric myrobalansSeedsUse for hair dyingpreparation[109, 111]Betula pendula RothBirchLeavesAntidandruff properties[109, 111]Centella asiatica (L.) Urb.PennywortWhole plantImproving circulation and promoting stronger hair growth[109, 111, 114]Terminalia chebula Retz.GingerSeedsUse in hair care formulations[109, 111]Lawsonia inermis L.HennaLeavesUse for hair dyeing and nourishment[109, 111–114]Nardostachys jatamansi (D.Don) DC.SpikenardRhizomeUse in hair tonics for growth[109, 111, 112, 114]Lavandula angustifolia Mill.LavenderInflorescenceStimulating circulation in the scalp, strengthening new hair growth, and helping balance the natural oil production of the scalp[109]Calendula officinalis L.MarigoldFlowersSmoothening effect of hair[109, 111]Brassica spp.MustardSeedsNourishing the hair[109, 111]Cocos nucifera L.CoconutKernelUse for preparing hair oils and tonics[109, 111, 113, 114]Mentha × piperita L.PeppermintUse as a healing scalp treatment[109]Sapindus mukorossi Gaertn.Soap nutFruit coatNatural shampoo and cleansing hair[109, 111]Carthamus tinctorius L.SafflowerUse in hair tonics[109, 111]Salvia officinalis L.SageUse as a hair conditioner[109, 111]Acacia concinna (Willd.) DC.Soap podPodsUse as hair cleanser and for control of dandruff[109, 111, 112, 114]Sesamum indicum L.SesameSeedsMajor source of hair oils and use for preparing specific hair oils[109, 111, 114]Nasturtium officinale R.Br.WatercressSupporting the stronger hair growth[109]Oral careAchyranthes aspera L.Prickly chaff flowerRootUse as a toothbrush, good for dental caries[115]Argemone mexicana L.Mexican pricklypoppySeedsGood for gum troubles[115]Azadirachta indica A.Juss.NeemTwigsUse to clean teeth and is considered good for dental caries and gum infection[113, 115]Berberis lycium RoyleIndian lyciumPeeled stemConsidered good for scouring teeth[115]Calotropis procera (Aiton) Dryand.SodomLatexUsed for toothache[115]Capsicum annuum L.PaprikaFruitsGood for toothache[115]Senna occidentalis (L.) LinkCoffee sennaLeavesUse for scouring teeth[115]Cinnamomum tamala (Buch.-Ham.) T.Nees & Eberm.Bay leafLeavesUse for scouring teeth[115]Good for gum inflammationCitrus limon (L.) OsbeckLemonLeavesUse for scouring teeth[115]Good as a mouth freshenerCitrus medica L.CitronLeaves and rind of fruitsGood for scouring teeth[115]Curcuma angustifolia Roxb.East Indian arrowrootRhizomeAppling on gums for pyorrhoea[115]Ficus hispida L.f.Hairy figLatexUse for toothache[115]Ipomoea carnea Jacq.Bush morning gloryLeavesGood for toothache[115]Jatropha curcas L.Physic nutTwigsUse as a toothbrush[115]Good against dental cariesJuglans regia L.WalnutBark and leavesUse for scouring teeth[115]Mangifera indica L.MangoLeavesUse for scouring teeth[115]Murraya koenigii (L.) Spreng.Curry leafStemUse for scouring teeth and for healthy gums[115]Carya illinoinensis (Wangenh.) K.KochPecanLeavesUsed for scouring teeth[115]Good for gumsPlumbago zeylanica L.Ceylon leadwortStemGood for scouring teeth[115]Prunus cerasoides Buch.-Ham. ex D.DonWild Himalayan cherryTwigsUse for scouring teeth[115]Psidium guajava L.GuavaLeaves and stemUse for scouring teeth[115]Robinia pseudoacacia L.Black locustBarkGood for toothache[115]Vitex negundo L.Chinese chaste treeTwigsGood for cleaning teeth[115]Good for pyorrhoea, gum inflammation, dental cariesZanthoxylum armatum DC.Winged prickly ashTwigsUse for scouring teeth[115]


## 3.1.1. Specialty Plant Materials for Herbal Cosmetic Production

In line with the U.S. Food and Drug Administration (FDA), the law defines cosmetics as “articles intended to be rubbed, poured, sprinkled, sprayed on, introduced into, or otherwise applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance” [3]. However, products that are formulated using various permissible cosmetic ingredients to form the base in which one or more herbal ingredients are used to provide defined cosmetic benefits, e.g., influencing the functions of the skin and providing nutrients necessary for healthy skin or healthy hair, can be described as “herbal cosmetics” [13, 14]. Free-radical scavenging, anti-inflammatory, antiaging, sun protection, the reduction of hyperpigmentation, and antimicrobial effects are some of the functional benefits [15]. In the formulation of herbal cosmetics, plants are used in three ways: a total extract, a single molecule obtained from the purification of extracts, or a selective extract [16]. Some important plant-derived ingredients used in cosmetics are oils, fats, waxes, essential oils, plant extracts, and colorants. These ingredients have numerous roles in the final cosmetic products, such as coloring, scenting, moisturizing, thickening, and stabilizing [15]. The usage amount of these specialty plant materials or their extracts in herbal cosmetic products is varied according to the product category, plant materials used, national, regional (e.g., EU cosmetics regulations), and international (e.g., The International Organization for Standardization (ISO), Food and Drug Administration (FDA)) rules and regulations. For instance, the allowable level of Citrus bergamia Risso (Bergamot oil) in cosmetics is 0.1 ppm in Austria. Furthermore, in line with the EU Cosmetics Regulation, the permissible concentration of essential oil in shower gels and baths (rinse-off products) is 0.01%, while the permissible concentration of essential oil in body oils, massage oils, and creams is 0.001% [17]. However, information on the acceptable concentrations of these individual specialty plant materials in cosmetics is scarce.(1) Essential Oils. People have been using aromatic plants and oils for thousands of years in incense, perfumes, cosmetics, medicinal, and culinary applications [15]. Essential oils are highly concentrated, volatile, hydrophobic mixtures of chemicals extracted from plants. It is estimated that more than 3000 essential oils are of commercial importance and are used in flavor and cosmetic industries [18]. The largest consumer of essential oils is the United States of America, followed by western European countries, namely France, Germany, and the United Kingdom. At present, the United States and developing countries are dominant in the production of the most important essential oils. Essential oils are primarily used for their fragrance properties in cosmetic products. However, certain essential oils possess other interesting properties, such as antibacterial or antifungal, conditioning hair, and improving skin elasticity. Because of the unique functional properties and fragrances of plant-derived essential oils, the cosmetic industry uses them profoundly in a wide range of cosmetic products [11]. Table 1 lists the examples of plant-derived essential oils used in cosmetic products.Table 1
Examples for plant-derived essential oils used in cosmetic products.
Vernacular nameScientific nameFunctional property/propertiesReference(s)BasilOcimum basilicum L.Fragrance[11]Antimicrobial propertiesBayLaurus nobilis L.Fragrance[11]Bergamot oilCitrus bergamia RissoFragrance[19]CalamusAcorus calamus L.Use in aromatherapy[11]CarawayCarum carvi L.Fragrance flavouring agent (mouth washes, toothpastes)[11]CardamomElettaria cardamomum (L.) MatonUse in aromatherapy[11]Carrot seedDaucus carota L.Use in aromatherapy[11]CitronCitrus medica L.Fragrance[11]Antimicrobial propertiesCitronella oilCymbopogon winterianus Jowitt ex BorFragrance[11, 19]Clary sageSalvia sclarea L.Fragrance[11]Garden sageSalvia officinalis L.Spanish sageSalvia lavandulifolia VahlCloveSyzygium aromaticum (L.) Merr. & L.M.PerryAntimicrobial properties[11, 20]German chamomileMatricaria chamomilla L.Herbaceous odour[17, 20]Anti-inflammatory and antiseptic propertiesImmortelleHelichrysum italicum (Roth) G. DonFragrance[17]Stimulates blood circulation in the skin and regenerates the skinAntiwrinkle propertiesJasmine oilJasminum officinale L.Flowery fragrance[19]LavenderLavandula angustifolia Mill.Sweet floral aroma[11, 17, 20, 21]Anti-inflammatory, carminative, and sedativeHeadache-relieving propertiesSkin-healing propertiesLemonCitrus limon (L.) OsbeckAntimicrobial properties[11, 20]Mint oilMentha × piperita L.Fragrance[11, 19, 20]NeroliCitrus × aurantium L.Antimicrobial properties and antidepressant properties[11, 17]Antiseptic propertiesCarminativeSedative propertiesPatchouli oilPogostemon cablin (Blanco) Benth.Fragrance[11, 19]Rose oilRosa × damascena Herrm.[17, 19]Antimicrobial, anti-inflammatory, and antioxidant properties, and moisturizing dry skinCleansing propertiesRosemary oilRosmarinus officinalis L.Fragrance (is widely used for hair care), nourishes the hair[17, 19]Promotes hair growthAntidandruff propertiesPrevents hair lossSandal oilSantalum album L.Fragrance[11, 19]Spike lavenderLavandula latifolia Medik.Antibacterial propertiesAntiviral properties,Anti-inflammatory, and nourishing propertiesSri Lanka cinnamonCinnamomum zeylanicum BlumeFragrance[11]Antimicrobial propertiesStar aniseIllicium verum Hook.f.Fragrance[11]Sweet orangeCitrus sinensis (L.) OsbeckAntiseptic properties[11, 20]SedativeCarminativeTonicTea tree oilMelaleuca alternifolia (Maiden & Betche) CheelFragrance[17, 20]Melaleuca linariifolia Sm.Antiseptic propertiesMelaleuca dissitiflora F.Muell.Antifungal propertiesAnti-inflammatoryVetiver oilChrysopogon zizanioides (L.) RobertyFragrance[11, 19](2) Dye and Colorants. Currently, the market for natural colors in cosmetics continues to grow throughout the world. Manufacturers seek natural plant-based coloring materials that offer health benefits, such as antioxidant, antimicrobial, anti-inflammatory, antiaging, and UV protection properties, beyond their coloring properties alone [22–25]. At present, the main exporting countries of natural dyes are China, Peru, and India [11]. Plant colorants and pigments are used in a whole range of cosmetic products, such as creams, soaps, lotions, hair dyes, and make-up products [15, 26]. Table 2 lists various plant origin colorants and dyes used in the cosmetic industry.Table 2
Plants containing natural dye/colorant compounds used in the cosmetic industry.
English nameSource plantChemical classColorReference(s)AlkanetAlkanna tinctoria (L.) TauschAlkanninRed/purple[24, 25]AnnattoBixa orellana L.Norbixin, bixinOrange/red[11, 22, 27]Butterfly peaClitoria ternatea L.DelphinidinPurple/blue[24, 25]CalendulaCalendula officinalis L.FlavoxanthinOrange[24, 25]CarrotDaucus carota L.Beta-caroteneOrange[27]CatechuSenegalia catechu (L. f.) P.J.H. Hurter & Mabb.CatechinRed[25]ChamomileMatricaria recutita L.ChamazuleneBlue[24, 25]Dyer’s woadIsatis tinctoria L.AlkaloidBlue (indigo)[11]European barberryBerberis vulgaris L.AlkaloidYellow-brown[11]French marigoldTagetes patula L.FlavonoidsYellow[11, 22, 27]Grape vineVitis vinifera L.AnthocyaninRed/blue[11]HennaLawsonia inermis L.NaphthoquinoneRed[11, 22, 27]HibiscusHibiscus rosa-sinensis L.Cyanidin-3-sophoroside, cyanidin-3-sambubioside, delphinidin-3-sambubiosideRed/pink[27]IndigoIndigofera tinctoria L.IndigotinBlue[22]IrisIris × germanica L.Mangiferin, delphinidinPurple/blue/green[24, 25]MadderRubia tinctorum L.Alizarin, purpurinRed/purple[11, 27]PaprikaCapsicum annuum L.CarotenoidsOrange/red[11, 22]Persian walnutJuglans regia L.NaphthoquinoneBrown[11]PomegranatePunica granatum L.PunicalaginRed/purple[22]Red beetBeta vulgaris L.BetaninPink/red[11]Red cabbageBrassica oleracea L.Cyanidin-3-glucoside and delphinidin-3-glucosidePink/purple[25]Red sandalwoodPterocarpus santalinus L.f.SantalinRed[22]RosehipRosa canina L.Lycopene, beta-caroteneRed/orangeSafflowerCarthamus tinctorius L.FlavonoidYellow/red[11, 22]SaffronCrocus sativus L.Crocin, crocetin, picrocrocin, riboflavinYellow[22, 27]SappanwoodCaesalpinia sappan L.AnthocyaninRed[24, 25]SpinachSpinacia oleracea L.ChlorophyllGreen[25]TomatoSolanum lycopersicum L.LycopeneRed/orange[22]TurmericCurcuma longa L.PolyphenolBright yellow[11, 22, 27](3) Oils. Oils are rich sources of fatty acids. Plant-derived oils from edible vegetables, fruits, seeds, plant seedlings, groundnuts, and trees have been safely consumed by humans for millennia. Various oils have been used on the skin since ancient times for cosmetic purposes. Oils are used as the base in a wide variety of cosmetic products, such as creams, emulsions, cosmetic milk, creams, ointments, hair conditioners, brilliantine, cosmetic masks, protective lipstick, bath fluids, nail varnish, and nail cleaners, along with their conditioning, occlusive, emollient, and moisturizing properties [28, 29]. As highlighted by Lubbe and Verpoorte [11], Zielinska and Nowak [29], and Athar and Nasir [30], Table 3 summarizes some commonly used plant-derived oils in cosmetic products.Table 3
Some commonly used plant-derived oils in cosmetic products.
OilSource plantPropertiesReference(s)Almond oilPrunus dulcis (Mill.) D.A.WebbReduces hypertrophic scarring, smoothing, rejuvenating, emollient, improving complexion and skin tone, anti-inflammatory, immunity-boosting[31, 32]Apricot kernel oilPrunus armeniaca L.Nourishing, revitalizing, emollient[33]Avocado oilPersea americana Mill.Hydrating, regenerating, antiaging, antiwrinkle, stimulating hair growth, having extraordinary transepidermal penetration capacity[34]Brazil nut oilBertholletia excelsa Bonpl.Antioxidative[35]Camellia oilCamellia sinensis (L.) KuntzeAntimicrobial, antioxidative, antiallergic, antiviral, skin healing properties, antiwrinkle[36]Carrot oilDaucus carota L.Antiaging, antioxidant, suntan accelerator, photo protection, hair colour protection, emollient[37]Cashew nut oilAnacardium occidentale L.Antiaging, restoring moisture, smoothing[38]Castor oilRicinus communis L.Emollient, lubricant, nourishing[39, 40]Coconut oilCocos nucifera L.Emollient, hydrating, lubricating, cooling, soothing[32]Corn oilZea mays L.Antioxidative, nourishing, antiaging, regenerating damaged cell membranesCotton seed oilGossypium hirsutum L.Emollient, cleansing, antioxidative, anti-inflammatory, soothing[41]Hyptis oilHyptis suaveolens (L.) Poit.Emollient, antimicrobial[42]Jojoba oilSimmondsia chinensis (Link) C.K. Schneid.Soothing, healing, immune booster, antiacne, antibacterial[32]Linseed oilLinum usitatissimum L.Antiseptic, astringent[43]Marula oilSclerocarya birrea (A.Rich.) Hochst.Moisturizing, occlusive[44]Neem oilAzadirachta indica A.Juss.Emollient, antiacne, immunostimulatory, antimicrobial, anti- inflammatory[45]Peanut oilArachis hypogaea L.Emollient, anti-inflammatory[32, 46]Pine nut oilPinus pinea L.Nourishing, curative, antiaging[47]Pumpkin seed oilCucurbita pepo L.Antibacterial, antioxidative, anti-inflammatory[48]Rice bran oilOryza sativa L.Antioxidative, antiaging[49, 50]Sesame oilSesamum indicum L.Antioxidative, antiaging, healing effect[32]Soybean oilGlycine max (L.) Merr.Anti-inflammatory, skin lightening, antioxidative, antiaging, photoprotective[51]Starflower oilBorago officinalis L.Skin barrier repair effect, anti-inflammatory[32]Sunflower seed oilHelianthus annuus L.Emollient, moisturizing, nourishing, conditioning, antioxidative, antimicrobial[32]Walnut oilJuglans regia L.Antioxidative, moisturizing, antimicrobial, nourishing[52, 53]Watermelon seed oilCitrullus lanatus (Thunb.) Matsum. & NakaiNourishing, soothing, skin lightening, moisturizing[54](4) Fat and Waxes. Fats and waxes form an important group of ingredients for the manufacture of personal care products and decorative cosmetics. These are harder substances and very resistant to moisture, oxidation, and microbial attack. Waxes are widely used in a large variety of cosmetic products, such as creams, lotions, balms, ointments, lipsticks, mascara, foundations, and eye shadows for their emollient, moisturizing, thickening, and emulsifying properties. Kokum butter (Garcinia indica (Thouars) Choisy), Sal butter (Shorea robusta Gaertn.), Illipe butter (Shorea stenoptera Burck), avocado butter (Persea americana Mill.), cocoa butter (Theobroma cacao L.), carnauba wax (Copernicia prunifera (Mill.) H.E.Moore), candelilla wax (Euphorbia spp.), berry wax (Rhus verniciflua Stokes), sunflower wax (Helianthus annuus L.), and rice bran wax (Oryza sativa L.) are the most commonly used plant-derived fats and waxes used in cosmetic industry [11, 30, 55].


## 3.1.2. China and India as Premier Exporters of Herbal Cosmetics

As CHEMEXCIL (Basic Chemicals, Cosmetics, and Dyes Export Promotion Council), set up by the Ministry of Commerce and Industry, Government of India, and Singh [56] highlight, China is the largest exporter of herbal cosmetics. Traditional Chinese medicine (TCM) has a deep history of herbal cosmetics production. There are plentiful instances where herbal skincare therapies have been popularly used in TCM. Most cosmetic products belong to the two categories called “antiaging products” and “moisturizer products.” Herbal drugs utilized in TCMs for medicinal purposes are used in cosmetics and personal care products. Therefore, the use of TCM compounds in the production of cosmetic products is very much derived from the medicinal and pharmaceutical applications of TCM [57]. TCM uses approximately 5000 plant species in a wide variety of herbal products [58]. Table 4 indicates some commonly used medicinal plants in TCM for cosmetic treatments [104].Table 4
Some commonly used medicinal plants in TCM for cosmetic treatments.
Source plantEnglish namePlant partFunction and usageReference/sAchyranthes bidentata BlumeOx kneeRootAnti-inflammatory, antioxidant, antiaging properties[59]Adenophora stricta Miq.Lady bellRootHumectant and skin conditioning[60]∗Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav.Chinese angelicaRootAngelica sinensis (Oliv.) DielsFemale ginsengRootAnti-inflammatory and antioxidant properties[61]∗Asarum sieboldii Miq.Chinese wild gingerWhole plant∗Asarum heterotropoides F.SchmidtChinese wild gingerWhole plant∗Astragalus propinquus SchischkinMongolian milkvetchRootPlatycladus orientalis (L.) FrancoChinese arborvitaeShootAnti-inflammatory properties[62]Bletilla striata (Thunb.) Rchb.f.Chinese ground orchidRhizomeAntimicrobial, antioxidant, antiaging properties[63]Bupleurum falcatum L.Chinese thoroughwaxRootAnti-inflammatory and antioxidant properties[64]Calendula officinalis L.Scotch marigoldFlower, leavesCleansing and antimicrobial properties[65]Used in numerous cosmetic formulations, i.e., creams, lotions, shampooCamellia sinensis (L.) KuntzeTeaLeavesAnti-inflammatory, antimicrobial, antiviral, antioxidant properties[66]Relieving skin damage and promoting wound healingCentella asiatica (L.) Urb.Asiatic pennywortLeavesWound healing, anti-inflammatory, antiviral, antibacterial, antifungal, and antioxidant properties[67]Chrysanthemum indicum L.ChrysanthemumStem, flowerAnti-inflammatory properties[68]Cimicifuga dahurica (Turcz. ex Fisch. & C.A.Mey.) Maxim.SilberkerzeRootAnti-inflammatory, antiviral and antioxidant properties[69]Coptis chinensis Franch.GoldthreadRhizomeAntimicrobial properties[70]Eucommia ulmoides Oliv.EucommiaBarkAntioxidant, anti-inflammatory, antimicrobial, and antiaging properties[71]∗Evodia ruticarpa (A.Juss.) Hook.f. & ThomsonEvodiaFruitForsythia suspensa (Thunb.) VahlWeeping forsythiaFruitAnti-inflammatory, antioxidant, antiviral, antibacterial properties[72]Ginkgo Biloba L.Maidenhair treeLeavesAntiaging properties[73]Glycyrrhiza glabra L.European liquoriceRootAntiaging, anti-inflammatory, and antioxidant properties[74]Glycyrrhiza uralensis Fisch.Chinese liquoriceRootSkin conditioning, antioxidant, and anti-inflammatory properties[75, 76]∗Hippophae rhamnoides L.Sea buckthornFruit∗Saccharina japonica (J.E.Areschoug) C.E.Lane, C.Mayes, Druehl & G.W.SaundersBrown algaeWhole plant∗Lavandula angustifolia Mill.Common lavenderFlower, leavesLentinus edodes (Berk.) SingerShiitake mushroomMushroomAntimicrobial, anti-inflammatory, and antioxidant properties[77]Faster skin renewal and increasing skin elasticityLeonurus japonicus Houtt.Chinese motherwortFruitMoisturizing, antiaging, and antioxidant properties[78]∗Ligusticum striatum DC.Szechwan lovageRootLigusticum sinense Oliv.Chinese lovage rootRhizomeAntimelanogenic and moisturizing properties[79]Ligustrum lucidum W.T. AitonChinese privetRootPromoting growth and darkening of hair, reducing facial dark spots[80]Lycium chinense Mill.WolfberryFruitAntiaging, anti-inflammatory, and antioxidant properties[81]Magnolia biondii Pamp.Chinese willow leaves magnoliaBarkAnti-inflammatory and antimicrobial properties[82]Magnolia officinalis Rehder & E.H.WilsonHoupu magnoliaFlowerAntioxidant and anti-inflammatory properties[83]∗Matricaria reticulata L.Scented mayweedFlower, seedMorus alba L.MulberryFruitAntioxidant, anti-inflammatory, antimicrobial, and antiviral properties[84]Tyrosinase inhibitors activityNelumbo nucifera Gaertn.LotusLeavesReduction of hyperpigmentation and antiwrinkling properties[85]Paeonia × suffruticosa AndrewsPeonyLeaves, rootAntioxidant, anti-inflammatory, and antiaging properties[86]Panax ginseng C.A. Mey.Asian ginsengLeavesAntiaging and antiwrinkling properties[87]Phellodendron amurense Rupr.Amur cork treeBarkUsed to treat acne[88]∗Pinus tabuliformis CarrièreChinese red pineWood, leavesPolygonatum officinale All.Solomon’s sealRootAnti-inflammatory and healing properties[89]Polygonum cuspidatum Siebold & Zucc.Japanese knotweedRootPotent tyrosinase inhibition, anti-inflammatory, antimicrobial, antiviral properties[90]Polygonum multiflorum Thunb.Chinese knotweedLeaves, root tuber, rhizomesTonic and antiaging agents[91, 92]Used for promoting hair growth and treating early hair greying (blackening).Prunus armeniaca L.ApricotSeedAntiaging, antioxidant, anti-inflammatory, antimicrobial, and radioprotective properties[93, 94]Rehmannia glutinosa (Gaertn.) DC.RehmanniaRootUsed to treat premature aging, greying hair, and wrinkles[95]Rhodiola rosea L.Golden rootRhizomeAntiaging and anti-inflammatory properties[96]Salvia miltiorrhiza BungeChinese sageRootAnti-inflammatory and antioxidant properties[97]Scutellaria baicalensis GeorgiChinese skullcapRootAntibacterial, antioxidation, and UV protection effects, and it can be used as a skin-whitening ingredient in the beauty industry because of its ability to inhibit melanin synthesis[98]Silybum marianum (L.) Gaertn.Milk thistleSeedAntioxidant and UV B-protective properties[99]Slowing down skin (photo) aging.Sophora flavescens AitonKorean cream peaRootReduction of skin hyperpigmentation[100]Tribulus terrestris L.Land caltropsFruitAntiaging, anti-inflammatory, and antioxidant properties[101]Vitis vinifera L.GrapeFruit, seedAntioxidant and skin conditioning properties[102]Zanthoxylum alatum Roxb.Prickly ashBarkAntifungal, anti-inflammatory, and antioxidant properties[103]Used for scouring teeth∗The plants that were not included in the “Inventory of Existing Cosmetic Ingredients in China (IECIC)-2015.”However,Angelica dahurica Fisch.ex Hoffm., Asarum sieboldii Miq., Asarum heterotropoides F.Schmidt, Astragalus propinquus Schischkin, Evodia ruticarpa (A.Juss.) Hook.f. & Thomson, Hippophae rhamnoides L., Saccharina japonica (J.E.Areschoug) C.E.Lane, C.Mayes, Druehl & G.W.Saunders, Lavandula angustifolia Mill., Ligusticum striatum DC. (Benth. & Hook.fil.) Franch., Matricaria reticulata L., and Pinus tabuliformis Carrière, which were listed in Table 4, are no longer considered cosmetic ingredients according to the IECIC 2015.IECIC 2015 was the latest version issued by the China Food and Drug Administration (CFDA) in 2015. It is a list of existing cosmetic ingredients that have already been used in cosmetics in China. According to IECIC [105], 8783 cosmetic ingredients are allowed to be used in China. Approximately, one-third of these ingredients are classified as “botanical extracts.” However, many of these ingredients are various formulations of the same plant material [104]. Cosmetic ingredients that are not listed are regarded as new cosmetic ingredients. Therefore, new cosmetic ingredients, including botanicals, must be approved by CFDA first before they can be used in cosmetics in China. Furthermore, more information about the approved cosmetic plant ingredients can be found from this link (http://www.cirs-reach.com/China_Chemical_Regulation/SFDA_Registration_of_New_Cosmetic_Ingredient_in_China.html).In India, traditional medicine literature like the Ayurveda has proved the concept of using herbs for beautification in the past. The cosmetic preparations were used for worship and sensual enjoyment. Moreover, herbal extracts have been used for various skin and hair ailments and for enhancing the overall appearance over centuries. Over the last couple of decades, the Indian cosmetics industry has witnessed rapid and strong growth. Today, it is recognized as one of the emerging industries with immense growth potential [106]. Next to China, India is the largest producer of medicinal plants, and India owns more than 40% of global diversity [16]. According to the research report [107], India is one of the 12 mega biodiverse countries around the world. In India, nearly 45,000 plants are used in the Indian system of medicine, while 9,500 plant species are used by tribals in their daily requirements. Out of these 9500 species, 7,500 plants have direct medicinal use, while 950 are giving new leads and claims that require scientific scrutiny [108]. Furthermore, in India, more than 70% of the population uses herbal cosmetics for health care [109]. However, as indicated in the “International cosmetic ingredient dictionary and handbook” issued in 2016, India has not been included as the country that recognizes the need for uniformity in cosmetic ingredient nomenclature and has not formally identified dictionary (potential cosmetic ingredients) in its regulations [110]. Table 5 lists the most common herbal plants used for cosmetics and toiletries in India.Table 5
Most common herbal plants used for cosmetics and toiletries in India.
CategorySource plantEnglish namePlant partFunction and usageReference(s)Skin careMangifera indica L.MangoPlantAntioxidant properties[109, 111]Juniperus communis L.JuniperWhole plantRejuvenation properties[109, 111]Cuscuta reflexa Roxb.DodderPlantAntimicrobial properties[109, 111]Phyllanthus emblica L.Indian gooseberryFruitAntioxidant properties[109, 111–113]Withania somnifera (L.) DunalWinter cherryWhole plantAntioxidant properties[109, 111]Cullen corylifolium (L.) Medik.PsoraleaSeedsAntimicrobial properties[109, 111]Matricaria chamomilla L.ChamomileLeavesAntiacne properties, skin fairness properties[109, 111]Prunus dulcis (Mill.) D.A.WebbAlmondKernelAntiacne properties[109, 113]Skin fairness propertiesLagerstroemia speciosa (L.) Pers.Giant crape-myrtleLeavesAntiaging properties[109]Cydonia oblonga Mill.QuinceSeedsBeautification and skin protection[109, 111]GenusArctiumBurdockRootDeep cleaning the pores and purifying the surface of the skin[109]Jasminum grandiflorum L.Spanish JasmineFlowersControlling skin diseases, protecting from sunburn[109, 111]Santalum album L.SandalwoodHardwoodAntioxidant properties and beautification[109, 111]Salvia hispanica L.ChiaSeedsAntiaging properties[109]Euphorbia thymifolia L.Milk wortPlantAntimicrobial properties[109, 111]Cucumis sativus L.CucumberPeelCooling, toning, and skin-tightening properties[109, 111]Butea monosperma (Lam.) Taub.Bastard teakLeaves and seedsAntifungal properties[109, 111]Allium sativum L.GarlicClovesControlling sores, pimples, and acne[109, 111]Aloe vera (L.) Burm.f.AloeLeavesImproving skin smoothness, healing, controlling skin burn[109, 111]GenusVitisGrapeSeedsProtecting skin elasticity[109, 113]Curcuma longa L.TurmericRhizomeAnti-inflammatory and antioxidant properties[109, 111–113]Leucas aspera (Willd.) LinkThumbaiLeavesControlling scabies, skin psoriasis, chronic skin, skin eruption, and eczema[109, 111]Mallotus philippensis (Lam.) Müll.Arg.Monkey face treeFlowersControlling scabies ringworm, leprous eruption[109, 111]Mimosa pudica L.Humble plantHerbControlling itching[109]Rosa × damascena Herrm.Damask roseFlowersFor beautification, smoothness, and protection from sunburns[109, 111, 113]Lavandula vera DC.LavenderInflorescenceAntiacne properties[109, 111]Lepidium meyenii Walp.MacaRootPromoting elasticity and maintaining the suppleness of the skin[109]Ailanthus excelsa Roxb.Tree of heavenLeavesChecking skin eruption[109, 111]Zea mays L.MaizeStigmaRejuvenation properties[109, 111]Cocos nucifera L.CoconutKernelFor skin itching and rashes[109, 111, 113]Azadirachta indica A.Juss.NeemBark, seeds, fruits and leavesAntioxidant properties[109, 111–113]Citrus limon (L.) OsbeckLemonFruitReducing skin itching and nourishing the skin[109, 111]Senna tora (L.) Roxb.Sickle sennaLeaves and seedAntimicrobial properties[109, 111]Carica papaya L.PapayaLeaves and seedImproving skin softness and removing blemishes[109, 111]Plukenetia volubilis L.Mountain peanutPromoting skin elasticity[109]GenusHippophaeSea buckthornNourishing the skin[109]GenusHelianthusSunflowerEnhancing the brightness of the skin[109, 113]Sesamum indicum L.SesameSeedsRejuvenation properties[109, 111]Ocimum basilicum L.BasilLeavesProtecting from skin infections and rejuvenation properties[109, 111]Pistia stratiotes L.Water lettuceLeavesControlling chronic skin disorders[109, 111]Justicia adhatoda L.Malabar nutLeavesProtecting skin and controlling scabies[109, 111]Hair careJuglans regia L.WalnutLeaves and hullHair dyeing[109, 113]Aloe vera (L.) Burm.f.AloeGelDissolving the dead skin cells and excessive sebum that can clog hair follicles[109, 113]Phyllanthus emblica L.Indian gooseberryFruitPromoting hair growth[109, 111, 114]Ocimum basilicum L.BasilAnti-inflammatory properties, strengthening hair against breakage, and improving circulation in the hair follicles, which helps to stimulate growth[109]Eclipta prostrata (L.) L.False daisyHerbEncouraging hair growth[109, 111, 112]Thymus serpyllum L.Wild thymeHerbUseful for preparing hair tonics[109, 111]Ficus racemosa L.Cluster figAerial rootChecking falling hairs[109, 111]Terminalia bellirica (Gaertn.) Roxb.Belleric myrobalansSeedsUse for hair dyingpreparation[109, 111]Betula pendula RothBirchLeavesAntidandruff properties[109, 111]Centella asiatica (L.) Urb.PennywortWhole plantImproving circulation and promoting stronger hair growth[109, 111, 114]Terminalia chebula Retz.GingerSeedsUse in hair care formulations[109, 111]Lawsonia inermis L.HennaLeavesUse for hair dyeing and nourishment[109, 111–114]Nardostachys jatamansi (D.Don) DC.SpikenardRhizomeUse in hair tonics for growth[109, 111, 112, 114]Lavandula angustifolia Mill.LavenderInflorescenceStimulating circulation in the scalp, strengthening new hair growth, and helping balance the natural oil production of the scalp[109]Calendula officinalis L.MarigoldFlowersSmoothening effect of hair[109, 111]Brassica spp.MustardSeedsNourishing the hair[109, 111]Cocos nucifera L.CoconutKernelUse for preparing hair oils and tonics[109, 111, 113, 114]Mentha × piperita L.PeppermintUse as a healing scalp treatment[109]Sapindus mukorossi Gaertn.Soap nutFruit coatNatural shampoo and cleansing hair[109, 111]Carthamus tinctorius L.SafflowerUse in hair tonics[109, 111]Salvia officinalis L.SageUse as a hair conditioner[109, 111]Acacia concinna (Willd.) DC.Soap podPodsUse as hair cleanser and for control of dandruff[109, 111, 112, 114]Sesamum indicum L.SesameSeedsMajor source of hair oils and use for preparing specific hair oils[109, 111, 114]Nasturtium officinale R.Br.WatercressSupporting the stronger hair growth[109]Oral careAchyranthes aspera L.Prickly chaff flowerRootUse as a toothbrush, good for dental caries[115]Argemone mexicana L.Mexican pricklypoppySeedsGood for gum troubles[115]Azadirachta indica A.Juss.NeemTwigsUse to clean teeth and is considered good for dental caries and gum infection[113, 115]Berberis lycium RoyleIndian lyciumPeeled stemConsidered good for scouring teeth[115]Calotropis procera (Aiton) Dryand.SodomLatexUsed for toothache[115]Capsicum annuum L.PaprikaFruitsGood for toothache[115]Senna occidentalis (L.) LinkCoffee sennaLeavesUse for scouring teeth[115]Cinnamomum tamala (Buch.-Ham.) T.Nees & Eberm.Bay leafLeavesUse for scouring teeth[115]Good for gum inflammationCitrus limon (L.) OsbeckLemonLeavesUse for scouring teeth[115]Good as a mouth freshenerCitrus medica L.CitronLeaves and rind of fruitsGood for scouring teeth[115]Curcuma angustifolia Roxb.East Indian arrowrootRhizomeAppling on gums for pyorrhoea[115]Ficus hispida L.f.Hairy figLatexUse for toothache[115]Ipomoea carnea Jacq.Bush morning gloryLeavesGood for toothache[115]Jatropha curcas L.Physic nutTwigsUse as a toothbrush[115]Good against dental cariesJuglans regia L.WalnutBark and leavesUse for scouring teeth[115]Mangifera indica L.MangoLeavesUse for scouring teeth[115]Murraya koenigii (L.) Spreng.Curry leafStemUse for scouring teeth and for healthy gums[115]Carya illinoinensis (Wangenh.) K.KochPecanLeavesUsed for scouring teeth[115]Good for gumsPlumbago zeylanica L.Ceylon leadwortStemGood for scouring teeth[115]Prunus cerasoides Buch.-Ham. ex D.DonWild Himalayan cherryTwigsUse for scouring teeth[115]Psidium guajava L.GuavaLeaves and stemUse for scouring teeth[115]Robinia pseudoacacia L.Black locustBarkGood for toothache[115]Vitex negundo L.Chinese chaste treeTwigsGood for cleaning teeth[115]Good for pyorrhoea, gum inflammation, dental cariesZanthoxylum armatum DC.Winged prickly ashTwigsUse for scouring teeth[115]


## 3.2. Sri Lanka as an Example for Tropical Asian Country: Possible Contribution to the Development of Herbal Cosmetics

Sri Lanka, formerly known as Ceylon, is an island with an area of approximately 65,610 km2. Despite its relatively small size, Sri Lanka possesses a high level of biodiversity because of its varied climate and topographical conditions. In view of that, it is recognized as a biodiversity hotspot of global and national importance. Sri Lanka has a traditional system of medicine, which is as ancient as the civilization of the island and practiced from generation to generation [116]. Natural resources, including herbal, mineral, and animal products, are the key resources of the Ayurveda and indigenous systems of medicine in Sri Lanka. Since time immemorial, plants have been playing a vital role in the healthcare system of Sri Lankans’ livelihoods [117].As specified in the literature, Sri Lanka has rich traditional systems of medicine, such as Ayurveda, Siddha, Unani, and Deshiya Chikitsa. It plays a pivotal role by fulfilling 60% to 70% of the rural populations’ primary health care needs [118]. Sri Lanka is one of the most biologically diverse countries in Asia and currently possesses 29.7% of forest cover [119]. There are 3,771 flowering plant species, out of which about 927 (24%) are endemic to the country [120]. According to Sugathadasa et al. [121], 1,430 species representing 181 families and 838 genera can be considered medicinal plants. Out of the total number of species, 174 (12%) are endemic to Sri Lanka. About 250 species of medicinal plants are commonly used in traditional medicine, of which 50 species are heavily used [122]. The study conducted by Kankanamalage et al. [123] reveals the sources of medicinal plant materials that are obtained for numerous medicinal plant-based trades. Approximately 71.13% of these medicinal plants/herbal materials are obtained from local sources, and 26% are imported. Moreover, it reveals that 80% of the fresh and dry plant materials contribute to the herbal industry. Thus, it implies the importance of medicinal plants in different systems of medicine in Sri Lanka. Moreover, the study conducted by Dissanayake [124] on “Medicinal plant research in Sri Lanka: A scientometric study based on Scopus database” highlights the research studies of 190 plants, including 22 endemic plants. It reveals that most of the conducted studies were activity-based studies, such as toxicity, antibacterial, antifungal, hypoglycemic, antioxidant, anti-inflammatory, and diuretic activities. It was followed by general studies, such as physicochemical, chemical, postharvest, horticultural, and propagation studies of plants. This study shows the largely unexplored knowledge gap of medicinal plants in Sri Lanka.However, considering the herbal cosmetics in Sri Lanka, the available data on herbal cosmetics’ production and cosmetic potential medicinal plants are very scarce. Although the herbal cosmetic industry has exponentially increased throughout the world, the supply of potential cosmetic herbal products from Sri Lanka is still very limited. As Napagoda et al. [125] stated, only a handful of scientific evidence is available on the bioactivity studies of medicinal plants in Sri Lanka that could lead to the development of herbal cosmetics. Apart from the study on “cosmetic perspective of ethnobotany in the northern part of Sri Lanka,” [126] there has been hardly any ethnobotany report on the cosmetic potential of Sri Lankan medicinal plants. A total of 62 plant species belonging to 36 families have been identified based on the traditional knowledge and practices of the local community through this study. The identified plants are used for beautifying purposes, such as skin care, hair care, nail care, lip care, and eye care. However, the assembling of the multidisciplinary cooperation of botanists, chemists, toxicologists, researchers, and biologists is crucial to analyze interesting functional properties, efficacy, and effectiveness of documented cosmetic potential medicinal plants. Furthermore, Napagoda et al. [125] highlighted the probable usage of Atalantia ceylanica (Arn.) Oliv., Hibiscus furcatus Mullend., Leucas zeylanica (L.) W.T.Aiton, Mollugo cerviana (L.) Ser., Olax zeylanica L., and Ophiorrhiza mungos L. for the development of photoprotective cosmetic products by analyzing the antioxidant activity and the sun protection factor (SPF). Moreover, the research study conducted by Liyanaarachchi et al. [9] reveals the possible usage of Artocarpus nobilis Thwaites, Artocarpus altilis (Parkinson ex F.A.Zorn) Fosberg, Elaeocarpus serratus Heyne, Curcuma aromatica, and Artocarpus heterophyllus Lam. in the treatment of various skin disorders, such as hyperpigmentation, wrinkling, premature aging, and biological aging by analyzing tyrosinase, elastase, and hyaluronidase enzyme inhibitory and antioxidant activities.Furthermore, Dissanayake [124] reports that most of the medicinal plant-related studies in Sri Lanka are still on the laboratory scale. Thus, investigating the cosmetic potential medicinal plants, isolation of active compounds, and bioactivity studies of medicinal plants has become necessary for Sri Lanka to support herbal cosmetic productions and innovations.


### 3.2.1. Strengths of Sri Lanka as a Tropical Asian Country for the Development of Herbal Cosmetic Industry

Medicinal plants have played a pivotal role in many ancient traditional systems of medicine in Asia, such as the Ayurvedic and Unani systems of India and the traditional Chinese medicine and their derivatives in most Asian countries. Tropical Asian countries are unique among the geographical regions of the world because of high biological diversity, high cultural diversity, diverse ancient civilizations, and abundant raw materials. Because of their widely diversified ecological conditions, particularly in tropical rain forests, they have relatively high biological diversity that is the greatest of all world regions. This high diversity of the region is reflected by the number of species of plants and animals, including medicinal plants. The areas of high biological diversity are among the most culturally disparate, with large numbers of distinct communities inhabiting adjacent areas, each with its own language, culture, and system of traditional medicine. A wealth of traditional knowledge about medicinal plants to cure illnesses has been accumulated over a long period and has been handed down from generation to generation until the present time [127].Medicinal plants have been used for centuries in medicinal, therapeutic, and beauty applications in Sri Lanka by different traditional systems of medicine, which have a documented history of over 2,500 years. Many formulae of medicinal preparations in the Sri Lankan traditional system of medicine are handed down from generation to generation. Some formulae are found only in the scripts of old “ola leaf” books treasured by traditional and Ayurvedic practitioners [128]. Table 6 lists the traditional usage of medicinal plants in Sri Lanka for cosmetic treatments.Table 6
Traditional usage of medicinal plants in cosmetic treatments of Sri Lanka.
NoFamilyScientific nameEnglish nameVernacular nameTraditional usesReference/s1AcanthaceaeBarleria prionitis L.∗CrossandraKatu karanduThe juice of the crushed leaves is applied to promote skin and scalp health[116, 129]Prevent early grey or white hair2Justicia adhatoda L.Malabar nutAdhatodaHerbal toothpaste formulated with other plants is effective for oral hygiene[116]3AcoraceaeAcorus calamus L.∗Sweet flagWada-kahaGround rhizome is applied for pediculosis and to improve skin complexion[116, 130]4AmaranthaceaeAlternanthera sessilis (L.) R.Br. ex DC.Sessile joyweedMukunuwennaLeaf juice promotes healthy hair and is used for manufacturing shampoos[116, 130]5AmaryllidaceaeAllium sativum L.∗GarlicSudulunuGround garlic mixed with honey or mixed with turmeric and honey is applied for curing pimples[130]6AnnonaceaeAnnona muricata L.∗Prickly custard appleKatu-anodaThe juice of crushed young leaves is applied for pediculosis[116, 129]7ApiaceaeCentella asiatica (L.) Urb.Indian pennywortGotukolaThe crushed leaves are used for damaged hair treatments and skin healing[116, 131]8ApocynaceaeHemidesmus indicus(L.) R. Br. ex Schult.Indian sarsaparillaIramusuThe juice of the crushed leaves is applied to reduce hair loss and to improve skin complexion[116, 129]9Holarrhena pubescens Wall. ex G.Don∗KurchiKelindaThe decoction of the bark is used as a mouth wash[131]10ArecaceaeAreca catechu L.∗Areca nutPuwakThe decoction of the flowers is used as a mouth wash and is used in toothpaste manufacturing[116, 131]11Caryota urens L.∗Wine palmKithulThe bark and tender flowers improve hair growth[116]12Cocos nucifera L.King coconut/PolThambili/CoconutKernel oil promotes hair growth[116]13AsparagaceaeAsparagus racemosus Willd.Wild asparagusHathawariyaThe juice of the crushed leaves is applied to improve hair colour, promote hair growth, and prevent hair loss and early grey hair or white hair[130]Possesses antiaging propertiesThe juice of the crushed leaves is applied to improve skin complexion and to remove skin freckles14AsphodelaceaeAloe vera (L.) Burm.f.Aloe plantKomarikaSustaining youthful appearance, leaf gel is used to remove dead cells around the eye, freckles, and for curing pimples,[116, 131]Leaf gel is applied to prevent hair loss and leaf gel with passion fruit (Passiflora edulis Sims) is applied to treat dandruff15AsteraceaeEclipta prostrata (L.) L.False daisyKeekirindiyaLeaf oil promotes hair growth[116, 131]The juice of the crushed leaves is used to treat skin discolorations, and it possesses antiaging properties16Baccharoides anthelmintica (L.) Moench∗Purple fleabaneSanninayamCrushed seeds are applied to treat freckles[132]Crushed seeds with lime juice is applied for pediculosis17BerberidaceaeBerberis aristata DC.∗Indian barberryDaruharidraThe decoction of the bark is used as a mouth wash[131]18BombacaceaeBombax ceiba L.∗Red silk cotton treeImbulCrushed thrones are applied to improve the skin complexion, to remove freckles, and for curing pimples[129]Seed oil is used for manufacturing soaps19BrassicaceaeBrassica juncea (L.) Czern.∗Indian mustardAbaSeed oil is applied on the hands and legs to soften the skin and improve the complexion[129]20CalophyllaceaeMesua ferrea L.Iron woodNaThe crushed flower stamens mixed with khas-khas powder is applied on the body to remove the malodors of the body, remove freckles, and improve complexion by frequent application[116]21CannabaceaeCeltis timorensis Span.∗StinkwoodGurenda/BurendaWood powder mixed with gingelly oil is applied on the skin for dryness to improve complexion[116]22CaricaceaeCarica papaya L.PapayaGaslabuThe ripe fruit is used to remove freckles[116]23CelastraceaeKokoona zeylanica ThwaitesKokunSoaps made from the crushed bark with water have been used for bathing by men and women since ancient times[132]The bark powder is used to treat pimples and to improve skin complexion24ClusiaceaeGarcinia × mangostana L.∗MangosteenMangusThe decoction of the bark is used as a mouth wash for healthy gums and teeth[116]25Garcinia quaesita PierreRed mangoGorakaIt is used for manufacturing toothpastes[131]26CombretaceaeTerminalia arjuna (Roxb. ex DC.) Wight & Arn.∗Arjuna myrobalanKumbukThe bark powder mixed with honey is applied on pimples, and the bark is used for manufacturing toothpaste[131]27Terminalia bellirica (Gaertn.) Roxb.Beleric myrobalanBuluApplying the seeds’ oil improves the black colour of hair and controls hair loss[131]28Terminalia chebula Retz.MyrabalansAraluThe infusion of the powdered, dried, young fruit is used as a mouthwash[116, 129]Possesses antiaging properties and is used to manufacture yellow colour dye29ConvolvulaceaeArgyreia populifolia Choisy∗Sri Lankan elephant creeperGiritillaThe juice of the young shoots is applied on the gums for sanitation[116]30Cuscuta chinensis Lam.∗DodderAgamula nathi walConcentrated plant extract with gingelly oil upon boiling is applied to improve the black color of hair and prevent hair loss, and it is used to treat dandruff[132]31Evolvulus alsinoides(L.)L.∗Slender dwarf morning- gloryVishnukranthiPlant extracted oil is applied to promote healthy hair growth[130]32Ipomoea pes-caprae (L.) R. Br.∗Goats foot creeperBinthamburuThe decoction of the leaves is used for foot health[131]33CostaceaeCheilocostus speciosus (J.Koenig) C.D.Specht∗Crape gingerThebuThe bark is used to remove freckles, especially those that occurred during chicken pox[132]34CucurbitaceaeCucumis melo L.∗Bitter cucumberGon kakiriThe crushed fruit mixed with the nux-vomica tree (Strychnos nux-vomica L.) seeds is used to treat pimples[131]35Cucumis sativus L.CucumberPipingnaFruit slices are used to treat darkness under the eyes and are used for skin cooling, soothing, and healing[116]36Trichosanthes cucumerina L.∗Wild snake gourdDummallaThe decoction of leaves is used to control early grey or white hair[131]37CyperaceaeCyperus rotundus L.NutgrassKalanduruCrushed tubers are used to treat acne[129]38DilleniaceaeDillenia retusa Thunb.GodaparaThe fruit pulp is used to cleanse the scalp and promote healthy hair growth[116, 131]39EbenaceaeDiospyros malabarica (Desr.) Kostel.∗Riber ebonyTimbiriThe decoction of unripe fruit slices is used as a mouthwash or gargle for mouth sanitation[116]40ElaeocarpaceaeElaeocarpus serratus L.Wild oliveWeraluThe leaves are boiled with true lime slices to clean the scalp and hair[116]41EuphorbiaceaeJatropha curcas L.Purging nutRata endaruThe decoction of the bark is used for mouth sanitation[116]42FabaceaeAbrus precatorius L.∗Wild liquoriceOlindaGrounded seeds with true lime are used to treat acne[116]43Caesalpinia bonduc (L.) Roxb.∗Molucca beanKumburuSeeds’ oil is applied to cure pimples, and fried seeds’ powder is used for brushing the teeth[131]44Crotalaria verrucosa L.∗Blue rattle weedNil-adanahiriyaGargling and the infusion of young shoots and leaves promote mouth sanitation[116]45Entada rheedii Spreng.∗Elephant creepes mackayPus wellSeed kernel powder mixed with white sandalwood powder in true lime juice is used to treat pimples[116, 132]The ground seeds, stem, and bark, along with water, are used to clean the scalp and hair46Indigofera tinctoria L.IndigoNilawariMedicated oil prepared with fresh leaf juice and king coconut oil is applied to improve skin complexion[116]Ground with false daisy, turmeric, and kurchi, it is applied to control hair loss, and the oil extracted from the leaves promotes hair growth47Mimosa pudica L.∗Sensitive plantNidikumbaThe ground aerial parts with gingelly oil are applied on the skin because of healing properties, and a decoction of the roots is used as a mouth wash to improve mouth hygiene[116]48Pongamia pinnata (L.) PierreIndian beechKarandaSeed oil is used in soap manufacturing because of its antimicrobial properties[130]49Pterocarpus marsupium Roxb.∗Indian kino treeGammaluDissolved dried gum in warm water is used as a mouthwash for healthy gums and teeth[116, 131]50Pterocarpus santalinus L.f.Red sandalwoodRath-handunCrushed heartwood mixed with turmeric powder and milk is used to treat pimples and is used in soap manufacturing[116, 130]51Senna alata (L.) Roxb.Candle bushEththoraThe leaves are used in antiseptic soap manufacturing because of antimicrobial properties[116, 129]52Senna auriculata (L.) Roxb.∗Tanner’s cassiaRanawaraCrushed flowers are applied to the skin to improve complexion[130]53Tephrosia purpurea (L.) Pers.Purple tephrosiaKathurupilaThe roots are used for mouth sanitation and are used in manufacturing toothpastes[116, 131]54Trigonella foenum-graecum L.FenugreekUluhalBoiled with unripe true limes to treat dandruff[131]55HypoxidaceaeCurculigo orchioides Gaertn.∗Black musaleBinthalThe crushed tuber has been used to improve the beauty of the face by men and women since ancient times[131]56LamiaceaeOcimum tenuiflorum L.Holy basilHeen maduruthalaThe extracted leaf oil is used as a fragrant agent, and the juice of the crushed leaves is used to treat pimples and freckles[130]57Pogostemon heyneanus Benth.∗PatchouliGas-kollankolaInfusion of fresh or dried leaves is used as a mouthwash for healthy gums and teeth[116]58Premna obtusifolia R.Br.∗Heen midiLeaves mixed with coconut oil are used to clean the scalp and hair[130]59Tectona grandis L.f.∗TeakThekkaDried fruit powder promotes hair growth[116]60LauraceaeCinnamomum verum J.PreslCeylon cinnamonKurunduThe dried inner bark is used as a mouth wash for gum and teeth sanitation[116]Cinnamon powder mixed with honey is applied to treat pimples61LecythidaceaeBarringtonia acutangula (L.) Gaertn.∗Indian oakMidellaThe decoction of the leaf, bark, and flower is used as a mouth wash for healthy, strong gums[130]62Careya arborea Rroxb.∗Patana oakKahataBark gum is used to soften the skin[132]63Couroupita guianensis Aubl.∗Cannon ball treeSalLeaves stimulate the dermal fibroblast proliferation[116]64LythraceaeLawsonia inermis L.HennaMarathondiLeaves are boiled in water with true lime fruit pieces are used to treat grey or white hair, and the leaves stimulate hair growth and are used to colour nails[116]65Punica granatum L.PomegranateDelumThe decoction of the roots and fruit rind is used as a mouth wash, and the decoction of the leaves is good for the eyes[116, 131]66MalvaceaeAbutilon indicum (L.) Sweet∗Country mallowBehethanodaCrushed leaves are used as a mouth wash[131]67Gossypium arboreum L.∗CottonKapuLeaves stimulate dermal fibroblast proliferation[116]68Abelmoschus moschatus Medik.Musk mallowKapukinissaSeeds’ paste is applied for skin itching, and chewing the seeds removes the malodors of the mouth[116, 129]69Hibiscus rosa-sinensis L.Shoe flowerPokuru wadaOil prepared by boiling the leaves and flowers with coconut oil or gingelly oil is applied to promote healthy hair growth, prevent early grey or white hair, hair loss, and dandruff[116]Crushed flowers and leaves are applied to remove suntan, to cure pimples, and to remove freckles on the skin70Theobroma cacao L.CocoKokovaPossesses emollient properties and is used to soften and treat dry skin and chapped lips[116]71MeliaceaeAzadirachta indica A.Juss.NeemKohombaCrushed leaves mixed with true lime juice are applied on pimples, and a decoction of the roots is used as a mouth wash and is used in manufacturing soaps and toothpastes[131]72MenispermaceaeCoscinium fenestratum (Goetgh.) Colebr.Calumba woodWeniwelStem powder mixed with honey is used to exfoliate the skin, and it possess antiacne properties[116, 130]73MoraceaeFicus racemosa L.Country figAttikkaCrushed leaves are used to treat freckles and skin discoloration[129]74MyristicaceaeMyristica fragrans Houtt.NutmegSadhikkaThe seed extracted oil is used in soap and toothpaste manufacturing, the herbal shampoo is prepared for pediculosis, it is used to clean the scalp and hair, and it is used to protect skin keratinocytes from UV B- induced damage[116, 130]75MyrtaceaeMelaleuca leucadendra (L.) L.Cajuput treeLothsumbuluImproves skin complexion, and the bark acts as a stimulant and tonic[116]76Syzygium aromaticum (L.) Merr. & L.M.PerryCloveKarabuIt is used in toothpaste manufacturing[116, 129]77Syzygium cumini (L.) Skeels∗Indian black berryMadanThe bark is used to prepare mouth washes for healthy gums and teeth used in manufacturing toothpastes[116, 130]78NymphaeaceaeNymphaea nouchali Burm.f.Blue water lilyNil manelThe flowers are mixed with cow milk and stored in a covered clay pot approximately a month to colour grey or white hair into black[130]79OleaceaeJasminum grandiflorum L.JasmineSamanpichchaGround roots and flowers improve skin discoloration, used to treat skin discolorations, plant-extracted oil is applied to cool the scalp[116, 130]80Jasminum multiflorum (Burm.f.) Andrews∗Sambac JasmineGeta pichchaPaste made by grinding the flower buds is applied on the skin for improved complexion[116]81OxalidaceaeAverrhoa bilimbi L.∗BilimbiBilinLeaf juice is applied to cure pimples, herbal shampoo prepared from the plant is effective for pediculosis[116]82PedaliaceaeSesamum indicum L.GingellyThel-thalaLiniments to promote hair growth, possesses healing properties[116]83PhyllanthaceaePhyllanthus emblica L.Emblic myrobalanNelliImproves skin complexion, prevents hair loss and early grey or white hair[131]Used in manufacturing herbal hair oil, shampoo, conditioner, and skin care products84PlantaginaceaeBacopa monnieri (L.) Wettst.Thyme leaved gratiolaLunuwilaPossesses antiaging properties and antidandruff properties[116]85PoaceaeCymbopogon citratus (DC.) StapfLemon grassSeraShampoo containing essential oil is effective for pediculosis and dandruff[116, 130]86Chrysopogon zizanioides (L.) RobertyKhas-khasSawandaraRoot-extracted oil is used in the perfume industry and soap manufacturing and is used as a fragrant agent, and the crushed roots are applied on the skin[116, 130]87PonterderiaceaeMonochoria vaginalis (Burm.f.) C.PreslOval leafed pondweedDiyahabaralaRoot infusion is used as a mouthwash for mouth inflammations[116]88RubiaceaeMorinda citrifolia L.∗Indian mulberryAhuThe juice of the fruits in salt water is used as a mouthwash for healthy gums, and the crushed leaves are used to exfoliate the skin and for dermal fibroblast proliferation[116, 129]89Rubia cordifolia L.Heart leaved madderVelmadataCrushed roots mixed with honey are used to remove freckles and skin discolorations[130]90RutaceaeAcronychia pedunculata (L.) Miq.Claw flowered laurelAnkendaCrushed leaves are used to treat pimples[116]91Aegle marmelos (L.) CorrêaBael fruit treeBeliRipe fruit mixed with green gram powder is applied to improve skin complexion and can be used as an eye lotion[116, 131]92Citrus aurantiifolia (Christm.) SwingleTrue limeDehiActs as a cleanser, unripe fruits are boiled with fenugreek to treat dandruff, fruits are ground with lotus leaves to treat pediculosis[131]93Citrus hystrix DC.∗Kaffir limeGada dehiFruit juice is used to treat dandruff and is used in aromatic baths and as a shampoo[116]94Melicope lunu-ankenda (Gaertn.) T.G. Hartley∗Lunu-ankendaCrushed leaves are used to improve complexion[116]95Murraya koenigii (L.) Spreng.∗Curry leafKarapinchaThe juice of the crushed leaves is used to promote healthy hair growth[129]96Ruta graveolens L.Garden rueArudaHerbal oil prepared with fresh leaves and pure coconut oil is applied for healthy hair[129]97SantalaceaeSantalum album L.SandalwoodSudu handunHeartwood powder mixed with lime juice is applied gently on pimples to improve skin complexion, the powder mixed with cow milk is used to treat freckles, and it possesses antiaging properties[116, 130]98SapindaceaeSchleichera oleosa (Lour.) Merr.Ceylon oakKonSeed oil is applied to promote healthy hair[116]99SapotaceaeMimusops elengi L.Bullet wood treeMunamalThe decoction of the mature bark is used as a mouthwash for healthy gums and teeth, herbal toothpaste formulated with other plants is effective for oral hygiene[116, 130]100SolanaceaeDatura metel L.∗DaturaAttanaThe root powder is applied on the gums for mouth sanitation[116]101SymplocaceaeSymplocos cochinchinensis (Lour.) S. Moore∗BombuBark decoction is used as a mouthwash for healthy gums[116]102TheaceaeCamellia sinensis (L.) KuntzeTeaThaePossesses antiwrinkle properties[116]103VitaceaeLeea indica (Burm. f.) Merr.∗Bandicoot berryGurullaCrushed leaves are applied on skin patches to improve skin complexion[130]104ZingiberaceaAlpinia malaccensis (Burm.f.) RoscoeRankihiriyaFlower bud juice in lukewarm water is used as a mouth wash for healthy gums and teeth[116]105Curcuma longa L.TurmericAth kahaThe crushed rhizome is used to improve skin complexion, prevents UV B-induced skin aging[116]106Curcuma zedoaria (Christm.) RoscoeZedoaryHaran kahaCrushed rhizome improves skin complexion, and it is used as a fragrant agent[130]107Kaempferia galanga L.∗Java galangaIngurupiyaliDried sliced rhizome infusion is used as a mouth wash, powdered rhizome with coconut oil on the skin to improves skin complexion, improves lustrous of hair, possesses antidandruff properties and skin whitening properties[116, 129]108Zingiber officinale RoscoeGingerInguruJuice-extracted ginger pulp is applied on pimples, and it is used to improve skin complexion[129]∗The plant species that are currently not used in the herbal cosmetic industry of Sri Lanka (in comparison with the survey conducted on “Emerging herbal cosmetic production in Sri Lanka: Identifying the possible interventions for the development of herbal cosmetic industry” [12]).As listed in Table6, a total of 108 different plant species belonging to 58 families were identified from the books, “Compendium of medicinal plants, Sri Lankan study, Volume I to IV” and “A collection of medicinal plants in Sri Lanka.” The most dominant family was the family Fabaceae (13 plant species). A wide range of plant parts has been used for traditional cosmetic treatments. Based on the remedies, the identified plant parts were the leaves, bark, seeds, fruits, roots, flowers, rhizome, stem, heartwood, flower buds, tuber, gum, fruit rind, shoots, bulb, flower stamens, fruit kernel, inner bark, leaf gel, thorns, and wood. Medicinal plants are used in cosmetic treatments for various reasons, such as skin care, hair care, and oral care. Myristica fragrans Houtt. (Sadhikka) and Kaempferia galanga L. (Ingurupiyali) are reported in all three cosmetic treatment categories. Furthermore, 04 plants, namely Ocimum tenuiflorum L. (Heen Maduruthala), Chrysopogon zizanioides (L.) Roberty (Sawandara), Citrus hystrix DC. (Gada dehi), and Curcuma zedoaria (Christm.) Roscoe (Haran Kaha) are fragrant agents that have possible usage in the perfume industry.The recent survey conducted by Gamage et al. [12] discloses the current usage of 115 plant species in herbal cosmetic productions in Sri Lanka. Furthermore, this study highlights the lack of proper cultivation systems of medicinal plants with cosmetic potential within the country for continuous herbal cosmetic productions. Although established cultivation systems are available for some highly used plants in the herbal cosmetic industry of Sri Lanka, such as Aloe vera (L.) Burm.f., most of the other medicinal plant materials are obtained either from the wild or through importation. Consequently, harvesting restrictions were imposed by the government for some wild species, such as Coscinium fenestratum (Goetgh.) Colebr. The adulteration of medicinal plant materials, lack of growers, declining suppliers, and lack of proper cultivation systems are major hindrances to the success of the herbal cosmetic industry in Sri Lanka. However, a comparison between the plant list identified through this survey and the plant list identified from the local books shows the possible usage of 49 plant species in the herbal cosmetic industry as new ingredients. Thus, these findings can be utilized for inventing new products in the future. As global demand for herbal cosmetics increases, there are ample opportunities for Sri Lanka to expand global export with its unique biodiversity and a rich base of traditional knowledge. It will lead to the upliftment of people’s livelihoods and the county’s economic development.


### 3.2.2. Major Challenges and Possible Solutions for Sri Lanka to Develop Plant-Based Cosmetic Productions

At present, most developed countries’ cosmetic manufacturers are continuously probing for new products and ingredients of tropical origin because their raw materials often have interesting properties. The interesting properties of tropical origin ingredients could vary based on climatic and topographical conditions [11]. However, the Association of Southeast Asian Nations (ASEAN) integration report issued in 2015 clearly indicates that developing cosmetic products and cosmetic product markets based on indigenous ingredients is one of the major challenges [133]. The lack of ethnobotanical and ethnopharmacological surveys to identify the cosmetic potential plants, insufficient or absence of continuous supply of raw materials for production in line with the existing demand, lack of quality control of raw materials and finished cosmetic products, improper systematic cultivation systems for medicinal plants, poor postharvest practices, lack of innovations, and the lack of efficacy tests (in vivo and in vitro) to ensure the safety are the major challenges found in Sri Lanka for the development of the herbal cosmetic industry [12, 104, 123, 124, 134].To overcome the aforementioned challenges, collecting information on medicinal plants, traditional drugs, ethnobotany, and ethnopharmacology related to cosmetic treatments with traditional practitioners, Ayurveda physicians, and local communities in each country is required. As most of the traditional knowledge on medicinal plants and treatments in Sri Lanka is passed from generation to generation within families, conducting ethnobotanical and ethnopharmacological surveys will aid to identify cosmetic potential plants, important plant parts, remedies while preserving the traditional knowledge. Furthermore, information gathered through surveys could ultimately be utilized to develop the herbal cosmetic industry by the isolation and characterization of bioactive compounds from identified plants. Cosmetic companies work with a wide range of suppliers to obtain botanical raw materials. These suppliers purchase plant biomass from a wide array of sources ranging from large to small scale. However, harvesting plants from the wild is still popular for many medicinal herbs among local suppliers. Consequently, overharvesting can reduce plant populations to the point where the species’ biodiversity is threatened, some species even to their extinction. Therefore, establishing proper systematic cultivation systems for identified medicinal plants is paramount. Furthermore, future research must be focused on nursery techniques, field establishments, and the harvest management of medicinal plants. Cultivated plant materials are preferred for the cosmetic industry as it is easier to control the whole supply chain and chemical variations. With the use of cultivated plants, problems such as adulteration and misidentification of material are mostly eliminated. It is also easier to adhere to quality standards and has less batch-to-batch variation as the plants are grown under controlled conditions. Furthermore, the utilization of biotechnology techniques, such as tissue culture, will benefit from preserving biodiversity by utilizing the endangered or unavailable plants using conventional production or wildcrafting. Product development and innovation are other key factors to succeed in the herbal cosmetic industry in Sri Lanka. The process to bring a medicinal plant from field to finished good can be quite complicated with many challenges along the way. Stability testing on raw materials to anticipate any issues with color change, odor, viscosity, precipitation, separation, or degradation of actives must be carried out routinely by cosmetic manufacturers. The characteristics of cosmetic products can be affected by environmental factors, such as temperature, pH, light, air, and humidity, which impact their stability contributing to severe damage to the constituents of the product [135]. Because of the wide variety of cosmetic products and their inherent complexity, it is hard to find standard stability tests that can be applied to a vast range of products. However, generally used stability tests can be categorized into several categories namely stability and physical integrity of cosmetic products (under appropriate conditions of storage, transport, and use), chemical stability, microbiological stability, and the compatibility between the contents and the container. For example, the organoleptic characteristics of cosmetic preparations, such as color, smell, texture, and consistency, can be evaluated by visual inspection. Additionally, several physicochemical analyses can be performed, such as centrifugation, mechanical vibration, light tests, pH, density, viscosity determination, and spectrophotometric assays, besides accelerated and microbial stability tests [136]. Quality control testing must be performed and continuously monitored to ensure its physical and analytical characteristics are up to standard. Some current techniques used by the cosmetic industry can be applied to the evaluation of cosmetic’s quality control in an efficient manner, such as sensory analysis, rheology, and small-angle X-ray scattering [137]. Efficacy/safety tests should be performed on medicinal plant ingredients as well. For instance, cosmetics companies can perform in vitro testing to screen for cell damage in skin cell cultures or irritation in skin construct models and animal testing to avoid adverse events. However, the European Commission Cosmetics Directive has executed an animal testing ban on finished cosmetic products and ingredients. In such situations, cosmetic manufacturers have to find an alternative method to ensure product safety. At present, many alternatives to animal testing have been developed and validated for the safety and efficacy testing of cosmetic products and cosmetic ingredients. For example, 2D cell culture models derived from the human skin for evaluating anti-inflammatory properties, or predicting skin sensitization potential and 3D human skin equivalent models for evaluating skin irritation potential and excised human skin are being currently used as the gold standard for evaluating dermal absorption [138]. If a medicinal plant ingredient is safe and stable, it can move on to the formulation phase, where it is added to a cosmetic formula and retested for the same parameters, safety, and stability. With careful management, cosmetic companies can offer innovative beauty products that enhance living standards while conserving natural resources, promoting economic development for the poor, and protecting the environmental resources of Sri Lanka [11, 104, 108, 124, 127, 139, 140].In addition, the cosmetics industry must employ scientists from the discovery stage to product development. Universities can play an active role in medicinal plant research in Sri Lanka. Universities can initiate transferring technology to industries for product development using active natural compounds. In the discovery stage, many different strategies should be used, including monitoring consumer trends, evaluating scientific advances in developed countries for possible technology transfer opportunities, monitoring scientific publications, and press reports. Furthermore, external collaborations with universities, institutes, or non-governmental organizations will secure the supply chains of raw materials, gain certification of their raw materials, or find higher quality and more sustainable plant-based raw materials. For instance, collaborative research studies on medicinal plants between different faculties in the Wayamba University of Sri Lanka, faculty of agriculture and plantation management, faculty of technology, faculty of medicine, and the pioneer semigovernmental research organization, Industrial Technology Institute in Sri Lanka would be ideal for new discoveries in herbal cosmetics discipline by sharing knowledge and utilizing available facilities to a maximum extent in these two entities. Through these partnerships, the companies not only increase cosmetic manufacturers’ scientific knowledge and acquire innovative raw materials but also contribute positively to society [104, 124].


## 3.2.1. Strengths of Sri Lanka as a Tropical Asian Country for the Development of Herbal Cosmetic Industry

Medicinal plants have played a pivotal role in many ancient traditional systems of medicine in Asia, such as the Ayurvedic and Unani systems of India and the traditional Chinese medicine and their derivatives in most Asian countries. Tropical Asian countries are unique among the geographical regions of the world because of high biological diversity, high cultural diversity, diverse ancient civilizations, and abundant raw materials. Because of their widely diversified ecological conditions, particularly in tropical rain forests, they have relatively high biological diversity that is the greatest of all world regions. This high diversity of the region is reflected by the number of species of plants and animals, including medicinal plants. The areas of high biological diversity are among the most culturally disparate, with large numbers of distinct communities inhabiting adjacent areas, each with its own language, culture, and system of traditional medicine. A wealth of traditional knowledge about medicinal plants to cure illnesses has been accumulated over a long period and has been handed down from generation to generation until the present time [127].Medicinal plants have been used for centuries in medicinal, therapeutic, and beauty applications in Sri Lanka by different traditional systems of medicine, which have a documented history of over 2,500 years. Many formulae of medicinal preparations in the Sri Lankan traditional system of medicine are handed down from generation to generation. Some formulae are found only in the scripts of old “ola leaf” books treasured by traditional and Ayurvedic practitioners [128]. Table 6 lists the traditional usage of medicinal plants in Sri Lanka for cosmetic treatments.Table 6
Traditional usage of medicinal plants in cosmetic treatments of Sri Lanka.
NoFamilyScientific nameEnglish nameVernacular nameTraditional usesReference/s1AcanthaceaeBarleria prionitis L.∗CrossandraKatu karanduThe juice of the crushed leaves is applied to promote skin and scalp health[116, 129]Prevent early grey or white hair2Justicia adhatoda L.Malabar nutAdhatodaHerbal toothpaste formulated with other plants is effective for oral hygiene[116]3AcoraceaeAcorus calamus L.∗Sweet flagWada-kahaGround rhizome is applied for pediculosis and to improve skin complexion[116, 130]4AmaranthaceaeAlternanthera sessilis (L.) R.Br. ex DC.Sessile joyweedMukunuwennaLeaf juice promotes healthy hair and is used for manufacturing shampoos[116, 130]5AmaryllidaceaeAllium sativum L.∗GarlicSudulunuGround garlic mixed with honey or mixed with turmeric and honey is applied for curing pimples[130]6AnnonaceaeAnnona muricata L.∗Prickly custard appleKatu-anodaThe juice of crushed young leaves is applied for pediculosis[116, 129]7ApiaceaeCentella asiatica (L.) Urb.Indian pennywortGotukolaThe crushed leaves are used for damaged hair treatments and skin healing[116, 131]8ApocynaceaeHemidesmus indicus(L.) R. Br. ex Schult.Indian sarsaparillaIramusuThe juice of the crushed leaves is applied to reduce hair loss and to improve skin complexion[116, 129]9Holarrhena pubescens Wall. ex G.Don∗KurchiKelindaThe decoction of the bark is used as a mouth wash[131]10ArecaceaeAreca catechu L.∗Areca nutPuwakThe decoction of the flowers is used as a mouth wash and is used in toothpaste manufacturing[116, 131]11Caryota urens L.∗Wine palmKithulThe bark and tender flowers improve hair growth[116]12Cocos nucifera L.King coconut/PolThambili/CoconutKernel oil promotes hair growth[116]13AsparagaceaeAsparagus racemosus Willd.Wild asparagusHathawariyaThe juice of the crushed leaves is applied to improve hair colour, promote hair growth, and prevent hair loss and early grey hair or white hair[130]Possesses antiaging propertiesThe juice of the crushed leaves is applied to improve skin complexion and to remove skin freckles14AsphodelaceaeAloe vera (L.) Burm.f.Aloe plantKomarikaSustaining youthful appearance, leaf gel is used to remove dead cells around the eye, freckles, and for curing pimples,[116, 131]Leaf gel is applied to prevent hair loss and leaf gel with passion fruit (Passiflora edulis Sims) is applied to treat dandruff15AsteraceaeEclipta prostrata (L.) L.False daisyKeekirindiyaLeaf oil promotes hair growth[116, 131]The juice of the crushed leaves is used to treat skin discolorations, and it possesses antiaging properties16Baccharoides anthelmintica (L.) Moench∗Purple fleabaneSanninayamCrushed seeds are applied to treat freckles[132]Crushed seeds with lime juice is applied for pediculosis17BerberidaceaeBerberis aristata DC.∗Indian barberryDaruharidraThe decoction of the bark is used as a mouth wash[131]18BombacaceaeBombax ceiba L.∗Red silk cotton treeImbulCrushed thrones are applied to improve the skin complexion, to remove freckles, and for curing pimples[129]Seed oil is used for manufacturing soaps19BrassicaceaeBrassica juncea (L.) Czern.∗Indian mustardAbaSeed oil is applied on the hands and legs to soften the skin and improve the complexion[129]20CalophyllaceaeMesua ferrea L.Iron woodNaThe crushed flower stamens mixed with khas-khas powder is applied on the body to remove the malodors of the body, remove freckles, and improve complexion by frequent application[116]21CannabaceaeCeltis timorensis Span.∗StinkwoodGurenda/BurendaWood powder mixed with gingelly oil is applied on the skin for dryness to improve complexion[116]22CaricaceaeCarica papaya L.PapayaGaslabuThe ripe fruit is used to remove freckles[116]23CelastraceaeKokoona zeylanica ThwaitesKokunSoaps made from the crushed bark with water have been used for bathing by men and women since ancient times[132]The bark powder is used to treat pimples and to improve skin complexion24ClusiaceaeGarcinia × mangostana L.∗MangosteenMangusThe decoction of the bark is used as a mouth wash for healthy gums and teeth[116]25Garcinia quaesita PierreRed mangoGorakaIt is used for manufacturing toothpastes[131]26CombretaceaeTerminalia arjuna (Roxb. ex DC.) Wight & Arn.∗Arjuna myrobalanKumbukThe bark powder mixed with honey is applied on pimples, and the bark is used for manufacturing toothpaste[131]27Terminalia bellirica (Gaertn.) Roxb.Beleric myrobalanBuluApplying the seeds’ oil improves the black colour of hair and controls hair loss[131]28Terminalia chebula Retz.MyrabalansAraluThe infusion of the powdered, dried, young fruit is used as a mouthwash[116, 129]Possesses antiaging properties and is used to manufacture yellow colour dye29ConvolvulaceaeArgyreia populifolia Choisy∗Sri Lankan elephant creeperGiritillaThe juice of the young shoots is applied on the gums for sanitation[116]30Cuscuta chinensis Lam.∗DodderAgamula nathi walConcentrated plant extract with gingelly oil upon boiling is applied to improve the black color of hair and prevent hair loss, and it is used to treat dandruff[132]31Evolvulus alsinoides(L.)L.∗Slender dwarf morning- gloryVishnukranthiPlant extracted oil is applied to promote healthy hair growth[130]32Ipomoea pes-caprae (L.) R. Br.∗Goats foot creeperBinthamburuThe decoction of the leaves is used for foot health[131]33CostaceaeCheilocostus speciosus (J.Koenig) C.D.Specht∗Crape gingerThebuThe bark is used to remove freckles, especially those that occurred during chicken pox[132]34CucurbitaceaeCucumis melo L.∗Bitter cucumberGon kakiriThe crushed fruit mixed with the nux-vomica tree (Strychnos nux-vomica L.) seeds is used to treat pimples[131]35Cucumis sativus L.CucumberPipingnaFruit slices are used to treat darkness under the eyes and are used for skin cooling, soothing, and healing[116]36Trichosanthes cucumerina L.∗Wild snake gourdDummallaThe decoction of leaves is used to control early grey or white hair[131]37CyperaceaeCyperus rotundus L.NutgrassKalanduruCrushed tubers are used to treat acne[129]38DilleniaceaeDillenia retusa Thunb.GodaparaThe fruit pulp is used to cleanse the scalp and promote healthy hair growth[116, 131]39EbenaceaeDiospyros malabarica (Desr.) Kostel.∗Riber ebonyTimbiriThe decoction of unripe fruit slices is used as a mouthwash or gargle for mouth sanitation[116]40ElaeocarpaceaeElaeocarpus serratus L.Wild oliveWeraluThe leaves are boiled with true lime slices to clean the scalp and hair[116]41EuphorbiaceaeJatropha curcas L.Purging nutRata endaruThe decoction of the bark is used for mouth sanitation[116]42FabaceaeAbrus precatorius L.∗Wild liquoriceOlindaGrounded seeds with true lime are used to treat acne[116]43Caesalpinia bonduc (L.) Roxb.∗Molucca beanKumburuSeeds’ oil is applied to cure pimples, and fried seeds’ powder is used for brushing the teeth[131]44Crotalaria verrucosa L.∗Blue rattle weedNil-adanahiriyaGargling and the infusion of young shoots and leaves promote mouth sanitation[116]45Entada rheedii Spreng.∗Elephant creepes mackayPus wellSeed kernel powder mixed with white sandalwood powder in true lime juice is used to treat pimples[116, 132]The ground seeds, stem, and bark, along with water, are used to clean the scalp and hair46Indigofera tinctoria L.IndigoNilawariMedicated oil prepared with fresh leaf juice and king coconut oil is applied to improve skin complexion[116]Ground with false daisy, turmeric, and kurchi, it is applied to control hair loss, and the oil extracted from the leaves promotes hair growth47Mimosa pudica L.∗Sensitive plantNidikumbaThe ground aerial parts with gingelly oil are applied on the skin because of healing properties, and a decoction of the roots is used as a mouth wash to improve mouth hygiene[116]48Pongamia pinnata (L.) PierreIndian beechKarandaSeed oil is used in soap manufacturing because of its antimicrobial properties[130]49Pterocarpus marsupium Roxb.∗Indian kino treeGammaluDissolved dried gum in warm water is used as a mouthwash for healthy gums and teeth[116, 131]50Pterocarpus santalinus L.f.Red sandalwoodRath-handunCrushed heartwood mixed with turmeric powder and milk is used to treat pimples and is used in soap manufacturing[116, 130]51Senna alata (L.) Roxb.Candle bushEththoraThe leaves are used in antiseptic soap manufacturing because of antimicrobial properties[116, 129]52Senna auriculata (L.) Roxb.∗Tanner’s cassiaRanawaraCrushed flowers are applied to the skin to improve complexion[130]53Tephrosia purpurea (L.) Pers.Purple tephrosiaKathurupilaThe roots are used for mouth sanitation and are used in manufacturing toothpastes[116, 131]54Trigonella foenum-graecum L.FenugreekUluhalBoiled with unripe true limes to treat dandruff[131]55HypoxidaceaeCurculigo orchioides Gaertn.∗Black musaleBinthalThe crushed tuber has been used to improve the beauty of the face by men and women since ancient times[131]56LamiaceaeOcimum tenuiflorum L.Holy basilHeen maduruthalaThe extracted leaf oil is used as a fragrant agent, and the juice of the crushed leaves is used to treat pimples and freckles[130]57Pogostemon heyneanus Benth.∗PatchouliGas-kollankolaInfusion of fresh or dried leaves is used as a mouthwash for healthy gums and teeth[116]58Premna obtusifolia R.Br.∗Heen midiLeaves mixed with coconut oil are used to clean the scalp and hair[130]59Tectona grandis L.f.∗TeakThekkaDried fruit powder promotes hair growth[116]60LauraceaeCinnamomum verum J.PreslCeylon cinnamonKurunduThe dried inner bark is used as a mouth wash for gum and teeth sanitation[116]Cinnamon powder mixed with honey is applied to treat pimples61LecythidaceaeBarringtonia acutangula (L.) Gaertn.∗Indian oakMidellaThe decoction of the leaf, bark, and flower is used as a mouth wash for healthy, strong gums[130]62Careya arborea Rroxb.∗Patana oakKahataBark gum is used to soften the skin[132]63Couroupita guianensis Aubl.∗Cannon ball treeSalLeaves stimulate the dermal fibroblast proliferation[116]64LythraceaeLawsonia inermis L.HennaMarathondiLeaves are boiled in water with true lime fruit pieces are used to treat grey or white hair, and the leaves stimulate hair growth and are used to colour nails[116]65Punica granatum L.PomegranateDelumThe decoction of the roots and fruit rind is used as a mouth wash, and the decoction of the leaves is good for the eyes[116, 131]66MalvaceaeAbutilon indicum (L.) Sweet∗Country mallowBehethanodaCrushed leaves are used as a mouth wash[131]67Gossypium arboreum L.∗CottonKapuLeaves stimulate dermal fibroblast proliferation[116]68Abelmoschus moschatus Medik.Musk mallowKapukinissaSeeds’ paste is applied for skin itching, and chewing the seeds removes the malodors of the mouth[116, 129]69Hibiscus rosa-sinensis L.Shoe flowerPokuru wadaOil prepared by boiling the leaves and flowers with coconut oil or gingelly oil is applied to promote healthy hair growth, prevent early grey or white hair, hair loss, and dandruff[116]Crushed flowers and leaves are applied to remove suntan, to cure pimples, and to remove freckles on the skin70Theobroma cacao L.CocoKokovaPossesses emollient properties and is used to soften and treat dry skin and chapped lips[116]71MeliaceaeAzadirachta indica A.Juss.NeemKohombaCrushed leaves mixed with true lime juice are applied on pimples, and a decoction of the roots is used as a mouth wash and is used in manufacturing soaps and toothpastes[131]72MenispermaceaeCoscinium fenestratum (Goetgh.) Colebr.Calumba woodWeniwelStem powder mixed with honey is used to exfoliate the skin, and it possess antiacne properties[116, 130]73MoraceaeFicus racemosa L.Country figAttikkaCrushed leaves are used to treat freckles and skin discoloration[129]74MyristicaceaeMyristica fragrans Houtt.NutmegSadhikkaThe seed extracted oil is used in soap and toothpaste manufacturing, the herbal shampoo is prepared for pediculosis, it is used to clean the scalp and hair, and it is used to protect skin keratinocytes from UV B- induced damage[116, 130]75MyrtaceaeMelaleuca leucadendra (L.) L.Cajuput treeLothsumbuluImproves skin complexion, and the bark acts as a stimulant and tonic[116]76Syzygium aromaticum (L.) Merr. & L.M.PerryCloveKarabuIt is used in toothpaste manufacturing[116, 129]77Syzygium cumini (L.) Skeels∗Indian black berryMadanThe bark is used to prepare mouth washes for healthy gums and teeth used in manufacturing toothpastes[116, 130]78NymphaeaceaeNymphaea nouchali Burm.f.Blue water lilyNil manelThe flowers are mixed with cow milk and stored in a covered clay pot approximately a month to colour grey or white hair into black[130]79OleaceaeJasminum grandiflorum L.JasmineSamanpichchaGround roots and flowers improve skin discoloration, used to treat skin discolorations, plant-extracted oil is applied to cool the scalp[116, 130]80Jasminum multiflorum (Burm.f.) Andrews∗Sambac JasmineGeta pichchaPaste made by grinding the flower buds is applied on the skin for improved complexion[116]81OxalidaceaeAverrhoa bilimbi L.∗BilimbiBilinLeaf juice is applied to cure pimples, herbal shampoo prepared from the plant is effective for pediculosis[116]82PedaliaceaeSesamum indicum L.GingellyThel-thalaLiniments to promote hair growth, possesses healing properties[116]83PhyllanthaceaePhyllanthus emblica L.Emblic myrobalanNelliImproves skin complexion, prevents hair loss and early grey or white hair[131]Used in manufacturing herbal hair oil, shampoo, conditioner, and skin care products84PlantaginaceaeBacopa monnieri (L.) Wettst.Thyme leaved gratiolaLunuwilaPossesses antiaging properties and antidandruff properties[116]85PoaceaeCymbopogon citratus (DC.) StapfLemon grassSeraShampoo containing essential oil is effective for pediculosis and dandruff[116, 130]86Chrysopogon zizanioides (L.) RobertyKhas-khasSawandaraRoot-extracted oil is used in the perfume industry and soap manufacturing and is used as a fragrant agent, and the crushed roots are applied on the skin[116, 130]87PonterderiaceaeMonochoria vaginalis (Burm.f.) C.PreslOval leafed pondweedDiyahabaralaRoot infusion is used as a mouthwash for mouth inflammations[116]88RubiaceaeMorinda citrifolia L.∗Indian mulberryAhuThe juice of the fruits in salt water is used as a mouthwash for healthy gums, and the crushed leaves are used to exfoliate the skin and for dermal fibroblast proliferation[116, 129]89Rubia cordifolia L.Heart leaved madderVelmadataCrushed roots mixed with honey are used to remove freckles and skin discolorations[130]90RutaceaeAcronychia pedunculata (L.) Miq.Claw flowered laurelAnkendaCrushed leaves are used to treat pimples[116]91Aegle marmelos (L.) CorrêaBael fruit treeBeliRipe fruit mixed with green gram powder is applied to improve skin complexion and can be used as an eye lotion[116, 131]92Citrus aurantiifolia (Christm.) SwingleTrue limeDehiActs as a cleanser, unripe fruits are boiled with fenugreek to treat dandruff, fruits are ground with lotus leaves to treat pediculosis[131]93Citrus hystrix DC.∗Kaffir limeGada dehiFruit juice is used to treat dandruff and is used in aromatic baths and as a shampoo[116]94Melicope lunu-ankenda (Gaertn.) T.G. Hartley∗Lunu-ankendaCrushed leaves are used to improve complexion[116]95Murraya koenigii (L.) Spreng.∗Curry leafKarapinchaThe juice of the crushed leaves is used to promote healthy hair growth[129]96Ruta graveolens L.Garden rueArudaHerbal oil prepared with fresh leaves and pure coconut oil is applied for healthy hair[129]97SantalaceaeSantalum album L.SandalwoodSudu handunHeartwood powder mixed with lime juice is applied gently on pimples to improve skin complexion, the powder mixed with cow milk is used to treat freckles, and it possesses antiaging properties[116, 130]98SapindaceaeSchleichera oleosa (Lour.) Merr.Ceylon oakKonSeed oil is applied to promote healthy hair[116]99SapotaceaeMimusops elengi L.Bullet wood treeMunamalThe decoction of the mature bark is used as a mouthwash for healthy gums and teeth, herbal toothpaste formulated with other plants is effective for oral hygiene[116, 130]100SolanaceaeDatura metel L.∗DaturaAttanaThe root powder is applied on the gums for mouth sanitation[116]101SymplocaceaeSymplocos cochinchinensis (Lour.) S. Moore∗BombuBark decoction is used as a mouthwash for healthy gums[116]102TheaceaeCamellia sinensis (L.) KuntzeTeaThaePossesses antiwrinkle properties[116]103VitaceaeLeea indica (Burm. f.) Merr.∗Bandicoot berryGurullaCrushed leaves are applied on skin patches to improve skin complexion[130]104ZingiberaceaAlpinia malaccensis (Burm.f.) RoscoeRankihiriyaFlower bud juice in lukewarm water is used as a mouth wash for healthy gums and teeth[116]105Curcuma longa L.TurmericAth kahaThe crushed rhizome is used to improve skin complexion, prevents UV B-induced skin aging[116]106Curcuma zedoaria (Christm.) RoscoeZedoaryHaran kahaCrushed rhizome improves skin complexion, and it is used as a fragrant agent[130]107Kaempferia galanga L.∗Java galangaIngurupiyaliDried sliced rhizome infusion is used as a mouth wash, powdered rhizome with coconut oil on the skin to improves skin complexion, improves lustrous of hair, possesses antidandruff properties and skin whitening properties[116, 129]108Zingiber officinale RoscoeGingerInguruJuice-extracted ginger pulp is applied on pimples, and it is used to improve skin complexion[129]∗The plant species that are currently not used in the herbal cosmetic industry of Sri Lanka (in comparison with the survey conducted on “Emerging herbal cosmetic production in Sri Lanka: Identifying the possible interventions for the development of herbal cosmetic industry” [12]).As listed in Table6, a total of 108 different plant species belonging to 58 families were identified from the books, “Compendium of medicinal plants, Sri Lankan study, Volume I to IV” and “A collection of medicinal plants in Sri Lanka.” The most dominant family was the family Fabaceae (13 plant species). A wide range of plant parts has been used for traditional cosmetic treatments. Based on the remedies, the identified plant parts were the leaves, bark, seeds, fruits, roots, flowers, rhizome, stem, heartwood, flower buds, tuber, gum, fruit rind, shoots, bulb, flower stamens, fruit kernel, inner bark, leaf gel, thorns, and wood. Medicinal plants are used in cosmetic treatments for various reasons, such as skin care, hair care, and oral care. Myristica fragrans Houtt. (Sadhikka) and Kaempferia galanga L. (Ingurupiyali) are reported in all three cosmetic treatment categories. Furthermore, 04 plants, namely Ocimum tenuiflorum L. (Heen Maduruthala), Chrysopogon zizanioides (L.) Roberty (Sawandara), Citrus hystrix DC. (Gada dehi), and Curcuma zedoaria (Christm.) Roscoe (Haran Kaha) are fragrant agents that have possible usage in the perfume industry.The recent survey conducted by Gamage et al. [12] discloses the current usage of 115 plant species in herbal cosmetic productions in Sri Lanka. Furthermore, this study highlights the lack of proper cultivation systems of medicinal plants with cosmetic potential within the country for continuous herbal cosmetic productions. Although established cultivation systems are available for some highly used plants in the herbal cosmetic industry of Sri Lanka, such as Aloe vera (L.) Burm.f., most of the other medicinal plant materials are obtained either from the wild or through importation. Consequently, harvesting restrictions were imposed by the government for some wild species, such as Coscinium fenestratum (Goetgh.) Colebr. The adulteration of medicinal plant materials, lack of growers, declining suppliers, and lack of proper cultivation systems are major hindrances to the success of the herbal cosmetic industry in Sri Lanka. However, a comparison between the plant list identified through this survey and the plant list identified from the local books shows the possible usage of 49 plant species in the herbal cosmetic industry as new ingredients. Thus, these findings can be utilized for inventing new products in the future. As global demand for herbal cosmetics increases, there are ample opportunities for Sri Lanka to expand global export with its unique biodiversity and a rich base of traditional knowledge. It will lead to the upliftment of people’s livelihoods and the county’s economic development.


## 3.2.2. Major Challenges and Possible Solutions for Sri Lanka to Develop Plant-Based Cosmetic Productions

At present, most developed countries’ cosmetic manufacturers are continuously probing for new products and ingredients of tropical origin because their raw materials often have interesting properties. The interesting properties of tropical origin ingredients could vary based on climatic and topographical conditions [11]. However, the Association of Southeast Asian Nations (ASEAN) integration report issued in 2015 clearly indicates that developing cosmetic products and cosmetic product markets based on indigenous ingredients is one of the major challenges [133]. The lack of ethnobotanical and ethnopharmacological surveys to identify the cosmetic potential plants, insufficient or absence of continuous supply of raw materials for production in line with the existing demand, lack of quality control of raw materials and finished cosmetic products, improper systematic cultivation systems for medicinal plants, poor postharvest practices, lack of innovations, and the lack of efficacy tests (in vivo and in vitro) to ensure the safety are the major challenges found in Sri Lanka for the development of the herbal cosmetic industry [12, 104, 123, 124, 134].To overcome the aforementioned challenges, collecting information on medicinal plants, traditional drugs, ethnobotany, and ethnopharmacology related to cosmetic treatments with traditional practitioners, Ayurveda physicians, and local communities in each country is required. As most of the traditional knowledge on medicinal plants and treatments in Sri Lanka is passed from generation to generation within families, conducting ethnobotanical and ethnopharmacological surveys will aid to identify cosmetic potential plants, important plant parts, remedies while preserving the traditional knowledge. Furthermore, information gathered through surveys could ultimately be utilized to develop the herbal cosmetic industry by the isolation and characterization of bioactive compounds from identified plants. Cosmetic companies work with a wide range of suppliers to obtain botanical raw materials. These suppliers purchase plant biomass from a wide array of sources ranging from large to small scale. However, harvesting plants from the wild is still popular for many medicinal herbs among local suppliers. Consequently, overharvesting can reduce plant populations to the point where the species’ biodiversity is threatened, some species even to their extinction. Therefore, establishing proper systematic cultivation systems for identified medicinal plants is paramount. Furthermore, future research must be focused on nursery techniques, field establishments, and the harvest management of medicinal plants. Cultivated plant materials are preferred for the cosmetic industry as it is easier to control the whole supply chain and chemical variations. With the use of cultivated plants, problems such as adulteration and misidentification of material are mostly eliminated. It is also easier to adhere to quality standards and has less batch-to-batch variation as the plants are grown under controlled conditions. Furthermore, the utilization of biotechnology techniques, such as tissue culture, will benefit from preserving biodiversity by utilizing the endangered or unavailable plants using conventional production or wildcrafting. Product development and innovation are other key factors to succeed in the herbal cosmetic industry in Sri Lanka. The process to bring a medicinal plant from field to finished good can be quite complicated with many challenges along the way. Stability testing on raw materials to anticipate any issues with color change, odor, viscosity, precipitation, separation, or degradation of actives must be carried out routinely by cosmetic manufacturers. The characteristics of cosmetic products can be affected by environmental factors, such as temperature, pH, light, air, and humidity, which impact their stability contributing to severe damage to the constituents of the product [135]. Because of the wide variety of cosmetic products and their inherent complexity, it is hard to find standard stability tests that can be applied to a vast range of products. However, generally used stability tests can be categorized into several categories namely stability and physical integrity of cosmetic products (under appropriate conditions of storage, transport, and use), chemical stability, microbiological stability, and the compatibility between the contents and the container. For example, the organoleptic characteristics of cosmetic preparations, such as color, smell, texture, and consistency, can be evaluated by visual inspection. Additionally, several physicochemical analyses can be performed, such as centrifugation, mechanical vibration, light tests, pH, density, viscosity determination, and spectrophotometric assays, besides accelerated and microbial stability tests [136]. Quality control testing must be performed and continuously monitored to ensure its physical and analytical characteristics are up to standard. Some current techniques used by the cosmetic industry can be applied to the evaluation of cosmetic’s quality control in an efficient manner, such as sensory analysis, rheology, and small-angle X-ray scattering [137]. Efficacy/safety tests should be performed on medicinal plant ingredients as well. For instance, cosmetics companies can perform in vitro testing to screen for cell damage in skin cell cultures or irritation in skin construct models and animal testing to avoid adverse events. However, the European Commission Cosmetics Directive has executed an animal testing ban on finished cosmetic products and ingredients. In such situations, cosmetic manufacturers have to find an alternative method to ensure product safety. At present, many alternatives to animal testing have been developed and validated for the safety and efficacy testing of cosmetic products and cosmetic ingredients. For example, 2D cell culture models derived from the human skin for evaluating anti-inflammatory properties, or predicting skin sensitization potential and 3D human skin equivalent models for evaluating skin irritation potential and excised human skin are being currently used as the gold standard for evaluating dermal absorption [138]. If a medicinal plant ingredient is safe and stable, it can move on to the formulation phase, where it is added to a cosmetic formula and retested for the same parameters, safety, and stability. With careful management, cosmetic companies can offer innovative beauty products that enhance living standards while conserving natural resources, promoting economic development for the poor, and protecting the environmental resources of Sri Lanka [11, 104, 108, 124, 127, 139, 140].In addition, the cosmetics industry must employ scientists from the discovery stage to product development. Universities can play an active role in medicinal plant research in Sri Lanka. Universities can initiate transferring technology to industries for product development using active natural compounds. In the discovery stage, many different strategies should be used, including monitoring consumer trends, evaluating scientific advances in developed countries for possible technology transfer opportunities, monitoring scientific publications, and press reports. Furthermore, external collaborations with universities, institutes, or non-governmental organizations will secure the supply chains of raw materials, gain certification of their raw materials, or find higher quality and more sustainable plant-based raw materials. For instance, collaborative research studies on medicinal plants between different faculties in the Wayamba University of Sri Lanka, faculty of agriculture and plantation management, faculty of technology, faculty of medicine, and the pioneer semigovernmental research organization, Industrial Technology Institute in Sri Lanka would be ideal for new discoveries in herbal cosmetics discipline by sharing knowledge and utilizing available facilities to a maximum extent in these two entities. Through these partnerships, the companies not only increase cosmetic manufacturers’ scientific knowledge and acquire innovative raw materials but also contribute positively to society [104, 124].


## 4. Conclusion

Medicinal plants provide accessible and culturally relevant sources of health care for most of the world’s human population. There has been an increase in preference for herbal beauty products globally in recent years with rising consumer awareness regarding long-term health benefits. India and China have successfully utilized their traditional systems of medicine to become major producers in the global plant-based cosmetic industry. As cosmetic manufacturers in developed countries show their interest in herbal ingredients of tropical origin, Sri Lanka has a good potential to create numerous new avenues in herbal cosmetics, which can be easily capitalized on the global trends. However, the increasing interest in herbal cosmetics has raised important issues and highlighted vital gaps in the knowledge of cosmetics medicinal plants, their usages, cultivation technologies, postharvest technologies, and bioactivity studies in Sri Lanka. To overcome these issues, conducting ethnobotanical and ethnopharmacological surveys to identify medicinal plants with cosmetic potential, product development, and innovation in collaboration with universities, institutes, and non-governmental organizations are possible solutions. The study’s findings could ultimately be utilized for the development of the herbal cosmetic industry by the isolation and characterization of bioactive compounds from identified plants while preserving traditional knowledge.



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