Query: stinging nettle

title: Effect of high hydrostatic pressure extraction on biological activities of stinging nettle extracts.
abstract: Stinging nettle is traditionally used as a therapeutic herb. In the present work, the biological properties and toxicity of novel nettle leaf extracts obtained by high pressure assisted extraction (HPE) were studied and compared with similar extracts obtained with the same solvent under atmospheric pressure conditions. The studied extracts were obtained at pressure levels of 200 and 500 MPa, 10 min, 0 to 70% ethanol water (v/v) Each extract was characterized for its individual compound profile and different biological properties, such as antioxidant activity, pro oxidant activity (DNA degradation capacity) and antihypertensive activity, as well as cytotoxicity against Caco 2 and HaCat cell cultures. The main results indicate that in addition to the antioxidant and antihypertensive activities observed for the control extracts, a clear improvement of all the biological activities of the extracts obtained by HPE was observed. The extracts obtained at 200 MPa, 10 min, 35 and 70% ethanol were the ones presenting higher concentrations of phenolic acids and flavonoids, such as chlorogenic acid, isoferulic acid, and rutin; besides, they showed better results concerning all the studied biological activities. Those extracts also showed potential for DNA protection, since they were able not only to cause less damage in the DNA molecule than the controls, but also showed no pro oxidant activity. Concerning cytotoxicity, it was observed that HPE extracts, at a concentration up to 1.0 mg mL 1, presented a metabolism inhibition below 10 and 15% for Caco 2 and HaCat cell lines, respectively.

title: Stinging nettle, Urtica dioica L. botanical, phytochemical and pharmacological overview
abstract: Urtica dioica L. (Urticaceae) commonly known as stinging nettle, is an herbaceous perennial plant belonging to the group of phytoalimurgic vegetables, including the wild edible species that were all used in the past when there was a shortage of food. The plant is well known from everybody for the dermatitis it causes when touched, due to biochemical mediators such as histamine and acetylcholine. Recently there was a rediscovery of the plant as food and medicine because of the range of biological activities exhibited such as antirheumatic, anti infective, immuno modulatory, anti hyperglycaemic, and allergy relief. This review, providing a botanical, phytochemical and pharmacological overview of the species, aims to contribute to arouse interest in the scientific community on this promising plant.

title: Native stinging nettle (Urtica dioica L. growing spontaneously under short rotation coppice for phytomanagement of trace element contaminated soils: Fibre yield, processability and quality
abstract: This work assesses the potential of stinging nettle (Urtica dioica L. growing on trace element contaminated soils to produce fibres for material applications. The nettles studied in this work grew spontaneously and dominated the vegetation cover in poplar short rotation coppices planted for the phytomanagement of lands contaminated by trace elements. Two sites were studied, contaminated by Hg for the first one and a mix of As, Cd, Pb and Zn for the second one. Results show that, for the considered soils, the contaminant contents in nettle bast fibres were at low levels, comparable to those collected at unpolluted control areas. It makes it possible to consider this biomass for material use. The measured matter yield was lower than those obtained with traditional fibre crops cultivated in Europe on agricultural lands. However, the tensile properties of the bast fibres mechanically extracted without field retting or prior alkaline treatment were equal to or better than those of industrial hemp and flax, making spontaneous nettles an interesting supplement to traditional European fibre crops for material applications.

title: Effect of drying methods on chemical composition and antioxidant activity of underutilized stinging nettle leaves
abstract: Stinging nettles provide low cost quality nutrition for alleviating malnutrition. Previous research on stinging nettles focused mainly on the nutritional quality of fresh leaves. In this study, the effect of drying method on macronutrients, mineral content, ascorbic acid, b carotene content and total phenols content and antioxidant activity were investigated. The contribution of fresh, oven dried or freeze dried stinging nettle leaves to the required daily value for the nutrients were also determined. Oven drying of nettle leaves resulted in a higher loss of b carotene and ascorbic acid content compared to freeze drying. In contrast, the total phenols content and total antioxidant activity were higher in oven dried stinging nettle leaves compared to freeze dried leaves. Overall, freeze dried and oven dried nettle leaves can be considered as a rich source of Ca, Mg and vitamin A; a good source of vitamin C, Fe, and Mn; and a source for Mg and K. Stinging nettle leaves could potentially be used as a cheap natural source of antioxidants and for addressing micronutrient malnutrition.

title: Optimization of high hydrostatic pressure assisted extraction of stinging nettle leaves using response surface methodology experimental design
abstract: High hydrostatic pressure assisted extraction (HPE) is a very promising extraction methodology since it can operate at room temperature and therefore can avoid heat sensitive compounds changes. Furthermore, it is recognized as a fast technology (only a few minutes) and it is also an already proven environmentally friendly technology. This is the first work to study HPE effect as a new extraction method to obtain improved extracts from stinging nettle, a commonly known weed, traditionally used as folk medicine and with several biological properties proven scientifically. In this work, the HPE process was optimized by an experimental design via response surface methodology using a central composite face centered design. The effect of pressure level, extraction time, and solvent concentration were evaluated, as also the impact of HPE on total phenolics (TPC) flavonoids, pigments, and antioxidant activity. Results showed that experimental data could be well fitted to second order polynomial mathematical models, since lack of fit values were non significant and the regression coefficients were above 75% The optimal conditions for the overall maximization of extraction yield, TPC and antioxidant activity were 200 MPa, 10.2 15.6 min, and 0% ethanol (aqueous extracts) which were tested in a further experiment confirming the predictability of all models (difference by percentage between predicted and experimental optimum were all below 10% When compared to extraction at atmospheric pressure, HPE allowed increasing the extraction yield about 50.5% TPC about 84.4% and antioxidant activity about 77.7% All the models fitted well the experimental data, being the observed values close to the predicted ones by the model equation.

title: Antibacterial Finishing of Cotton Fabric Using Stinging Nettle (Urtica dioica L. Plant Leaf Extract
abstract: Natural organic fibers such as cotton, linen, and wool are readily attacked by microorganisms. Microbial growth on a textile fabric causes loss of strength and elongation, discoloration, and changes in appearance. The antibacterial finishing agents extracted from nettle plant leaf have been used to impart finish to the cotton fabric by using the Pad Dry Cure application method. The antibacterial activity of the finish was assessed quantitatively using the AATCC 100:2004 test method, and the antibacterial activity against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria was measured. There was a 100 to 99.75 percent reduction in the count of test bacteria. Physical properties of treated and untreated cotton fabrics such as absorbency, fabric stiffness, air permeability, and strength were analyzed. To evaluate the laundering effect of stinging nettle leaf finished fabric, samples were subjected to laundry with 5, 10, 15, 20, 25, 30, 35, and 40 washing cycles using standard AATCC test method 61, and bacterial count of treated samples was tested. The results showed gradual decrease in antibacterial property, with a 100 to 44% reduction in the bacterial count for Staphylococcus aureus and a 100 to 30% reduction in the bacterial count for Escherichia coli. The results of this investigation suggested that nettle leaf, a low cost abundant plant in Ethiopia, can be used for antibacterial activity in woven cotton fabric.

title: Effect of Drying Temperature and Natural Fermentation on the Phytochemical Composition of Stinging Nettle Buds (Urtica parviflora)
abstract: Article Info Stinging nettle (Urtica parviflora) locally known as sisnu in Nepal, is rich in phytochemicals. Phytochemical are non nutritive bioactive chemical compounds found naturally in plants; possess antioxidant activity and reduce the risk of different diseases by serving structural and functional role as well as an electrolyte. The effect of drying temperature (50, 60, 70oC) and natural fermentation (24+ 1oC for 15 days) of fresh nettle buds on the phytochemical composition (polyphenol, tannin, flavonoid and antioxidant activity) were studied. The phytochemical screening of the samples was carried out using 80% ethanol through maceration technique. The tannin, flavonoid, total phenol content and antioxidant activity in ethanolic extract of fresh nettle buds were found to be 1.02+ 0.08 mg/g, 0.126+ 0.005 mg/g, 145.69+ 2.01 mg/g and 59.53+ 0.03% on dry basis respectively. The increase in drying temperature, significantly (p<0.5) decreased the polyphenol contents but had no significantly effect on the tannin, flavonoid content and antioxidant activity. The DPPH radical scavenging activity of leaves dried at 50oC was found to be maximum (56.72+ 0.07% on db) and minimum (47.56+ 0.02% at 70oC. The natural fermentation significantly (p<0.05) increased the total phenol (273.2+ 2.33 mg/g) flavonoid (0.408+ 0.08 mg/g) and tannin (3.56+ 0.11 mg/g) content on dry basis. The increase in total phenol and flavonoid content exhibited the subsequent increment in the antioxidant activity (87.69+ 0.02% It was found that, nettle buds contained a number of health promoting bioactive compounds such as tannins, polyphenol and flavonoid and their concentration increased significantly by natural fermentation but were not significantly affected by drying temperature (50 70oC) Article history: Received date: 16 September 2019

title: Influence of stinging nettle (Urtica dioica L. extract loaded nano emulsion on the storage stability and antioxidant attributes of Doogh (Traditional Iranian yoghurt beverage)
abstract: In the present study, stinging nettle extract (SNE) loaded nano emulsion was produced utilizing tween 20 and cress seed gum as the wall materials. The developed nanoparticles were evaluated based on their particle size, zeta potential and encapsulation efficiency. Then, fabricated extract loaded nano emulsion was added to Doogh as a functionalizing agent (at 5 and 10% w/w concentrations) and consequently the properties of the samples including total phenolic content (TPC) DPPH radical scavenging activity, reducing power (FRAP) pH, acidity, phase stability and sensorial characteristics were assessed during 21 days of storage. The untreated Doogh as well as fortified Doogh with free extract (at 5 and 10% w/w concentrations) were used as the control samples. The average droplet size of the fabricated nano emulsion was 404.6 nm, the overall formulation possessed a negative charge and the encapsulation efficiency was 58.04% After 3 weeks of analysis, Doogh sample enriched with 10% SNE bearing nano emulsion displayed the highest TPC (30.3 mg GAE/100 mL) DPPH (50% FRAP (0.76) pH (3.45) and phase stability (64% as well as the lowest acidity (2.1% (p 0.05) SNE possesses astringent and bitter flavors which could limit its application in food products. However, compared to the free extract enriched Doogh, fortified samples with nano emulsion had closer sensory characteristics scores to untreated Doogh which clarified the minimization of these undesired flavors following encapsulation. In conclusion, SNE can be successfully entrapped within tween 20 and cress seed gum nano emulsions with an excellent encapsulation efficiency and be utilized in the functionalization of dairy fermented beverages.

title: Identification of Callose Synthases in Stinging Nettle and Analysis of Their Expression in Different Tissues
abstract: Callose is an important biopolymer of b 1,3 linked glucose units involved in different phases of plant development, reproduction and response to external stimuli. It is synthesized by glycosyltransferases (GTs) known as callose synthases (CalS) belonging to family 48 in the Carbohydrate Active enZymes (CAZymes) database. These GTs are anchored to the plasma membrane via transmembrane domains. Several genes encoding CalS have been characterized in higher plants with 12 reported in the model organism Arabidopsis thaliana. Recently, the de novo transcriptome of a fibre producing clone of stinging nettle (Urtica dioica L. was published and here it is mined for CalS genes with the aim of identifying members differentially expressed in the core and cortical tissues of the stem. The goal is to understand whether specific CalS genes are associated with distinct developmental stages of the stem internodes (elongation, thickening) Nine genes, eight of which encoding full length CalS, are identified in stinging nettle. The phylogenetic analysis with CalS proteins from other fibre crops, namely textile hemp and flax, reveals grouping into 6 clades. The expression profiles in nettle tissues (roots, leaves, stem internodes sampled at different heights) reveal differences that are most noteworthy in roots vs. leaves. Two CalS are differentially expressed in the internodes sampled at the top and middle of the stem. Implications of their role in nettle stem tissue development are discussed.

title: Plants and Purinergics: A Study of Stinging Nettle Extract and the Male Rodent Urogenital System
abstract: This thesis examined the effect of stinging nettle extracts on the contractility of the rat prostate gland and on male mouse fertility. It showed the potential of the leaf extract to contain a small drug like molecule for the development of new therapeutics for the symptomatic relief of benign prostatic hyperplasia and for the development of a novel oral male contraceptive.