Physicochemical, Phytochemical, Heavy Metal and Microbiological Analysis of Moringa oleifera Lam. Leaves

Plants continue to serve as valuable therapeutic agents, and are an integral part of both modern and traditional systems of medicine. The patronage of natural therapies in the management and treatment of diseases have been on the rise. This can be attributed to the massive contribution made by herbal medicines towards providing effective therapeutic outcomes. Poverty and limited access to modern medicine have caused a high percentage of the world’s population, especially those living in developing countries to use plant medicine as their primary source of health care.1 Evidently, most of the traditional systems of medicines are effective, but lack standardization or quality control parameters for evaluating the herbal medicines.2 The safety and efficacy of herbal materials largely require monitoring the quality of the product from the collection, through processing, to the finished product. Standardization and quality control of herbal medicine involves physico-chemical evaluation of crude drugs whereby attention is usually given to indices such as authentication, foreign matter content, organoleptic evaluation, diagnostic tissue features present in drug powder, ash values, extractive values, moisture content determination, chromatographic and spectroscopic evaluation, determination of pesticide residues, microbial contamination, aflatoxins and radioactive contamination.3 As such, the need for standardization is essential, given the global acceptance of herbal products as remedies for various ailments. Moringa oleifera Lam. of the family Moringaceae is commonly known as horse radish or drumstick tree and ranges in height from 5 to 10 m. It is found mostly in Africa, India, Arabia, Southeast Asia, the Pacific and Caribbean Islands.4-6 This plant is among the most widely patronized herbal medicines on the Ghanaian market.7 The leaves are small and oval to ovate, with leaflets averaging 1 2 cm in length and 5 -10 cm in width. All parts of the plant, bark, fruit, leaves, nuts, seeds, tubers, roots and flowers have rich folkloric usage against a variety of ailments such as fever, abscess, wound, infections, diabetes, asthma, urinary tract infection, gastric ulcer, several metabolic diseases, including hypercholesterolemia, high blood pressure, non-alcoholic liver disease, cancer and inflammation Pharmacological studies have also demonstrated the ability of this plant to have corresponding biological activities which substantiate its use in the afore mentioned disease states.7-10 Additionally the moringa is known to have analgesic, antipyretic, anticancer, hepatoprotective, antioxidant, antiepileptic, nootropic, anti-allergic, local anesthetic, anthelmintic, antimicrobial, wound healing, immunomodulatory, and antidiarrheal properties.5,10,11 The genus Moringa consists of 13 plant species. Moringa species are well-known for their antioxidant, anticancer, anti-inflammatory, and antidiabetic properties. Their biological activities have been attributed to the high content of flavonoids, glucosinolates, and glucosides.9 Studies have been conducted on the nutritional value and bio-active constituents of these herbs.12 M. oleifera is one of the richest plant sources of nutrients, ABSTRACT Background: Moringa oleifera leaves is one of the highly patronized herbs on the Ghanaian market. It is used for the treatment and prevention of several diseases. It is imperative that available and effective methods can be utilized to assess the quality of samples before being consumed. Objective: A study of the leaves was conducted to ascertain its physicochemical, phytochemical, heavy metal and microbiological content to develop a simple but acceptable criteria which could be useful in ensuring the quality of this crude drug. Materials and Methods: The qualitative and quantitative morphological features, physicochemical, phytochemical, microbial load and flouresent features of the leaves of M. oleifera were evaluated. Results: M. oleifera leaves were found to be glaborous with opposite leaflet, leaflet tripinnate, with a micronate apex and possessing an entire margin. Microscopy showed vein islets, rosette calcium oxalate crystals, polygonal epidermal cells and unicellular trichomes. The 50 % ethanol soluble extractives of M. oleifera were highest, followed by the water and petroleum ether. Tannins, alkaloids, gylcosides, phenols, flavonoids, phenols, gums, and mucilage were present. Conclusion: The documented pharmacognostic features may be used as part of daily protocols to correctly identify and determine the quality of the the crude plant. The preliminary phytochemical, heavy metal and microbiological limits can be further used to ascertain the quality of raw materials of M. oleifera before they are used.