AIM OF THE REVIEW: This review aims to provide a comprehensive report on the ethnomedicinal use, phytochemistry, pharmacological activities, molecular mechanisms, and nutritional values of C. nutans. The present review will open new avenues for further in-depth pharmacological studies of C. nutans for it to be developed as a potential nutraceutical and to improve the available products in the market.
MATERIAL AND METHODS: All the available information on C. nutans was collected using the key words "Clinacanthus nutans" and/or "ethnomedicine" and/or "phytochemicals" and/or "anticancer" and/or "anti-inflammatory" and/or "antiviral" through an electronic search of the following databases: PubMed, Web of Science, EMBASE, Cochrane Library, Clinical Trials.org, SciFinder Scholar, Scopus, and Google Scholar. In addition, unpublished materials, Ph.D. and M.Sc. dissertations, conference papers, and ethnobotanical textbooks were used. The Plant List (www.theplantlist.org) and International Plant Name Index databases were used to validate the scientific name of the plant.
RESULTS: The literature supported the ethnomedicinal uses of C. nutans as recorded in Thailand, Indonesia, and Malaysia for various purposes. Bioactivities experimentally proven for C. nutans include cytotoxic, anticancer, antiviral, anti-inflammatory, immunomodulatory, antidiabetic, antioxidant, antihyperlipidemic, antimicrobial, and chemotherapeutic (in aquaculture) activities. Most of these activities have so far only been investigated in chemical, cell-based, and animal assays. Various groups of phytochemicals including five sulfur-containing glycosides, eight chlorophyll derivatives, nine cerebrosides, and a monoacylmonogalactosyl glycerol are present in C. nutans. The presence of two glycerolipids, four sulfur-containing compounds, six known flavones, a flavanol, four flavonols, two phytosterols, one polypeptide, and various phenolics and fatty acids largely influences its diverse bioactivities. Numerous reports justify the ethnomedicinal use of C. nutans as an antiviral agent in treating herpes simplex virus and varicella-zoster virus infections and as part of a traditional anticancer anti-inflammatory concoction agent for various inflammatory diseases. C. nutans tea was reported to have a good percentage of carbohydrate, crude protein, minerals, essential amino acids, nonessential amino acids, and essential fatty acids. Acute, subacute, and subchronic toxicity studies demonstrated that oral administration of ethanol and methanol extracts of C. nutans to male Swiss albino mice and male Sprague-Dawley (SD) rats, respectively, did not lead to any toxicity or adverse effects on the animal behavior and organs when used in amounts as high as 2g/kg.
CONCLUSION: The collected literatures demonstrated that, as an important traditional medicine, C. nutans is a promising ethnomedicinal plant with various extracts and bioactive compounds exhibiting multifarious bioactivities. However, it is important for future studies to conduct further in vitro and in vivo bioactivity evaluations systematically, following the standard pharmacology guidelines. It is crucial to elucidate in-depth molecular mechanisms, structure-activity relationships, and potential synergistic and antagonistic effects of multi-component extracts and bioactive constituents derived from C. nutans. Further studies should also focus on comprehensive toxicity that includes long-term effects and adverse effects on target organs of C. nutans and bioactive compounds in correlation with the specific pharmacological effects.
AIM OF THE REVIEW: The present review aims to collate and analyze the available data and information on distribution, traditional uses, chemical constituents and pharmacological activities of Blepharis.
METHODS: Scientific information of genus Blepharis was retrieved from the online bibliographic databases such as MEDLINE/PubMed, SciFinder, Web of Science and Google Scholar and secondary resources including books and proceedings.
RESULTS: Seven species of Blepharis were found to be reported frequently as useful in folklore in African and Asian countries. B. maderaspatensis was found to be widely used in Indian traditional medicines whereas the B. ciliaris and B. edulis were common in folklore of Egypt, Jordan, and Arabia. Active phytochemicals of Blepharis are flavonoids from B. ciliaris, alkaloids from B. sindica, phenolic acid derivatives, and phytosterols, and derivatives of hydroxamic acids from B. edulis resulted in possessing diverse biological properties such as anti-microbial, anti-inflammatory, and anti-cancer.
CONCLUSIONS: Various species of Blepharis were found to be used in traditional medicine systems in African and Asian countries. Few of these species were studied for their bioactive chemical constituents however the activity guided isolation studies are not performed. Similarly, detailed pharmacological studies in animal models to explore their mechanism of action are also not reported. Future studies should focus on these aspects related to the medicinally used species of Blepharis. The detailed and comprehensive comparative analysis presented here gives valuable information of the currently used Blepharis species and pave the way to investigate other useful species of Blepharis pertaining to ethnobotany, phytochemistry and discovery of new drugs.