The Pantropical Genus Rhynchosia Lour. (Fabaceae: Cajaninae): Diversity of Medicinal Uses, Phytochemistry, Pharmacology, and Toxicology

The pantropical genus Rhynchosia belongs to the family Fabaceae and consists of approximately 230 species distributed mainly in Africa, America, and Asia. Several species of the genus have been used ethnomedicinally since 300–400 AD. This review presents for the first time a global overview of the extent of ethnomedicinal uses of species in the genus in addition to their phytochemistry, pharmacological activities, and toxicology. Online databases such as NCBI, PubMed, Science Direct, Scopus, SpringerLink, Taylor and Francis Online, etc., were used to source for publications on Rhynchosia species. Based on this review, 30 species (19 %) are traditionally used for treating an array of ailments around the globe, most especially in Africa and Asia. Flavonoids are the most detected/isolated phytochemicals from the Rhynchosia species. Pharmacological activities such as anticancer, antidiabetic, anti‐hyperlipidemic, antifungal, antioxidant, anti‐inflammatory, antinociceptive, butyrylcholinesterase, as well as eye‐protective and melanogenic effects were elicited by the extracts and isolated compounds from Rhynchosia species. Toxicity tests have only been carried out on R. sublobata and R. elegans extracts. Future studies should focus on the toxicological evaluation and validation of ethnomedicinal claims on the traditional uses of Rhynchosia species that have not been pharmacologically tested.