Chemistry & Bioactivity of Costus Speciosus: An Anti-Diabetic Plant: In-Depth Analysis Rhizome Phytochemistry, Key Saponins, and Pharmacological Effects

Costus speciosus Koen. (Family: Zingiberaceae), is a reputed Indian ornamental and medicinal plant. The rhizomes of this plant are attributed to be bitter, astringent, acrid, cooling, aphrodisiac, purgative, anthelmintic, depurative, febrifuge, expectorant, tonic, improves digestion and as stimulant herb that clears toxins. Phytochemistry of C. speciosus after thorough literature survey revealed various varied and copious metabolites such as sesquiterpenes, triterpenes, sterols and saponins. Many of these compounds have been found to possess a wide range of biological activity such as anti-diabetic, anti-inflammatory, hepatoprotective, anti-microbial etc. Among saponins, dioscin, gracillin, diosgenin, protogracillin, methyl protodioscin, methyl protogracillin were major chemical constituents of C. speciosus. Other metabolites of medicinal significance namely eremanthine and costunolide have been also reported in C. speciosus. This book covers literature up to 2021 with an emphasis on secondary metabolites of C. speciosus and pharmacological activities of various extracts, fractions and isolated compounds.