Withania somnifera (Linn.) Dunal: a review of chemical and pharmacological diversity

Withania somnifera dunal, is a commonly used herb in indian ayurvedic medicine system. due to its pharmacological value and an inexhaustible source of novel biologically active compounds, it has been a great interest for researchers. the plant is known to possess anti-inflammatory, antitumor, antistress, antioxidant, immunomodulatory and hemopoetic properties. various withanolides, steroidal lactones, have been isolated from w. somnifera and were known to have high therapeutic value. based on the differences in the substitution patterns of withanolides the species has been classified into various chemotypes. so far, three different chemotypes have been identified, which have been further classified into ecotypes based on the contents of withanolides. present review summarizes the phytochemical variability and pharmacological advances reported in literature.