Chemistry and pharmacology of withania somnifera: An update

Withania somnifera (Ashwagandha) is an important Rasayana herb and widely considered as Indian ginseng in Ayurveda. In traditional system of Indian medicine, it is used as tonic to rejuvenate the body and increase longevity. In Ayurvedic preparations, various parts of the plant have been used to treat variety of ailments that affect the human health. However, dried roots of the plant are widely used for the treatment of nervous and sexual disorders. The major active chemical constituents of this plant are withanolides, which is responsible for its wide range of biological activities. Since the beginning of the 20 th century, a significant amount of research has been done and efforts are ongoing to further explore other bioactive constituents, and many pharmacological studies have been carried out to describe their disease preventing mechanisms. In this chapter, we have reviewed the chemistry and pharmacological basis of W. somnifera in various human ailments.