Withania somnifera (L.) Dunal – an overview of bioactive molecules, medicinal properties and enhancement of bioactive molecules through breeding strategies.

Withania somnifera is a very unique medicinal plant explored by number of orthodox medicinal systems such as Ayurveda, Siddha and Unani. It is commonly known as Ashwagandha, Indian ginseng and winter cherry, and finds its potential medicinal properties in the Ayurvedic Pharmacopoeia of India and Siddha Pharmacopoeia of India. The Withania genus is classified under the Solanaceae family and includes around 60 species, among which W. somnifera and W. coagulans are often mentioned in Ayurveda. Ashwagandha is a treasure house of widespread array of metabolites such as steroids, flavones, alkaloids, carbohydrates, glycosides, saponins, tannins, terpenoids and coumarin. Eight different polyphenols (five phenolic acids, vanillic, benzoic, p-coumaric, gallic and syringic acid, and three types of flavonoids, naringenin, catechin and kaempferol) were reported from Ashwagandha. Each part of this plant holds an assortment of different metabolites, and the metabolite concentrations vary among the different chemotypes. Ashwagandha has been used for a variety of ailment since a long time by traditional medicinal systems. It has been used for a range of diseases such as diabetes, emaciation, arthritis and rheumatoid arthritis-related inflammations, some kinds of seizures, diarrhoea, dermatitis and insect bite and specially used in the treatment of nervous disorder. The importance of Ashwagandha in medicinal treatments has attracted the attention of a large number of scientists; as a result, numerous experiments have been carried out, which have verified the therapeutic properties of Ashwagandha. Further, the efforts are being taken for the breeding strategies via conventional breeding as well as plant tissue culture techniques and gene transformation for the improvement of withanolide contents. This chapter gives an extensive insight on the various aspects such as basic introduction, classification, botanical description, bioactive molecules, medicinal properties and commercially available products. Furthermore, this chapter narrates the several breeding approaches for the improvement of withanolide contents of Ashwagandha.