Withania somnifera (L.) Dunal - Modern perspectives of an ancient Rasayana from Ayurveda

Ethnopharmacological relevance: Withania somnifera (L.) Dunal, commonly known as Ashwagandha, is an important medicinal plant that has been used in Ayurvedic and indigenous medicine for more than 3,000 years. According to Charaka Samhita, Susruta Samhita and other ancient texts, Ashwagandha is known as Balya (increases strength), Brusya (sexual performance enhancer), vajikari (spermatogenic), Kamarupini (libido-enhancing), Pustida (nourishing).

Aim of the review: This review article documented and critically assessed W. somnifera regarding its ethnopharmacology, traditional use, botanical description, phytochemicals present, pharmacological activities, clinical trials, and marketed formulations.

Materials and methods: The sources of information used in the study are traditional Ayurvedic books like Charaka Samhita, Susruta Samhita, Astanga Hridaya etc, government reports, dissertations, books, research articles and databases like Science-Direct, SciFinder, Web of Science, PubMed, Wiley Online Library, and ACS Publications on Ashwagandha and Withania somnifera (L.) Dunal.

Results: Traditional uses of Ashwagandha in Ayurveda are very prominent in several texts where formulations with various dosage forms have been mentioned in Charaka Samhita, Susruta Samhita, Astanga Hridaya, different nighantus etc. The drugs were identified based on their composition containing Ashwagandha as one of the major ingredients and their medicinal uses. Phytochemical studies on W. somnifera revealed the presence of important chemical constituents such as flavonoids, phenolic acids, alkaloids, saponins, tannins, and withanolides. The phytochemicals showed various pharmacological activities like anti-cancer, immunomodulatory, cardioprotective, neuroprotective, anti-aging, anti-stress/adaptogenic and anti-diabetic. Various clinical trials show that the plant extract and its bioactive compounds are used in the prevention and treatment of many diseases, such as arthritis, impotence, amnesia, anxiety, cancer, neurodegenerative and cardiovascular diseases, and others.

Conclusions: Pharmacological data reviewed here revealed that W. somnifera is a potential source for the treatment of a wide range of diseases especially anxiety and other CNS disorders. From its ancient use to its modern application it has been proven to be non-toxic and effective clinically for human health and wellness. W. somnifera based herbal formulation has been marketed in the form of supplement, extract, capsule, powder etc. This review will be helpful to correlate the mechanism of action with the phytochemical profile of this well-known plant from Ayurveda.

Keywords: Ayurveda; Clinical trial; Phytochemistry Pharmacology; Solanaceae; Withania somnifera (L.) Dunal.