Withania somnifera, known commonly as ashwagandha,[2][3][4] is an evergreen shrub in the Solanaceae or nightshade family that grows in Nepal, India, the Middle East, and parts of Africa. Several other species in the genus Withania are morphologically similar.[3]
The plant, particularly its root powder, has been used for centuries in traditional Indian medicine.[5] Ashwagandha supplements, typically containing root or leaf powder or extracts, are commonly sold.[4] Its use in herbal medicine and dietary supplements notwithstanding, there is insufficient scientific evidence that W. somnifera is safe or effective for treating any health condition or disease.[3][4]
Description
This species is a short shrub growing 35–75 cm (14–30 in) tall. Tomentose branches extend radially from a central stem. Leaves are dull green, elliptic, usually up to 10–12 cm (3.9–4.7 in) long. The flowers are small, green and bell-shaped. The ripe fruit is orange-red.[3]
Etymology
The Latin species name somnifera means 'sleep-inducing'.[6] The name ashwagandha is a combination of the Sanskrit words ashva, meaning 'horse', and gandha, meaning 'smell', reflecting that the root has a strong horse-like odor.[3]
Cultivation
W. somnifera is cultivated in many of the drier regions of India. It is also found in Nepal, Sri Lanka, China, and Yemen.[7][8] It prefers dry stony soil with sun to partial shade. It can be propagated from seeds in the early spring or from greenwood cuttings in the later spring.[9]
Limited clinical studies have found that supplementation with various ashwagandha extracts may decrease anxiety and perceived stress, and improve sleep.[3][4][16] As the studies used different extract preparations, durations of use, doses, and types of subjects, it remains undetermined how ashwagandha may have effects in people, as of 2023.[3][4][16]
^Pandit, S.; Chang, K.-W.; Jeon, J.-G. (February 2013). "Effects of Withania somnifera on the growth and virulence properties of Streptococcus mutans and Streptococcus sobrinus at sub-MIC levels". Anaerobe. 19: 1–8. doi:10.1016/j.anaerobe.2012.10.007. PMID23142795.
^Hugh Scott & Kenneth Mason, Western Arabia and the Red Sea, Naval Intelligence Division: London 1946, p. 597 ISBN0-7103-1034-X.
^Sharma, A; Pati, P.K. (2011). "First report of Withania somnifera (L.) Dunal, as a New Host of Cowbug (Oxyrachis tarandus, Fab.) in plains of Punjab, Northern India". World Applied Sci. J. 14 (9): 1344–1346.
^Sharma, A.; Pati, P. K. (2013). "First record of Ashwagandha as a new host to the invasive mealybug (Phenacoccus solenopsis Tinsley) in India". Entomological News. 123 (1): 59–62. doi:10.3157/021.123.0114. S2CID85645762.