Withania somnifera, known commonly as ashwagandha or winter cherry,[2][3][4] is an evergreen shrub in the Solanaceae or nightshade family that grows in 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] Although used in herbal medicine and sold as a dietary supplement, 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]
A treehopper (Oxyrachis tarandus) feeds on the apical portions of the stem, making them rough and woody in appearance and brown in colour.[12]
The carmine red spider mite (Tetranychus urticae) is the most prevalent pest of the plant in India.[13] In recent years, this plant has been serving as a new reservoir host for an invasive mealybug species Phenacoccus solenopsis.[14]
Limited, low-quality clinical studies have found that supplementation with various ashwagandha extracts may decrease perceived stress and anxiety, and improve sleep.[3][4][16] Because 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]
Adverse effects
W. somnifera may cause adverse effects if taken alone or together with prescription drugs.[3][4][17] A review of 30 clinical trials found that use of W. somnifera may cause problems with sleep, blurred vision, stomach pain, dry mouth, vertigo, among others.[18] The most common side effects include diarrhea, headache, sedation, or nausea, and the product should not be used during pregnancy or breastfeeding.[4][17] Ashwagandha may increase testosterone levels which could adversely interact with cancer medications.[3][17][19]
Gallery
Fruits
Druggist's jar containing dried roots of Withania somnifera
^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.
^ abc"Ashwagandha". Memorial Sloan Kettering Cancer Center. 21 March 2023. Retrieved 4 April 2024.
^Tandon N, Yadav SS (June 2020). "Safety and clinical effectiveness of Withania somnifera (Linn.) dunal root in human ailments". Journal of Ethnopharmacology. 255: 112768. doi:10.1016/j.jep.2020.112768. PMID32201301.
