Withania somnifera, known commonly as ashwagandha, Indian ginseng, poison gooseberry, or winter cherry is a plant in the Solanaceae or nightshade family. Several other species in the genus Withania are morphologically similar. Although commonly used as a medicinal herb in Ayurvedic medicine, there is no conclusive clinical evidence that it is effective for treating any ailment.
This species is a short, tender perennial 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 (4 to 5 in) long. The flowers are small, green and bell-shaped. The ripe fruit is orange-red.
The species name somnifera means "sleep-inducing" in Latin. The name, ashwagandha, is a combination of the word ashva, meaning horse, and gandha, meaning smell, reflecting that the root has a strong horse-like odor.
Diseases and pests
Withania somnifera is prone to several pests and diseases. Leaf spot disease caused by Alternaria alternata is the most prevalent disease, which occurs in a severe form in Punjab, Haryana, and Himachal Pradesh. A decline in the concentration of its secondary metabolites occurs by leaf spot disease. A treehopper feeds on the apical portions of the stem, making them rough and woody in appearance and brown in colour. The apical leaves are shed and the plant gradually dies. The carmine red spider mite (Tetranychus urticae) is the most prevalent pest of the plant in India. In recent years, this plant have been serving as a new reservoir host for an invasive mealybug species Phenacoccus solenopsis.
The main phytochemical constituents are withanolides – which are triterpene lactones – withanolides, withaferin A, alkaloids, steroidal lactones, tropine, and cuscohygrine. Some 40 withanolides, 12 alkaloids, and numerous sitoindosides have been isolated. Withanolides are structurally similar to the ginsenosides of Panax ginseng, leading to a common name for W. somnifera, "Indian ginseng".
The plant, particularly its root powder, has been used for centuries in traditional Indian medicine. There is insufficient evidence that it has any medicinal effects. Dietary supplements containing ashwagandha are marketed in the U.S., but there is insufficient evidence they provide any benefit.
- "Withania somnifera (L.) Dunal". Tropicos. Missouri Botanical Garden. Retrieved 25 Feb 2012.
- "Withania somnifera". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2011-10-29.
- "Withania somnifera (L.) Dunal". PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale) [Online Database]. Wageningen, Netherlands: Gurib-Fakim A. and Schmelzer G. H. Retrieved 2012-08-07.
- "Ashwagandha". Drugs.com. 2009. Retrieved 27 August 2017.
- "Ashwagandha". MedlinePlus, US National Library of Medicine. 26 June 2017. Retrieved 21 December 2017.
- Stearn, W. T. (1995). Botanical Latin: History, Grammar, Syntax, Terminology and Vocabulary (4th ed.). Timber Press. ISBN 978-0-88192-321-6.
- 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. PMID 23142795.
- Hugh Scott & Kenneth Mason, Western Arabia and the Red Sea, Naval Intelligence Division: London 1946, p. 597 ISBN 0-7103-1034-X.
- Pati, P. K.; Sharma, M.; Salar, R. K.; Sharma, A.; Gupta, A. P.; Singh, B. (2009). "Studies on leaf spot disease of Withania somnifera and its impact on secondary metabolites". Indian Journal of Microbiology. 48 (4): 432–437. doi:10.1007/s12088-008-0053-y. PMC 3476785. PMID 23100743.
- 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" (pdf). World Applied Sciences Journal. 14 (9): 1344–1346. ISSN 1818-4952.
- Sharma, A.; Pati, P. K. (2012). "First record of the carmine spider mite, Tetranychus urticae, infesting Withania somnifera in India" (pdf). Journal of Insect Science. 12 (50): 1–4. doi:10.1673/031.012.5001. ISSN 1536-2442. PMC 3476950. PMID 22970740.
- 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.
- "Ashwagandha". New York City: Memorial Sloan Kettering Cancer Center. 13 April 2018. Retrieved 26 May 2018.
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