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]
| Withania somnifera | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Solanales |
| Family: | Solanaceae |
| Genus: | Withania |
| Species: | W. somnifera |
| Binomial name | |
| Withania somnifera | |
| Synonyms[1] | |
| |
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]
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. Leaf spot disease reduces the concentration of its secondary metabolites.[10] The leaves are also prone to Alternaria dianthicola in India.[11]
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]
Phytochemistry
The main phytochemical constituents of W. somnifera are withanolides, a group of triterpene lactones that include withaferin A, alkaloids, steroidal lactones, tropine, and cuscohygrine.[3] Forty withanolides, twelve alkaloids, and various sitoindosides have been isolated from this plant species.[3][15] Because these withanolides are structurally similar to the ginsenosides of Panax ginseng, W. somnifera is commonly referred to as "Indian ginseng".[3]
Research
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
Dried graded roots of Withania somnifera
References
External links
Media related to Withania somnifera at Wikimedia Commons
