Ashwagandha (Withania somnifera), also called winter cherry, comes from the roots of a shrub cultivated in India and North America. Ayurvedic practitioners have been using it for thousands of years as a powerful rasayana (a tonic for greater vitality and longevity). The herb has traditionally been used for calming the mind, relieving weakness, nervous exhaustion and arthritis, and for building sexual energy. It is beneficial to people who do physical labor or exercise a lot to help the body adapt to physical stress. It has also been used for strengthening the female reproductive system.
Ashwagandha contains flavonoids and many active ingredients of the withanolide class. Numerous studies over the past two decades indicate that it has anti-inflammatory, anti-tumor, anti-stress, antioxidant, mind-boosting, and rejuvenating properties.1
Withanolides are believed to account for the multiple medicinal applications of Ashwagandha.2 These molecules are steroidal and bear a resemblance, both in their action and appearance, to the active constituents of Asian ginseng (Panax ginseng) known as ginsenosides. Ashwagandha’s withanolides have been extensively studied in a variety of animal studies examining their effects on immune function, and even cancer.
Demonstrated healing abilities
- Provides potent antioxidant protection3 15 21
- Stimulates the activation of immune system cells, such as lymphocytes and phagocytes4 5 6 7
- Counteracts the effects of stress and generally promotes wellness, making it an important tonic or adaptogen.8 9
A recent study at the Institute of Basic Medical Sciences, Calcutta University, examined the effect that Ashwagandha has on chronic stress in rodents. For 21 days, the animals’ feet were given a mild electrical shock, which resulted in hyperglycemia, glucose intolerance, increase in plasma corticosterone levels, gastric ulcerations, male sexual dysfunction, cognitive deficits, immunosuppression and mental depression. Animals that were given Ashwagandha an hour before the foot shock experienced a significantly reduced level of stress, confirming the researchers’ theory that the herb produces a significant anti-stress adaptogenic effect.10
A study done at the Department of Pharmacology, University of Texas Health Science Center indicated that extracts of Ashwagandha produce GABA-like activity, which may account for the herb’s anti-anxiety effects.11 GABA (Gamma Amino-butyric acid) is an inhibitory (calming) neurotransmitter in the brain. Its function is to decrease neuron activity and inhibit nerve cells from over firing. Too much neuronal activity can lead to restlessness and insomnia, but GABA inhibits the number of nerve cells that fire in the brain, and helps to induce sleep, uplift mood, and reduce anxiety.
Ashwagandha has traditionally been used to stabilize mood in patients with behavioral disturbances, and another study showed that it does indeed produce an anti-depressant and anti-anxiety effect in rodents comparable to the anti-depressant drug imipramine and anti-anxiety drug lorazepam (Ativan).12
Provides a potent antioxidant effect
Researchers from Banaras Hindu University in Varanasi, India13, and from the Drug Research and Development Center, Calcutta14, discovered that some of the chemicals in Ashwagandha are powerful antioxidants. They tested these compounds for their effects on rat brains and found an increase in the levels of three natural antioxidants; superoxide dismutase, catalase, and glutathione peroxidase.
According to the researchers, “These findings are consistent with the therapeutic use of Withania somnifera (Ashwagandha) as an Ayurvedic rasayana. The antioxidant effect of active principles of W. somnifera may explain, at least in part, the reported anti-stress, cognition-facilitating, anti-inflammatory and anti-aging effects produced by them in experimental animals, and in clinical situations.”14
Another study examined Ashwagandha’s effect on copper-induced lipid peroxidation and antioxidant enzymes in aging spinal cords of laboratory mice. The herb produced a strong antioxidant effect and stopped the lipid peroxidation,15 which, in humans, is a cause of atherosclerosis leading to heart disease.
Supports cardiovascular health
A study of six human subjects with high cholesterol showed that treatment with Ashwagandha for 30 days decreased their blood glucose, serum cholesterol, triglycerides, and LDL (bad cholesterol). The herb also had a diuretic effect, and no one experienced any adverse effects.16
Increases NO production 17
This is important for a number of reasons. Nitric oxide production plays a role in maintaining cardiovascular health. Here’s how: Inside your body nitric oxide is produced by endothelial cells that line your blood vessels, and acts as a messenger molecule by telling the blood vessels when to relax and expand. When adequate nitric oxide is produced, it causes an “endothelial relaxing factor,” which is needed by the arterial system to expand and contract with each heartbeat. This helps regulate blood flow and pressure, so that oxygen-carrying blood is delivered to your tissues and organs.18 19 Ashwagandha has traditionally been used as a sex enhancer, which makes sense because nitric oxide dilates blood vessels-a key factor in maintaining penile erection.
Enhances cognition and boosts memory
Ashwagandha is used in India to treat mental deficits in geriatric patients, including amnesia. Researchers from the University of Leipzig in Germany wanted to find out which neurotransmitters were influenced by Ashwagandha. After injecting some of the compounds found in Ashwagandha into rats, they examined slices of the animals’ brains and found an increase in acetylcholine receptor activity. Acetylcholine is the most abundant and essential neurotransmitter in the brain that is responsible for numerous functions, including many related to cognition and memory. It is released into the synapse, or space between two nerve cells, where it stimulates the transfer of nerve impulses from one nerve cell to another. According to the researchers, the increase in acetylcholine receptor capacity might partly explain the cognition-enhancing and memory-improving effects of extracts from Ashwagandha observed in animals20 and humans.21
Supports normal brain function
Two studies done in Japan also indicate that Ashwagandha stimulates the growth of axons and dendrites in human neuroblastoma cells22 23, and in rat neurons.22 This is significant because the extension of dendrites and axons-which bring information to and from the brain-may compensate for and repair damaged neuronal circuits in the dementia brain.24 Ashwagandha’s antioxidant properties have also been shown to help protect the brain from damage in several other studies25 26, including one in which it was used as a prophylactic against damage caused by stroke.27
Reduces cancer cell growth
A recent Japanese in vitro study found that a number of the compounds in Ashwagandha reduced the growth of human colon, breast and lung cancer cells, leading the researchers to suggest that the herb may prevent or decrease the growth of tumors in humans.28 A number of animal studies, both in vivo and in vitro, also showed that Ashwagandha reduces cancer cell growth, and increased the longevity of the animals.29 30 31 32
How safe is it?
Ashwagandha is a safe and gentle herb when used as directed. It should not be used by pregnant women or by individuals taking barbiturates, because the herb increases their effects. Although Ashwagandha has been used for thousands of years in Ayurvedic medicine, the Western world is just beginning to learn about its amazing benefits. Its antioxidant and adaptogenic effects are second to none, and as consumers learn about its benefits, it is sure to take its place among the most revered health tonics known to modern man.
- Bone K. Clinical Applications of Ayurvedic and Chinese Herbs. Queensland, Australia: Phytotherapy Press, 1996, 137-41.
- Grandhi, A. Comparative pharmacological investigation of ashwagandha and ginseng. Journal of Ethnopharmacology (Ireland), 1994: vol. 3, pp 131-135
- Panda S, Kar A. Evidence for free radical scavenging activity of Ashwagandha root powder in mice. Indian J Physiol Pharmacol. 1997 Oct;41(4):424-6.
- Wagner H, Nörr H, Winterhoff H. Plant adaptogens. Phytomed 1994;1:63-76.
- Anabalgan K, Sadique J. Antiinflammatory activity of Withania somnifera. Indian J Exp Biol 1981;19:245-9.
- Davis L, Kuttan G. Effect of Withania somnifera on CTL activity. J Exp Clin Cancer Res. 2002 Mar;21(1):115-8.
- Davis L, Kuttan G. Immunomodulatory activity of Withania somnifera. J Ethnopharmacol. 2000 Jul;71(1-2):193-200.
- Ziauddin M, Phansalkar N, Patki P, Diwanay S, Patwardhan B. Studies on the immunomodulatory effects of Ashwagandha. J Ethnopharmacol. 1996 Feb;50(2):69-76.
- Mehta, A.K., Binkley, P., Gandhi, S.S., Ticku, M.K. Pharmacological effects of Withania somnifera root extract on GABA receptor complex. Indian J Med Res , Aug. 1991;94:312-5
- Singh B, Chandan BK, Gupta DK. Adaptogenic activity of a novel withanolide-free aqueous fraction from the roots of Withania somnifera Dun. (Part II). Phytother Res. 2003 May;17(5):531-6.
- Bhattacharya SK, Muruganandam AV. Adaptogenic activity of Withania somnifera: an experimental study using a rat model of chronic stress. Pharmacol Biochem Behav. 2003 Jun;75(3):547-55.
- Mehta AK, Binkley P, Gandhi SS, Ticku MK. Pharmacological effects of Withania somnifera root extract on GABAA receptor complex. Indian J Med Res. 1991 Aug;94:312-5.
- Bhattacharya SK, Bhattacharya A, Sairam K, Ghosal S. Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study. Phytomedicine. 2000 Dec;7(6):463-9.
- Bhattacharya, S., Goel R., Kaur, R., Ghosal, S. Anti-stress Activity of Sitoindosides VII and VIII, New Acylsterylglucosides from Withania Somnifera. Phytotherapy Res 1987;1:32-39.
- Gupta SK, Dua A, Vohra BP. Withania somnifera (Ashwagandha) attenuates antioxidant defense in aged spinal cord and inhibits copper induced lipid peroxidation and protein oxidative modifications. Drug Metabol Drug Interact. 2003;19(3):211-22.
- Andallu B, Radhika B. Hypoglycemic, diuretic and hypocholesterolemic effect of winter cherry (Withania somnifera, Dunal) root. Indian J Exp Biol. 2000 Jun;38(6):607-9.
- Dhuley JN. Nootropic-like effect of ashwagandha (Withania somnifera L.) in mice. Phytother Res. 2001 Sep;15(6):524-8.
- Iuvone T, Esposito G, Capasso F, Izzo AA. Induction of nitric oxide synthase expression by Withania somnifera in macrophages. Life Sci. 2003 Feb 21;72(14):1617-25.
- Huang, P.L. and E.H. Lo (1998) Prog. Brain. Res. 118:13.
- Bhattacharya A, Ghosal S, Bhattacharya SK. Anti-oxidant effect of Withania somnifera glycowithanolides in chronic footshock stress-induced perturbations of oxidative free radical scavenging enzymes and lipid peroxidation in rat frontal cortex and striatum. J Ethnopharmacol. 2001 Jan;74(1):1-6.
- Schliebs R, Liebmann A, Bhattacharya SK, Kumar A, Ghosal S, Bigl V. Systemic administration of defined extracts from Withania somnifera (Indian Ginseng) and Shilajit differentially affects cholinergic but not glutamatergic and GABAergic markers in rat brain. Neurochem Int. 1997 Feb;30(2):181-90.
- Kuboyama T, Tohda C, Zhao J, Nakamura N, Hattori M, Komatsu K. Axon- or dendrite-predominant outgrowth induced by constituents from Ashwagandha. Neuroreport. 2002 Oct 7;13(14):1715-20.
- Tohda C, Kuboyama T, Komatsu K. Dendrite extension by methanol extract of Ashwagandha (roots of Withania somnifera) in SK-N-SH cells. Neuroreport. 2000 Jun 26;11(9):1981-5.
- Parihar MS, Hemnani T.Phenolic antioxidants attenuate hippocampal neuronal cell damage against kainic acid induced excitotoxicity. J Biosci. 2003 Feb;28(1):121-8.
- Jain S, Shukla SD, Sharma K, Bhatnagar M. Neuroprotective effects of Withania somnifera Dunn. in hippocampal sub-regions of female albino rat. Phytother Res. 2001 Sep;15(6):544-8.
- Chaudhary G, Sharma U, Jagannathan NR, Gupta YK. Evaluation of Withania somnifera in a middle cerebral artery occlusion model of stroke in rats. Clin Exp Pharmacol Physiol. 2003 May-Jun;30(5-6):399-404.
- Davis L, Kuttan G. Effect of Withania somnifera on CTL activity. J Exp Clin Cancer Res. 2002 Mar;21(1):115-8.
- Singh DD, Dey CS, Bhutani KK. Downregulation of p34cdc2 expression with aqueous fraction from Withania somnifera for a possible molecular mechanism of anti-tumor and other pharmacological effects. Phytomedicine. 2001 Nov;8(6):492-4.
- S. Chemopreventive activity of Withania somnifera in experimentally induced fibrosarcoma tumours in Swiss albino mice. Phytother Res. 2001 May;15(3):240-4.
- Prakash J, Gupta SK, Kochupillai V, Singh N, Gupta YK, Joshi S. Chemopreventive activity of Withania somnifera in experimentally induced fibrosarcoma tumours in Swiss albino mice. Phytother Res. 2001 May;15(3):240-4.
- Davis L, Kuttan G. Effect of Withania somnifera on DMBA induced carcinogenesis. J Ethnopharmacol. 2001 May;75(2-3):165-8.
- Prakash J, Gupta SK, Dinda AK. Withania somnifera root extract prevents DMBA-induced squamous cell carcinoma of skin in Swiss albino mice. Nutr Cancer. 2002;42(1):91-7.