Ashwagandha Clinical Studies
Ancient medicine, modern use: Withania somnifera and its potential role in integrative oncology.
Altern Med Rev. 2006 Dec;11(4):269-77.
Withania somnifera Dunal, commonly known as ashwagandha, has been used for centuries in Ayurvedic medicine to increase longevity and vitality. Western research supports its polypharmaceutical use, confirming antioxidant, anti-inflammatory, immune-modulating, and antistress properties in the whole plant extract and several separate constituents. This article reviews the literature pertaining to Withania somnifera and its botanical constituents as antitumor agents and in conjunction with radiation and chemotherapy treatment. Following a search of MEDLINE and EBSCO databases, it can be concluded that Withania somnifera reduces tumor cell proliferation while increasing overall animal survival time. Furthermore, it has been shown to enhance the effectiveness of radiation therapy while potentially mitigating undesirable side effects. Withania somnifera also reduces the side effects of chemotherapeutic agents cyclophosphamide and paclitaxel without interfering with the tumor-reducing actions of the drugs. These effects have been demonstrated in vitro on human cancer cell lines, and in vivo on animal subjects, but there have been no human trials to date. Given its broad spectrum of cytotoxic and tumor-sensitizing actions, Withania somnifera presents itself as a novel complementary therapy for integrative oncology care.
Enhancement of antitumor effect of paclitaxel in combination with immunomodulatory Withania somnifera on benzo(a)pyrene induced experimental lung cancer.
Senthilnathan P, Padmavathi R, Banu SM, Sakthisekaran D.
Department of Medical Biochemistry, Dr. ALM Postgraduate Institute of Basic
Medical Sciences, University of Madras, Taramani, Chennai 600113, India.
Chem Biol Interact. 2006 Feb 25;159(3):180-5. Epub 2005 Dec 22.
The current experimental work deals with the immunomodulatory studies on the extract of Withania somnifera (L.) Dunal root powder against benzo(a)pyrene induced lung cancer in male Swiss albino mice. In our previous study, we reported the antioxidant and anticarcinogenic effect of W. somnifera (L.) Dunal along with paclitaxel. Immune dysfunction has been found to be associated with cancer and chemotherapy. Benzo(a)pyrene induced cancer animals were treated with 400mg/kg bodyweight of W. somnifera (L.) Dunal extract for 30 days significantly alters the levels of immunocompetent cells, immune complexes and immunoglobulins. Based on the data, the carcinogen as well as the paclitaxel affects the immune system, the toxic side effects on the immune system is more reversible and more controllable by W. somnifera (L.) Dunal. These results concluded the immunomodulatory activity of W. somnifera (L.) Dunal extract, which is a known immunomodulator in indigenous medicine.
Withania somnifera Dunal (Ashwagandha): potential plant source of a promising drug for cancer chemotherapy and radiosensitization.
Department of Radiobiology, Kasturba Medical College, Manipal, India.
Indian J Exp Biol. 1996 Oct;34(10):927-32.
Study of antitumor and radiosensitizing properties of W. somnifera (Ashwagandha), a well known medicinal plant, have yielded encouraging results. The alcoholic extract of the dried roots of the plant as well as the active component withaferin A isolated from the extract showed significant antitumor and radiosensitizing effects in experimental tumors in vivo, without any noticeable systemic toxicity. Withaferin A gave a sensitizer enhancement ratio of 1.5 for in vitro cell killing of V79 Chinese hamster cells at a non toxic concentration of approximately 2 microM. The mechanism of action of this compound is not known. The studies so far indicate that W. somnifera could prove to be a good natural source of a potent and relatively safe radiosensitizer/chemotherapeutic agent. Further studies are needed to explore the clinical potential of this plant for cancer therapy.
Systemic administration of defined extracts from Withania somnifera (Indian Ginseng) and Shilajit differentially affects cholinergic but not glutamatergic and GABAergic markers in rat brain.
Schliebs R, Liebmann A, Bhattacharya SK, Kumar A, Ghosal S, Bigl V.
Paul Flechsig Institute for Brain Research, Department of Neurochemistry, University of Leipzig, Germany.
Neurochem Int. 1997 Feb;30(2):181-90.
Although some promising results have been achieved by acetylcholinesterase inhibitors, an effective therapeutic intervention in Alzheimer's disease still remains an important goal. Sitoindosides VII-X, and withaferin-A, isolated from aqueous methanol extract from the roots of cultivated varieties of Withania somnifera (known as Indian Ginseng), as well as Shilajit, a pale-brown to blackish brown exudation from steep rocks of the Himalaya mountain, are used in Indian medicine to attenuate cerebral functional deficits, including amnesia, in geriatric patients. The present investigation was conducted to assess whether the memory-enhancing effects of plant extracts from Withania somnifera and Shilajit are owing to neurochemical alterations of specific transmitter systems.
Therefore, histochemistry to analyse acetylcholinesterase activity as well as receptor autoradiography to detect cholinergic, glutamatergic and GABAergic receptor subtypes were performed in brain slices from adult male Wistar rats, injected intraperitoneally daily with an equimolar mixture of sitoindosides VII-X and withaferin-A (prepared from Withania somnifera) or with Shilajit, at doses of 40 mg/kg of body weight for 7 days. Administration of Shilajit led to reduced acetylcholinesterase staining, restricted to the basal forebrain nuclei including medial septum and the vertical limb of the diagonal band. Systemic application of the defined extract from Withania somnifera, however, led to differential effects on AChE activity in basal forebrain nuclei: slightly enhanced AChE activity was found in the lateral septum and globus pallidus, whereas in the vertical diagonal band AChE activity was reduced following treatment with sitoindosides VII-X and withaferin-A. These changes were accompanied by enhanced M1-muscarinic cholinergic receptor binding in lateral and medial septum as well as in frontal cortices, whereas the M2-muscarinic receptor binding sites were increased in a number of cortical regions including cingulate, frontal, piriform, parietal and retrosplenial cortex. Treatment with Shilajit or the defined extract from Withania somnifera affected neither GABAA and benzodiazepine receptor binding nor NMDA and AMPA glutamate receptor subtypes in any of the cortical or subcortical regions studied. The data suggest that Shilajit and the defined extract from Withania somnifera affect preferentially events in the cortical and basal forebrain cholinergic signal transduction cascade. The drug-induced increase in cortical muscarinic acetylcholine receptor capacity might partly explain the cognition-enhancing and memory-improving effects of extracts from Withania somnifera observed in animals and humans.
Adaptogenic activity of Withania somnifera: an experimental study using a rat model of chronic stress.
Bhattacharya SK, Muruganandam AV.
Department of Pharmacology, Postgraduate Institute of Basic Medical Sciences, Calcutta University, 244 B Acharya JC Bose Road, Calcutta 700 020, India.
Pharmacol Biochem Behav. 2003 Jun;75(3):547-55.
Withania somnifera (WS) Dunal is classified in Ayurveda, the ancient Hindu system of medicine, as a rasayana, a group of plant-derived drugs reputed to promote physical and mental health, augment resistance of the body against disease and diverse adverse environmental factors, revitalise the body in debilitated conditions and increase longevity. These attributes are remarkably similar to the properties ascribed to adaptogens like Panax ginseng (PG) in contemporary medicine. As such, the adaptogenic activity of a standardised extract of WS roots was investigated against a rat model of chronic stress (CS). The stress procedure was mild, unpredictable footshock, administered once daily for 21 days to adult male Wistar rats. CS induced significant hyperglycaemia, glucose intolerance, increase in plasma corticosterone levels, gastric ulcerations, male sexual dysfunction, cognitive deficits, immunosuppression and mental depression. These CS induced perturbations were attenuated by WS (25 and 50 mg/kg po) and by PG (100 mg/kg po), administered 1 h before footshock for 21 days. The results indicate that WS, like PG, has significant antistress adaptogenic activity, confirming the clinical use of the plant in Ayurveda.
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.
Bhattacharya A, Ghosal S, Bhattacharya SK. Drug Research and Development Centre, Calcutta, India.
J Ethnopharmacol. 2001 Jan;74(1):1-6.
The antioxidant activity of Withania somnifera (WS) glycowithanolides was assessed in chronic footshock stress induced changes in rat brain frontal cortex and striatum. The stress procedure, given once daily for 21 days, induced an increase in superoxide dismutase (SOD) and lipid peroxidation (LPO) activity, with concomitant decrease in catalase (CAT) and glutathione peroxidase (GPX) activities in both the brain regions. WS glycowithanolides (WSG), administered orally 1 h prior to the stress procedure for 21 days, in the doses of 10, 20 and 50 mg/kg, induced a dose-related reversal of the stress effects. Thus, WSG tended to normalise the augmented SOD and LPO activities and enhanced the activities of CAT and GPX. The results indicate that, at least part of chronic stress-induced pathology may be due to oxidative stress, which is mitigated by WSG, lending support to the clinical use of the plant as an antistress adaptogen.
Antistressor effect of Withania somnifera.
Archana R, Namasivayam A.
Department of Physiology, Dr ALM PG. Institute of Basic Medical Sciences, University of Madras, Taramani, India.
J Ethnopharmacol. 1999 Jan;64(1):91-3.
Withania somnifera is an Indian medicinal plant used widely in the treatment of many clinical conditions in India. Its antistressor properties have been investigated in this study using adult Wistar strain albino rats and cold water swimming stress test. The results indicate that the drug treated animals show better stress tolerance.
Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study.
Bhattacharya SK, Bhattacharya A, Sairam K, Ghosal S.
Department of Pharmacology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Phytomedicine. 2000 Dec;7(6):463-9.
The roots of Withania somnifera (WS) are used extensively in Ayurveda, the classical Indian system of medicine, and WS is categorized as a rasayana, which are used to promote physical and mental health, to provide defence against disease and adverse environmental factors and to arrest the aging process. WS has been used to stabilize mood in patients with behavioural disturbances. The present study investigated the anxiolytic and antidepressant actions of the bioactive glycowithanolides (WSG), isolated from WS roots, in rats. WSG (20 and 50 mg/kg) was administered orally once daily for 5 days and the results were compared by those elicited by the benzodiazepine lorazepam (0.5 mg/kg, i.p.) for anxiolytic studies, and by the tricyclic anti-depressant, imipramine (10 mg/kg, i.p.), for the antidepressant investigations. Both these standard drugs were administered once, 30 min prior to the tests. WSG induced an anxiolytic effect, comparable to that produced by lorazepam, in the elevated plus-maze, social interaction and feeding latency in an unfamiliar environment, tests. Further, both WSG and lorazepam, reduced rat brain levels of tribulin, an endocoid marker of clinical anxiety, when the levels were increased following administration of the anxiogenic agent, pentylenetetrazole. WSG also exhibited an antidepressant effect, comparable with that induced by imipramine, in the forced swim-induced 'behavioural despair' and 'learned helplessness' tests. The investigations support the use of WS as a mood stabilizer in clinical conditions of anxiety and depression in Ayurveda.
Scientific basis for the therapeutic use of Withania somnifera (ashwagandha): a review.
Mishra LC, Singh BB, Dagenais S.
Los Angeles College of Chiropractic (LACC), 16200 E Amber Valley Dr., Whittier,CA 90609-1166.
Altern Med Rev. 2000 Aug;5(4):334-46.
OBJECTIVE: The objective of this paper is to review the literature regarding Withania somnifera (ashwagandha, WS) a commonly used herb in Ayurvedic medicine. Specifically, the literature was reviewed for articles pertaining to chemical properties, therapeutic benefits, and toxicity.
DESIGN: This review is in a narrative format and consists of all publications relevant to ashwagandha that were identified by the authors through a systematic search of major computerized medical databases; no statistical pooling of results or evaluation of the quality of the studies was performed due to the widely different methods employed by each study.
RESULTS: Studies indicate ashwagandha possesses anti-inflammatory, antitumor, antistress, antioxidant, immunomodulatory, hemopoietic, and rejuvenating properties. It also appears to exert a positive influence on the endocrine, cardiopulmonary, and central nervous systems. The mechanisms of action for these properties are not fully understood. Toxicity studies reveal that ashwagandha appears to be a safe compound.
CONCLUSION: Preliminary studies have found various constituents of ashwagandha exhibit a variety of therapeutic effects with little or no associated toxicity. These results are very encouraging and indicate this herb should be studied more extensively to confirm these results and reveal other potential therapeutic effects. Clinical trials using ashwagandha for a variety of conditions should also be conducted.
Subacute toxicity study of the combination of ginseng (Panax ginseng) and ashwagandha (Withania somnifera) in rats: a safety assessment.
Aphale AA, Chhibba AD, Kumbhakarna NR, Mateenuddin M, Dahat SH. Department of Pharmacology, Government Medical College, Aurangabad.
Indian J Physiol Pharmacol. 1998 Apr;42(2):299-302.
Ginseng (Panax ginseng) and Ashwagandha (Withania somnifera) are widely used as geriatric tonics. Both individually have not shown any toxicity on long term administration. Study was planned to assess the safety of the combination by doing subacute toxicity study in rats with 90 days oral administration using three doses. Food consumption, body weight, haematological, biochemical and histopathological parameters were studied. There was significant increase in body weight, food consumption and liver weight, and improved hematopoiesis was observed. Brain, heart, lung, liver, spleen, kidneys, stomach, testis and ovaries were normal on gross examination and histopathologically. Subacute toxicity studies in rats did not reveal any toxicity.
PMID: 10225062 [PubMed - indexed for MEDLINE]