INTRODUCTION

Ashwagandha is one of the most revered plants in traditional Ayurvedic medicine in India. It is an erect, greyish, subshrub with inconspicuous yellow or greenish flowers followed by small, spherical, orangish-red berries containing yellow, kidney-shaped seeds. It grows three-to-five feet tall, mainly on waste land, but is cultivated widely as the whole plant; most commonly the root and leaf are used medicinally.^1,2

The species is widely distributed in the northwestern Indian states of Gujarat, Madhya Pradesh, Maharashtra, Rajasthan, Uttar Pradesh, and the Punjab plains extending to the mountainous regions of Himachal Pradesh and Jammu.³ It also is cultivated in parts of Madhya Pradesh and Rajasthan.⁴ Northwest of India, its habitat extends into the Pakistani provinces of Sindh and Baluchistan, and on into Afghanistan. To the southeast of India, it occurs in Sri Lanka.⁵ In China, it is reported to grow in the western provinces of Gansu and Yunnan.⁶

HISTORY AND CULTURAL SIGNIFICANCE

The species name, somnifera, refers to ashwagandha’s use as a sedative.¹ The common name comes from the Sanskrit ashvagandha,^2,7 i.e., ashwa for horse, and gandha for smell, hence the common idea that the name means “smells like a horse.” The Ayurvedic health practitioner Vaidya R. K. Mishra states that the translation can be taken literally, or that it could be interpreted to mean “horse essence” and that ashwagandha provides the strength, character, essence, or stamina of a horse.⁸

Ashwagandha is the Bengali name and variations are used in Nepalese (aasogandha) and Japanese (aswangandha).² Other common names include asgandh (Hindi), amukkara (Sinhalese), asgandh valaiti (Unani), bahman (Persian, Arabian), ba-dzi-gandha (Tibetan), kutilad (Pustu), amurkkuralckizhangu (Tamil), winter cherry (English), and blærebæger (Danish).^2,9 It is sometimes erroneously called Ayurvedic or Indian ginseng, an incorrect appellation because it is not in the genus Panax or in the ginseng family, Araliaceae.¹⁰

Preparations of various plant parts have been credited with the following actions: abortifacient, adaptogenic, alterative, analgesic, antiarthritic, antiasthmatic, antibiotic, antidyspeptic, anti-inflammatory, antimitotic, antiproliferative, antitumor, aphrodisiac, astringent, bactericide, carminative, contraceptive, depurative, diuretic, emetic, febrifuge, fungicidal, hypnotic, immune-modulating, laxative, proteolytic, tonic, and nervine sedative.^1,2,7,9,11 Additionally, it may have cytotoxic, chemopreventative, and radiosensitizing actions.⁹

Ashwagandha is one of the rasayana herbs in Ayurveda — one of the herbs that purportedly promotes youth and longevity and alleviates suffering.¹² It is thought to be especially rejuvenative for men; to strengthen bone marrow, muscle, and semen; and to imbue the user with intellectual facility, in addition to long life and youthful vitality.1 However, it also is believed to be quite helpful to the elderly by providing energy and relieving pain, inflammation, and nervous debility.¹²

Ashwagandha has a wide variety of traditional uses, many of which have not been tested scientifically. Ethnobotanist James Duke, PhD, writes that ashwagandha (various plant parts) is a folk remedy for “adenopathy, anthrax, arthritis, asthma, bronchitis, cancer, candida, cold, cough, cystitis, debility, diarrhea, dropsy, dyspepsia, erysipelas, fever, furuncle, gynecopathy, hiccups, hypertension, inflammation, lumbago, marasmus, nausea, piles, proctitis, psoriasis, rheumatism, ringworm, scabies, senility, smallpox, sores, syphilis, tuberculosis, tumors, typhoid, uterosis, and wounds.”¹¹ Additional uses attributed to the plant, in general, are the treatment of alcoholism, anemia, colds, dropsy, fever, hypertension, insomnia, lumbago, ulcers, wasting in children, and removal of obstructions in any human body system.^1,7,9,12

Some of the documented uses of the root of ashwagandha include as a hypnotic for treating alcoholism (along with leaf); treatment for brain fog, colds and chills, childhood emaciation, emphysematous dysphonia (difficult speech caused by emphysema, with leaf), fever, glandular swelling, impotence or seminal debility; to increase breast milk; and to counteract loss of memory and muscular energy, nervous exhaustion, rheumatic fever, rheumatic swelling, senile and general debility, spermatorrhea, syphilis, and ulcers.^2,7,11 In Tanzania, the root is used as a sexual stimulant and to promote uterine contractions.¹¹

The leaves are used to expel worms and are combined with warm castor oil (Ricinis communis, Euphorbiaceae) on carbuncles, inflammations, and swellings.^2,7,11 The Masai use the leaf juice for conjunctivitis.¹¹ The fresh bruised berries are used on ringworm.^2,11 The fruits or seeds are used to coagulate milk.^2,7,11 The seeds also are used as a masticatory.¹¹ A bark infusion is used in Lesotho internally for asthma and externally for bedsores.¹¹ The tender shoots are eaten as a vegetable in India.¹¹

The dried root and the whole plant are used in the traditional medicine systems of Ayurveda, Siddha, Sowa-Rigpa (Amchi), and Unani, as well as in Indian folk medicine. The materials of commerce are obtained from both cultivated and wild-collected sources, mainly in India.¹³

Although ashwagandha is now cultivated on farms outside of its native habitat, and the unprocessed dried roots are being used as components of dietary supplement products and natural health products, in the Indian systems of medicine, the dried roots may be subjected to certain traditional fermentation, purification, or detoxification processes prior to therapeutic use.¹⁴

There are W. somnifera standards monographs published in the Ayurvedic Pharmacopoeia of India (Vol. I, 1989),¹⁵ Siddha Pharmacopoeia of India (Vol. I, 2008),¹⁶ Unani Pharmacopoeia of India (Vol. I, 2007),¹⁷ the World Health Organization (WHO) Monographs (Vol. 4, 2009),¹⁸ as well as in the currently valid editions of the British Pharmacopoeia (BP 2012),¹⁹ Indian Pharmacopoeia (IP 2010),²⁰ and United States Pharmacopeia (USP 36).²¹

CURRENT AUTHORIZED USES IN COSMETICS, FOODS, AND MEDICINES

In countries where the Ayurvedic system of medicine is officially recognized and practiced (e.g., India, Bangladesh, Bhutan, Malaysia, Nepal, and Sri Lanka), the powdered dried root of ashwagandha is used, as a component of preparations, for treating inflammatory disorders, phthisis (any wasting or atrophic disease, weakness, diseases due to vata dosha), and male impotence.¹⁵

In countries where the Unani system of medicine is officially recognized and practiced (e.g., Bangladesh, India, Malaysia, Pakistan, and Sri Lanka), the dried mature root, referred to as “asgand,” is used as a component of medicinal formulations to treat leucorrhoea, spermatorrhoea, decreased viscosity of semen, sexual debility, lumbago, and arthritis. Ashwagandha is often dispensed as a component of compound Unani medicines known as majoon or halwa. These preparations are made with prepared and powdered botanicals mixed with honey, resulting in a soft or semi-solid consistency like the popular confection halva.¹⁷

In Siddha medicine — a Dravidian system of medicine originating in the southeastern Indian state of Tamil Nadu, now also practiced in the neighboring states of Karnataka, Kerala, and Andhra Pradesh, as well as in parts of Malaysia, Singapore, and Sri Lanka — the dried root (purified before use), referred to as amukkara, is used as a component of formulations indicated for treatment of conditions including oligospermia, lancinating pain, loss of body strength, anemia, convulsions/seizures/fits, disordered humor, eczema, edema/swelling, and tuberculosis.²²

In Canada, ashwagandha root is classified as an active ingredient of licensed natural health products (NHPs), requiring pre-marketing authorization from the Natural Health Products Directorate (NHPD) and manufacture in compliance with NHP Good Manufacturing Practices (GMPs). Authorized uses outlined in its NHPD compendial monograph include “traditionally used in Ayurveda as rasayana (rejuvenative tonic),” “traditionally used in Ayurveda to relieve general debility, especially during convalescence or old age,” “traditionally used in Ayurveda as a sleep aid,” “traditionally used in Ayurveda to balance aggravated Vata (nervine tonic, sedative),” and “traditionally used in Ayurveda for memory enhancement.”²³

In the United States, ashwagandha is not listed as Generally Recognized as Safe (GRAS) in the Code of Federal Regulations (CFR) for any uses in conventional food products, nor does it appear in FDA’s GRAS Notice Inventory database. Ashwagandha is permitted, however, for use as a dietary supplement component, requiring FDA notification within 30 days of marketing a product (if a “structure-function” claim is made) and product manufacturing according to dietary supplement GMPs. USP has developed dietary supplement quality standards monographs for “Ashwagandha Root,” “Powdered Ashwagandha Root,” and for “Powdered Ashwagandha Root Extract.” These USP monographs are acceptable for use as dietary supplement component specifications and quality control testing to verify conformance to specification before use in a product.²¹

In the European Union (EU), ashwagandha is not subject to the Novel Food Regulation because it was on the market as a food or food ingredient and consumed to a significant degree before May 15, 1997. Other specific legislation, however, may restrict the placing of ashwagandha as a food or food ingredient on the market in some Member States.²⁴

For example, in 2008, the Government of India, Department of Ayurveda, Yoga & Naturopathy, Unani, Siddha and Homoeopathy (AYUSH) — as part of a global strategy for brand-building of Ayurvedic medicine — prioritized the promotion of ashwagandha preparations, in particular, for attaining marketing authorizations as medicinal products in several foreign markets including selected EU member states, as well as in Australia, Canada, and Commonwealth of Independent States (CIS) countries. The ashwagandha strategy was developed in collaboration with the International Trade Centre (ITC) of UNCTAD (Geneva, Switzerland).²⁵

By 2010, the BP developed a quality standards monograph for the dried mature root of W. somnifera specifically for use in Traditional Herbal Medicinal Products (THMPs), as defined under the EU Traditional Herbal Medicinal Products Directive (THMPD).¹⁹ The BP monograph was an important first step that provided applicants with a requisite quality control specification, thus paving the way for the use of ashwagandha as an active ingredient of THMPs that could be authorized by the Medicines and Healthcare products Regulatory Agency (MHRA) for marketing in the United Kingdom.

In July 2011, the Committee on Herbal Medicinal Products (HMPC) of the European Medicines Agency (EMA) began the process of developing a labeling standards monograph (for use by applicants for the labeling of ashwagandha THMPs in the EU) by putting out a call for submission of scientific data that would be used in the assessment of W. somnifera radix as part of the establishment of Community herbal monographs and/or Community list entries.²⁶

ollowing their assessment, in October 2012, the EMA issued a draft public statement with the opinion that a Community herbal monograph on W. somnifera radix could not yet be established because the HMPC had not been able to find adequate evidence allowing them to develop a description of ashwagandha preparations, i.e., insufficient extract specifications according to EU pharmaceutical quality requirements, despite the existence of data on uses within the EU of products containing W. somnifera radix. Additionally, the HMPC stated that they were unable to find evidence demonstrating the requirement of at least 30 years of medicinal use of ashwagandha preparations including at least 15 years in an EU member state.²⁷ As of the time of this publication, there are still no known ashwagandha-containing THMPs with marketing authorization granted in any EU member state.

Concerning its use in cosmetic products, the European Commission Health and Consumers Directorate lists several defined W. somnifera ingredients (root powder, root extract, leaf and root extract, and flower extract) for skin-conditioning function (maintains the skin in good condition). “Withania somnifera leaf extract,” however, is approved for several functions in cosmetic products, including as an antimicrobial (helps control the growth of micro-organisms on the skin), antioxidant (inhibits reactions promoted by oxygen, thus avoiding oxidation and rancidity), bleaching (lightens the shade of hair or skin), emollient (softens and smoothes the skin), and humectant (holds and retains moisture).²⁸

MODERN RESEARCH

The main active chemical constituents in ashwagandha are steroid lactones (withaferin A, sitoindoside IX and X, [carbon-27 glycowithanolides], and acylsteryl glucosides [sitoindosides VII, VIII]); phytosterols; and alkaloids: tropane type (tropine and pseudotropine), plus isopelletierine, and anaferine.^1,9

An open-label, prospective, non-randomized, comparative clinical study published in 2013 addressed the potential use of ashwagandha root extract powder (Himalaya Drug Co.; New Delhi, India) for the mitigation of fatigue caused by chemotherapy and for improving quality of life in patients with breast cancer.²⁹ Patients undergoing chemotherapy for breast cancer were assigned alternately into the study group (n=50) or control group (n=50) and assessed for fatigue. The study group took 500 mg ashwagandha dry extract three times daily throughout six cycles of chemotherapy. The ashwagandha patients experienced less fatigue and better quality of life during chemotherapy than the control group.

In another 2013 clinical trial, three groups of infertile male patients were recruited from the infertility clinic at King George’s Medical University, Lucknow, India; 60 with normal semen profile and infertility of unknown etiology, 60 with low sperm count and normal morphology, and 60 with normal sperm count and normal morphology but reduced sperm motility.³⁰ Controls were 50 age-matched men with normal semen profile who had initiated at least one pregnancy previously. Each patient in the study group took 5 g/day ashwagandha root powder (roots purchased from the Central Council for Research in Unani Medicine; New Delhi, India; dried in shade and ground to fine powder) orally in milk for three months. Semen samples were collected and centrifuged and the seminal plasma was assessed. Results showed that ashwagandha normalized markers in seminal plasma and may resolve infertility via action on metabolic, enzymatic, and hormonal pathways.

A 2010 prospective clinical study investigated the impact of ashwagandha on semen profile, oxidative biomarkers, and reproductive hormone levels in infertile men.³¹ The control group comprised normal healthy, fertile men (n=75) with normal semen profile who had initiated at least one pregnancy previously. The test groups comprised patients with infertility for more than one year (n=75; 25 with normal semen profile and infertility of unknown etiology, 25 with below-normal semen profile, and 25 with below-normal sperm motility). Patients with conditions known to influence oxidative stress were excluded from the study. For three months, the test group took 5 g/day ashwagandha root powder (Central Council for Research in Unani Medicine, New Delhi) orally with milk. Sperm concentration increased significantly in all three test groups after treatment. Sperm motility improved in all three groups but not significantly in the group with below-normal sperm motility. Semen volume increased significantly in all test groups except the group with below normal sperm motility. The ashwagandha also inhibited lipid peroxidation in the test groups, effectively reducing oxidative stress. Finally, the ashwagandha groups experienced increased serum testosterone and luteinizing hormone levels and reduced levels of follicle-stimulating hormone and prolactin — all indicators of semen quality.

A 2012 clinical study with a pilot arm and a therapeutic arm investigated the efficacy of ashwagandha as an adjunct therapy in treating tuberculosis.³² Recently diagnosed pulmonary tuberculosis patients who had yet to take any anti-tuberculor drugs (ATD) were enlisted. In the pilot study, Phase 1 patients took either ATD or ATD plus ashwagandha (Stresscom, standardized to 4.5% withanolides, Dabur Research Foundation; New Delhi, India). In Phase 2, patients took either ATD, ATD plus ashwagandha, or ATD plus the Ayurvedic multi-herb-and-fruit formulation Chyawanprash (Dabur Research Foundation; New Delhi, India). The treatment groups in the therapeutic study were the same as those in Phase 2 of the pilot study. More improvement was seen in both herbal adjunct groups than in the ATD-only group, including reduced bacterial counts after 26 days in the ashwagandha group and 29 days in the Chyawanprash group.

A 2012 single-arm, uncontrolled, observational, dose-response study assessed the safety, tolerability, and activity of escalating doses of ashwagandha.³³ For 30 days, at 10-day intervals, 18 healthy participants took increasing doses of ashwagandha (8:1 pulverized ashwagandha root extract; source, preparation, and manufacturer not stated) starting with 250 mg in the morning and 500 mg in the evening (750 mg total/day) on days 1-10, 500 mg in the morning and 500 mg in the evening (1000 mg total/day) on days 11-20, and 500 mg in the morning and 750 mg in the evening (1250 mg total/day) on days 21-30. There were no significant changes in vital signs (blood pressure, pulse, body temperature, and respiration rate, taken at baseline and on days 11, 21, and 31), body weight, or blood markers during the study, nor were any significant changes in appetite, waste elimination habits, or sleep duration reported — although 33% of the subjects reported improved sleep quality. Muscle strength increased significantly and, although body weight and body mass index (BMI) did not change significantly, there was a trend toward increased lean body weight and decreased body fat percentage. Total cholesterol decreased significantly and decreasing trends were seen in fasting blood sugar, triglycerides, and LDL cholesterol.

A six-week clinical trial in 2012 evaluated the safety of an Ayurvedic formula used in the treatment of osteoarthritic knees.³⁴ The formula (preparation and manufacturer not stated) contained ashwagandha root powder, ginger (Zingiber officinale, Zingiberaceae), Indian tinospora or guduchi (Tinospora cordifolia, Menispermaceae), and tribulus (Tribulus terrestris, Zygophyllaceae). The formula showed no serious adverse events and none of the participants withdrew due to any drug-related toxicity.

A 2010 uncontrolled clinical study assessed the efficacy of ashwagandha and arjuna (Terminalia arjuna, Combretaceae) alone and in combination on physical performance and cardiorespiratory endurance in healthy young adults.³⁵ Of 40 subjects over the course of eight weeks, 10 received 500 mg/day standardized aqueous root extract of ashwagandha, 10 received 500 mg/day standardized aqueous bark extract of arjuna, and 10 received 500 mg/day both ashwagandha and arjuna extracts encapsulated together (all herbs provided by the Central Council for Research in Ayurveda and Siddha; Delhi, India). A control group of 10 participants received encapsulated flour. The ashwagandha group experienced increased velocity, power, and maximum oxygen consumption, while the arjuna group experienced increased maximum oxygen consumption and lowered resting systolic blood pressure. In combination, participants experienced improvement in all the parameters mentioned above. None of the groups experienced improved balance or diastolic blood pressure.

Two 2009 double-blind, pilot studies investigated ashwagandha and four other Ayurvedic herbs for their immune-enhancing effect.³⁶ Study 1 included 32 volunteers randomized to two treatment groups of 16 each who consumed three cups daily of Natural Care tea (ashwagandha [0.5%]; licorice [Glycyrrhiza glabra, Fabaceae, 0.5%]; ginger [1.5%]; holy basil [Ocimum tenuiflorum, Lamiaceae, 0.5%]; and cardamom [Elettaria cardmomum, Zingiberaceae, 1.5%]; Hindustan Unilever Research Center; Bangalore, India) or regular tea (Camellia sinensis, Theaceae) for two months. Natural killer (NK) cell activity was measured after one and two months of tea consumption. There were no significant changes in either group at the end of month one, but NK cell activity was significantly increased after two months in the NC tea drinkers but not in the regular tea group.

Study 2 was a larger, double-blind, crossover study in which 110 subjects (60 male, 40 female [sic]) were randomly assigned to two groups.³⁶ Each group consumed three cups of tea (Natural Care or regular tea) per day for two months. NK cell activity was measured before a 15-day washout period when no tea was drunk. The groups then switched to the other tea for another two months, after which NK cell activity was measured again. NK cell activity increased in both groups after two months, but the increase in the Natural Care tea drinking groups was approximately 4.2 times higher than before, while the NK cell activity in the regular tea group was about 2.9 times higher.

A randomized, controlled trial published in 2009 addressed the efficacy of ashwagandha for moderate-to-severe anxiety lasting more than six weeks per self-assessment.³⁷ Participants were randomized to receive naturopathic care with ashwagandha (n=41), a multi-vitamin, dietary counseling, and cognitive-behavioral therapy, or standardized psychotherapy intervention (n=40). The ashwagandha group took 300 mg, two per day, for six weeks of ashwagandgha extract standardized to 1.5% withanolides from root obtained from Swiss Herbals (now Swiss Natural; Richmond Hill, ON, Canada). Outcomes were measured at four, eight, and 12 weeks, with the results suggesting that both treatments caused a significant reduction in anxiety, but the ashwagandha group also experienced significant improvement in quality of life, including reduction of stress, improved vitality, motivation, general health, and patient-specific concerns. The authors stated that it is difficult to assess the precise effect of each of the component therapies and that future studies should focus on isolating the effects of component therapies and use a blinded independent assessment rather than a patient-reported assessment.

A small, uncontrolled study assessed the immunologic effects of ashwagandha.38 Twice a day for 96 hours, five participants consumed 6 mL ashwagandha root liquid extract (grain ethanol and spring water extraction, Gaia Herbs; Brevard, NC) followed by 8 fl oz whole cow’s milk. Blood samples were taken at 0, 24, and 96 hours, and analyzed for immune cell activation. A significant change in immune cell activation occurred across the sample indicating that further study is warranted to determine if ashwagandha might be helpful in the prevention and treatment of infectious disease, cancer, and other immune-related conditions.

Bone and Mills (2013) reported on four studies between 1980 and 2008 that investigated ashwagandha for its tonic activity, a concept often misunderstood in Western medicine. Tonics are restorative, supportive, sometimes adaptogenic (i.e., helping the body to adapt to stressors) substances. In these studies, ashwagandha was found to significantly increase hemoglobin, red blood cell count, seated stature, and hair melanin content, as well as decrease serum cholesterol and erythrocyte sedimentation, improve men’s sexual performance, and counter decrease in nail calcium. It also improved alertness and state of awareness, responsiveness, sleep patterns, and physical capabilities of trainee mountaineers over a six-day trek with a 5,200 m (17,000 ft.) altitude gain; modestly improved muscle strength and muscle performance in healthy elderly men; and improved stress markers for chronically stressed patients.⁹

FUTURE OUTLOOK

Of the estimated 960 medicinal plant species that form the source of 1,289 botanical raw drugs in trade in India, W. somnifera is among the top 117 species whose annual domestic consumption exceeds 100 metric tons (MT). Ranking at #4 in terms of volume, Indian domestic consumption of ashwagandha is estimated at 4,575 MT, of which about 24% relates to production by large herbal manufacturing units and about 76% by small and very small companies. Annual trade volume was estimated at between 2,000 to 5,000 MT in 2008. Much of the commercial supply is now produced by cultivation in Madhya Pradesh, Rajasthan, and parts of peninsular India.³⁹

Although the Government of India’s strategy to promote Ayurvedic medicine to the world, initially focusing on ashwagandha as an emblematic Indian medicinal product, has not yet manifested as hoped — in part due to the EU regulatory framework, which makes it exceedingly complex, expensive, and almost impossible for even the larger Indian Ayurvedic medicine manufacturing companies to achieve marketing authorization for any non-European herbal medicinal products — ashwagandha-based products are taking hold in non-EU markets. The EU’s THMPD is viewed by Indian herbal medicine companies as a legislative market access barrier while entering the market in Commonwealth of Nations countries; in particular, entering Australia, Canada, Malaysia, and New Zealand has been less burdensome. Additionally, there are herbal companies situated in these countries interested in formulating new products that contain ashwagandha.

At the same time, some ashwagandha-containing Ayurvedic medicines are being labeled and marketed as food products, even in some EU member states. For example, the well-known Ayurvedic multi-herb tonic formulation Chyawanprash is available in the EU from several different Indian manufacturing companies. Some EU companies also are marketing products with food supplement labeling, for example Pukka Organic Ashwagandha vegetarian capsules (Pukka Herbs Ltd.; Bristol, England).

In the Australian market, at the time of this writing, there are 130 listed medicines that contain ashwagandha as an active ingredient.⁴⁰ In the Canadian market there are presently 325 licensed NHPs that contain ashwagandha as a medicinal ingredient.⁴¹ In the United States, ashwagandha dietary supplement products are marketed by many of the major herbal brands.

—Gayle Engels and Josef Brinckmann

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