A popular Ayurvedic herb, ashwagandha is often used in formulations prescribed for stress, strain, fatigue, pain, skin diseases, diabetes, gastrointestinal disease, rheumatoid arthritis, and epilepsy (1). It is also used as a general tonic, to increase energy and improve health and longevity (2). Externally, it can be applied as a local analgesic (3). The active constituents are thought to include alkaloids, steroidal lactones, saponins, and withanolides.
In vitro studies suggest that ashwagandha has neuroprotective (26) and anti-inflammatory properties which may protect against cartilage damage in osteoarthritis (4). Animal studies suggest antitumor, immunomodulatory, antioxidant, and anti-stress properties. In addition, improvements in hyperglycemia, hyperinsulinemia, and insulin sensitivity have been detected in an animal model of type 2 diabetes (5). Other studies indicate cytotoxic, chemopreventative, immunomodulating (8), and radiosensitizing effects (1) (9) (10) and enhancement in chromosomal stability (11).
Ashwagandha is rich in iron (2); small scale human studies suggest that it may promote growth in children and improve hemoglobin level, red blood cell count, sexual performance in adults (2), and may also be useful in treating male infertility (27). An herbal tea containing ashwagandha was shown to increase natural killer cell activity in healthy volunteers with recurrent coughs and colds (22). Data also indicate that ashwagandha may be useful in the treatment of anxiety (23). In another clinical trial, an herbomineral formula containing ashwagandha was shown to benefit osteoarthritis (13). Preliminary data suggest benefits of ashwagandha in improving balance in patients with progressive degenerative cereberral ataxias (24).
Ashwagandha also reduced growth of breast, central nervous system, colon, and lung cancer cells (6) without affecting normal cells (7). Ashwagandha may help prevent chemotherapy-induced neutropenia (12), but it has not been studied in cancer patients.