RESUMO
BACKGROUND: Ashwagandha (Withania somnifera (L.) Dunal) is a herb traditionally used to reduce stress and enhance wellbeing. The aim of this study was to investigate its anxiolytic effects on adults with self-reported high stress and to examine potential mechanisms associated with its therapeutic effects. METHODS: In this 60-day, randomized, double-blind, placebo-controlled study the stress-relieving and pharmacological activity of an ashwagandha extract was investigated in stressed, healthy adults. Sixty adults were randomly allocated to take either a placebo or 240âmg of a standardized ashwagandha extract (Shoden) once daily. Outcomes were measured using the Hamilton Anxiety Rating Scale (HAM-A), Depression, Anxiety, and Stress Scale -21 (DASS-21), and hormonal changes in cortisol, dehydroepiandrosterone-sulphate (DHEA-S), and testosterone. RESULTS: All participants completed the trial with no adverse events reported. In comparison with the placebo, ashwagandha supplementation was associated with a statistically significant reduction in the HAM-A (Pâ=â.040) and a near-significant reduction in the DASS-21 (Pâ=â.096). Ashwagandha intake was also associated with greater reductions in morning cortisol (Pâ<â.001), and DHEA-S (Pâ=â.004) compared with the placebo. Testosterone levels increased in males (Pâ=â.038) but not females (Pâ=â.989) over time, although this change was not statistically significant compared with the placebo (Pâ=â.158). CONCLUSIONS: These findings suggest that ashwagandha's stress-relieving effects may occur via its moderating effect on the hypothalamus-pituitary-adrenal axis. However, further investigation utilizing larger sample sizes, diverse clinical and cultural populations, and varying treatment dosages are needed to substantiate these findings. TRIAL REGISTRATION: Clinical Trials Registry-India (CTRI registration number: CTRI/2017/08/009449; date of registration 22/08/2017).