Evaluation of the Anxiolytic and Antidepressant Effects of Standardized Ashwagandha (Withania somnifera) Root Extract in Wistar Rats

Ashwagandha (Withania somnifera) is a popular herb in Ayurveda, the traditional medicine system in India. It is known to exert stress-mitigating properties and has been extensively studied for its safety and efficacy in various disorders. This in vivo study assessed the effects of Ashwagandha root extract (ARE) on stress in rats. The anxiolytic and antidepressant effects of ARE were assessed using the elevated plus maze test, sucrose preference test, and forced swim test. The rats were divided into the following groups: control group (no disease), disease control group (no treatment), standardized ARE group (test; ARE administered in doses of 27, 54, and 108 mg/kg body weight), and fluoxetine group (active control). Biochemical parameters in the serum [monoamine oxidase (MAO)-A, MAO-B, serotonin, cortisol, adrenocorticotropic hormone (ACTH), corticotropin-releasing hormone (CRH), interleukin (IL)-6, tumor necrosis factor (TNF)-α, and brain-derived neurotrophic factor (BDNF)] and brain tissue (serotonin) were estimated at the end of 36 days to understand the potential mechanism behind the anxiolytic and antidepressant effects of ARE. The behavior test results indicated significant improvement in anxiety and depression-like behavior with ARE treatment in a rat model exposed to a validated protocol of chronic variable stress. The results of biochemical analyses revealed a significant increase in serotonin and BDNF levels and a decrease in CRH, ACTH, and cortisol levels. The inflammatory markers IL-6 and TNF-α were also significantly reduced with ARE treatment. ARE demonstrated notable effects on anxiety and depression markers in rats, indicating its potential as a prophylactic and therapeutic agent.