Adaptogenic and Immunomodulatory Activity of Ashwagandha Root Extract: An Experimental Study in an Equine Model

Abstract

Ashwagandha ( Withania somnifera L. Dunal.) is an important “ Rasayana ” of Ayurveda. The roots are extensively used as an adaptogen and for different health issues. Anti-inflammatory, antioxidant, and immune-stimulating effects of Ashwagandha are well-documented. The present study aimed to evaluate the clinical efficacy of Ashwagandha root extract as an adaptogen against various types of stress in horses. A total of 24 Kathiawari horses were selected and randomly divided into four groups. All the horses were provided with normal feed and water ad libitum . Group 1 (G1) was treated as the control group, and the horses were given a normal diet. Group 2 (G2), Group 3 (G3), and Group 4 (G4) horses received varying doses of Ashwagandha root extract along with the normal diet. All the animals were subjected to different types of stress including exercise-induced stress, separation, and noise stress on three different days and evaluated for various hematological, biochemical, hormonal, and immunological parameters. Over the 21 days, a statistically significant ( p < 0.05) increase in total erythrocyte count, total leucocyte count, hemoglobin content, lymphocyte percentage, reduced glutathione, and superoxide dismutase activities was observed. A statistically significant ( p < 0.05) decrease in cortisol, epinephrine, glucose, triglycerides, creatinine, IL-6, alanine aminotransferase, and aspartate aminotransferase was observed in the Ashwagandha treated groups (G2, G3, and G4) when compared to the control group (G1). The results suggest that Ashwagandha root extract has potent hemopoietic, antioxidant, adaptogenic, and immune-stimulant properties.

Effects of Withania somnifera (Ashwagandha) on Stress and the Stress- Related Neuropsychiatric Disorders Anxiety, Depression, and Insomnia

“…Other methods of inducing stress included sleep deprivation [ 45 ], exposing animals to cold [ 40 ], hypoxia [ 46 ], and/or prolonged restraint [ 17 , 38 , 40 , 47 , 48 ], either alone or in combination [ 41 , 42 , 49 , 50 ], or applying electrical shocks to the feet of animals [ 51 - 54 ]. In these studies, WS attenuated a variety of stress-induced changes, including behavioral changes ( e.g ., memory impairment [ 45 , 46 , 52 , 53 , 55 ]), biochemical changes ( e.g ., increased glucocorticoids [ 38 , 39 , 41 , 42 , 46 - 48 , 50 , 54 , 56 ]) and physical changes ( e.g ., gastric ulcers [ 17 , 38 , 40 , 52 ]).…”

“…Most of the extracts studied were derived from the root of WS [ 37 - 39 , 41 , 42 , 46 - 49 , 51 , 53 - 56 ]. Anti-stress effects were also seen for a leaf extract [ 45 ], a leaf and root extract [ 36 ] and an extract made from defatted seeds [ 40 ].…”

“…Cortisol and corticosterone are elevated during periods of stress and play a central role in stress-induced HPA axis dysfunction. As described in Table 2 , various preparations of WS root attenuated the stress-induced increase in peripheral cortisol and corticosterone levels [ 38 , 39 , 41 , 42 , 46 - 48 , 50 , 54 , 56 ]. WS was also found to reverse the stress-induced decrease in adrenal cortisol content [ 38 , 40 ].…”

“…In the reviewed studies, the effect of WS on immune markers depended on the animal model used. In a horse model of exercise-, separation-, and noise-induced stress, white blood cell count and lymphocyte percentage decreased while the pro-inflammatory cytokine IL-6 increased [ 56 ]. A root powder of WS reversed these effects, demonstrating immune-stimulating and anti-inflammatory effects.…”

Critical review of the Withania somnifera (L.) Dunal: ethnobotany, pharmacological efficacy, and commercialization significance in Africa

“…In the Lagos state of Nigeria, people commonly use W. somnifera for amenorrhoea and aphrodisiac purposes (Sharaibi et al 2017 ). Given the vast ethnomedicinal usage, the findings of numerous recent studies in clinical and experimental settings further reveal the efficacy of W. somnifera for the management of several pathological conditions and provide added substantial highlights on its medicinal significance (Priyanka et al 2020 ; Fuladi et al 2021 ).…”