Anti-nociceptive and anti-inflammatory effects of Withania somnifera root in fructose fed male rats.

Abstract

Insulin resistance is a metabolic disorder which affects the diabetes mellitus pathophysiology and alters the cell excitability. This study has been designed to evaluate the anti-nociceptive and anti-inflammatory effects of chronic administration of Withania somnifera root (WSR) in fructose drinking water rats. An experiment was carried out on 48 Wistar-Albino male rats, weighting 200±30 g, which were divided into six groups (n=8): control group (C), control morphine (CM), W. somnifera group (WS) which received WSR (62.5 mg/g diet), W. somnifera naloxone group (WSN) which received WSR and naloxone, fructose (F) group which received fructose drinking water and FWS group which received fructose-enriched drinking water and WSR during the trial period. A biphasic pain response was induced after intraplantar injection of formalin (50 μL, 1%). Pain behavior was measured using Dubuisson methods. The obtained data were analyzed by SPSS software V. 18, using ANOVA and Tukey test. Results were expressed as mean±SD. Statistical differences were considered significant at p<0.05. The results showed that the insulin resistance index, blood sugar, insulin, IL-6, TNF-α, and acute and chronic pain score in the F group were significantly increased in comparison with the control group, but these parameters in the FWS group were significantly decreased compared with the F group (p<0.001). Our findings indicated that chronic oral administration of WSR has analgesic and anti-inflammatory effects in fructose drinking water rats and causes improved insulin resistance index.