Protective effect of ashwagandha (Withania somnifera) against neurotoxicity induced by aluminum chloride in rats

Objective: To evaluate the neuroprotective effect of ashwagandha extract against aluminum chloride-induced neurotoxicity in rats. Methods: Rats were divided into control, aluminumintoxicated rats treated daily with aluminum trichloride(Al Cl3)(100 mg/kg, orally) for 30 d and aluminum-intoxicated animals protected by receiving daily ashwagandha extract(200 mg/kg, orally) one hour before Al Cl3 administration for 30 d. Levels of lipid peroxidation, nitric oxide, reduced glutathione and tumor necrosis factor-α were measured in the cortex, hippocampus and striatum. In addition, the activities of Na+, K+, ATPase and acetylcholinesterase were determined in the three studied brain regions. Results: Aluminum increased the levels of lipid peroxidation and nitric oxide in the cortex, hippocampus and striatum and decreased the reduced glutathione level in the hippocampus and striatum. In rats protected with ashwagandha extract, non significant changes were observed in lipid peroxidation, nitric oxide and reduced glutathione. In addition, ashwagandha extracts prevented the increased activity of acetylcholinesterase and Na+, K+, ATPase induced by Al Cl3 in the cortex, hippocampus and striatum. The present findings also showed that the significant increase in tumor necrosis factor-α induced by Al Cl3 in the cortex and hippocampus was prevented by ashwagandha extract. Conclusions: The present results suggest that ashwagandha extract possesses antioxidant and anti-inflammatory effects against aluminum neurotoxicity. In addition, ashwagandha extract could prevent the decline in cholinergic activity by maintaining normal acetylcholinesterase activity. The later effect could recommend the use of ashwagandha as a memory enhancer.