Effect of λ-Cyhalothrin on Redox Homeostasis and Neuropharmacological Activities in Wistar Rats

Abstract

The present study was carried out to assess the behavioral, neurobiochemical changes following λ-cyhalothrin exposure and to evaluate the neuropharmacological activity in in Wistar rats using well defined animal models. Neurobehavioral assessment was carried as per modified Irwin test. To determine the oxidative profile of brain tissue, rats were randomly divided into two groups consisting of six rats each. Group I served as vehicle-treated control and Group II received λ-cyhalothrin at 7.8 mg/kg (per os) for a period of 7 days. The neuropharmacological studies were carried out in rats following administration of λ-cyhalothrin at a dose rate (per os) of either 1/5th or 1/10th LD50. Neurobehavioral assessment showed prominent autonomic sign(s) followed by depression following single administration of λ-cyhalothrin (1/10th LD50). Short-term exposure to λ-cyhalothrin-induced lipid peroxidation as evident by significant increase in malondialdehyde levels in the brain tissue. Marked alteration of antioxidant defense mechanism(s) in the brain tissue was observed by the reduced activity of superoxide dismutase and catalase. Further, the tissue glutathione (GSH) (reduced; GSH) content was also significantly (P < 0.05) depleted. λ-cyhalothrin exerted a significant reduction in spontaneous motor activity as well as forced motor activity in dose-dependent manner, thus demonstrated reduced activity of central nervous system. Interestingly, λ-cyhalothrin exerted nociceptive action, which was comparable to control group. Further, there was marked increase in the duration of strychnineinduced (2 mg/kg; i.p.) tonic-clonic convulsions in rats. Overall, short-term exposure to sub lethal dose of λ-cyhalothrin causes disturbances in brain redox homeostasis and alters neuropharmacological activity in Wistar rats.