Vitamin E-mediated protection on methomyl-induced alterations in rat liver

Abstract

The present study was carried out to observe the possible beneficial effects of Vitamin E, a natural antioxidant on methomyl-induced biochemical and histological alterations in rat liver. To carry out the investigations, animals were segregated in four different groups. Animals in Group I served as normal controls. Animals in Group II were given single methomyl dose orally in water (9 mg kg−1 b.wt). Animals in Group III were injected intraperitoneally with Vitamin E (50 mg kg−1 b.wt) for 1 week on alternate days. Animals in Group IV were administered Vitamin E 1 week before subjecting them to methomyl treatment. Animals in all the groups were sacrificed 24 h after the end of treatments. Different biochemical estimations were carried out, which included estimation of aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), alkaline phosphatase (ALP) and acetylcholinesterase (AChE). Further, to examine the oxidative damage lipid peroxidation (LPO) and glutathione (GSH) levels as well as antioxidant enzymes such as superoxide dismutase (SOD), catalase, glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GSHPx), and glutathione-6-phosphate dehydrogenase were estimated in liver samples. AchE activity was inhibited significantly both in serum and liver following methomyl treatment. Administration of methomyl caused a significant increase in serum AST, ALT and ALP which indicated hepatic damage. LPO was found to be significantly increased, whereas GSH levels were decreased in the liver of methomyl-treated animals. The activities of SOD and catalase were significantly decreased whereas GST and GSHPx activities were found to be elevated significantly following methomyl treatment. No significant change in the enzyme activity of GR and glutathione-6-phosphatase dehydrogenase was observed after methomyl treatment. Vitamin E supplementation was able to attenuate appreciably the methomyl-induced changes in LPO levels along with SOD and GST activities. Histopathological studies following methomyl treatment revealed that hepatocytes, were not very well delineated and nuclei showed degenerative changes. Whereas, following Vitamin E supplementation in combined treatment group nuclei showing degenerative changes become less in number. The study, therefore, concludes that Vitamin E has a potential in mitigating most of the adverse effects induced by methomyl acute toxicity.