Comparative evaluation of oral and dermal cypermethrin exposure on antioxidant profile in Bubalus bubalis

Cypermethrin, a type II synthetic pyrethroid insecticide, @ 0.5 mg/kg/day for 14 consecutive weeks produced mild signs of toxicity in buffalo calves. Significant changes were observed in various antioxidant parameters in blood. There was a marked increase in the extent of lipid peroxidation (33.9%) and enzymic activity of glutathione peroxidase (6.7%), superoxide dismutase (35.0%), catalase (43.7%), glutathione-S-transferase (64.4%), glutathione reductase (36.7%) and glucose-6-phosphate dehydrogenase (32.1%). A significant decrease in blood glutathione (16.7%), total antioxidant activity (45.4%) and vitamin E (40.8%) was observed and no significant effect was found on blood selenium levels. However, the extent of lipid peroxidation (42%) and the depletion of glutathione (28.8%) was greater after dermal sub-acute toxicity of cypermethrin (0.25%) for 14 consecutive days. Similarly, it was observed that the incline in the enzymic activity of glutathione peroxidase (29.7%), superoxide dismutase (38.3%) and glutathione reductase (38.3%) was higher in dermally cypermethrin exposed animals. Thus, the present investigation contemplates that oxidative stress is the important mechanisms involved in cypermethrin-induced toxicity and the oxidative insult produced by dermal route is more severe as compared to oral intoxication.