Rajdeep Kaur

In vivo changes in antioxidant system and protective role of selenium in chlorpyrifos-induced subchronic toxicity in bubalus bubalis

Chlorpyrifos, an organophosphate, is one of the widely used insecticides for control of pests in various agricultural and animal husbandry operations. The objective of the present investigation was to assess the effect of subchronic exposure of chlorpyrifos on the antioxidant status of buffalo calves and to perceive the role of selenium in cases of chlorpyrifos toxicity. Chlorpyrifos at a dose rate of 0.05mg/kg per day for 20 consecutive weeks, significantly elevated the enzymic activity of glutathione peroxidase (GPx) (54.8%), glutathione reductase (GR) (79.4%), glutathione-S-transferase (GST) (34.2%), glucose-6-phosphate dehydrogenase (G6PD) (33.2%), superoxide dismutase (SOD) (19.3%) and catalase (CAT) (63.8%). The altered antioxidant status was well evident from the depleting glutathione levels and a two-fold rise in the extent of lipid peroxidation. Supplementation of selenium in the form of sodium selenite @ 0.05mg/kg per day for 20 weeks in chlorpyrifos intoxicated calves had a marked beneficial effect on the overall antioxidant potential of the animals as evident by no significant alteration in the extent of lipid peroxidation, levels of blood glutathione and activities of various antioxidant enzymes viz. GST, GR, SOD, CAT and G6PD. There was only a significant increase in the activity of GPx to the tune of 27.4%. Therefore, on the basis of the present investigation it can be suggested that oxidative stress is one of the main mechanism involved in chlorpyrifos toxicity and supplementation with sodium selenite in such cases can have significant beneficial and therapeutic effects.

Evaluation of lipid peroxidation and antioxidant status on fenvalerate, nitrate and their co-exposure in Bubalus bubalis

The toxic effects of pesticides and minerals have been explored in different species, but still there is paucity of information regarding their combined toxicological effects. The present investigation reports oxidative stress induced by oral subacute exposure to fenvalerate (1 mg/kg) and sodium nitrate (20 mg/kg) alone, as well as in combination daily for 21 days in buffalo calves. Fenvalerate exposure produced significant elevation in lipid peroxidation (LPO), glutathione peroxidase (GPx), while it produced significant decline in blood glutathione (GSH) levels, superoxide dismutase (SOD) and catalase (CAT). No significant alteration was evidenced in nitric oxide (NOx) levels. Oral exposure to sodium nitrate produced significant inclination in LPO and NOx, while on the other hand significant depreciation in SOD and CAT with no significant change in GPx activity. Combined exposure to fenvalerate and sodium nitrate produced severe effects with an appreciably more prominent elevation in extent of LPO and decline in blood GSH levels.

Hematobiochemical evaluation of dermal subacute cypermethrin toxicity in buffalo calves.

Dermal exposure of cypermethrin, a type II synthetic pyrethroid insecticide, at dose rate of 0.25% for 14 consecutive days produced mild signs of toxicity in buffalo calves. It produced significant elevation in the levels of alanine aminotransferase (ALT; 39.5%), aspartate aminotransferase (AST; 32.0%), blood urea nitrogen (BUN; 57.7%), and plasma creatinine (30.0%). Cypermethrin also produced significant decrease in the hemoglobin (Hb) concentration (5.4%), packed cell volume (PCV; 3.4%), and total erythrocytic count (4.0%). Additionally, there was a significant increase in erythrocytic sedimentation rate (ESR; 3.1%). On the basis of the present study, it can be concluded that cypermethrin induces significant biochemical and hematological alterations in buffalo calves when exposed dermally.

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

Cypermethrin, a type II synthetic pyrethroid insecticide, @ 0.5mg/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.