Antioxidant biomarkers and oxidative damage in lipids and proteins of blood following exposure of arsenic and imidacloprid in wistar rats

Blood cells especially erythrocytes are extremely sensitive to chemical induced oxidative damage. As overloading of the delicate antioxidant machinery inherent in normal RBCs may cause changes in their morphology, function, and affect their lifespan. The present study evaluated the effect of simultaneous exposure of imidacloprid (IMI) and arsenic on levels of antioxidant biomarkers, malondialdehyde (MDA) and advanced oxidation protein product (AOPP) in rat blood. Forty eight male Wistar rats randomly divided into eight groups of six rats each were subjected to various daily oral administrations of IMI and arsenic for 28 days. Group I served as control, group II received IMI, groups III, IV and V received arsenic at the dose rate of 50, 100 and 150 ppb in drinking water respectively, whereas groups VI, VII and VIII received arsenic at 50, 100 and 150 ppb respectively along with IMI. Repeated oral administrations of IMI or As(150 ppb) alone resulted in a significant (P<0.05) elevation in the levels of MDA and AOPP along with a significant (P<0.05) decline in reduced glutathione, total thiols and other antioxidant enzymatic activities indicating lowering of antioxidant defenses of erythrocytes in exposed rats. Concurrent administration of IMI and arsenic not only produced more severe changes in antioxidant biomarker profile but also caused significantly higher elevations in MDA and AOPP levels when compared to exposure to any one chemical alone. Our findings indicate that IMI potentiates arsenic-induced toxicity in erythrocytes of Wistar rats.