Toxicolgical impact of chlorpyrifos and ameliorative potentials of vitamin e on nuclear abnormalities in erythrocytes of <i>Heteroclarias</i>

Abstract

Chlorpyrifos is commonly used as an agricultural insecticide which is extremely toxic to non-target organisms like fish. The effect of chlorpyrifos and ameliorative potentials of vitamin E on nuclear abnormalities in the erythrocytes of Heteroclarias was investigated. Juveniles Heteroclarias were exposed to varying concentrations (0, 1, 2, 3, 4 and 5 ppm) of chlorpyrifos for 96 hours and fed on varying concentrations (50, 250, 500 and 1000 mg/kg diet) of vitamin E for 28 days. The LC50 value was calculated as 2.4 ppm. After the exposure period, the fish were sacrificed and blood was collected for micronucleus assay. Different abnormalities such as micronucleated, binucleated, multinucleated and altered cells were evident in the erythrocytes of chlorpyrifos-exposed fish compared to control. The micronucleus induction and percentage frequency increased (P<0.05) as the concentration of chlorpyrifos increased, but, decreased (P<0.05) in the groups ameliorated with vitamin E. However, a gradual decrease occurred as the concentration of vitamin E inclusion in the diet increased with a great reduction (P<0.05) in the group fed on 500 mg vitamin E/kg diet. This study revealed that chlorpyrifos induced micronucleus formation, but, 500mg vitamin E/kg diet is capable of minimizing micronucleus formation in Heteroclarias.

Keywords: Amelioration, Chlorpyrifos, Heteroclarias, Micronucleus, vitamin E