Assessment of endosulfan induced genotoxicity and mutagenicity manifested by oxidative stress pathways in freshwater cyprinid fish crucian carp (Carassius carassius L.).

ABSTRACT

Over the past few decades, endosulfan, one of the polychlorinated pesticides still in use, has received considerable attention of a number of international regulations and restriction action plans worldwide. This study aimed to evaluate the cytogenetic effects of endosulfan using robust genotoxicity assays, along with the oxidative stress pathways in order to understand biochemical mechanism, in Carassius carassius L. The LC50-96 h (95% confidence limits) value of endosulfan was 0.070 (0.046-0.093) ppm; and on its basis three test concentrations (sub-lethal I 0.052, II 0.035 and III 0.017 ppm) were selected for 35 d in vivo exposure. The mean concentration of endosulfan in aquaria was always constant, when analyzed by dispersive liquid-liquid micro extraction (DLLME) followed by GC-MS. Autopsy was done on days 1, 2, 3, 4, 7, 14, 21, 28 and 35 of endosulfan exposure; the micronucleus formation (MN), authenticated by scanning electron microscopy, and chromosomal aberrations (CA), were induced significantly (p<0.05) in all the treated groups, including positive control cyclophosphamide (4 ppm), when compared to negative control. Similarly lipid peroxidation (LPO) was induced significantly with the maximal at higher concentration (SL-I) on 4th day (722.45%; p<0.01). Antioxidant biomarkers like glutathione reduced, superoxide dismutase and catalase also fluctuated significantly (p<0.01) in all treatment groups. Collective findings demonstrated that genotoxic effects were invariably accompanied and correlated with increased oxidative stress and disturbance of antioxidant enzymes; and the MN and CA assays are useful tools in determining potential genotoxicity of aquatic xenobiotics and might be appropriate as a part of monitoring program.