Bioaccumulation, Oxidative Stress, Immune Responses in Channa Argus Exposure to Waterborne Hexavalent Chromium

Abstract Hexavalent chromium (Cr (VI)) is a very common and harmful heavy metal pollutant in the world. However, the responses of Cr (VI) to aquatic environmental toxicants have not been well described. In this study, we evaluated the waterborne Cr (VI) [ 0 mg/L (C1), 0.5 mg/L (C2), 1 mg/L (C3), 2 mg/L (C4)] exposed chronically to Channa argus. After 14 and 28 days, we measured biochemical parameters, Cr (VI) accumulation, antioxidant activity and immune response in the serum, liver and gill, respectively. Our results shown that Cr (VI) accumulation will occur in certain tissues as the time of exposure in water prolongs, and the biochemical parameters in the serum will increase. Antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) gradually decreased with the increasing time of Cr (VI) concentration, while the malondialdehyde concentration increases. In addition, in the immune response, cortisol, aminotransferase (ALT), aspartate aminotransferases (AST), alkaline phosphatase (AKP), immunoglobulin M increase, but lysozyme decrease. These results indicated that exposure to waterborne Cr (VI) can exert adverse effects in C. argus by inducing Cr (VI) accumulation, immune responses and oxidative stress.