Evaluation of the Effect of Pollution on the Level of Antioxidant Enzymes in Freshwater Fishes

Abstract

To assess the impact of polluted water on fishes, biochemical studies were carried out to determine the biochemical alterations in tissues of fishes collected from the control and upstream, midstream and downstream sites of the Varahanadhi river in Tamil Nadu, India. Two fish species such as Catla (Catla catla) and Mrigal (Cirrhinus mrigala) were taken and the tissues such as liver and kidney were excised and tissue homogenate was prepared. Using the tissue homogenate lipid peroxide and lipid hydroperoxide, CAT and SOD activity, GPx activity, GR and GST activities and non-enzymatic antioxidants such as vitamin C and vitamin E was estimated. An increase in lipid peroxide and lipid hydroperoxide level was observed in all the organs of fishes collected from the downstream site when compared with the control, upstream and midstream site of the river. A decrease in CAT and SOD activity and in non-enzymatic antioxidants such as vitamin C and vitamin E, increased Glutathione reductase and GST activities was observed in the fishes collected from the downstream site. These changes might be due to the exposure of fish to pollutants, industrial waste and heavy metals present in water sample causing adverse effects on fishes inhabiting the river.