Comparative Study Of Catalase Activity Of Normal And Heavy Metal Stressed Liver Of Labeo Rohita

Abstract

Heavy metal contamination of water cause toxicity and production of ROS (reactive oxygen species) in the fish body which react with the vital biomolecules of the cells resulted in lethal effects and fish mortality. Catalase (CAT) is an oxido-reductase enzyme and important component of antioxidant defense mechanism, inhibit the production of these free radicals. The work is aimed to determine catalase (CAT) enzyme activity in heavy metal (Pb + Cr) exposed liver of Labeo rohita (L.rohita). Significant difference of about 15.3 % was found in specific activity of catalase (CAT) in normal and metal stressed fish liver with values upto 88.00 U mg^-1 and 74.50 U mg^-1, respectively. The enzyme purity of metal stressed and normal liver was found upto 1.00-fold with 100 %age recovery and was 0.99-fold purified with 99 % age recovery, respectively. However, maximum enzyme activity was found at pH 7 and 25^oC up to 119.5 U mL^-1 and 129 U mL^, pH range between 4 to 12. Statistical analysis showed all data significantly different with P<0.01.The main aim of this study was to determine the response of Labeo rohita fish liver catalase (CAT) enzyme to external stress induced by heavy metal stressor i-e chromium and lead in order to explore changes in general pattern of its activity. Catalase plays an important role in the acquisition of tolerance to oxidative stress in the adaptive response of cells and in cells to prevent the drug-induced consumption of O2 either for destroying H₂O₂ to oxygen or for direct interaction with the drug. Therefore, high catalase activity which is good indicator of oxidative stress might lead to the consequences of respective metal deposition in human body and will adversely affect their health.