Pollution Research Paper

Vol 40, May Suppl. Issue, 2021; Page No.(218-230 )

EFFECT OF HEAVY METALS (LEAD AND CADMIUM) ON THE ACTIVITY OF ANTIOXIDANTS AND METABOLIC ENZYMES IN OREOCHROMIS NILOTICUS: A COMPARATIVE AND SYNERGISTIC STUDY

CINNIE SUSAN ANTONY AND A. P. THOMAS

Abstract

Presence of heavy metals in aquatic environment induces stress in aquatic life. Present study has been taken up to assess the effect of two heavy metals (lead and cadmium), individually and in combination, on a freshwater fish Oreochromis niloticus. The study aimed to evaluate the impact of the heavy metals (sublethal dose) on the activity of two antioxidants, catalase (CAT) and superoxide dismutase (SOD) and two metabolic enzymes, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the liver, gills, muscle and kidney of the fish after one week and three weeks exposure to heavy metals. Differential variations were observed in the activity of antioxidant enzymes (CAT & SOD) as well as the metabolic enzymes (AST & ALT) in the organs when applied individually as well as in mixture (lead + cadmium). It was found that the impact of the metals is more significant when applied in combination rather than individually indicating the synergistic effect. It was noted that more significant changes occurred in the liver, the major metabolic organ of the fish compared to gills, muscle and kidney. The study thus tries to illustrate the potential of the above mentioned antioxidants and metabolic enzymes as biomarkers in toxicological studies.