European Journal of Biomedical and Pharmaceutical Sciences

STUDY OF POLLUTION INDUCED OXIDATIVE STRESS IN A CAT FISH (MYSTUS TENGARA)

Dr. Reddy P.B.*

ABSTRACT

Antioxidant enzyme systems help to correct the balance of free radicals and reactive oxygen species (ROS) and protect the cell against free radical-induced damage. The intensity of oxidative stress can be measured either by measuring the reactive oxygen species (ROS) directly or measuring the presence of antioxidants or by measuring the resulting damage to proteins, lipids, DNA or RNA. The freshwater cat fish Mystus tengara was collected from upstream (non polluted) and downstream (polluted) zones of Chambal River during winter months at Nagda, M.P. India. Homogenate of liver of fish from both the two sited were comparatively assayed for glutathione-Stransferase (GST), catalase (CAT), glutathione peroxidase (GPx), glucose-6-phosphate dehydrogenase (G6PDH) and superoxide dismutase (SOD). Lipid peroxidation (LPO) was also estimated by means of malondialdehyde measurements (MDA). Simultaneously with the level of reduced glutathione (GSH) and GSH/GSSG ratio were estimated. All systems were significantly (p<0.1) affected at the polluted site. A comparison was made between the water quality parameters and antioxidant biomarker responses. Results clearly shown that a significant increase ((P<0.001) in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase, and glutathione reductase (GR) activities in the liver of fish from polluted site was observed. Similarly, the pollution load induced significant increase in the reduced (GSH) and oxidized (GSSG) glutathione content, along with with a significant decrease in [GSH]/ [GSSG] ratio. On the whole, the results demonstrate that alteration in the antioxidant enzymes, glutathione system and induction of lipid peroxidation reflects the presence of heavy metals which may cause oxidative stress in the Mystus tengara and other aquatic fauna from Chambal River at Nagda. The increased activity of antioxidant enzymes suggest that fish from polluted site were well protected from oxidative stress.

Keywords: Antioxidant enzymes; Biomarkers. Oxidative stress; biomarkers, pollution.