Abstract

IMPACT OF HEPTACHLOR ON ANTIOXIDANT ENZYME MARKERS OF FISH CATLA CATLA

D. Vineela, S. Janardana Reddy* and B. Kiran Kumar

Abstract

Heptachlor is an Organochlorine insecticide used world wide in Agriculture and Aquaculture due to its activity against a broad spectrum of Insect pests. Acute toxicity of an organochlorine insecticide is characterized by their persistence and ability to accumulate in aquatic organisms. Our present study is aimed to elucidate the effect of heptachlor and antioxidant system of carp fish Catla catla. 1/5th sub lethal concentration of heptachlor is 1.46mg/L (LC50 7.86 mg/L for 96hrs) was used for the toxicity experiment. ROS are highly reactive molecules and can damage cell structures such as carbohydrates, nucleic acids, lipids, and proteins and alter their functions. The shift in the balance between oxidants and antioxidants in favour of oxidants is termed “oxidative stress”. Heptachlor is also induced a gradual and significant (P < 0.05) increase in Lipid Peroxidation and antioxidant enzymes like SOD, GST and CAT activities is gradually increased throughout the study period. The modified activities of antioxidant enzymes imply the activation of physiological mechanism to scavenge the reactive oxygen species produced by the toxicant exposure. The antioxidant enzymes like Superoxide dismutase, Glutathione-S-transferase and Catalase can be used as biomarkers for non specific immune responses caused by acute exposure of pesticides or other similar aquatic pollutants. The present study explained that even at sub lethal concentration level of heptachlor is harmful to Catla catla like aquatic culture organisms and applications of heptachlor close to bodies of water lead to havoc to aquatic life, then to the humans.

Keywords: Catla catla, Heptachlor, Antioxidant Enzymes, Superoxide dismutase (SOD), Catalase (CAT), Glutathione -S - Transferase (GST) and Lipid Peroxidation (LPO).