The Bioscan, 3(2): 129-133, 2008
An International Quarterly Journal of Life Sciences
web site: www.thebioscan.in 
AMELIORATIVE EFFECT OF MELATONIN ON INORGANIC MERCURY 
INDUCED OXIDATIVE STRESS IN THE TESTIS OF RATS
BINDU GANGADHARAN AND MANDAVA V. RAO* 
Reproductive Physiology and Toxicology Unit, Department of Zoology,
School of Sciences, Gujarat University, Ahmedabad - 380 009
E-mail: zooldept@satyam.net.in


KEY WORDS
Mercuric chloride 
Melatonin 
Reactive Oxygen Species
Testis
Steroidogenesis
Rat
Received on: 05.09.2007 Accepted on: 18.01.2008 *Corresponding Author

ABSTRACT

This study was undertaken to investigate the amelioration action of melatonin (MLT) against mercury induced oxidative stress in the testis of rats. Male rats were given mercuric chloride (MC, 2 and 4mg/ kg body wt., po) and mercuric chloride (4mg/ kg body wt, po) + melatonin (5mg/ kg body wt, ip) daily for 60 days. Controls were treated with distilled water only followed by the melatonin alone treated group. On day 61, rats were weighed and killed using anesthetic ether. The testis was dissected out carefully, cleared from adhering tissues and used for various biochemical estimations. The activities of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase and glutathione reductase and steroidogenic enzymes such as 3ß and 17ß hydroxy steroid dehydrogenases (HSDs) were decreased while the levels of lipid peroxidation, H2O2 generation, cholesterol and mercury levels were found to be increased in a dose dependent manner in mercury treated rats as compared to the control groups. Co-treatment with MLT reversed the effect of mercury induced oxidative stress and impaired steroidogenesis in the testis of rats. Thus, the results of this study strongly suggest that graded doses of mercuric chloride elicit depletion of antioxidant defence system and steroidogenesis in the testis. Co-treatment with MLT has a protective effect against the mercury induced toxicity.