Calcium carbonate supplementation causes preventive approach to toxic effects of mercuric chloride on metabolic regulation in liver of C. punctata

Abstract

Mercury (Hg) shows the toxic effects in the environment although the etiology is not well characterized and the prevention of toxic effects induced by Hg is an important aspect of metabolic regulation in organisms. Channa punctata, a variety of species of fish was used in this study and the role of calcium carbonate on cholesterol, triglyceride and protein level in liver induced by HgCl2 was adopted. Fish were exposed to 1 and 10 µM of HgCl2 for 1h and cholesterol and triglyceride levels in excised liver were enhanced in response to HgCl2 when compared to respective controls however the effects were more pronounced for 1 µM concentration. Similar stimulatory effects on protein contents were demonstrated whenever they were exposed to HgCl2 (1 and 10 µM) and higher proteins were recorded for 10 µM concentration. The results indicate that HgCl2 causes severe toxic effects enhancing the above parameters. To clarify the role of CaCO3 on prevention of these effects, fish were treated with different concentrations (100 µM and 1 mM) of CaCO3 and CaCO3 + HgCl2. Cholesterol and triglyceride in liver were effectively reduced with CaCO3 (1 mM) + HgCl2 (10 µM) and CaCO3 (100 µM) + HgCl2 (1 µM) while 100 µM of CaCO3 potentially reduced the effects of HgCl2. Although CaCO3 was shown to reduce protein content effectively, however 100 µM concentrations have been found to inhibit the effects of HgCl2 preferentially. Our findings suggest that calcium carbonate might be involved in prevention of the toxic effects of Hg and may contribute to the survival process of this species.