Genotoxicity of two heavy metal compounds: Lead nitrate and cobalt chloride in Polychaete Perinereis cultrifera

Abstract

The present study explores the in vivo and in vitro genotoxic effects of lead nitrate, [Pb(NO3)2] a recognized environmental pollutant and cobalt chloride (CoCl2), an emerging environmental pollutant in polychaete Perinereis cultrifera using comet assay. Despite widespread occurrence and extensive industrial applications, no previous published reports on genotoxicity of these compounds are available in polychaete as detected by comet assay. Polychaetes were exposed in vivo to Pb(NO3)2 (0, 100, 500, and 1000 mu g/l) and CoCl2 (0, 100, 300, and 500 mu g/l) for 5 days. At 100 mu g/l Pb(NO3)2 concentration, tail DNA (TDNA) values in coelomocytes were increase by 1.16, 1.43, and 1.55-fold after day 1, day 3, and day 5, whereas, OTM showed 1.12, 2.33, and 2.10-fold increase in in vivo. Pb(NO3)2 showed a concentration and time-dependent genotoxicity whereas CoCl2 showed a concentration-dependent genotoxicity in in vivo. A concentration-dependent increase in DNA damage was observed in in vitro studies for Pb(NO3)2 and CoCl2. DNA damage at 500 mu g/L showed almost threefold increase in TDNA and approximately fourfold increase in OTM as compared to control in in vitro. Our studies suggest that Pb(NO3)2 and CoCl2 have potential to cause genotoxic damage, with Pb(NO3)2 being more genotoxic in polychaete and should be used more carefully in industrial and other activities.