Effect of Polychlorinated Biphenyls on Biochemical Parameters of the Black Sea Bivalve Mollusk Mytilus galloprovincialis Lam.

Polychlorinated biphenyls (PCBs) are known amongst the most dangerous toxicants entering the coastal marine waters from various polluting sources. Even the smallest PCBs doses are capable to change physiological and biochemical processes exerting toxic, mutagenic and carcinogenic effects. So, the aim of this study was to analyze the impact of PCBs at 1, 100, 1000 & mu;g/L on oxidative stress parameters (level of oxidized proteins (neutral aldehydes and ketones, basic aldehydes and ketones) and lipid peroxidation), antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT)) and cholinesterase (ChE) activity in the hepatopancreas of mussel Mytilus galloprovincialis during 5 days' of the toxicological experiment. Level of all forms of the oxidized proteins was found significantly increased at 100 & mu;g/L and 1000 & mu;g/L (+50-78% and +150-282%, respectively) compared to the control (p<0.05). Level of lipid peroxidation was considerably higher at 1, 100, 1000 & mu;g/L (+59%, +134%, +269%, respectively) compared to the control (p<0.05). SOD activity significantly raised at 1, 100, 1000 & mu;g/L (+63%, +200%, +118%, respectively) compared to the control (p<0.05), while CAT activity reduced at 1000 & mu;g/L compared to the control, 1 & mu;g/L and 100 & mu;g/L (-29%, -66%, -40%, respectively) (p<0.05). ChE activity was found lower at 1, 100, 1000 & mu;g/L (-60%, -93%, -30%, respectively) compared to the control (p<0.05). Possible mechanisms of M. galloprovincialis biochemical response to PCBs are discussed. Studied biochemical parameters can be suitable biomarkers for evaluating the toxicity of PCBs and M. galloprovincialis can be used as a bioindicator in the monitoring of marine ecosystems contaminated with these pollutants.