Effects of cadmium and benzo[a]pyrene on phase I and phase II detoxification on the polychaete Nereis diversicolor

The acute effects of cadmium and benzo[a]pyrene, individually and as a mixture, were evaluated on the phase I and phase II biotransformation enzymes of Nereis diversicolor (Polychaeta) collected from unpolluted sites. In the acute assay (1 μM) after 12, 24, 36 and 48 h, the comparison between worms exposed to cadmium and their controls showed an inhibited activity of NADPH cytochrome C reductase after 12, 24 and 36 h. For the activity of glutathione-S-transferase (GST), however, inhibition in the presence of Cd was only noted after 36 h of exposure. Although exposure to benzo[a] pyrene resulted in a significant increase in NADPH cytochrome C reductase activity after 12, 24 and 36 h, a significant difference in glutathione-S-transferase (GST) activity between treated and control animals was only observed after 36 h. The mixture (Cd/B[a]P) seemed to inhibit the activity of NADPH cytochrome C reductase and to induce the activity of GST in individuals but only up until 36 h of exposure. These findings illustrate the interactions between pollutants and their effects on organisms.