Abstract
This study evaluated the biomarker responses indicative of exposure to Benzo[a] Pyrene (B[a]P) in Mytilus galloprovincialis and Ruditapes decussatus. A significant increase of the total oxyradical scavenging capacity (TOSC) was observed after seven days of exposure to two concentrations of B[a]P (100 and 300 μg.L−1), in the digestive gland with the lowest concentration tested. The TOSC in the gills increased notably only after the exposure to 300 μg.L−1 of B[a]P. Interestingly, the superoxide dismutase (SOD) and catalase (CAT) activities in gills and digestive gland on one hand and glutathione S-transferase (GST) in gills in the other, were positively correlated with the concentration of B[a]P with a significant induction noticed at the highest concentration. In contrast, a significant increase of the GST activity was observed in the digestive gland following the exposure of bivalves to 100 μg.L−1. In pelagic (M. galloprovincialis) or benthic (R. decussatus) bivalves, the AChE activity decreased discernibly in digestive glands and gills with the increase of B[a]P concentrations as evidence of neurotoxic effects. In clams, the exposure to B[a]P was followed by a significant increase of Malondialdehyde level (MDA) in gills and digestive gland, this does not occur in gills of Mytilus galloprovincialis at the concentration of 100 μg.L−1. Overall, the results found seems to indicate that the mussel was more suitable as a predictor tool of toxicity of B[a]P.
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•B[a]P induces phases I and II enzymes in Mytilus galloprovincialis and Ruditapes decussatus.•An inhibition of AChE activity was observed in R. decussatus (gills and digestive gland).•M. galloprovincialis biomarker responses to B[a]P were mostly higher than those of R. decussatus.