Toxic effects of the antihistamine cetirizine in mussel Mytilus galloprovincialis

Recent studies have become increasingly focused on the assessment of pharmaceuticals occurrence in aquatic ecosystems, however the potential toxicity to non-target organisms is still largely unknown. The antihistamine cetirizine is a commonly used pharmaceutical, already detected in surface waters of marine aquatic systems worldwide. In the present study Mytilus galloprovincialis mussels were exposed to a range of cetirizine concentrations (0.3, 3.0, 6.0 and 12.0 μg/L), resembling moderate to highly contaminated areas, over 28 days. The responses of different biochemical markers were evaluated in mussels whole soft tissue, and included energy-related parameters (glycogen content, GLY; protein content, PROT; electron transport system activity, ETS), and oxidative stress markers (superoxide dismutase activity, SOD; catalase activity, CAT; glutathione S-transferases activity, GSTs; lipid peroxidation levels, LPO; reduced (GSH) and oxidized (GSSG) glutathione content). The results obtained demonstrated that with the increase of exposure concentrations mussels tended to increase their energy reserves and maintain their metabolic potential, which was significantly higher only at the highest concentration. Our findings clearly revealed that cetirizine inhibited the activity of GSTs and although induced the activity of antioxidant enzymes (SOD and CAT) mussels were not able to prevent cellular damages observed through the increase of LPO associated to the increase of exposure concentrations. Thus, this study confirmed that cetirizine induces toxic effects in Mytilus galloprovincialis, which, considering their trophic relevance, wide use as bioindicator and wide spatial distribution of this species, can result in ecological and economic negative impacts at a large scale.