Exploring the functional effects of the ACE inhibitor Enalapril and its metabolite Enalaprilat on Mytilus galloprovincialis

Pharmaceuticals in water environments are posing a risk to the whole ecosystem, challenging animal limits for adaptation. The antihypertensive Enalapril (EN) and its metabolite Enalaprilat (ENT) are found in wastewater and urban effluents. However, data on their effects on the health of aquatic animals are limited. This study analyzed the effect of EN or ENT on functional parameters of Mytilus galloprovincialis, a sentinel of water pollution. Mussels were exposed for 10 days to 2 concentrations of EN [0.6 ng/L (E1); 600 ng/L (E2)], or ENT [7ng/L (ET1); 7μg/L (ET2)] to analyse: cell viability [digestive gland (DG) and hemocytes], cell volume regulation (DG cells), and oxidative stress markers (DG and gills). At the highest concentrations, both drugs compromised DG cell volume regulation, but did not affect DG cells and hemocytes viability. In the DG, EN unaffected oxidative status, while ENT increased catalase activity. In the gills, EN reduced superoxide dismutase activity in E1 group, and modulated lipid peroxidation and protein carbonylation, while ENT increased catalase activity and affected lipid peroxidation. A modulation of HSPs expression was also observed. Our results showed that, in M. galloprovincialis, EN and ENT elicited a tissue-specific modulation of oxidative status and compromised DG cells ability to face osmotic changes, with potential consequences on animal performance.