Cellular mechanisms altered by environmental dosages of anti-inflammatory and antiviral drugs in marine mussels.

In recent years, pharmacologically active compounds (PhACs) have accounted among emerging classes of contaminants. Hence, due to their wide use and the general inefficiency of wastewater treatment plants (WWTPs) against this group of pollutants, PhACs are usually detected in the environment at concentrations in the ng/L-μg/L range, and therefore referred as ‘micropollutants’. Previous studies have focused on the effects of PhACs on non-target organisms.1,2 However, the Covid-19 pandemic has certainly increased the release of PhACs into the environment, especially anti-inflammatory and antiviral drugs. Therefore, this study evaluated the effects of realistic concentrations3,4 of the anti-inflammatory dexamethasone (C0: 0, C1: 4 ng/L, C2; 40 ng/L; C3: 400 ng/L, C4: 2000 ng/L), and of the main metabolite of the antiviral Remdesivir, namely GS-1224 (C0: 0, C1: 4 ng/L, C2: 40 ng/L; C3: 400 ng/L, C4: 2000 ng/L) on marine mussel Mytilus galloprovincialis at different exposure times (T0: 0 days, T3: 3 days, T6: 6 days, T12: 12 days). By assessment of endpoints related to the oxidative stress (CAT, GST, SOD, LPO) and neurotoxicity (AChE), a pro-oxidative effect was observed at the different timepoints for both PhACs tested, with an inhibition of AChE activity prompted by the higher concentrations of dexamethasone. These results highlight the necessity to mitigate the environmental occurrence of these two PhACs even at low concentrations, as well as to carry out further investigations to better elucidate the possible onset of cellular pathways impairment in non-target organisms. Overall, the final purpose of these studies is to provide useful input for improving the efficacy of WWTPs, promoting the use of novel materials able to trap these emerging contaminants