Subcellular tissue-specific responses of Mytilus galloprovincialis to fluoroquinolone antibiotics

The study aimed to investigate the in vitro effects of the fluoroquinolone antibiotics (FQs) Ciprofloxacin (CIP), Enrofloxacin (ENR) and Danofloxacin (DAN) on the mussel Mytilus galloprovincialis exposed to environmentally relevant concentrations. In vitro exposure was performed on subcellular fractions of the digestive gland and gills through a multi-biomarker approach, which included the assessment of cellular damage, antioxidant and biotransformation enzyme activities, neurotoxicity, and DNA single-strand breaks (DNAssb). Results showed a decrease in protein carbonyl content in the gills when exposed to all concentrations of ENR. A significant overall decrease in the enzymatic activity of antioxidant defences was observed in the digestive gland exposed to the highest concentration of DAN and CIP, with a similar trend observed in the gills. Neurotoxicity was observed in the digestive gland at all tested concentrations of all FQs, but no effects were detected in the gills. DNAssb was evident in both tissues at all higher FQ concentrations.