Environmentally relevant concentrations of glibenclamide induce oxidative stress in common carp (Cyprinus carpio)

The hypoglycemic pharmaceutical glibenclamide (GLB) is widely used around the world. This medication is released into the environment by municipal, hospital and industrial wastewater discharges. Although there are reports of its environmental occurrence in the scientific literature, toxicity studies on aquatic species of commercial interest such as the common carp Cyprinus carpio are scarce. The present study aimed to evaluate the oxidative stress induced on C. carpio by environmentally relevant concentrations of GLB. Biomarkers of oxidative damage such as hydroperoxide content, lipid peroxidation and protein carbonyl content were evaluated as well as the activity of the antioxidant enzymes superoxide dismutase and catalase. The concentration of GLB was determined in water as well as in gill, liver, muscle, brain and blood of carp at 12, 24, 48, 72 and 96 h. The findings obtained in the study prove that GLB induces increases in biomarkers of oxidative damage and antioxidant enzyme activity in the teleost C. carpio, that this response is not concentration dependent and that the organs evaluated bioconcentrate this hypoglycemic agent. These findings permit us to conclude that the presence of GLB in water bodies represents a risk for aquatic species.