Resumen:
Thirty million people worldwide consume each day nonsteroidal anti-inflammatory drugs (NSAIDs), a heterogeneous group of pharmaceuticals used for its analgesic, antipyretic, and anti- inflammatory properties. Recent studies report high NSAID concentrations in wastewater treat- ment plant effluents, in surface, ground, and drinking water, and in sediments. NSAIDs are also known to induce toxicity on aquatic organisms. However, toxicity in natural ecosystems is not usu- ally the result of exposure to a single substance but to a mixture of toxic agents, yet only a few studies have evaluated the toxicity of mixtures. The aim of this study was to evaluate the toxicity induced by diclofenac (DCF), ibuprofen (IBP), and their mixture on a species of commercial inter- est, the common carp Cyprinus carpio. The median lethal concentration of IBP and DCF was determined, and oxidative stress was evaluated using the following biomarkers: lipid peroxidation and activity of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxi- dase. Cyto-genotoxicity was evaluated by micronucleus test, comet assay, and the specific activity of caspase-3. Results show that DCF, IBP, and a mixture of these pharmaceuticals induced free radical production, oxidative stress and cyto-genotoxicity in tissues of C. carpio. However, a greater effect was elicited by the mixture than by either pharmaceutical alone in some biomarkers evaluated, particularly in gill.