An in vitro biomarker approach for the evaluation of the ecotoxicity of non-steroidal anti-inflammatory drugs (NSAIDs)

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most frequently detected pharmaceuticals in aquatic environments. They are the sixth most sold drugs worldwide and are usually found in significant quantities in municipal effluents. The aim of this study was to assess a first screening evaluation of the cytogenotoxicity of three common NSAIDs (diclofenac, ibuprofen and paracetamol) using an in vitro biomarker approach on the haemocytes of the freshwater bivalve zebra mussel (Dreissena polymorpha). Genotoxicity was evaluated by SCGE (single cell gel electrophoresis) and DNA diffusion assay while cytotoxicity was evaluated by neutral red retention assay (NRRA). The exposure of the haemocytes to increasing concentrations of the three drugs, chosen based on the results of a viability test, revealed high cytogenotoxic potential and allowed the creation of the first toxicity scale for zebra mussel haemocytes (paracetamol < diclofenac < ibuprofen). The present results lay the groundwork for in vivo exposures, which will allow for a better definition of the observed cytogenotoxicity of these molecules in a setting miming real environmental exposure.