Ecotoxicological evaluation of veterinary pesticides in marine environments: Oxidative stress and neurotoxicity of Dinotefuran and Pyriproxyfen in Mytilus galloprovincialis

This study evaluates the ecotoxicological impact of the neonicotinoid Dinotefuran and the insect growth regulator Pyriproxyfen on the marine mussel Mytilus galloprovincialis. Adult specimens were exposed for 14 days to nominal concentrations of each pesticide (0.1 mu g/L and 0.05 mu g/L) and their mixture. While individual exposures triggered compensatory antioxidant responses (SOD and GPx), the mixture caused a collapse of these defenses, leading to severe lipid peroxidation (MDA) and protein carbonylation (PC) in the gills and digestive gland. Additionally, significant inhibition of acetylcholinesterase (AChE) activity indicated acute neurotoxicity. Multivariate analyses (PCA and HCA) confirmed a unique toxicological signature for the combined treatment. Although lack of bioaccumulation data and formal mixture modeling precludes definitive claims of synergy, the results clearly demonstrate enhanced combined toxicity. This highlights the critical need to include pesticide mixture assessments in marine environmental risk management.