099 | Mechanistic insights into the ecotoxicity of bisphenol analogues and their mixtures in marine mussels: oxidative stress and neuro-immune responses

Antonella Iaconis¹, Marika Cordaro², Davide Di Paola¹ | ¹Department of Chemical, Biological, Pharmaceutical, and Environmental Sciences, University of Messina, Italy; ²Department of Biomedical, Dental and Morphological and Functional Imaging, University of Messina,, Italy.

Bisphenol analogues such as bisphenol F (BPF) and bisphenol S (BPS) are increasingly used as substitutes for bisphenol A and are now widely detected in marine environments, yet their ecotoxicological effects at environmentally realistic concentrations, particularly when occurring as mixtures, remain insufficiently characterized. This contribution presents an organ-specific assessment of the biochemical, neurotoxic and immunological responses induced by BPF and BPS, administered individually and in combination (35 ng L⁻¹ each), in the marine mussel Mytilus galloprovincialis. After a 14-day laboratory exposure, metabolic activity, antioxidant and detoxification responses, lipid peroxidation and acetylcholinesterase activity were evaluated in different tissues, together with hemocyte viability and phagocytic function as indicators of immune competence. The results reveal marked tissue-dependent effects, with gills and digestive glands showing pronounced metabolic activation, oxidative stress, enhanced detoxification pathways and significant neurotoxicity, while muscle and mantle displayed relative resilience. Hemocyte-based assays demonstrated reduced cell viability, impaired lysosomal stability and decreased phagocytic capacity, indicating immunotoxic effects. Multivariate analysis clearly discriminated treatment groups and highlighted the stronger impact of combined BPF and BPS exposure compared to single compounds. Overall, the findings demonstrate that bisphenol analogues, even at low and environmentally relevant concentrations, can induce significant biochemical and immunological alterations in a key marine sentinel species, with mixture exposure producing the greatest toxicity. These results support the inclusion of bisphenol analogues in marine risk assessment frameworks and underline the relevance of integrative, multi-biomarker approaches for evaluating emerging contaminants in coastal ecosystems.