Toxicometabolomic profiling of perfluorinated sulfonic acids and perfluorinated carboxylic acids reveals conserved effects on lipids and bile acids in Atlantic salmon hepatocytes

Per- and polyfluoroalkyl substances (PFAS) are highly persistent environmental contaminants that pose potential ecological and health risks to humans and wildlife. This study investigated the comparative toxicity of four PFAS compounds, PFOS, PFOA, PFNA, and PFHxS, using primary hepatocytes isolated from Atlantic salmon. Cells were exposed for 48 h to increasing concentrations (10 µM to 100-150 µM) and cytotoxicity, membrane fluidity, RT-qPCR and untargeted metabolomic profiles were subsequently assessed. The results showed no PFAS-induced cytotoxicity, and no clear dose-dependent effect on membrane fluidity. The transcriptional effect was generally minimal, except for a significant induction of Cyp7a after exposure to 100 µM PFOS. The metabolic profiles for the perfluorinated sulfonic acids PFOS and PFHxS differed from those observed with the perfluorinated carboxylic acids PFOA and PFNA. Pathway analysis revealed convergent effects across all four compounds on mechanisms associated with lipid metabolism, bile acids, cholesterol, mevalonate, extracellular matrix remodeling and biotransformation. Predicted adverse outcomes included dyslipidemia and cholestasis and biliary hyperplasia. In conclusion, this study identified metabolite biomarkers in Atlantic salmon associated with the four PFAS currently regulated under European food legislation and highlights the value of untargeted screening approaches such as metabolomics for detecting PFAS-induced perturbations.