Plasticiser-specific disruption of lipid homeostasis and oxidative balance in oysters: Implications for non-phthalate...

Plasticisers are widely used additives that can leach into aquatic environments and pose ecotoxicological risks to marine life. This study investigated the effects of four plasticisers: epoxidised methyl oleate (EMO), di(2-ethylhexyl) adipate (DEHA), diisononyl phthalate (DINP), and tris(2-ethylhexyl) trimellitate (TOTM) at 100 μg/L for 21 days on bioaccumulation, and lipid composition in Crassostrea (Magallana) saidii. The results showed that TOTM and DINP exhibited the highest levels of bioaccumulation in oyster tissue, at 0.776 μg/g and 0.126 μg/g, respectively. In contrast, EMO and DEHA showed minimal uptake at 0.003 μg/g and 0.009 μg/g, respectively. Exposure to DINP and TOTM also caused a significant depletion of polyunsaturated fatty acids (PUFAs), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), alongside a marked increase in saturated fatty acids (SFAs). These changes resulted in reduced PUFA/SFA and n3/n6 ratios, consistent with oxidative stress-related lipid remodelling. In contrast, oysters exposed to EMO and DEHA exhibited comparatively minor changes in lipid composition. Overall, the findings indicate that plasticisers can disrupt lipid homeostasis and redox balance in marine bivalves in a compound-dependent manner. While EMO and DEHA exhibited lower bioaccumulation and limited lipid perturbation under the conditions tested, further investigation is required to assess their environmental occurrence, long-term effects, and the potential toxicity of degradation products before confirming their suitability as environmentally safer alternatives.