Anthracene photoinduced toxicity to PLHC-1 cell line (Poeciliopsis lucida) and the role of lipid peroxidation in toxicity

Many polycyclic aromatic hydrocarbons (PAHs) are acutely toxic to fish and other aquatic organisms in the presence of solar ultraviolet radiation (SUVR) of environmentally realistic intensities. In the present study, the photoinduced toxicity of a PAH (anthracene; ANT) to topminnow hepatoma cell line (PLHC-1) was assessed. After the toxicity was characterized, the role of lipid peroxidation in PAH photoinduced toxicity was examined by measuring lipid peroxidation products and by assessing the effect of lipid peroxidation antagonist (Trolox) treatment. In cytotoxicity tests using two assays (MTT, neutral red), the SUVR/ANT treatment elicited toxicity to PLHC-1 cells in a concentration- and SUVR (exposure duration and intensity)-dependent pattern. As found in previous organism-level studies, no significant cytotoxicity was observed in the cells exposed either to fluorescent light/ANT or to SUVR only. The SUVR/ANT treatment elicited the lipid peroxidation process and Trolox pretreatment significantly reduced SUVR/ANT-induced cell mortality. Microscopic observation showed that Trolox pretreatment relieved the SUVR/ANT-inflicted damage, such as cell shrinkage and membrane disruption. Together with a recent finding in our lab that increased production of superoxide anion and a lipid peroxidation product (malondialdehyde) was found in SUVR/ANT-treated fish microsomes, the present study suggests that reactive oxygen radical-induced lipid peroxidation is an important factor in PAH photoinduced toxicity to fish.