Assessment of the toxicity of anthracene photo-modification products using the topminnow (Poeciliopsis lucida) hepatoma cell line (PLHC-1).

Many polycyclic aromatic hydrocarbons (PAHs) are acutely toxic to fish and other aquatic organisms in the presence of environmentally realistic intensities of solar ultraviolet radiation (SUVR). In this study, the cytoxicity/phototoxicity of anthracene photo-modified products to aquatic animals was assessed based on in vitro toxicity assays using a fish hepatoma cell line (PLHC-1 cell line). The results from this study showed that pre-exposure of anthracene/cell culture media to SUVR caused a significant amount of photo-modification and reduced the phototoxicity of parent anthracene compound. SUVR pre-exposed anthracene did not induce cytotoxicity in the absence of SUVR. It was shown that in comparison with anthracene, two major anthracene photo-modified products (anthraquinone, 1,2-dihydroxyanthraquinone) were significantly less phototoxic to PLHC-1 cells. Also in the absence of SUVR, these chemicals did not induce any detectable cytotoxicity to PLHC-1 cells. In conclusion, this study demonstrated that photo-modification reduced the phototoxicity of anthracene to PLHC-1 cells because major anthracene photo-modified products are not phototoxic. Also it was found that these photo-modified anthracene products were not cytotoxic in the absence of SUVR. This study indicated the need for separate toxicity assessments of individual photo-modified PAH products in both animal and plant models.