The combined effects of wood vinegar and perfluorooctanoic acid on enzymatic activities, DNA damage and gene transcription in Dugesia japonica

Perfluorooctanoic acid (PFOA) has been identified widely in aquatic environments, while there are few reports detailing the environmental risk of wood vinegar (WV) on freshwater ecosystems. The freshwater planarians, Dugesia japonica, were used to evaluate the combined effects of PFOA and WV by examining the adverse influence of enzymatic activities, DNA damage and gene transcription on planarians. Compared with control and PFOA groups, the malonaldehyde content was lower in planarians treated with WV. In addition, WV enhanced the activities of antioxidant enzymes and mitochondrial enzymes, relieving the toxicity effects of PFOA. We also studied the genotoxicity of PFOA and WV on planarians using the comet assay. WV decreased the proportion of DNA in the tail and the olive tail moment. Furthermore, expression of gpx, gst and gr genes in planarians was significantly altered following exposure to both PFOA and WV, compared with individual exposure. Our results suggest that WV could alleviate the adverse effects of PFOA on the aquatic environment, but ecological risk assessments and toxicological safety evaluations of WV are necessary.