Effects of the water soluble fraction of gasoline on ZFL cell line: Cytotoxicity, genotoxicity and oxidative stress

• Effects of gasoline water-soluble fraction (GSF) on Danio rerio hepatocyte cell line (ZFL) were assessed.
• The GSF exhibited concentration-dependent cytotoxicity
• Longer exposure resulted in lower cell viability as indicated by both MTT and TB assays.
• Oxidative stress in cells exposed to GSF was not observed.
• DNA damage was significantly increased after exposure to GSF.

This work aimed to evaluate the effects of different dilutions of gasoline water-soluble fraction (GSF) on Danio rerio hepatocyte cell line (ZFL). Two tests were used to assess cell viability, MTT reduction assay (MTT) and the Trypan blue (TB) exclusion test. Oxidative stress was evaluated through the quantification of reactive oxygen species (ROS) and the assessment of the total antioxidant capacity against peroxyl radicals (ACAP) and the comet assay was employed to assess DNA damage. ZFL cells were exposed to 5, 10, 25 and 50% GSF or only to saline for 1, 3 and 6 h. The GSF exhibited concentration-dependent cytotoxicity, and longer exposure times resulted in lower cell viability as indicated by both MTT and TB assays. The establishment of oxidative stress in cells exposed to GSF was not observed at any exposure period and the lower ROS levels could be related to the increased antioxidant capacity after 6-hour exposure. DNA damage was significantly increased after exposure to GSF at the three experimental times. Taking together these results show that GSF has a genotoxic potential at the lower concentrations and becomes cytotoxic at higher concentrations and that ZFL can be considered a good biological model for in vitro toxicological studies.