Oxidative stress and genotoxicity of 1-methyl-3-octylimidazolium chloride on loach (Misgurnus anguillicaudatus)

This study was a preliminary step to evaluate the acute toxicity of 1-methyl-3-octylimidazolium chloride ([C₈mim]Cl) on loach (Misgurnus anguillicaudatus) by determining the effects on hepatic antioxidant enzyme activities and by the comet assay. The results showed that [C₈mim]Cl had acute toxicity at concentrations above 20 mg L^?1, inducing oxidative stress and genotoxicity on fish liver cells. In respect to enzyme activities, [C₈mim]Cl induced changes in the activities of superoxide dismutase, catalase, and glutathione content the livers of fish exposed at 20–80 mg L^?1. [C₈mim]Cl at the same exposure level caused a remarkable increase in malondialdehyde level. The comet assay indicated that [C₈mim]Cl at 20–80 mg L^?1 induced genotoxicity in liver cells. With increased exposure concentration and time, the two comet parameters trailing rate and tail moment were significantly increased, with significant differences (P < 0.05) observed between control group and each treatment group. The present study shows that ionic liquids can be a threat to the health of aquatic organism when accidentally released to aquatic ecosystems.