Toxic effects of 1-decyl-3-methylimidazolium bromide ionic liquid on the antioxidant enzyme system and DNA in zebrafish (Danio rerio) livers

Ionic liquids were recently found to be toxic to aquatic organisms. Therefore, the present study investigated the effects of 1-decyl-3-methylimidazolium bromide ([C10mim]Br) on oxidative stress and DNA damage in zebrafish. Male and female zebrafish were separated and exposed to five concentrations of [C10mim]Br (0, 5, 10, 20, and 40 mg L−1) and were sampled on days 7, 14, 21 and 28. Compared to control groups, the activities of antioxidant enzymes were significantly decreased at most exposure intervals. This decreased activity resulted in the production of excess reactive oxygen species (ROS) and increased malondialdehyde (MDA) content in zebrafish liver. Additionally, it was noteworthy that a clear dose-response was found for DNA damage. As for sex differences, significant differences in catalase (CAT) and ROS were found on the 7th day. In conclusion, the exposure of [C10mim]Br caused DNA damage, leading to antioxidant responses in zebrafish livers.

► The activity of SOD and CAT was significantly inhibited in most sampling intervals.
► ROS generation and MDA level were accordingly enhanced.
► [C10mim]Br could induce DNA damage in zebrafish liver.
► Gender difference were found in CAT and ROS on the 7th day.