Evaluation of the biochemical effects of an acetamiprid-based insecticide on a non-target species,Gambusia holbrooki

The toxic effects of an acetamiprid-based insecticide (ABI) onGambusia holbrookiwere evaluated after 24 and 96-h exposure periods. The 24 and 96-h median lethal concentration (LC50) values of ABI were determined as 75.9 and 42.2 mg/L active ingredient (AI)/L, respectively. In addition, the activity of five biochemical marker enzymes, including glutathione S-transferase (GST), glutathione reductase (GR), carboxylesterase (CaE), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) was measured after 24 and 96-h exposure to three different concentrations of the ABI to evaluate its sublethal effects. The acetamiprid concentrations in the exposure media were measured using liquid chromatography-tandem mass spectrometry. Our results showed that GST and LDH activities were increased and there were concentration-dependent changes in the integrated biomarker response (IBR) indexes after 24-h ABI exposure. However, the examined biomarkers were not useful for examining the effects of the ABI exposure for 96-h exposure periods, even at the highest concentration.