Evaluation of cytotoxicity, genotoxicity and embryotoxicity of insecticide propoxur using flounder gill (FG) cells and zebrafish embryos

Abstract

Cytotoxicity, genotoxicity and embryotoxicity of carbamate insecticide propoxur were evaluated using flounder gill (FG) cells and zebrafish embryos. The cytotoxicity of propoxur in FG cells was analyzed by MTT, neutral red uptake (NRU), lactate dehydrogenase (LDH) release and Hoechst 33342 and propidium iodide double staining, and acute cytotoxic effects were observed in a concentration-dependent manner. The 24h-IC50 values of 89.96±1.04, 103.4±1.14 and 86.59±1.13μg/ml propoxur were obtained by MTT, NRU and LDH assays, respectively. The lethal effects were induced in FG cells mainly through necrosis but not apoptosis as evidenced by double fluorescence staining. Comet assay showed weak genotoxic effects and statistically significant DNA damages were recorded in the cells exposed to highest tested concentration of 75μg/ml propoxur (p<0.05). Propoxur exerted obvious acute toxic effects on the survival, spontaneous movement, hatching and heart rate, and development (yolk and pericardial sac edema) of zebrafish embryos in both time- and concentration-dependent manner only at ⩾100μg/ml. The corresponding 24h-, 48h- and 96h-LC50 values of propoxur in zebrafish embryos were 166.4±1.06, 146.3±1.07 and 134.8±1.06μg/ml, respectively. The above data obtained suggest a low acute toxicity of propoxur to the in vitro cultured FG cells and zebrafish embryos.