Phenylpyrazole insecticides are widely used as chiral pesticides. However, the enantioselective toxicity and potential endocrine-disrupting effects of these insecticides on aquatic organisms remain unclear. Herein, the enantioselective toxicity and potential endocrine-disrupting effects of flufiprole and ethiprole were investigated by using zebrafish embryos/larvae as a model. The acute toxicity of R-flufiprole and R-ethiprole toward zebrafish embryos and larvae was 1.8-3.1-fold higher than that of the S-configuration. Additionally, R-flufiprole and R-ethiprole had a greater effect on the expression of genes related to the hypothalamus-pituitary-gonad axis in zebrafish compared with the S-configuration. Nevertheless, both S-flufiprole and S-ethiprole exhibited a greater interference effect on the expression of genes related to the hypothalamus-pituitary-thyroid axis and a greater teratogenic effect on zebrafish than the R-configuration. Thus, this study demonstrates that both flufiprole and ethiprole exhibit enantioselective acute toxicity and developmental toxicity toward zebrafish. Furthermore, those pesticides potentially possess enantioselective endocrine-disrupting effects.
Keywords: enantioselectivity; endocrine-disruptive effects; ethiprole; flufiprole; toxicity.