Etoxazole, a
chitin synthesis inhibitor, is widely used to control insects and mites by causing developmental defects. Despite the many advantages of pesticides, the inhibitory effects of most pesticides including
etoxazole are based on biochemical reaction and their widespread application is considered as a major risk to human health and the environment because of bioaccumulation and non-target toxic effects. Though used in agricultural area, the
pesticide residues run off through rivers or ocean, where diverse aquatic organisms live. Since there are no studies evaluating the risks of
etoxazole exposure in embryogenesis of aquatic organisms, we investigated the adverse effects of
etoxazole on development and angiogenesis in zebrafish embryos, which are considered to be an effective model for detecting ecotoxicological effects of widely used compounds, especially affecting aquatic organisms.
Etoxazole induced yolk sac and heart
edema, as well as loss of viability, abnormal heart rate, and developmental deficiency. Through a mechanistic approach, we also showed that
etoxazole caused
reactive oxygen species accumulation, inhibited the expression of cell cycle activating genes, and induced apoptosis. In addition, we investigated effects of
etoxazole on cardiovascular development by demonstrating the loss of vascular structure in response to
etoxazole exposure in fli1:eGFP transgenic zebrafish model. Collectively, this first assessment demonstrating the effects of
etoxazole on embryogenesis and cardiovascular development provides clear evidence for the toxicity of
etoxazole and contributes important data towards formulating safety guidelines on the potential hazards of
etoxazole for aquatic environment.