Developmental and cardiotoxic effects of cyhalofop-butyl in zebrafish embryos

This study evaluates the developmental and cardiotoxic effects of cyhalofop-butyl, a commonly used herbicide in rice agriculture, on zebrafish (Danio rerio) embryos. Despite its widespread application, the risk assessment of cyhalofop-butyl for aquatic organisms, especially fish, is still lacking. Focusing on the cardiac system, we used a zebrafish model to evaluate developmental abnormalities, changes in cardiac morphology and function, markers of oxidative stress, and altered gene expression. The results suggest that cyhalofop-butyl induces oxidative stress, lipid accumulation, and apoptosis in zebrafish embryos. In addition, it can lead to abnormal embryonic development and cardiac morphological dysfunction (such as pericardial edema, decreased heart rate, and red blood cell (RBC) flow rate, and cardiac linearization). Cyhalofop-butyl also significantly alters the expression of cardiac-related genes, including myl7, vmhc, myh6, nkx2.5, tbx5, nppa, has2, and myh7. In summary, cyhalofop-butyl elicits both dysplasia and cardiotoxicity in zebrafish embryos, highlighting the need for further safety risk evaluation of this herbicide in aquatic ecosystems.