Exposure to chiral pydiflumetofen induces cardiovascular toxicity in early stages of zebrafish

Pesticides increase agricultural productivity, but with the widespread use of pesticides, concerns have arisen about their potential negative impacts on human health and aquatic organisms. Pydiflumetofen (PYD) is a novel chiral fungicide, and the potential environmental and health hazards of PYD and its chiral isomers are not sufficiently understood. In this work, zebrafish were employed as a model organism to study the toxicity of PYD, specifically investigating the developmental and cardiovascular toxicities in zebrafish exposed to 0.2 μg/mL of PYD for 72 h. The results showed that PYD severely impeded the development of zebrafish embryos, resulting in abnormal hatching rates, enlarged yolk sacs and shortened body length. In addition, PYD resulted in morphological and functional abnormalities of the embryonic heart and blood vessels, such as pericardial edema, linearization of the heart, impeded vascular production, slowed heart rate, and reduced erythrocyte flow rate. Mechanistically, we found that PYD caused oxidative stress, lipid accumulation and apoptosis in zebrafish. Simultaneously, the expression of genes associated with cardiac (nkx2.5, gata4, tbx5, hand2, has2) and vascular (vegfc, dll4, cdh5, hey2, and notch3) development was altered. Notably, our results indicate that (+)-R-PYD exhibits higher developmental and cardiovascular toxicity than (−)-S-PYD. This paper first reveals the cardiovascular toxicity of PYD and opens new avenues for assessing the environmental and health hazards caused by chiral fungicides.