Developmental defects induced by thiabendazole are mediated via apoptosis, oxidative stress and alteration in PI3K/Akt and MAPK pathways in zebrafish

Abstract

Thiabendazole, a benzimidazole fungicide, is widely used to prevent yield loss in agricultural land by inhibiting plant diseases derived from fungi. As thiabendazole has a stable benzimidazole ring structure, it remains in the environment for an extended period, and its toxic effects on non-target organisms have been reported, indicating the possibility that it could threaten public health. However, little research has been conducted to elucidate the comprehensive mechanisms of its developmental toxicity. Therefore, we used zebrafish, a representative toxicological model that can predict toxicity in aquatic organisms and mammals, to demonstrate the developmental toxicity of thiabendazole. Various morphological malformations were observed, including decreased body length, eye size, and increased heart and yolk sac edema. Apoptosis, reactive oxygen species (ROS) production, and inflammatory response were also triggered by thiabendazole exposure in zebrafish larvae. Furthermore, PI3K/Akt and MAPK signaling pathways important for appropriate organogenesis were significantly changed by thiabendazole. These results led to toxicity in various organs and a reduction in the expression of related genes, including cardiovascular toxicity, neurotoxicity, and hepatic and pancreatic toxicity, which were detected in flk1:eGFP, olig2:dsRED, and L-fabp:dsRed;elastase:GFP transgenic zebrafish models, respectively. Overall, this study partly determined the developmental toxicity of thiabendazole in zebrafish and provided evidence of the environmental hazards of this fungicide.

Keywords: Apoptosis; Oxidative stress; Signaling cascade; Thiabendazole; Zebrafish model.