Developmental toxicity induced by brodifacoum in zebrafish (Danio rerio) early life stages

Objectives The present study mainly focused on the assessment of developmental toxicity induced by exposure to brodifacoum (BDF) in zebrafish at early life stages. Material and Methods Zebrafish embryos were exposed to 0.2, 0.4, and 0.8 mg/L of BDF from 6 to 96 hr post-fertilization (hpf), and the toxic effects of BDF on early embryonic development were investigated in terms of morphological changes, oxidative stress, and alterations in heart development-related genes. Results The experimental results showed that BDF significantly decreased the heart rate, survival rate, body length, and spontaneous movements of zebrafish embryos at 0.8 mg/L, and the morphological developmental abnormalities were also observed at 96 hpf. In addition, exposure to BDF significantly increased oxidative stress levels in zebrafish embryos by increasing the enzymatic activities of catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) levels, and decreased glutathione (GSH) levels. Furthermore, BDF treatment-induced alterations in the expression levels of the heart development-related genes (gata4, sox9b, tbx2b, and nppa). Conclusion Results from this study indicated that exposure to BDF could lead to marked growth inhibition and significantly alter the activities of antioxidant enzymes in zebrafish embryos. Moreover, BDF exposure exhibited severe cardiotoxicity and significantly disrupted heart development-related genes. The results indicated that BDF could induce developmental and cardiac toxicity in zebrafish embryos.