Deoxynivalenol (DON) belongs to the type B group of trichothecenes family, which is composed of sesquiterpenoid metabolites produced by Fusarium and other fungi in grain. DON may cause various toxicities, such as cytotoxicity, immunotoxicity, genotoxicity as well as teratogenicity and carcinogenicity. In the present study, we focus on a hypothesis that DON alters the expressions of Nrf2/HO-1 pathway by inducing embryotoxicity in C57BL/6 mouse (5.0, 2.5, 1.0, and 0 mg/kg/day) and BeWo cell lines (0 and 50 nM; 3 h, 12 h and 24 h). Our results indicate that DON treatment in mice during pregnancy leads to ROS accumulation in the placenta, which results in embryotoxicity. At the same time Nrf2/HO-1 pathway is up-regulated by ROS to protect placenta cells from oxidative damage. In DON-treated BeWo cells, the level of ROS has time–effect and dose–effect relationships with HO-1 expression. Moderate increase in HO-1 protects the cell from oxidative damage, while excessive increase in HO-1 aggravates the oxidative damage, which is called in some studies the “threshold effect”. Therefore, oxidative stress may be the critical molecular mechanism for DON-induced embryotoxicity. Besides, Nrf2/HO-1 pathway accompanied by the “threshold effect” also plays an important role against DON-induced oxidative damage in this process.
Deoxynivalenol (DON) is a kind of natural pollutant belonging to the trichothecenes family. The aim of this study is to use diverse assays to evaluate oxidative damage as well as translocation of nuclear factor erythroid 2-related factor 2 (Nrf2), and to investigate their mechanisms in DON-induced toxicities on a placenta and embryo. Pregnant C57BL/6 mice were randomly assigned to three groups with different doses of DON: 0, 1.0, 2.5 mg/(kg·day). In gestation day (GD) 12.5 d and 18.5 d, DON induced an elevated resorption rate of the embryos as well as structural and functional damage of the placenta. In the placenta, altered levels of the antioxidant enzymes malondialdehyde, superoxide dismutase and glutathione indicated remarkable oxidative stress. Furthermore, an elevated level of heme oxygenase-1 (HO-1) and the translocation of Nrf2 from nucleus to cytoplasm indicated Nrf2/HO-1 pathway activation in DON-L group (1.0 mg/(kg·day)). It is noteworthy that the results in this experiment in GD 12.5 d were similar to those in GD 18.5 d. In conclusion, DON-induced placental oxidative damage and Nrf2 translocation were similar in GD 12.5 d and GD 18.5 d. Oxidative stress is one of the most important molecular mechanisms for embryotoxicity induced by DON, and Nrf2 translocation may play a substantial role against it.