Systemic oxidative toxicity induced by mixed exposure to food additives and food-contact chemicals in rats and its attenuation by α-tocopherol

Mixed exposure to food additives and food-contact chemicals better reflects real-life human exposure; however, its systemic toxicological consequences remain incompletely understood. In this study, we investigated oxidative toxicity induced by a defined chemical mixture in rats, focusing on reproductive and neural tissues. The chemical mixture increased reactive oxygen species (ROS) production in sperm and significantly reduced sperm motility. Levels of 4-hydroxynonenal (4-HNE), a lipid peroxidation marker, were elevated in spermatogenic cells, indicating oxidative stress during late-stage spermatogenesis. In the hippocampus, mixed chemical exposure increased the expression of NADPH oxidase–related proteins (Nox4 and Duox1) and activated ROS-associated signaling pathways, including phosphorylated ERK and JNK, after 8 weeks of exposure. Supplementation with α-tocopherol markedly attenuated oxidative stress responses in both spermatogenic cells and the hippocampus. In contrast, fecal microbiota analysis showed reduced bacterial diversity following mixed chemical exposure, which was not restored by α-tocopherol treatment. These findings demonstrate that mixed exposure to food additives and food-contact chemicals induces systemic oxidative toxicity in rats and that antioxidant intervention can partially mitigate oxidative damage, particularly in reproductive and neural tissues.