Zearalenone Depresses Lactation Capacity Through the ROS-Mediated PI3K/AKT Pathway

The effects of zearalenone (ZEA), a fungal toxin in food and feed, remain unclear on the mammary gland and lactation. This study examines ZEA-induced damage in lactating mice and bovine mammary epithelial cells (MAC-T), focusing on the role of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway in regulating cell proliferation and apoptosis. The results demonstrated that exposure to ZEA at different doses (5 mg/kg, 10 mg/kg, and 20 mg/kg) reduced lactation in female mice and slowed weight gain in their offspring. Hematoxylin and eosin (HE) staining and CSNK immunofluorescence staining of mammary tissue confirmed ZEA-induced mammary gland damage in vivo. Further analysis using PCNA immunohistochemistry and fluorescent TUNEL staining revealed that ZEA promoted apoptosis and decreased the proliferative capacity of mammary tissues. In vitro, 20 μM ZEA decreased MAC-T cell proliferation, increased apoptosis and oxidative stress, inhibited PI3K/AKT signaling, and decreased κ-casein (CSNK) expression. Pretreatment with a reactive oxygen species (ROS) scavenger (NAC) or PI3K/AKT activator (740-Y-P) reversed these effects, with NAC specifically restoring PI3K/AKT activity inhibited by ZEA. Overall, this study concludes that ZEA induces MAC-T cell apoptosis and disrupts proliferation via the ROS-mediated PI3K/AKT pathway, ultimately impairing lactation function. These findings highlight potential targets for managing ZEA contamination in food and its impact on lactation.