Abstract
Transition dairy cows face severe oxidative stress that disrupts mammary epithelial homeostasis through intertwined oxidative, inflammatory, and endoplasmic reticulum (ER) stress pathways. This study hypothesized that rutin, a natural flavonoid, alleviates hydrogen peroxide (H2O2)-induced oxidative damage in bovine mammary epithelial cells (BMECs) via AMPK/NFE2L2 signaling activation. In this study, BMECs were pre-incubated with rutin. Subsequently, cells were treated with or without H2O2. Additionally, by transfecting BMECs with NFE2L2 siRNA (siNFE2L2), we investigated how AMPK/NFE2L2 signaling mediated by rutin may prevent H2O2-induced oxidative damage. The results show that increases in reactive oxygen species (ROS), expression of inflammatory cytokines, expression of proteins related to endoplasmic reticulum stress and the apoptosis rate induced by H2O2 in cells, were attenuated in rutin cultures. Challenges with H2O2 led to a lower abundance of proteins related to AMPK and NFE2L2. Comparatively, these effects were reversed in cultures with rutin. Transfection with siNFE2L2 reversed the protection of rutin, suggesting that NFE2L2 is essential for the protective mechanism of rutin. These results elucidated the molecular mechanism of rutin's resistance to H2O2-mediated oxidative injury through the AMPK/NFE2L2 signaling pathway and suggested that it could be used as a potent in vivo antioxidant for ruminants during periods of stress, such as before and after calving.