Cryptotanshinone Inhibits Staphylococcus aureus-Induced Mastitis by Inhibiting Ferroptosis Through Activating Nrf2/GPX4 Pathway

Mastitis is a prevalent gynecological disorder in women, with Staphylococcus aureus ( S. aureus ) serving as a primary etiological pathogen of this condition. Cryptotanshinone (CPT) has been demonstrated to exert anti-oxidative stress and anti-inflammatory effects, conferring therapeutic benefits for a diverse range of inflammatory diseases. However, its efficacy and underlying regulatory mechanisms in ameliorating S. aureus -induced mastitis remain elusive. Therefore, the present study was designed to elucidate the protective effects and molecular regulatory mechanisms of CPT against S. aureus -induced mastitis. A murine model of S. aureus -induced mastitis was established via intramammary injection of S. aureus , and CPT was administered to the model mice for therapeutic intervention. In vivo experiments revealed that CPT administration mitigated S. aureus -induced mastitis in mice by suppressing the production of pro-inflammatory cytokines and inhibiting ferroptosis. In vitro, CPT abrogated the S. aureus -induced elevation of TNF-α, IL-1β, MDA, ROS, and Fe 2+ levels in mouse mammary epithelial cells (MMECs); additionally, it restored the ATP and GSH levels that were reduced by S. aureus stimulation in these cells. Furthermore, CPT concentration-dependently upregulated the expression of GPX4, Nrf2 and HO-1 in MMECs. Notably, the inhibitory effects of CPT on S. aureus -induced inflammatory responses and ferroptosis were abrogated in Nrf2-knockdown MMECs. In conclusion, this study demonstrates that CPT exerts a robust protective effect against S. aureus -induced mastitis by suppressing inflammatory responses and inhibiting ferroptosis through the activation of the Nrf2/GPX4 signaling pathway.