Mastitis,as an important disease that endangers the development of the dairy industry,causes huge economic losses to the breeding industry.Staphylococcus aureus is one of the impor-tant pathogenic bacteria that cause mastitis in dairy cows.Previous studies have found that deoxy-cholic acid(DCA)plays an important role in many diseases,but its effect on mastitis has not been reported yet.In order to investigate the effect and mechanism of DCA on Staphylococcus aureus in-duced mouse mastitis,this study constructed a Staphylococcus aureus induced mouse mastitis model,mice were intraperitoneally injected DCA(0.01,0.02,0.03 mg/g),breast tissue were col-lected,and the protective effect and mechanism of DCA on mastitis were evalued.The results showed that DCA dose dependently reduced the pathological damage of mouse breast tissue in-duced by Staphylococcus aureus;DCA inhibited the expression of inflammatory cytokines TNF-α and IL-1β and MPO activity induced by Staphylococcus aureus;DCA significantly reduced the con-centration of MDA and iron ions,while upregulating the expression of GSH and GPX4,indicating that DCA could inhibit ferroptosis induced by Staphylococcus aureus;Western blot results showed that DCA could upregulate TGR5 receptors,thereby inhibiting the NF-κB signaling pathway.The above results indicate that DCA inhibits mastitis by regulating the TGR5-NF-κB signaling pathway to inhibit the inflammatory response and ferroptosis induced by Staphylococcus aureus.

Mastitis,as an important disease that endangers the development of the dairy industry,causes huge economic losses to the breeding industry.Staphylococcus aureus is one of the impor-tant pathogenic bacteria that cause mastitis in dairy cows.Previous studies have found that deoxy-cholic acid(DCA)plays an important role in many diseases,but its effect on mastitis has not been reported yet.In order to investigate the effect and mechanism of DCA on Staphylococcus aureus in-duced mouse mastitis,this study constructed a Staphylococcus aureus induced mouse mastitis model,mice were intraperitoneally injected DCA(0.01,0.02,0.03 mg/g),breast tissue were col-lected,and the protective effect and mechanism of DCA on mastitis were evalued.The results showed that DCA dose dependently reduced the pathological damage of mouse breast tissue in-duced by Staphylococcus aureus;DCA inhibited the expression of inflammatory cytokines TNF-α and IL-1β and MPO activity induced by Staphylococcus aureus;DCA significantly reduced the con-centration of MDA and iron ions,while upregulating the expression of GSH and GPX4,indicating that DCA could inhibit ferroptosis induced by Staphylococcus aureus;Western blot results showed that DCA could upregulate TGR5 receptors,thereby inhibiting the NF-κB signaling pathway.The above results indicate that DCA inhibits mastitis by regulating the TGR5-NF-κB signaling pathway to inhibit the inflammatory response and ferroptosis induced by Staphylococcus aureus.