Forty adult male C57BL/6 mice were randomly divided into four groups:the control group,Salmonella typhimurium(S.typhimurium)(ST)group,phlorizin(PHZ)+S.typhimuri-um(ST)group,and PHZ(80 mg/kg)group,with 10 mice in each group.Morphological observa-tion,HE staining,ELISA,immunofluorescence and Western blot were performed,the results showed that PHZ significantly increased the cecal index,decreased the spleen index of S.typhi-murium-induced mice(P＜0.05),and reduce the pathological damage of cecum in mice.Mean-while,PHZ treatment also significantly reduced colonization of S.typhimurium in the cecum,spleen,mesenteric lymph nodes and liver(P＜0.05).The results of ELISA showed that PHZ treatment also significantly inhibited the S.ty phimurium-induced increase in the expression of IL-1β,INF-γ,TNF-a and IL-6 in the cecum of mice(P＜0.05).Immunofluorescence and Western blot results showed that PHZ significantly increased the protein expression levels of Occludin,Claudin-3,and ZO-1 in the cecal barrier of mice induced by S.typhimurium(P＜0.05).These results con-firmed that phlorizin could improve cecal inflammation and intestinal barrier damage induced by S.typhimurium in mice.

Mastitis is one of the common and prevalent diseases in dairy cows,and the natural prod-uct daidzein is a kind of natural flavonoids with a wide range of pharmacological and anti-inflam-matory effects.However,the effect of daidzein on mastitis in dairy cows has not been reported.Therefore,in this study,we explored the effects of daidzein on LPS-induced inflammatory response and tight junction damage in dairy mammary epithelial cells Firstly,we pretreated the MAC-T cell line using different concentrations of daidzein,and it was clarified that daidzein below 200 μmol/L had no effect on the cell activity.Next,we examined the production of pro-inflammatory mediators in LPS-stimulated MAC-T cell lines using qRT-PCR,and clarified that daidzein could reduce the production of pro-inflammatory mediators in a concentration-dependent manner.Subsequently,af-ter the expression of Occludin,Claudin3 and ZO-1 was detected by immunofluorescence and West-ern Blot,it was clear that daidzein could alleviate MAC-T cell intercellular tight junction injury.Fi-nally,it was demonstrated that daidzein significantly inhibited LPS-induced activation of the NF-κB signaling pathway within MAC-T using network pharmacological analysis and Western Blot.The above results suggest that daidzein can inhibit LPS-induced inflammatory response and tight junc-tion damage in mammary epithelial cells of cows by suppressing the activation of NF-κB signaling pathway.The present study provides a theoretical basis for the alleviation of mastitis by natural products and further expands the pharmacological effects of daidzein.

Mastitis is one of the common and prevalent diseases in dairy cows,and the natural prod-uct daidzein is a kind of natural flavonoids with a wide range of pharmacological and anti-inflam-matory effects.However,the effect of daidzein on mastitis in dairy cows has not been reported.Therefore,in this study,we explored the effects of daidzein on LPS-induced inflammatory response and tight junction damage in dairy mammary epithelial cells Firstly,we pretreated the MAC-T cell line using different concentrations of daidzein,and it was clarified that daidzein below 200 μmol/L had no effect on the cell activity.Next,we examined the production of pro-inflammatory mediators in LPS-stimulated MAC-T cell lines using qRT-PCR,and clarified that daidzein could reduce the production of pro-inflammatory mediators in a concentration-dependent manner.Subsequently,af-ter the expression of Occludin,Claudin3 and ZO-1 was detected by immunofluorescence and West-ern Blot,it was clear that daidzein could alleviate MAC-T cell intercellular tight junction injury.Fi-nally,it was demonstrated that daidzein significantly inhibited LPS-induced activation of the NF-κB signaling pathway within MAC-T using network pharmacological analysis and Western Blot.The above results suggest that daidzein can inhibit LPS-induced inflammatory response and tight junc-tion damage in mammary epithelial cells of cows by suppressing the activation of NF-κB signaling pathway.The present study provides a theoretical basis for the alleviation of mastitis by natural products and further expands the pharmacological effects of daidzein.

Forty adult male C57BL/6 mice were randomly divided into four groups:the control group,Salmonella typhimurium(S.typhimurium)(ST)group,phlorizin(PHZ)+S.typhimuri-um(ST)group,and PHZ(80 mg/kg)group,with 10 mice in each group.Morphological observa-tion,HE staining,ELISA,immunofluorescence and Western blot were performed,the results showed that PHZ significantly increased the cecal index,decreased the spleen index of S.typhi-murium-induced mice(P＜0.05),and reduce the pathological damage of cecum in mice.Mean-while,PHZ treatment also significantly reduced colonization of S.typhimurium in the cecum,spleen,mesenteric lymph nodes and liver(P＜0.05).The results of ELISA showed that PHZ treatment also significantly inhibited the S.ty phimurium-induced increase in the expression of IL-1β,INF-γ,TNF-a and IL-6 in the cecum of mice(P＜0.05).Immunofluorescence and Western blot results showed that PHZ significantly increased the protein expression levels of Occludin,Claudin-3,and ZO-1 in the cecal barrier of mice induced by S.typhimurium(P＜0.05).These results con-firmed that phlorizin could improve cecal inflammation and intestinal barrier damage induced by S.typhimurium in mice.