To explore the protective effect and mechanism of paeoniflorin on oxidative stress-induced damage in mice with mastitis,female BALB/c mice 6 days postpartum were randomly assigned into 6 groups:a negative control group,a model group,and four treatment groups receiving varying doses of paeoniflorin(10mg/kg,20mg/kg,and 40mg/kg,respectively),as well as a positive control group(5mg/kg),with 8 mice in each group.Except for the negative control group,mastitis was induced in the remaining mice by intraductal injection of lipopolysaccharides(LPS).The mice were subjected to drug intervention 14 hours prior to induction,2 hours post-induction,and 6 hours after induction.24 hours following the induction of mastitis,the mice in each group were euthanized for examination of morphological alterations in the mammary gland tissue.Pathological sections of the mammary gland tissue in mice from each group were prepared to observe pathological changes.The levels of reactive oxygen species(ROS)in the mammary gland tissue of the mice were determined using a fluorescent probe method.The protein expression levels of 4-hydroxynonenal(4-HNE)in the mammary gland tissue of the mice were assessed via immunofluorescence histochemistry.The levels of superoxide dismutase(SOD),malondialdehyde(MDA),and glutathione peroxidase(GSH-Px)in the mammary gland tissue of the mice were quantified using biochemical assay kits.Real-time fluorescence quantitative PCR(RT-qPCR)and western blot were employed to detect the mRNA transcription and protein expression levels of key molecules in the nuclear factor erythroid2-related factor 2(Nrf2)pathway,including Nrf2,heme oxygenase-1(HO-1),glutamate-cysteine ligase(GC1C),and NADH quinone oxidoreductase 1(NQO1)in the mammary gland tissue of the mice.The results showed that compared to the negative control group,the model group mice exhibited redness and bleeding points in the mammary gland area,and the pathological structure of mammary gland tissues revealed significant infiltration of inflammatory cells in the mammary acinar cells with morphological changes.Compared to the negative control group,the model group mice showed a marked elevation in ROS and MDA levels,along with increased 4-HNE protein expression within mammary gland tissues(P＜0.01 or P＜0.05).Conversely,the activity of GSH-Px and SOD enzymes were significantly decreased(P＜0.01 or P＜0.05).The transcription levels of Nrf2,HO-1,GCLC,and NQO1 mRNA were significantly upregulated(P＜0.01 or P＜0.05),with their protein expression levels showing a similar trend to mRNA transcription levels.In comparison to the model group,the treatment groups demonstrated a substantial reduction in pathological damage to mammary gland tissues.The protein expression levels of ROS,MDA,and 4-HNE in mammary gland tissues were significantly decreased(P＜0.01),while GSH-Px and SOD were increased(P＜0.01).The transcription levels of Nrf2,HO-1,GCLC,and NQO1 were all significantly upregulated(P＜0.01 or P＜0.05),with protein expression patterns paralleling those of mRNA transcription.The above results indicate that paeoniflorin effectively mitigate oxidative damage in the mammary tissue of mice with mastitis,with the high-dose group showing particularly optimal therapeutic effect.The specific mechanism appears to involve the significant activation of the Nrf2 pathway by paeoniflorin,which counteracts oxidative stress damage.
维普
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