| Objective:The purpose of this study is to study the prevention and repair effect ofLycium barbarum polysaccharide?LBP?on alcoholic liver injury and its antioxidant mechanism through in vivo experiment and in vitro experiment,so as to provide experimental and theoretical basis for the high-value utilization of LBP.Methods:1.Study on the protective effect of LBP on alcoholic liver injury in mice.Mice were randomly divided into eight groups:control group,model group,LBPlow-dose group,LBP middle-dose group,LBP high-dose group and positive control low-dose group,positive control middle-dose group and positive control high-dose group.An animal model of alcoholic liver injury protected by LBP was established,and liver indexes and serum transaminase content of mice were detected.2.Mechanism of LBP on prevention and repair of alcoholic hepatocyte injury.?1?L-02 cells were cultured and MTT method was used to screen the concentration andtime of ethanol and LBP to establish alcoholic liver cell injury model.Hepatocytes were randomly divided into six groups:normal control group,model group,positive control group+ethanol prevention group,LBP+ethanol prevention group,ethanol+positive control repair group,ethanol+LBP repair group.?2?The effect of LBP on apoptosis was detected by flow cytometry,and the intracellularROS level was detected by laser confocal microscopy and fluorescence spectrophotometry.The content of ALT and AST,the level of GSH and MDA,the activity of SOD and GSH-Px,the ability of anti-O2-·and the content of NO were determined by chemical method.?3?Western blot was used to detect the expression of cytoplasm and nucleus Nrf2 incells and the expression of HO-1,NQO1 and GCLC in total proteins.Results:1.The positive control middle-dose group and high-dose group,LBP low-dose groupand middle-dose group can significantly reduce the liver index of alcoholic liver injury in mice.The liver index of high-dose group was not statistically different from the model group.LBP doses significantly reduced serum ALT levels in mice with alcohol-induced liver injury.The serum AST levels in the low-dose and middle-dose LBP groups also decreased.Compared with the model group,the positive control doses significantly reduced the ALT content in mice.The positive control low-dose group and the middle-dose group also decreased serum AST content.2.?1?The model of ethanol-induced hepatocyte injury.Finally,an ethanol-inducedhepatocyte model was established after 4 hours of absolute ethanol concentration of 5%?V/V?.Intervention with LBP at a concentration of 24?g/ml for 24 h.?2?The prevention and repair effect of LBP can reduce the apoptosis rate of L-02 cellsdamaged by alcohol.Compared with the normal control group,the early+late apoptosis rate in the model group was significantly increased?P<0.05?.Compared with the model group,the apoptosis rate of the LBP prevention and repair group were decreased?P<0.05?.Compared with the normal control group,the activity of SOD and GSH-Px and content of GSH in the model group is significantly reduced?P<0.05?,MDA and NO content were increased?P<0.05?,and the ability of anti-O2-·was weakened in cells.Compared with the model group,GSH-Px activity and GSH production were increased in the LBP prevention group and the repair group,and the amount of MDA and NO decreased?P<0.05?,increased the level of superoxide anion radical in the repair group.The SOD activity and the ability of anti-O2-·of the prevention group was no statistical difference compared with the model group in cells.?3?Compared with the normal control group,the expression level of Nrf2 protein in thenucleus of hepatocytes and the protein expression levels of downstream antioxidant genes HO-1,NQO1 and GCLC were significantly lower in the ethanol-induced model group?P<0.05?.However,LBP intervention can increase the nuclear expression of Nrf2 protein and significantly up-regulate the expression levels of Nrf2 protein and its downstream genes HO-1,NQO1 and GCLC in the cell nucleus?P<0.05?.Conclusion:LBP has a protective effect on alcoholic liver injury in mice.Its mechanismis related to the regulation of Nrf2/HO-1 signaling pathway,scavenging of reactive oxygen species and reactive nitrogen levels,and anti-apoptosis. |
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