| Objective: To observe the effect of Extract Ginkgo biloba(EGB)on chronic intermittent hypoxia(CIH)pancreatic tissue through Nrf2-ARE signaling pathway and its intervention mechanism.Methods :Fifty-four wild male rats were randomly divided into 9 groups: normal control group 1,2,intermittent hypoxia group 1,2,antibody blocking group,Nrf2 activator group,low,medium and high concentration EGB group,6 rats in each group.Thirty male Nrf2 knockout mice were randomly divided into five groups: normal control group,intermittent hypoxia group and low,medium and high concentration EGB group,with 6 rats in each group.All mice were fed adaptively for one week.The mice in the normoxic control group were fed in the normal air.The mice in the normoxic control group 1 were injected with saline 1 ml intraperitoneally once a day,and were compared with the antibody activation group and the antibody blocking group respectively.Normal oxygen control group 2 groups: 10 ml/kg/d saline intragastric administration,and EGB intervention group control.In the intermittent hypoxia group,hypoxia chamber was placed to make the model.Intervention was started after successful modeling.Intermittent hypoxia group 1: intraperitoneal injection of saline 1 ml,once a day,was compared with antibody activation group and antibody blocking group.Intermittent hypoxia group 2 groups: 10 ml/kg/d saline intragastric administration,and EGB intervention group control.Nrf2 antibody blocking group: intraperitoneal injection of anti-Nrf2 antibody once a day;Nrf2 activator group: intraperitoneal injection of sulforaphane 5mg/Kg·d,Nrf2;low,medium and high concentration of EGB group: intragastric administration of EGB at doses of 50mg/Kg·d,100mg/Kg·d,200mg/Kg·d,respectively.After 10 weeks of intervention,nuclear factor erythroid 2-related factor 2(Nrf2),heme oxygenase-1(HO-1),?-glutamyl cysteine synthase(?-GCS),NAD(P)H-quino oxidoreductase 1(NQO1)mRNA and protein.Results: In wild type mice,1.Protein expression:Compared with normoxia control group 1,the expression levels of HO-1 and NQO1 in intermittent hypoxia group 1 decreased and the expression of ?-GCS increased(P < 0.05).Compared with the intermittent hypoxia group 1,the expression levels of HO-1,NQO1 and ?-GCS in the Nrf2 activator group increased(P < 0.05),the expression levels of HO-1,NQO1 and ?-GCS in anti-Nrf2 antibody group decreased(P < 0.05).Compared with normoxia control group 2,the expression levels of HO-1 and NQO1 in intermittent hypoxia group 2 decreased,and the expression of ?-GCS increased(P < 0.05).Compared with the intermittent hypoxia group 2,the expression level of ?-GCS in low-concentration EGB group increased(P < 0.05),but there was no significant difference in HO-1 and NQO1(P > 0.05).the expression levels of NQO1 and ?-GCS increased in the middle concentration group of EGB(P < 0.05),but there was no significant difference in HO-1(P > 0.05).The expression levels of HO-1,NQO1 and ?-GCS in the high concentration group of EGB increased,and the changes were more obvious in the high concentration group than in the low concentration group(P < 0.05).2.The expression of mRNA:Compared with normoxia control group 1,the expressions of HO-1,NQO1 and ?-GCS in intermittent hypoxia group decreased(P < 0.05).Compared with intermittent hypoxia group 1,the expression of HO-1,NQO1 and ?-GCS in anti-Nrf2 antibody group decreased(P < 0.05),while the expression of NQO1,?-GCS and HO-1 in Nrf2 activator group increased(P < 0.05).Compared with normoxia control group 2,the expression of HO-1,NQO1 and ?-GCS in intermittent hypoxia group 1 decreased(P < 0.05).Compared with the intermittent hypoxia group 2,HO-1 and NQO1 and ?-GCS were decreased and increased in the EGB low concentration group(P < 0.05).The expression of HO-1 and ?-GCS and NQO1 decreased in the middle concentration group of EGB(P < 0.05).The expression of HO-1,?-GCS and NQO1 was increased in the high concentration group of EGB(P < 0.05).In knockout mice,1.Protein expression:Compared with the normoxic control group,the expression of HO-1,NQO1 and ?-GCS in the intermittent hypoxia group had no significant difference(P > 0.05).Compared with the intermittent hypoxia group,there was no significant difference in HO-1,NQO1 and ?-GCS between the low-concentration EGBgroup and the intermittent hypoxia group(P > 0.05).The expression levels of NQO1 and ?-GCS increased in the middle concentration group of EGB(P < 0.05),but there was no significant difference in HO-1(P > 0.05).The expression levels of HO-1,NQO1 and ?-GCS in the downstream pathway of EGB high concentration group increased,and the changes were more obvious in the high concentration group than in the low concentration group(P < 0.05).2.The expression of mRNA:Compared with the normoxic control group,the expression of NQO1 and ?-GCS in the intermittent hypoxia group was not significantly different(P > 0.05),but the expression of HO-1 was increased(P < 0.05).Compared with the intermittent hypoxia group,the expression of NQO1 and HO-1 and ?-GCS in the EGB low concentration group had no significant difference(P > 0.05),but the expression of HO-1 and ?-GCS increased(P < 0.05).The expression of NQO1,HO-1 and ?-GCS was increased in the middle concentration group of EGB(P < 0.05).There was no significant difference in the expression of NQO1 and HO-1 and ?-GCS in the high concentration group of EGB(P > 0.05),but the expression of HO-1 and?-GCS increased(P < 0.05).Conclusions: 1.Intermittent hypoxia-induced oxidative stress participates in the occurrence and development of OSAS,which may be an important mechanism of pancreatic tissue damage,oxidative damage and apoptosis of islet beta cells in OSAS.2.Nrf2-ARE signaling pathway can regulate the levels of oxidative stress and inflammatory factors induced by intermittent hypoxia,alleviate pancreatic tissue damage,protect islet beta cells and improve islet function.3.Ginkgo biloba extract can alleviate oxidative stress injury after intermittent hypoxia and protect pancreatic tissue.Its mechanism may be related to activation of Nrf2-ARE signaling pathway.EGB has potential clinical value in the treatment of diabetes mellitus with OSAS. |
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