Experimental Study On Protection And Mechanism Of 1, 2, 3, 4, 6-penta-O-galloy-β-D-glucose On The Cell Model Of Parkinson's Disease

Part I PGG ameliorates oxidative stress.induced byMPP+in PC 12 cellsObject:To investigate whether PGG could induce the expression of HO-1 and Whether HO-1 could ameliorate oxidative stress induced by MPP+in PC 12 cells Methods:we treated the PC 12 cells,which were incubated by NGF one week before drug treatment, for 10h with various concentrations of PGG and treated the PC 12 cells, which were incubated by NGF one week before drug treatment,for various time points with 30μM PGG;we used these various time points-0,3,6,12,18,24h when we studied the production of HO-1 mRNA, and we used these various time points-0,5,10,15,20,30h when we studied the expression of HO-1 protein.Then we examined the relationship between various concentrations and various time points of PGG and the production of HO-1 mRNA and protein by Western blotting, RT-PCR, DCFH-DA and MTT assay. the relationship between activity of HO-1 and various concentrations and various time points of PGG; and whether PGG could ameliorate oxidative stress.induced by MPP+in PC12 cells.Results:The production of HO-1 mRNA and protein is in dose-dependent concentration-dependent manners. HO-1 mRNA levels showed an initial rise at 20μM,a peak induction at 50μM,and a decrease by 80μM. Induction of the HO-1 mRNA in PC12 cells is a time-dependent manner, HO-1 mRNA levels showed an initial rise at 6h,a peak induction at 12h,followed by a decrease at 18h. Exposure of PC 12 cells to various concentrations of PGG for 10h resulted in a concentration-dependent increase in HO-1 protein expression,and the increase trend is similar to production of HO-1 mRNA.And the trend of HO-1 protein levels showed an initial rise atlOh,a peak induction at 15h,followed by a decrease at 20h. HO-1 activity was also increased in dose-dependent and time-dependent manners which is similar to the dose-dependent and time-dependent manners of HO-1 protein expression. And PGG could ameliorate induced byMPP+in PC 12 cells. Part II Effect of PGG on the expression of HO-1 via ERK1/2 signaling pathwayObject:Here, we study the role of ERK1/2 signaling pathway in induction of HO-1 by PGG in the PC 12 cells.. Methods:The PC12 cells were divided into different groups,and then were incubated by PGG, PD98059 and ZnPP according to different groups. And then Western blotting and MTT assay were used to investigate the difference of p-ERK1/2,Nrf2,HO-1 expression,and activity of the PC 12 cells after the treatment with different drugs.Results: PGG could promote the phosphorylation of ERK1/2 which promoted Nrf2 nuclear translocation which promoted the expression of HO-1 and thus protected PC 12 from damage by MPP+.But PD98059 produced opposite role in the process that PGG protected PC 12 cells-PD98059 suppressed the protection of PC 12 cells by PGG partly.Conclusion:ERK1/2 signaling pathway played a role in the protection of PC12 cells by PGG. PartⅢEffect of PGG on the expression of HO-1 via PI3K/AKT signaling pathwayObject:Here, we study the role of PI3K/AKT signaling pathway in induction of HO-1 by PGG in the PC 12 cells.Methods:The PC12 cells were divided into different groups,and then were incubated by PGG, PD98059 and ZnPP according to different groups. And then Western blotting and MTT assay were used to investigate the difference of p-AKt,Nrf2,HO-1 xpression,and activity of the PC 12 cells after the treatment with different drugs.Results:PGG could promote the phosphorylation of AKt which promoted Nrf2 nuclear translocation which promoted the expression of HO-1 and thus protected PC 12 from damage by MPP+。But LY294002 produced opposite role in the process that PGG protected PC 12 cells-LY294002 suppressed the protection of PC 12 cells by PGG partly.LY294002 and PD98059 together could blocked Nrf2 nuclear translocation and expression of HO-1 completely, but could not abolish completely the protection of PC 12 cells by PGG.Conclusion:PI3K/AKT signaling pathway played a role in the protection of PC 12 cells by PGG.