Korean red ginseng decreases 1-methyl-4-phenylpyridinium-induced mitophagy in SH-SY5Y cells

Objective:Mitophagy is known to contribute towards progression of Parkinson’s disease.Korean red ginseng(KRG)is a widely used medicinal herb in East Asia,and recent studies have reported that KRG prevents 1-methyl-4-phenylpyridinium ion(MPP^(+))-induced cell death.This study was undertaken to investigate whether KRG suppresses MPP^(+)-induced apoptosis and mitophagy.Methods:SH-SY5 Y cells were incubated with KRG for 24 h,and subsequently exposed to MPP^(+).The MPP^(+)-induced cell death was confirmed with the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay,and the terminal deoxynucleotidyl transferase-mediated d UTP nick end-labeling assay.Changes in the structure and function of mitochondria were confirmed using mitotracker,Mito SOX red mitochondrial superoxide indicator,parkin,and phosphatase and tensin homolog deleted on chromosome ten-induced putative kinase 1(PINK1)immunofluorescent staining.Western blotting was performed to evaluate the expression of apoptosis-related factors in whole cells,including Bax,Bcl-2 and cleaved caspase-3,and mitophagy-related factors in the mitochondrial fraction,including cytochrome c,parkin,PINK1,translocase of the outer membrane 20(TOM20),p62 and Beclin 1.Results:MPP^(+)induced cell death by cytochrome c release and caspase-3 activation;however,this effect was suppressed by KRG’s regulation of the expressions of Bcl-2 and Bax.Moreover,MPP^(+)exposure increased the mitochondrial expressions of parkin,PINK1,Beclin 1 and p62,and decreased TOM20,cytochrome c and Bcl-2 expressions.These MPP^(+)-induced changes in the mitochondrial fraction were attenuated by treatment with KRG.Conclusion:KRG effectively prevents MPP^(+)-induced SH-SY5 Y cell death by regulating cytochrome c release from mitochondria and PINK1/parkin-mediated mitophagy,through regulation of the Bcl-2 family.