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-SY5Y 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 bro-mide assay, and the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. Changes in the structure and function of mitochondria were confirmed using mitotracker, MitoSOX red mitochondrial superoxide indicator, parkin, and phosphatase and tensin homolog deleted on chromo-some 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-SY5Y cell death by regulating cytochrome c release from mitochondria and PINK1/parkin-mediated mitophagy, through regulation of the Bcl-2 family. (C) 2021 Shanghai Yueyang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. Published by Elsevier B.V. All rights reserved.

Automated summary

The study shows that Korean red ginseng effectively prevents MPP+-induced SH-SY5Y cell death by regulating cytochrome c release from mitochondria and PINK1/parkin-mediated mitophagy, through the regulation of the Bcl-2 family.