Hepatitis C virus (HCV) alters mitochondrial dynamics associated with persistent viral infection and suppression of innate immunity. Mitochondrial dysfunction is also a pathologic feature of direct-acting antiviral (DAA) treatment. Despite the high efficacy of DAAs, their use in treating patients with chronic hepatitis C in interferon-sparing regimens occasionally produces undesirable side effects such as fatigue, migraine, and other conditions, which may be linked to mitochondrial dysfunction. Here, we show that clinically prescribed DAAs, including sofosbuvir, affect mitochondrial dynamics. To counter these adverse effects, we examined HCV-induced and DAA-induced aberrant mitochondrial dynamics modulated by ginsenoside, which is known to support healthy mitochondrial physiology and the innate immune system. We screened several ginsenoside compounds showing antiviral activity using a robust HCV cell culture system. We investigated the role of ginsenosides in antiviral efficacy, alteration of mitochondrial transmembrane potential, abnormal mitochondrial fission, its upstream signaling, and mitophagic process caused by HCV infection or DAA treatment. Only one of the compounds, ginsenoside Rg3 (G-Rg3), exhibited notable and promising anti-HCV potential. Treatment of HCV-infected cells with G-Rg3 increased HCV core protein-mediated reduction in the expression level of cytosolic p21, required for increasing cyclin-dependent kinase 1 activity, which catalyzes Ser616 phosphorylation of dynamin-related protein 1. The HCV-induced mitophagy, which follows mitochondrial fission, was also rescued by G-Rg3 treatment.

Conclusion

G-Rg3 inhibits HCV propagation. Its antiviral mechanism involves restoring the HCV-induced dynamin-related protein 1-mediated aberrant mitochondrial fission process, thereby resulting in suppression of persistent HCV infection. (Hepatology 2017;66:758-771).