Antiviral effects of Korean Red Ginseng on human coronavirus OC43

BACKGROUND: Panax ginseng Meyer is a medicinal plant well-known for its antiviral activities against various viruses, but its antiviral effect on coronavirus has not yet been studied thoroughly. The antiviral activity of Korean Red Ginseng (KRG) and ten ginsenosides against Human coronavirus OC43 (HCoV-OC43) was investigated in vitro. METHODS: The antiviral response and mechanism of action of KRG extract and ginsenoside Rc, Re, Rf, Rg1, Rg2-20 (R) and −20 (S), Rg3-20 (R) and −20 (S), and Rh2-20 (R) and −20 (S), against the human coronavirus strain OC43 were investigated by using plaque assay, time of addition assay, real-time PCR, and FACS analysis. RESULTS: Virus plaque formation was reduced in KRG extract-treated and HCoV-OC43-infected HCT-8 cells. KRG extract decreased the viral proteins (Nucleocapsid protein and Spike protein) and mRNA (N and M gene) expression, while increased the expression of interferon genes. CONCLUSION: KRG extract exhibits antiviral activity by enhancing the expression of interferons and can be used in treating infections caused by HCoV-OC43.