Antiviral activity of ginseng extract against respiratory syncytial virus infection.

Panax ginseng has been known to have a number of immuno-modulatory effects. In this study, we investigated whether Panax Korean red ginseng extract (KRGE) has in vitro and in vivo antiviral effects on respiratory syncytial virus (RSV) infection. KRGE improved the survival of human lung epithelial cells against RSV infection and inhibited RSV replication. In addition, KRGE treatment suppressed the expression of RSV-induced inflammatory cytokine genes (IL-6 and IL-8) and the formation of reactive oxygen species in epithelial cell cultures. Oral administration of mice with KRGE resulted in lowering lung viral loads after RSV infection. Additionally, the in vivo effects of KRGE showed an enhanced level of interferon-γ (IFN-γ) producing dendritic cells subsequent to RSV infection. Taken together, these results suggested that KRGE has antiviral activity against RSV infection.