Ginseng, the natural effectual antiviral: Protective effects of Korean Red Ginseng against viral infection

Im, Kyungtaek; Kim, Jisu; Min, Hyeyoung

In addition to antiviral activity, RGE also plays a role as a mucosal adjuvant against influenza virus A/PR8 during viral infection [35] . When administered with inactivated virus and RGE intranasally, immunized mice produced increased levels of influenza virus-specific antibodies with improved neutralizing activities in blood and mucosal secretions, notably the IgA antibody in the lung. RGE plus virus immunization also resulted in the enhanced secretion of Th1 and Th2-type cytokines in splenocytes upon challenge infection, although a Th2 type response was more remarkable. This adjuvant effect of RGE was comparable to that of conventional adjuvants such as aluminum hydroxide and cholera toxin. Additionally, immunization of mice with inactivated H3N2 influenza antigen and ginsenoside Re resulted in increased immune responses by elevating both Th1 and Th2 cell activities [2] . The secretion of serum-specific IgG1 and IgG2a and hemagglutination inhibition titers were all increased, and in vitro stimulation of splenocytes produced higher levels of Th1 and Th2 cytokines in ginsenoside Re-administered mice. Furthermore, dietary intake of RGE and Korean Red Ginseng saponin (KRGS) has also been shown to improve H1N1 vaccine efficacy by increasing anti-influenza virus A-specific IgG titers and survival rates [36] . In addition, GP induced cross-protective vaccine efficacy. When mice were vaccinated with influenza virus-like particles (VLPs) originating from H1N1 together with GP, the immunized mice developed heterosubtypic protection and survived a lethal challenge with the H3N2 virus. Taken together, the data suggest the use of RGE, KRGS, ginsenoside Re, and GP as adjuvant or dietary supplements to enhance the vaccine-induced immune response and improve protection against influenza virus infection.