In vivo antiinfluenza virus activity of Kampo medicine Sho-seiryu-to through mucosal immune system.

The Kampo (Japanese herbal) medicine, Sho-seiryu-to, which has traditionally been used for the treatment of colds and bronchial asthma, showed potent antiinfluenza A and B virus activity through augmentation of production of antiviral IgA antibody in the nasal and bronchoalveolar cavities of mice when administrated orally before viral infection. Sho-seiryu-to also showed antiinfluenza virus activity against A virus H1N1 subtype infected in aged mice (approximately 6 months old) with an increase of antiviral IgA antibody in the bronchoalveolar wash of the treated mice by similar administration. When mice infected with mouse nonadapted influenza A virus H3N2 subtype before 14 days were secondarily infected with mouse adapted A/PR/8 (H1N1) virus and administered Sho-seiryu-to orally after the second infection, replication of the virus in both nasal and bronchoalveolar cavities was significantly inhibited. Sho-seiryu-to had no effect on the mice which were not primed with mouse nonadapted virus when administered after the infection of mouse-adapted A/PR/8 virus. Oral administration of Sho-seiryu-to caused increment of viral-specific IgA antibody secreting cells in mouse nasal lymphocyte. Sho-seiryu-to also augmented IL-2 receptor beta chain+ T-cells in Peyer's patch of the infected mice. Sho-seiryu-to also significantly reduced viral titer in the nasal washes of the infected ovalbumin-sensitized bronchial asthma model mice. Oral administration of Sho-seiryu-to before and after vaccination significantly augmented hemagglutination-inhibiting antibody in the serum by nasal inoculation of influenza HA vaccine, and significantly augmented nasal antiviral IgA antibody and bronchoalveolar and serum antiviral IgG antibodies even after secondary vaccination although induction of antiviral antibody by intranasal vaccination was insufficient without Sho-seiryu-to. These results suggest that Sho-seiryu-to is able to prevent influenza virus infection by cross-protection of subtypes of influenza A virus and B virus. Sho-seiryu-to is also useful for the treatment of influenza virus infection in hosts with a history of influenza virus infection and/or influenza vaccination and allergic pulmonary inflammation, such as bronchial asthma, and can be used as an adjuvant to nasally inoculated influenza HA vaccine.