In vivo anti-influenza virus activity of Kampo (Japanese herbal) medicine ''Sho-seiryu-to'' - Effects on aged mice, against subtypes of A viruses and B virus, and therapeutic effect

When aged BALB/c mice (similar to 6 months old) were treated with a Kampo (Japanese herbal) medicine ''Sho-seiryu-to (SST)'' (I g/kg, 10 times) orally from 7 days before to 4 days after the infection and infected with mouse-adapted influenza virus A/PR/8/34 (H1N1 subtype) by nasal site-restricted infection, replication of the virus in the broncho-alveolar cavity was efficiently inhibited at 5 days after infection in comparison with water-treated mice. The antiviral IgA antibody in the broncho-alveolar wash of the SST treated aged mice increased significantly. When mice (7 weeks old) were administered orally with SST (1 and 2 g/kg, 7 times) from 4 days before to 3 days after the infection and infected with mouse-adapted influenza virus A/Guizhou/54/89 (H3N2 subtype) or B/Ibaraki/2/85, replication of the viruses in the nasal cavity and lung were significantly inhibited at 4 days after infection in comparison with control mice. When mice infected with influenza virus A/Fukuoka/C29/85 (H3N2) before 14 days were secondary infected with A/PR/8 virus and administered orally with SST (1 g/kg, 5 times) from 2 h to 5 days after the secondary infection, replication of the virus in both nasal and broncho-alveolar cavities were significantly inhibited at 5 days after the secondary infection in comparison with water-treated control. Oral administration of SST (1 g/kg, 18 times) from 7 days before to 14 days after vaccination followed by secondary nasal inoculation of influenza HA vaccine (5 mu g/mouse) at 14 days after the first vaccination significantly augmented nasal antiviral IgA antibody and broncho-alveolar and serum antiviral IgG antibodies. These results suggest that SST is useful for influenza virus infection on aged persons and for cross-protection of subtypes of influenza A viruses and influenza B virus. SST is also useful for the treatment of influenza virus infection on human which has a history of influenza virus infection and/or influenza vaccination.