THE ANTIVIRAL EFFECT OF KEISHI-NI-EPPI-ICHI-TO, A TRADITIONAL CHINESEHERBAL MEDICINE, ON INFLUENZA A(2)(H2N2) VIRUS-INFECTION IN MICE

The antiviral effect of Keishi-ni-eppi-ichi-to (TJS-064), a traditiona l Chinese herbal medicine, was investigated in mice infected with infl uenza A(2)(H2N2) virus. When mice exposed to a 5 LD(50) dose of the vi rus were treated orally with a 70 mg/kg dose of TJS-064 1 day before a nd 1 day and 4 days after the infection, 100% survived over a 25-day e xperimental period. At the end of this period all the control mice, tr eated with saline alone, had died; their mean survival time in days (M SD) was 11.2 days. When mice infected with a 10 LD(50) dose of the vir us were treated with TJS-064, the MSD was > 17.4 days and there was a 50% survival rate, while the control group had a MSD of 8.7 days and a 0% survival rate. No significant antiviral effect of TJS-064 was obse rved when the agent was administered orally to mice infected with a 10 0 LD(50) or larger dose of influenza virus. Pulmonary consolidations, virus titers in lung tissues and HAI titers in sera of infected mice t reated with TJS-064 were all significantly lower than those of infecte d mice treated with saline. Interferon activities were detected in ser a of mice treated with the agent at a dose of 100 mg/kg orally. Since viricidal and viristatic activities of the agent against influenza vir us were not demonstrated, the antiviral effects of TJS-064 may be expr essed through the host's antiviral functions including interferon prod uction.