Antiviral activity of Stachyflin in mice. Four BALB/c mice were intranasally infected with 10 MID50 of WSN (A) or Ibaraki (B). After inoculation, the solution of Stachyflin in polyethylene glycol 400 was intraperitoneally administered to each group every 12 h for 72 h. At 72 h post-inoculation, mice were sacrificed and the lungs were collected for virus titration. Dashed lines indicate virus titer less than the detectable dose (101.5 TCID50/g). *, P<0.05 compared to results for controls. **, P<0.01 compared to results for controls.