Fig. 6.

Diphyllin inhibited virus production against major types/subtypes of human influenza virus strains. (A–D) MDCK cells were pretreated with diphyllin 1 h prior to four different influenza virus strains infection at an MOI of 0.01. Infected cells without diphyllin treatment were used as controls (black bars). After a 1-h period of infection, cells were washed, overlaid with fresh media containing the same concentrations of diphyllin as in previous step, and incubated for another 24 h. The cell culture supernatant was harvested for HA tests. Values are mean ± SD from three replicates. Viral titers between each treated group and the untreated control group were compared by one-way ANOVA followed by Dunnett’s multiple comparisons test. (ns: non-significant, ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001, ^∗∗∗∗p < 0.0001).