Antiviral effect of water soluble substance from Elfvingia applanata alone and in combinations with interferons on vesicular stomatitis (Indiana serotype)

In order to find less toxic antiviral agents from Basidiomycetes, EA, the water soluble substance, was prepared from the carpophores of Elfvingia applanata (Pers.) Karst. Antiviral activity of EA against vesicular stomatitis virus [Indiana serotype, VSV(IND)] was examined in Vero cells using plaque reduction assay in vitro. And the combined antiviral effects of EA with interferon (IFN) alpha or gamma were examined on the multiplication of VSV(IND). EA caused a concentration-dependent reduction in the plaque formation of VSV(IND) with 50% effective concentration (EC₅₀) of 104.02 μg/ml. The results of combination assay were evaluated by the combination index (CI) that was analysed by the multiple drug effect analysis. All cases of the combinations of EA with IFN alpha or IFN gamma showed potent synergism with CI values of 0.38~0.52 for 50~90% effective levels.