Antiviral Activity of Isatis indigotica Extract and Its Derived Indirubin against Japanese Encephalitis Virus
Figure 2
Plaque reduction of JEV by I. indigotica and its major components in pre-, simultaneous, and post-treatment assays. Serial dilutions of ethyl acetate and methanol extracts of I. indigotica (a) and its components indigo and indirubin (b) were pretreated before virus absorption, simultaneously with virus infection, or posttreated after virus absorption (JEV at 100 pfu/well). BHK-21 cell monolayer was incubated with virus/compound mixture at 37°C for 1 h, then overlaid with MEM medium containing 1.1% methylcellulose. Viral plaques were stained with naphthol blue-black dye after 3 days of incubation.
