Eupafolin and Ethyl Acetate Fraction of Kalanchoe gracilis Stem Extract Show Potent Antiviral Activities against Enterovirus 71 and Coxsackievirus A16
Figure 7
Virucidal activity and attachment inhibition of eupafolin, EA, and BuOH fractions. In virucidal assay (a), eupafolin or each fraction was mixed with EV71 or CoxA16 (106 pfu), then incubated at 4°C for 1 h. Residual infectivity was performed by plaque assay with 1000-fold dilution of virus/compound mixture. In the attachment assay (b), EV71 or CoxA16 (50 pfu) was mixed with EA, BuOH fraction, or eupafolin, then immediately added onto RD cell monolayer for 1 h at 4°C. After washing twice with PBS, monolayer was overlaid with 2 mL of agarose medium for 2 days at 37°C in CO2 incubator. Attachment inhibition was calculated as residual plaques after crystal violet staining.
