Fig. 3From: Characterization and mechanisms of anti-influenza virus metabolites isolated from the Vietnamese medicinal plant Polygonum chinense Plaque inhibition assay of PC5 (a), PC7 (b) and PC8 (c) against PR8, HK and Lee. At 1 h after infection with influenza virus at an MOI of 0.001, MDCK cells were treated with serially diluted compounds dissolved in the overlay medium. At day 3 postinfection, viral plaques were visualized using crystal violet staining. The images are representative of three experiments (upper). The numbers of plaques in each well were counted (lower). Shown are averaged percentages and SD of three different wells. n.d., not detected. *P < 0.05Back to article page