Effects of quercetin and isoquercitrin on VZV and HCMV IE protein levels. HFF cells were (A) inoculated with VZV–pOka-infected HFF cells or (B) infected with HCMV–Towne at an MOI of 0.1, followed by treatment with DMSO, quercetin (Q), and isoquercitrin (Q3G) or 1,2,3,4,6-penta-O-galloyl-ß-D-glucose (PGG) at a concentration of 20 µg/mL. As a control, VZV- and HCMV-infected HFF cells were treated with ACV (1.2 µg/mL) and GCV (2.3 µg/mL), respectively. At 48 h after infection, equal amounts of cell lysates were subjected to Western blot with antibodies against VZV IE62, HCMV IE2, and tubulin. COMP, compound.