Figure 1

The inhibitory effects of TLCK, TPCK, E64, bortezomib, and MG132 on HSV-1 replication. (a–e) The bar graphs in a, b, c, d, and e show the anti-HSV-1 activities of TLCK, TPCK, E64, bortezomib, and MG132, respectively, calculated by plaque reduction assay. Vero cells cultured in 12-well tissue culture plate were infected with HSV-1 (HF strain) at 50 plaque forming units (PFU)/well for 30 min, and then cultured for 2 days with DMEM containing methylcellulose and serially diluted test compounds. Cell sheets were stained and fixed with crystal violet in 50% methanol, and the total number of plaques was quantified. The plaque number in vehicle (DMSO) treated cells was defined as 100%. Standard deviations were determined by analysis of data from three independent experiments, and are indicated by error bars. ^*P < 0.05 and ^**P < 0.01 indicate statistical significance compared with vehicle (DMSO) treated cells. N.S. indicates not statistically significant. (f) Cytotoxic effect of MG132 on Vero cells. Cells were incubated with various concentrations of MG132 for 48 hours and subjected to cell viability assays. The value of DMSO treated cells was defined as 100%.