Effect of pre-treatment of PHK (primary human keratinocyte) cell cultures with the drugs on herpesvirus infection.

Confluent PHK cell cultures were pretreated with the drugs for different periods. Then, the drugs were carefully removed by several washing steps, after which the cultures were infected with HSV-1 or HSV-2. A control experiment in which the drugs were added to the virus-infected cultures for the entire incubation period before the read-out was also carried out (treatment condition: +2 h to 72 h). aThe 50% effective concentration (compound concentration required to inhibit HSV infection by 50%) as determined by scoring cytopathogenicity upon microscopical inspection.