The infectivity of the lentivirus equine infectious anemia virus (EIAV) is not inhibited by H. perforatum subfractions E4.7 or E4.8. The subfractions were incubated with EIAV and added to ED cells (MOI = 0.005). Cultures were fixed at 40 h following infection and cells immunostained for EIAV antigens. Cytotoxicity of the subfractions on ED cells was performed in parallel, in the absence of EIAV. All data are shown as percent of control values.