A single dose of coumarin derivatives, warfarin, 4-hydroxycoumarin and umbelliferone, added at the time of inoculation either by free virus or by contact with U1 monocytes exhibited a dose-dependent inhibitory effect on viral replication in target MOLT-4 lymphocytes observable even at 5 days post infection. In addition, marked decrease of HIV-1 gap p24 release and reduction in reverse transcriptase activity was observed when chronically HIV-infected ACH-2 lymphocytes were treated with coumarins (ED50% range 10(-6)-10(-9) mol/l). However, the intracellular composition of HIV-1 core proteins in drug-exposed cells was not modified. Results suggest that although no complete inhibition of viral production has been observed in vitro this class of drugs may present potential interest as antiviral agents.
