RESUMEN
Crude extracts of leaves and fruits of Guarea guidona were tested antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the IB-RS-2 pig cell line and against bovine herpesvirus-1 (BHV-1) in the GBK bovine Cell line. The highest nontoxic doses of extracts from fruits and leaves were 125 mug/ml and 500 mug/ml, respectively. Crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 mug/ml. Virucidal activity was not observed at 62.5 mug/ml. Preformed cell monolayers showed no cytotoxic effect after 48 h in the presence of 500 mug/ml in pig cells. G. guidona leaves did not induce an antiviral state but exhibited antiviral effects during the early stage of viral infection.