Different parts of 67 plants from the Biological Reserve Alberto Manuel Brenes (REBAMB) of Costa Rica,were studied for the presence of active components against Trypanosoma cruzi. The hydroalcoholic extracts of fresh or dried materials, were analyzed, in principle, with pilot presumptive tests, and then more specific, for their potential activity against the parasite; the Silvio (ATCC-50799) strain was used in all analyzes. Plants with at least one of its parts with a IC50<100 ug / mL were: Beilschmedia pendula, Bocconia frutescens, Guarea rhopalocarpa, Hydrocotyle mexicana, Povedadaphne quadriporata, Piper auritum, Ruagea glabra and Xanthosoma undipes. Most of the fresh extracts showed activity against T. cruzi. The species B. frutescens had the major number of active parts and only 3 of all the extracts studied showed some degree of toxicity. The impact that these findings represent alternatives in terms of treatment of Chagas disease.
