%0 Journal Article %T In vitro antimalarial activity of fractions and constituents isolated from Tabebuia billbergii Actividad antimal¨¢rica in vitro de fracciones y constituyentes aislados de Tabebuia billbergii %A Harold G¨®mez-Estrada %A Ricardo Gait¨¢n-Ibarra %A Fredyc D¨ªaz-Castillo %A Hilda A P¨¦rez %J Revista Cubana de Plantas Medicinales %D 2012 %I ECIMED %X Introduction: in vitro antimalarial activity of naphthoquinones (1-5), isolated from Tabebuia billbergii (Bureau & K. Schum.) Standl., was investigated. Tabebuia billbergii, commonly known as guayac¨¢n, is a plant traditionally used in the Amazon in numerous conditions like bacterial and fungal infections, fever, syphilis, malaria, trypanosomiasis, as well as stomach and bladder disorders, and tumours. Objective: to study the dichloromethane extracts of both the trunk and the inner bark of Tabebuia billbergii and to demonstrate the antimalarial activity of some of its bioactive components. Methods: some bioactive components were evaluated for the antimalarial activity against Plasmodium berghei, by using the inhibition of the differentiation cycle of the parasite measure by the 3H-hypoxanthine incorporation and compared to that obtained for chloroquine. Results: conventional chromatographic techniques and bioassay-guided fractionation (Artemia salina) allowed isolating from the active fractions one naphthoquinone (lapachol) and four naphtho-furan-4,9-diones. These compounds proved to have an important antiplasmodial effect, with very encouraging IC50's, especially when compared to the results shown by Chloroquine in the same experiment. In addition, two triterpenes, ¦Â-sitosterol and stigmasterol, were obtained from the bark. Conclusions: the activity-guided fractionation (A. salina) of dichloromethane extracts of the trunk and the inner bark of Tabebuia billbergii led to the isolation and the identification of five quinonoid compounds with antiplasmodial effect. The significant inhibitory activity in vitro against Plasmodium berghei observed for compound 2-acetyl-naphtho-[2,3b]-furan-4,9-dione allow us to present them as a potential antimalarial compound. Introducci¨®n: se evalu¨® la actividad antimal¨¢rica in vitro de una serie de naftoquinonas (1-5), aisladas de Tabebuia billbergii (Bureau & K. Schum.) Standl., que es conocida com¨²nmente como guayac¨¢n, una planta utilizada tradicionalmente en la Amazon¨ªa en numerosos problemas de salud como infecciones bacterianas y f¨²ngicas, fiebre, s¨ªfilis, paludismo, tripanosomiasis, as¨ª como en problemas estomacales, tumores y trastornos de la vejiga. Objetivo: estudiar los extractos en diclorometano tanto del tronco como la corteza interna de Tabebuia billbergii y evaluar la actividad antimal¨¢rica de algunos de sus componentes bioactivos. M¨¦todos: la actividad antimal¨¢rica contra Plasmodium berghei se evalu¨® en algunos componentes bioactivos, por la inhibici¨®n del ciclo de la diferenciaci¨®n de la medida de los par¨¢sit %K Tabebuia billbergii %K naftoquinonas %K Plasmodium berghei %K Tabebuia billbergii %K naphthoquinones %K Plasmodium berghei %U http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S1028-47962012000200006