Evaluation of the trypanocidal activity of lignans isolated from the leaves of Zanthoxylum naranjillo

Seven lignans isolated from the hexane extract of the leaves of Zanthoxyllu m naranjillo (Rutaceae) were tested in both in vitro and in vivo assays aga inst two strains of Trypanosoma cruzi (Bolivia and Y). Of the seven assayed lignans, three were inactive [(+)-sesamin, (+)-piperitol-4'-O-gamma,gamma- dimethylallyl ether and (-)3,4-dimethoxy-3',4'-demethylenedioxycubebin] and three were partially active in the in vitro assays [(-)-hibalactone, (-)-k aerophylin and (-)-cubebin]. Healthy animals developed the disease after in jection of the tested infected blood samples containing these three compoun ds. One compound [(-)methylpluviatolide] was highly effective in the in vit ro assay and healthy animals injected with the tested samples did not devel op the disease. Moreover, only (-)-methylpluviatolide was highly active aga inst the bloodstream forms of both strains of T. cruzi for the in vivo assa y. However, it was not active against the tissue forms of the parasite.