ANTIPLASMODIAL TRITERPENE FROM VERNONIA-BRASILIANA

The hexane extract from leaves of Vernonia brasiliana (L.) Druce (Comp ositae) was active in vitro against Plasmodium folciparum and in vivo in mice infected with Plasmodium berghei. This extract was subjected t o a bioassay-guided fractionation protocol based on the in vitro model . Lupeol was identified as a compound responsible for the activity, in hibiting the P. falciparum growth by 45 % when tested at 25 mu g/ml. H owever, this triterpene was inactive in vivo when 15 mg/kg were admini stered per os during four consecutive days to mice infected with P. be rghei. beta-Amyrin and germanicol, isolated from the same fraction tha t yielded lupeol, were inactive in the in vitro assay.