This paper evaluates CHCl
3 and CH
3OH extracts of the stem bark, branches and leaves of
Drimys brasiliensis
and
drimane sesquiterpenes isolated from the stem bark against strains of
Leishmania amazonensis and
Leishmania braziliensis promastigotes and
Plasmodium falciparum trophozoites. All of the extracts and compounds were tested in cell lines in comparison with reference standards and cell viability was determined by the XTT method. The CHCl
3 and CH
3OH extracts from the stem bark and branches yielded promising results against two strains of Leishmania, with 50% inhibitory concentrations (IC
50) values ranging from 39-100 μg/mL. The CHCl
3 extract of the stem bark returned IC
50 values of 39 and 40.6 μg/mL for
L. amazonensis and
L. braziliensis, respectively. The drimanes were relatively effective: 1-β-(p-coumaroyloxy)-polygodial produced IC
50 values of 5.55 and 2.52 μM for
L. amazonensis and
L. braziliensis, respectively, compared with 1-β-(p-methoxycinnamoyl)-polygodial, which produced respective IC
50 values of 15.85 and 17.80 μM. The CHCl
3 extract demonstrated activity (IC
50 of 3.0 μg/mL) against
P. falciparum. The IC
50 values of 1-β-(p-cumaroyloxyl)-polygodial and 1-β-(p-methoxycinnamoyl)-polygodial were 1.01 and 4.87 μM, respectively, for the trophozoite strain. Therefore, the results suggest that
D. brasiliensis is a promising plant from which to obtain new and effective antiparasitic agents.
