Abstract
Several members of the genus Copaifera are present in Latin America,
mainly in the Amazon region. These plants produce oleoresins that are used
by indigenous people for medicinal purposes, with no distinction among
species. Their medicinal properties include the treatment of cutaneous
ulcerations associated with leishmaniasis and wounds caused by insect bites.
However, to date, no comparative studies of the antiparasitic activity of
copaiba oleoresins from different species against Trypanosoma cruzi
have been published. In the present study, copaiba oleoresins from eight
species were evaluated for activity against T. cruzi, including
observations of cytotoxic effects in mammalian cells and parasite cells. All
of the copaiba oleoresins exerted effects on all parasite life stages,
especially against the replicative forms. C. martii and C.
officinalis exhibited the best activity. For intracellular
amastigotes, the IC50 values varied from less than 5.0 µg/mL to
10.0 µg/mL. For epimastigotes and trypomastigotes, the maximum inhibition
was obtained with IC50 values of 17.0 µg/mL and 97.0 µg/mL,
respectively. Oleoresins showed moderate cytotoxicity to nucleated cells,
17.5 to 32.5 µg/mL being the concentration range needed to reduce the
monolayer integrity by 50 %. Toxicity to erythrocytes was observed by a
hemolytic effect of 50 % above 500 µg/mL for half of the oleoresins from
different species. Different oleoresins caused lipid peroxidation, increased
cell-membrane permeability and changed the mitochondrial potential.
Ultrastructural changes were observed after the treatment of the
intracellular amastigote forms of the parasite. The toxic potential differed
among oleoresins from distinct copaiba species, which can influence
medicinal efficacy. This is especially relevant for people who live far from
medical assistance and depend on medicinal plants.
Key words
antiprotozoal activity -
Copaifera
- Fabaceae - oleoresin -
Trypanosoma cruzi
- Chagasʼ disease
