Antileishmanial in vitro activity of essential oil from Myrciaria plinioides, a native species from Southern Brazil

In South American folk medicine members of the genus Myrciaria are used for the treatment of malaria, diarrhoea, asthma, inflammation and post-partum uterine cleansing. The aim of this work was to evaluate its antileishmanial properties (in vitro) of essential oil derived from leaves of Myrciaria plinioides D. Legrand, a plant species that is native in South of Brazil. The essential oil was obtained by hydro-distillation using fresh leaves of M. plinioides. The chemical composition of this essential oil (MPEO, M. plinioides essential oil) was determined by gas chromatography coupled to mass spectrometry (GC-MS). MPEO was assayed in vitro for antileishmanial properties against promastigotes of Leishmania amazonensis and Leishmania infantum, and for cytotoxicity against murine peritoneal macrophages. The MPEO comprised 66 components and was rich in oxygenated sesquiterpenes (82.66%) containing spathulenol (21.12%) as its major constituent. The MPEO was effective against L. amazonensis with IC50 value of 14.16 ± 7.40 µg/mL, while against L. infantum the IC50 value was higher with 101.50 ± 5.78 µg/mL. The MPEO showed significant activity against L. amazonensis, and presented a selectivity index (SI) of 6.60. The results suggest that the essential oil from leaves of M. plinioides is a promising source for new antileishmanial agents against L. amazonensis.

Activity of Brazilian and Bulgarian propolis against different species of Leishmania

Extracts of propolis samples collected in Brazil and Bulgaria were assayed against four Leishmania species - Leishmania amazonensis, L. braziliensis, L. chagasi from the New World, and L. major from the Old World - associated to different clinical forms of leishmaniasis. The composition of the extracts has been previously characterized by high temperature high resolution gas chromatography coupled to mass spectrometry. Considering the chemical differences among the extracts and the behavior of the parasites, it was observed significant differences in the leishmanicidal activities with IC50/1 day values in the range of 2.8 to 229.3 µg/ml . An overall analysis showed that for all the species evaluated, Bulgarian extracts were more active than the ethanol Brazilian extract. As the assayed propolis extracts have their chemical composition determined it merits further investigation the effect of individual components or their combinations on each Leishmania species.