Anti-Trichomonas vaginalis activity of essential oils extracted from Caatinga Myrtaceae species and chemical composition of Eugenia pohliana DC

The current trichomoniasis treatment is restrict to 5-nitroimidazole drugs and the emergence of resistant isolates points the need for new therapeutical alternatives. In this study the anti-Trichomonas vaginalis activity of essential oils obtained from Myrtaceae occurring in Caatinga, a plant family with potential antiparasitic activity, was showed. The essential oils varied in their capacity to kill ATCC and fresh clinical T. vaginalis isolates, which was associated with heterogeneity and different patterns of endosymbiosis. Essential oils caused moderate to strong cytotoxicity against mammalian cells, but essential oil of Eugenia pohliana (EOEp) exhibited promising selectivity index towards vaginal epithelial cells. A checkerboard assay revealed a synergistic effect when EOEp and metronidazole were associated, indicating different mechanisms of action. The GC/MS analysis demonstrated the volatile composition of EOEp, with δ-cadinene as majoritary component. This molecule seems to contribute to the trichomonacidal effect and shows potential for the prospection of new antiparasitic compounds.

Leishmanicidal and trypanocidal potential of the essential oil of Psidium myrsinites DC

Neglected tropical diseases (NTDs) are a group of pathologies caused by infectious agents or parasites, including the protozoa Leishmania sp. and Trypanosoma cruzi, which cause leishmaniasis and Chagas disease, respectively. The complications of the treatment regimen indicate the urgent need to search for new strategies and therapeutic agents. Among these is the essential oil of Psidium myrsinites DC. The essential oil of the leaves (PMEO) was evaluated in vitro, and cytotoxic activity was analysed against promastigotes of Leishmania braziliensis and Leishmania infantum and epimastigotes of Trypanosoma cruzi, as well as mammalian cells. The results showed that the PMEO had relevant activity against L. braziliensis, low cytotoxicity and a high selectivity index SI = 6.6. These results suggest that PMEO has antiparasitic potential against L. braziliensis, making this species is a possible alternative therapeutic source, given its effectiveness in the in vitro tests performed, opening the possibility of new biological studies in vivo.

Chemical composition, antioxidant and antiprotozoal activity of Eugenia gracillima Kiaersk. leaves essential oil

This work evaluated the volatile composition, antioxidant and antiprotozoal activities of the essential oil obtained from leaves of Eugenia gracillima Kiaersk. (EGEO) grown in Brazilian Northeast area (Araripe, Brazil). The volatile compounds of EGEO were analyzed by GC and GC-MS and its chemical composition is mainly composed of sesquiterpene hydrocarbons (91.22%), oxygenated sesquiterpenes (7.45%) and monoterpene (1.01%). The most abundant volatile constituents of the EGEO were germacrene D (16.10%), γ-muurolene (15.60%), bicyclogermacrene (8.53%), germacrene B (7.43%), and Δ-elemene (6.06%). The oil showed weak to moderate antioxidant activity. EGEO was highly selective to Leishmania braziliensis and Leishmania infantum promastigotes with selective indexes of 73.66 and 71.41, respectively. EGEO did not inhibit Trypanosoma cruzi. These data suggest that the E. gracillima essential oil is a relevant source of lead compounds for development of anti-Leishmania drugs.