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.

Oral administration of essential oil from Psidium glaziovianum Kiaersk leaves alleviates pain and inflammation in mice

Plants of the genus Psidium have been employed in "in natura" consumption and agroindustry, and owing to the diversity of phytochemicals, the development of new pharmaceutical forms has received remarkable research interest. In this study, the essential oil obtained from Psidium glaziovianum (PgEO) leaves were evaluated antinociceptive and anti-inflammatory activities were evaluated in mouse models. Initially, PgEO was characterized by gas chromatography-mass spectrometry and gas chromatography with flame ionization detection, and the profile was dominated by sesquiterpene compounds. In the evaluation of acute antinociceptive activity (abdominal contortions induced by acetic acid, formalin, tail immersion, and hot plate tests), PgEO promoted a reduction in nociception in the chemical and thermal models. Additionally, the potential underlying mechanism was investigated using pain pathway blockers, and the results revealed a combined action of opioidergic and muscarinic pathways. The anti-inflammatory potential was confirmed by anti-edematogenic action, reduced cell migration, pro-inflammatory cytokine production, and granuloma formation in chronic processes. This study provides evidence that PgEO can be effective for the treatment of pain and acute and chronic inflammation.

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.