Chemical Composition, in vitro Trypanocidal and Antibacterial Activities of the Essential Oil from the Dried Leaves of Eugenia dysenterica DC from Brazil

Abstract

Natural products are a very important source of bio-molecules for drug to treat infectious diseases. The essential oil of Eugenia dysenterica DC. dried leaves (Ed-EO), of the Myrtaceae family, was analyzed by gas chromatography with flame ionization detector (GC/FID) and by mass spectrometry (GC/MS) in order to identify their volatile components. A total of 24 compounds were identified from Ed-EO. The major compounds found in Ed-EO were limonene (16.0 %), caryophyllene oxide (15.0 %), citral (9.0 %), trans-caryophyllene (8.0 %), and 1,8-cineole (7.3 %). The in vitro biological activities of Ed-EO were investigated against trypomastigote forms of Trypanosoma cruzi and bacteria of the genus Streptococcus. Our results demonstrated that Ed-EO, tested against T. cruzi, affected trypomastigote growth in a dose-dependent manner. The IC50 of Ed-EO was 9.5 μg/mL, while the IC50 of benznidazole (positive control) was 9.8 μg/mL, revealing remarkable trypanocidal action. The minimum inhibitory concentrations (MICs) were determined by the broth dilution method in 96-well microplates. The Ed-EO displayed moderate antibacterial activity against Streptococcus mitis (MIC = 250 μg/mL), S. sanguinis (MIC = 200 μg/mL), S. sobrinus (MIC = 400 μg/mL), and S. salivarius (MIC = 400 μg/mL), and strong activity against S. mutans (MIC = 31.2 μg/mL). These results suggest that the oil of E. dysenterica dried leaves could be tested in future studies for the treatment of Chagas disease and dental caries.