This study analyses the anti-proliferative effect of lemongrass essential oil and its main constituent (citral) on all 3 evolutive forms of Trypanosoma cruzi. Steam distillation was used to obtain lemongrass essential oil, with chemical composition determined by gas chromatography (GC) and GC coupled to mass spectrometry (GC-MS). The IC50/24 h (concentration that reduced the parasite population by 50%) of the oil and of citral upon T. cruzi was determined by cell counting in a Neubauer chamber, while morphological alterations were visualized by scanning and transmission electron microscopy. Treatment with the essential oil resulted in epimastigote growth inhibition with IC50=126.5 microg/ml, while the IC50 for trypomastigote lysis was 15.5 microg/ml. The IC50/48 h for the Association Index (% macrophage infection x number of amastigotes per cell) was 5.1 microg/ml, with a strong inhibition of intracellular amastigote proliferation. Ultrastructural analysis demonstrated cytoplasmic and nuclear extraction, while the plasma membrane remained morphologically preserved. Our data show that lemongrass essential oil is effective against T. cruzi trypomastigotes and amastigotes, and that its main component, citral, is responsible for the trypanocidal activity. These results indicate that essential oils can be promising anti-parasitic agents, opening perspectives to the discovery of more effective drugs of vegetal origin for treatment of parasitic diseases. However, additional cytotoxicity experiments on different cell lines and tests in a T. cruzi-mouse model are needed to support these data.

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Abstract:The chemical composition of the essential oil from the leaves of Pelargonium odoratissimum (L.) L'Hér., Geraniaceae, was determined and the antimicrobial activities against the Aspergillus flavus CML 1816, Aspergillus carbonarius CML1815 and Aspergillus parasiticus CMLA 817 fungi, as well the Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25 992 bacteria were evaluated. The essential oil was isolated by steam distillation using a modified Clevenger apparatus, and its constituents were identified and quantified by GC/MS and GC-FID analyses. In vitro bioanalytical testing was performed using a completely randomized design. The concentrations of essential oil employed ranged from 0.1 to 2 µL.mL -1 (in dimethyl sulfoxide) for the fungus species and from 1 to 500 µL.mL -1 for the bacteria. The diameters of the inhibition zones formed for bacteria and the mean diameters of mycelial growth in perpendicular directions for fungi were measured, followed by calculation of the percentage of inhibition. The essential oil from the leaves of P. odoratissimum furnished methyleugenol (96.80%), a phenylpropanoid. This essential oil inhibited the growth of fungi (100% inhibition) and exhibited a small effect on the bacteria at the concentrations tested.

RESUMO-A goiabeira (Psidium guajava) é uma planta nativa brasileira, e seus frutos são ricos em compostos antioxidantes os quais podem causar a oxidação das lipoproteínas, reduzindo o estresse oxidativo. objetivou-se com este trabalho determinar essas substâncias e a atividade antioxidante das farinhas dos frutos das cultivares Pedro sato, Paluma e século XXi. Foram selecionados 35 frutos de cada cultivar, levando-se em consideração o grau de maturação. os frutos foram lavados, picados, congelados em nitrogênio líquido e liofilizados. Posteriormente, foram trituradas para a obtenção das farinhas. Os parâmetros analisados foram o teor de compostos fenólicos, vitamina C, betacaroteno, fibras alimentares, minerais (ferro, potássio, cobre, magnésio, manganês, zinco e cálcio) e atividade antioxidante, pelos métodos DPPH e betacaroteno/ ácido linoleico. Os teores de compostos fenólicos foram maiores para a cultivar Século XXI. O teor de betacaroteno e fibra alimentar não variaram entre as cultivares analisadas. As cultivares Século XXI e Paluma destacaram-se na atividade antioxidante pelos dois métodos. Em relação aos minerais, não houve diferença significativa para o potássio, cobre e zinco. O mineral cálcio não foi detectado pelo método empregado. Os teores de ferro, magnésio e manganês foram maiores para as cultivares Paluma, Pedro sato e século XXi, respectivamente. Termos para a indexação: goiaba, antioxidantes e minerais. EVALUATION OF FUNCTIONAL COMPOUNDS AND ANTIOXIDANT ACTIVITY IN GUAVA PULP FLOURABSTRACT-Guava (Psidium guajava) is a native brazilian plant and its fruits are rich in antioxidants compounds which can inhibit the liproteins oxidation, reducing the aggravations of oxidative stress. The objective of this study was to determine these substances and antioxidant activity of the flours from the fruits of Pedro sato, Paluma and século XXi cultivars. The parameters analyzed were phenolic compounds, vitamin C, beta-carotene, dietary fiber, minerals (iron, potassium, copper, magnesium, manganese, zinc and calcium) and antioxidant activity by DPPH methods and beta-carotene/acid linoleic. The levels of phenolic compounds were higher for the Século XXI cultivar.The level of beta-carotene and dietary fiber did not vary among cultivars analyzed. The Paluma and século XXi cultivars stood out in antioxidant activity by both methods. Regarding to minerals, there was no significant difference for potassium, copper and zinc. Calcium was not detected by the used method. iron, magnesium and manganese were higher for Paluma, Pedro sato and século XXi, respectively.