Juliana Mesquita Freire

Anti-proliferative effect of the essential oil of Cymbopogon citratus (DC) Stapf (lemongrass) on intracellular amastigotes, bloodstream trypomastigotes and culture epimastigotes of Trypanosoma cruzi (Protozoa: Kinetoplastida)

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.

Essential oil of Origanum majorana L., Illicium verum Hook. f. and Cinnamomum zeylanicum Blume: chemical and antimicrobial characterization

Essential oils of Origanum majorana L. (marjoram), Illicium verum Hook. f. (star- anise) and Cinnamomum zeylanicum Blume (cinnamon) were obtained by steam distillation using a modified Clevenger device. The antimicrobial activity of each oil was evaluated against the bacteria Staphylococcus aureus, Escherichia coli and the fungi Aspergillus flavus and Aspergillus parasiticus by observing their growth and/or mycelial inhibition through comparison with the standard dish (without oil). The essential oils were analyzed using a gas chromatograph coupled to a mass spectrometer for identification and coupled to a flame ionization detector for quantification. The major constituents of marjoram, star-anise and cinnamon essential oils were 4-terpineol, trans- anetole and cinnamic aldehyde, respectively. In in vitro tests, essential oils of marjoram and cinnamon promoted an inhibitory effect on the bacteria S. aureus and E. coli, while the essential oil of star-anise presented activity only against E. coli. Marjoram, star-anise and cinnamon oils were effective against the studied fungi, presenting an inhibitory effect. The minimal inhibitory concentration for the mycelial growth of A. parasiticus was 1 and 0.01 L mL -1 for star-anise and cinnamon oils, respectively. The minimal inhibitory concentration for A. parasiticus was 0.25, 2 and 2 L mL -1 for cinnamon, star-anise and marjoram oils, respectively.

Antioxidants from medicinal plants used in the treatment of obesity.

Aims: The objective of this work was to quantify phenolic compounds, flavonoids, vitamin C, total carotenoids, �≤ -carotene and lycopene and to measure the antioxidant activity in themedicinal plantsAloe vera(L.)Burm. (aloe),Simaba ferrugineaSt. Hil. (calunga), Baccharis trimera(Less.) DC (carqueja),Garcinia cambogia Desr., andTournefortia paniculataCham. (marmelinho) and of the phytotherapic made with the combination of these plants.

Atividade antioxidante de frutos de quatro cultivares de pessegueiro

Efforts have been spent in order to identify plants with antioxidant levels that provide health benefits. The antioxidant capacity of peach is due to phenolic compounds, vitamin C and carotenoids. This study aimed to characterize four peach cultivars (Aurora, Biuti, Diamante and Douradao), in relation to the antioxidant capacity, determining the content of antioxidant compounds related to this activity. The fruits were separated into two groups: not stored and stored for five days at room temperature. The contents of vitamin C, carotenoids, phenolic compounds and the antioxidant capacity were determined by DPPH and β-carotene/linoleic acid methods. All the cultivars proved to be rich in antioxidant substances; however, the intensity of this action was different among them. Cultivar Biuti presented highest levels of the analyzed substances and higher antioxidant activity compared to other cultivars. It was possible to observe that the antioxidant potential of peach fruits increased during the storage period.

Avaliação de compostos funcionais e atividade antioxidante em farinhas de polpa de goiabas

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 Seculo 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 Seculo XXI cultivar.The level of beta-carotene and dietary fiber did not vary among cultivars analyzed. The Paluma and Seculo 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 Seculo XXI, respectively.

Influência da temperatura de secagem sobre o rendimento e a composição química do óleo essencial de Tanaecium nocturnum (barb. Rodr.) bur. & K. Shum

The yields and chemical compositions of the essential oils obtained by steam distillation of the fresh and dried (30 and 40 oC) leaves, stems and roots of Tanaecium nocturnum are reported. The identification and quantification of the volatile constituents were accomplished by GC/MS and GC/FID, respectively. The essential oils obtained from the various parts of the plant were constituted mainly of benzaldehyde. Large losses and variations in the quantities of the components during the drying process were observed. The presence of mandelonitrile in higher concentration in the stem and roots indicates that this species produces cyanogenic glycosides.