Epidemiological studies suggest that consumption of tomato products reduces the risk of CVD via antioxidant, hypocholesterolaemic and anti-inflammatory mechanisms. Although experimental data also describe beneficial effects on endothelial function, clinical data in human subjects are lacking. To test the hypothesis that tomato ingestion ameliorates endothelial function, we randomised healthy non-smoking postmenopausal women to consume a buttered roll with and without tomato purée (70 g) in a cross-over design. Endothelial-dependent flow-mediated dilation (FMD) and endothelial-independent nitro-mediated dilation of the brachial artery were assessed with highresolution ultrasound (13 MHz linear array transducer). Acute (24 h) and long-term (7 d) effects were examined after daily consumption of the described meal. Nineteen volunteers completed the protocol and provided technically suitable ultrasound measurement data. Plasma lycopene levels increased from 0·30 (SEM 0·04) (baseline) to 0·42 (SEM 0·04) and to 0·74 (SEM 0·06) mM after 24 h and 7 d, respectively, with tomato purée consumption. These data indicated an effective absorption of the tomato product. However, both acute and long-term tomato purée consumption had no effects on endothelium-dependent or -independent dilation of the brachial artery. In addition, we found no correlation between lycopene plasma levels and FMD. In conclusion, consumption of tomato products associated with a significant increase in plasma lycopene levels had no effects on endothelial function in healthy postmenopausal women.
BackgroundDecreased levels of circulating bone marrow-derived progenitor cells have been associated with risk factors and cardiovascular diseases. Smoking is the most important modifiable risk factor for atherosclerosis in young women. The aim of this pilot study was to assess in healthy premenopausal women without other risk factors for cardiovascular disease the influence of nicotine abuse on the number of circulating progenitor cells in relation to endothelial function.MethodsThe number of endothelial progenitor cells, measured as colony-forming units in a cell-culture assay (EPC-CFU) and the number of circulating CD34 + and CD34 + /CD133 + cells, measured by flow cytometry, was estimated in 32 women at the menstrual phase of the menstrual cycle. In addition, flow-mediated dilation (FMD) was assessed as a marker for vascular function. In a subgroup of these women (n = 20), progenitor cells were also investigated at the mid-follicular and luteal phases of the menstrual cycle.ResultsCompared to non-smokers, the abundance of circulating CD34 + cells was significantly lower in smoking women in the menstrual, mid-luteal, and mid-follicular phases of the menstrual cycle. The number of CD34 + progenitor cells was revealed to have significant positive correlation with FMD in young healthy women, whereas CD34 + /CD133 + progenitor cells and EPC-CFU showed no significant correlation.ConclusionThe number of CD34 + progenitor cells positively correlates with FMD in young healthy women and is decreased by smoking.
Instituto Federal Sul-Rio-Grandense -IFSUL -Pelotas -Brasil toralles@pelotas.ifsul.edu.br 4 Universidade Federal do Rio Grande -FURG -Rio Grande -Brasil ResumoA frutohidrolase frutofuranosidase (EC 3.2.2.26), também chamada invertase ou sacarase, catalisa a hidrólise da sacarose, produzindo uma mistura equimolar de glicose e frutose, denominada açúcar invertido. Este produto tem alto poder edulcorante e cristalização lenta, causando um melhoramento na textura e no sabor dos alimentos. Para tal finalidade, a invertase foi extraída da levedura do purê e do resíduo de pêssego c.v. Jubileu, que é amplamente cultivada no sul do Rio Grande do Sul, Brasil. A invertase de levedura comercial de pão foi utilizada como testemunha. Os extratos enzimáticos foram obtidos usando o método de extração com bicarbonato de sódio. As condições de reação ótimas foram estudadas utilizando sacarose como substrato, a 40 mM para a invertase de pão e a 220 mM para a invertase de purê de pêssego. A glicose formada foi determinada por colorimetria utilizando DNS e as proteínas pelo método de Biureto. O pH ideal foi na faixa de 5 -6 para ambas as enzimas. As temperaturas ótimas foram na faixa de 40 -50 °C para invertase de levedura de pão e na faixa de 20 -30 °C para invertase de levedura de purê de pêssego. Ambas as enzimas foram afetadas pela desnaturação de calor, sendo a invertase de pão mais termoestável. Definidas as condições ótimas de hidrólise da sacarose, estudou-se o efeito da concentração do substrato na atividade das invertases, bem como para determinar seus parâmetros cinéticos. Ambas as enzimas apresentaram comportamento Michaeliano. Os parâmetros cinéticos foram calculados por regressão não linear, sendo que os valores de Km foram 20 mM e 180 mM para a invertase de levedura de pão e para invertase de levedura de purê de pêssego, respectivamente. Para ambas, o gráfico da velocidade de hidrólise em função da concentração de sacarose foi confirmado pela linearidade da Lineweaver-Burk. Finalmente, observou-se uma equivalência entre as atividades das invertases isoladas de purê de pêssego e de seu resíduo a 25 °C e no pH de 5.Palavras-chave: purê de pêssego; levedura; invertase; hidrólise da sacarose; açúcar invertido. IntroduçãoA produção nacional de pêssego ocupa 0,48% do volume total de frutas produzidas no país, ocupando 1% da área plantada. Em 2010, produziu-se 239149 toneladas de pêssego, sendo os
In healthy women, smoking eliminates the physiological amelioration of endothelial function during the menstrual cycle. This study underlines the importance of an exact description of menstrual cycle phase and smoking status in studies investigating endothelial function in premenopausal women.
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