Bioavailability of catechins from guaraná (Paullinia cupana) and its effect on antioxidant enzymes and other oxidative stress markers in healthy human subjects.

We assessed the effects of guaraná (Paullinia cupana) consumption on plasma catechins, erythrocyte antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase) and biomarkers of oxidative stress (ex vivo LDL oxidation, plasma total antioxidant status and ORAC, and lymphocyte single cell gel electrophoresis) in healthy overweight subjects. Twelve participants completed a 15-day run-in period followed by a 15-day intervention with a daily intake of 3 g guaraná seed powder containing 90 mg (+)-catechin and 60 mg (-)-epicatechin. Blood samples were taken on the first and last day of the intervention period, fasting and 1 h post-dose. The administration of guaraná increased plasma ORAC, while reducing ex vivo LDL oxidation (only in the first study day) and hydrogen peroxide-induced DNA damage in lymphocytes, at 1 h post-dose. Plasma catechin (0.38 ± 0.12 and 0.44 ± 0.18 nmol mL(-1)), epicatechin (0.59 ± 0.18 and 0.64 ± 0.25 nmol mL(-1)) and their methylated metabolites were observed at 1 h post-dose but were almost negligible after overnight fasting. The activities of catalase (in both study days) and glutathione peroxidase (in the last intervention day) increased at 1 h post-dose. Furthermore, the activity of both enzymes remained higher than the basal levels in overnight-fasting individuals on the last intervention day, suggesting a prolonged effect of guaraná that continues even after plasma catechin clearance. In conclusion, guaraná catechins are bioavailable and contribute to reduce the oxidative stress of clinically healthy individuals, by direct antioxidant action of the absorbed phytochemicals and up-regulation of antioxidant/detoxifying enzymes.

Medium light and medium roast paper-filtered coffee increased antioxidant capacity in healthy volunteers: results of a randomized trial.

We compared the effects of medium light roast (MLR) and medium roast (MR) paper-filtered coffee on antioxidant capacity and lipid peroxidation in healthy volunteers. In a randomized crossover study, 20 volunteers consumed 482 ± 61 ml/day of MLR or MR for four weeks. Plasma total antioxidant status (TAS), oxygen radical absorbance capacity (ORAC), oxidized LDL and 8-epi-prostaglandin F2α, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity were measured at baseline and after the interventions. MLR had higher chlorogenic acids-(CGA; 334 mg/150 mL) and less caffeine (231 mg/150 ml) than MR had (210 and 244 mg/150 ml, respectively). MLR also had fewer Maillard reaction products (MRP) than MR had. Compared with baseline, subjects had an increase of 21 and 26 % in TAS, 13 and 13 % in CAT, 52 and 75 % in SOD, and 62 and 49 % in GPx after MLR and MR consumption (P < 0.001), respectively. ORAC increased after MLR (P = 0.004). No significant alteration in lipid peroxidation biomarkers was observed. Both coffees had antioxidant effects. Although MLR contained more CGA, there were similar antioxidant effects between the treatments. MRP may have contributed as an antioxidant. These effects may be important in protecting biological systems and reducing the risk of diseases related to oxidative stress.

Bebida à base de subproduto da uva: efeitos sobre o estresse oxidativo e marcadores de risco de doenças cardiovasculares em mulheres saudáveis / Drink-based byproduct of grapes: effects on oxidative stress and markers of cardiovascular disease risk in healthy women

Introdução: Estudos epidemiológicos sugerem que o consumo de vinho, produtos de uva e outros alimentos contendo polifenóis está associado à diminuição do risco de doenças cardiovasculares. Na produção de vinhos e suco de uva são geradas quantidades expressivas de bagaço residual, que é prejudicial ao meio ambiente. Por outro lado, este subproduto possui alto teor de antioxidantes e de fibras. Objetivo: Produzir uma bebida à base de farinha de bagaço de uva proveniente do processamento de suco de uva (FBSU) e avaliar seus efeitos sobre o estresse oxidativo e marcadores de risco para doenças cardiovasculares em mulheres saudáveis. Métodos: A bebida de FBSU e um suco comercial de uva (usado como controle no estudo in vivo) foram avaliados : sensorialmente por escala hedônica de 9 pontos; composição proximal segundo a AOAC; características físico-químicas; compostos fenólicos totais por Folin, capacidade antioxidante: (a) absorbância de oxigênio radical - ORAC, (b) capacidade antioxidante total - TAS, (c) capacidade de sequestrar o radical DPPH e (d) sistema -caroteno/ácido linoléico. Sujeitos: mulheres saudáveis (n=15) foram randomizadas em um estudo clínico crossover, controlado, com quatro períodos de duas semanas de duração. Após washout, forneceu-se bebida de FBSU e suco de uva comercial, intercalados com outro washout. Quantificou-se triglicérides, colesterol total e suas frações, proteína C-reativa, IL-6, TNF- e MCP-1. A LDL foi submetida à oxidação e em seguida medidos os produtos de peroxidação lipídica. TAS e ORAC do plasma foram determinados. Nos eritrócitos, foram analisadas as enzimas antioxidantes superóxido dismutase (SOD), glutationa peroxidase (GSH-Px) e catalase (CAT). Realizou-se o ensaio cometa nos linfócitos. O consumo das voluntárias foi avaliado por diário alimentar de 3 dias durante a intervenção com a bebida de FBSU, com o suco comercial e no washout...

Introduction: Epidemiological studies suggest that consumption of wine, grape products and other foods containing polyphenols is associated with decreased risk of cardiovascular disease. In the production of wine and grape juice significant amounts of pomace flour are generated, which is harmful to the environment. Moreover, this byproduct is high in antioxidants and fiber. Objectives: To develop a beverage using grape pomace flour (GPF) from grape juice and to evaluate its effect on oxidative stress and inflammatory biomarkers for cardiovascular disease risk in healthy women. Methods: GPF beverage and a commercial grape juice (used as control in the in vivo study) were sensory evaluated using the 9-point hedonic scale and had the proximal composition determined using the AOAC methods; physicochemical characteristics were analysed; total phenolics compound were quantified with the Folin-Ciocalteu reagent; antioxidant capacity was determined by different methods: (a) oxygen radical absorbance capacity assay - ORAC, (b) total antioxidant status - TAS, (c) radical scavenging activity (DPPH) assay, (d) -carotene and linoleic acid system). Fifteen healthy women were randomized in a crossover clinical study, controlled with four periods of two weeks duration. It started with washout, followed by GPF beverage and commercial grape juice, interspersed with another washout. We evaluated triglycerides, total cholesterol and its fractions, C-reactive protein, IL-6, TNF- and MCP-1. The LDL was subjected to oxidation and then measured the lipid peroxidation products. TAS and ORAC of the plasma were determined. In erythrocytes, the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were analyzed. We carried out the comet assay in lymphocytes. We evaluated the dietary intake of volunteers in three separate stages during the intervention with GPF beverage, with commercial juice and washout...

Glicocorticóides e catecolaminas: efeitos sobre o metabolismo de nutrientes / Glucocorticoids and catecholamines: effects in nutrients metabolism

Introdução: Os hormônios isolados do córtex adrenal, os corticóides, são esteróides, derivados do colesterol. Além de alguns hormônios sexuais, os hormônios do córtex adrenal são enquadrados em glicocorticóides e mineralocorticóides. Os glicocorticóides atuam sobre o metabolismo de carboidratos, lipídios e proteínas, enquanto os mineralocorticóides atuam no metabolismo de eletrólitos, especialmente sódio e potássio, e no equilíbrio hídrico. Entre os corticóides, os mais importantes são os cortisol, corticosterona, desoxicorticosterona e aldosterona. Os hormônios produzidos pela medula adrenal são as catecolaminas, epinefrina e norepinefrina, derivados da tirosina. Ambos os hormônios são responsáveis pelas várias manifestações fisiológicas do sistema nervoso simpático, aumentam a glicogenólise hepática e muscular, e estimulam a liberação de ácido graxos pelo tecico adiposo. Objetivo: Descrever brevemente os efeitos dos glicocorticóides e catecolaminas sobre o metabolismo de nutrientes. Conclusões: A promoção da glicogenólise muscular e hepática, degradação dos triacilgliceróis do tecido adiposo e liberação de glicose na corrente sangüínea, são os principais efeitos dos glicocorticóides e catecolaminas, sendo esses efeitos muito bem documentados. No entanto, a maneira como ocorrem ainda não está bem definida. Apesar de have evidências do envolvimento desses hormônios na etiologia de doenças como diabetes, hipertensão, dislipidemias e obesidade, ainda não é bem esclarecido como isso corre, sendo os estudos bastante controversos. Diante dessas dúvidas, tornou-se necessários estudos futuros a fim de esclarecer estes aspectos que certamente contribuirão paa o entendimento e tratamento dessas doenças