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.

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.

RESUMO -Um experimento foi conduzido com pintos de corte macho para o estudo dos efeitos dos níveis de 20 e 23% de PB combinados com 0, 50, 100, 150, 200, 250 mEq/kg de balanço dietético eletrolítico (BDE) sobre a atividade da α-amilase pancreática de frangos de corte de 1 a 21 dias de idade. O delineamento utilizado foi o inteiramente casualizado. Dietas e água foram fornecidas ad libitum. Aos 1, 7, 14 e 21 dias, três aves de cada tratamento foram sacrificadas por deslocamento cervical para remoção do pâncreas, o qual foi removido, homogeneizado, congelado em nitrogênio líquido e liofilizado. Uma alíquota de cada amostra foi solubilizada em água deionizada e centrifugada a 7500 x g por 3 minutos a 4 o C, para determinação da atividade da α-amilase no sobrenadante. Aves alimentadas com 20% de PB apresentaram atividades específicas (U/mg de proteína) superiores à daquelas que receberam 23%, exceto para os níveis de BDE de 100 a 200 mEq/kg, aos 14 dias. Observou-se tendência de aumento da atividade específica dos 7 aos 14 dias e redução dos 14 aos 21 dias. Para maior atividade específica de α-amilase, 14 and 21, three birds from each treatment were sacrificed by cervical dislocation, pancreas were removed, homogeneized and frozen in liquid nitrogen which were then freeze-dried. An aliquot of each sample was solubilized with deionized water and centrifuged at 7500 x g for three minutes at 4 o C. Activities of the pancreatic α-amylase in the supernatants were determined.Chicks fed 20% of CP showed specific activities (U/mg protein) higher than those fed 23%, except for DEB levels from 100 to 200 mEq/kg at 14 days. A tendency to increase specific activity was observed from 7 to 14 days and to reduce from 14 to 21 days. The highest specific activity of pancreatic α-amylase was observed in diets with 20% CP and 200 mEq/kg of DEB from 1 to 7 days, diets with 20% of CP and 135 to 250 mEq/kg of DEB from 8 to 21 days of age.

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RESUMO -Foram investigados os efeitos nutricionais de dois níveis de ácido L-glutâmico (L-Glu) combinados com quatro níveis de vitamina K (Vit K) sobre a atividade de α-amilase no quimo e pâncreas de aves de corte. Frangos de corte machos de um dia foram criados em baterias aquecidas e alimentados, à vontade, com dietas contendo todos L-aminoácidos essenciais, minerais e vitaminas (exceto Vit K) até os 14 dias de idade. O experimento foi realizado em esquema fatorial, em delineamento inteiramente casualizado 2x4, com quatro repetições de oito aves cada. A dieta básica foi suplementada com 6,25 e 12,5% de L-Glu combinados com 0,02; 0,2; 20,0 e 200,0 mg de Vit K/kg de ração. Efeitos significativos de L-Glu e Vit K foram observados no quimo. A atividade específica máxima (1.005,78±245,25 UI/mg de proteína) foi observada nas aves alimentadas com 6,25% de L-Glu e 20,0 mg de Vit K. Houve redução da atividade com a suplementação de 12,5% de L-Glu. No pâncreas, não houve interação entre L-Glu e Vit K, todavia, foi observado efeito de L-Glu sobre as atividades relativas, expressas em UI/g de tecido e UI/100 g de peso corporal. Os resultados sugerem que a associação entre L-Glu e Vit K interfere na atividade enzimática de α-amilase em aves de corte submetidas a dietas purificadas. Os resultados indicam que o nível de 12,5% de L-Glu associado aos diferentes níveis de vitamina K reduziu a atividade enzimática.Palavras-chave: α-amilase, L-glutâmico, pintos de corte, vitamina K Effects of Dietary Levels of L-Glutamic Acid and Vitamin K in the Activity of α α α α α-Amylase of ChicksABSTRACT -The effects of two levels of L-glutamic acid (L-Glu) combined with four levels of vitamin K (Vit K) were studied with the objective of evaluating the activities of α-amylase in the chyme and pancreas of chicks. Day-old male broilers were reared in eletrically heated batteries, fed with purified amino acids diets, minerals and vitamins (except Vit K) at the requirement levels, for 14 days. Feed and water were provided ad libitum. The experimental design was a factorial 2x4 with four replicates with eight chicks each The experimental diet was supplemented with 6.25 and 12.5% of L-Glu combined with .02; .2; 20; 200 mg Vit K/kg diet. Effects of L-Glu and Vit K were observed in the chyme with maximum specific activity (1,005.78±245.25 IU/g tissue) observed in chicks fed with 6.25% of L-Glu and 20 mg of Vit K. Reduction in activity was observed with 12.5% L-Glu. In pancreas, there was no significant interaction between L-Glu and Vit K for α-amylase activity, but significant effect of L-Glu was observed (IU/g tissue and IU/100 g body weight). Results suggest that α-amylase activity is affected by an association between L-Glu and Vit K in chickens fed purified diets. In general, 12.5% L-Glu regardless of Vit K levels led to reduction in α-amylase activity.