Regular consumption of a flavanol-rich chocolate can improve oxidant stress in young soccer players.

The consumption of a diet rich in certain flavonoids, including the flavanol sub-class, has been associated with a reduced risk for vascular disease. We evaluated the effects of the regular consumption (14 d) of a flavanol-containing milk chocolate (FCMC) or cocoa butter chocolate (CBC) on variables related to vascular disease risk, oxidative stress and physical activity. Twenty-eight free-living, young (18-20 years old) male soccer players consumed daily 105 g of FCMC (168 mg of flavanols) or CBC (< 5 mg of flavanols), as part of their normal diet. The consumption of FCMC was significantly associated with a decrease in diastolic blood pressure (- 5 mm Hg), mean blood pressure (- 5 mm Hg), plasma cholesterol (-11%), LDL-cholesterol (-15%), malondialdehyde (- 12%), urate (- 11%) and lactate dehydrogenase (LDH) activity (- 11%), and an increase in vitamin E/cholesterol (+ 12%). No relevant changes in these variables were associated with CBC consumption. No changes in the plasma levels of (-)-epicatechin were observed following analysis of fasting blood samples. In conclusion, FCMC consumption was associated with changes in several variables often associated with cardiovascular health and oxidant stress. The presence of significant quantities of flavanols in FCMC is likely to have been one of the contributing factors to these results.

The regular supplementation with an antioxidant mixture decreases oxidative stress in healthy humans. Gender effect.

BACKGROUND: Antioxidant consumption is claimed to be associated with improved antioxidant defenses and with the prevention of free radical-associated diseases. We evaluated if the regular supplementation with an antioxidant mixture modified oxidative stress parameters in healthy humans. METHODS: Malondialdehyde (MDA), vitamin E (alpha-tocopherol), beta-carotene, and ubiquinol-10 were determined in plasma by HPLC; plasma 2-thiobarbituric acid reactive substances (TBARS) were evaluated fluorometrically. The supplement contained 106 IU vitamin E, 10 mg beta-carotene, 60 mg coenzyme Q-10, and 40 microg selenium. RESULTS: After a 10-day wash out period, 16 healthy, free-living adults (31-48 years old; 9 women, 7 men) consumed the supplement daily during 30 days. At day 20, plasma concentration of vitamin E (alpha-tocopherol), beta-carotene, and ubiquinol-10 increased 45%, 66%, and 104%, respectively, over baseline values. Plasma MDA concentrations were reduced at days 20 (25%) and 30 (32%). Plasma TBARS concentrations decreased steadily during the treatment, reaching at day 30 an 11% decrease compared to baseline. Segregating by gender, both MDA and TBARS plasma concentrations were higher in men than in women at baseline. However, such differences disappeared after 30 days of supplementation. CONCLUSION: The observed modifications in variables associated with oxidative stress are indicative of an effective antioxidant action of the used mixture of lipid soluble compounds, and gender differences suggest that men should optimize their antioxidants defenses earlier in life than women.

Epicatechin, catechin, and dimeric procyanidins inhibit PMA-induced NF-kappaB activation at multiple steps in Jurkat T cells.

The capacity of the flavan-3-ols [(-)-epicatechin (EC) and (+)-catechin (CT)] and a B dimeric procyanidin (DP-B) to modulate phorbol 12-myristate 13-acetate (PMA)-induced NF-kappaB activation in Jurkat T cells was investigated. The classic PMA-triggered increase in cell oxidants was prevented when cells were preincubated for 24 h with EC, CT, or DP-B (1.7-17.2 microM). PMA induced the phosphorylation of IKKbeta and the subsequent degradation of IkappaBalpha. These events were inhibited in cells pretreated with the flavonoids. PMA induced a 4.6-fold increase in NF-kappaB nuclear binding activity in control cells. Pretreatment with EC, CT, or DP-B decreased PMA-induced NF-kappaB binding activity and the transactivation of the NF-kappaB-driven gene IL-2. EC, CT, and DP-B inhibited, in vitro, NF-kappaB binding to its DNA consensus sequence, but they had no effect on the binding activity of CREB or OCT-1. Thus, EC, CT, or DP-B can influence the immune response by modulating NF-kappaB activation. This modulation can occur at early (regulation of oxidant levels, IKK activation) as well as late (binding of NF-kappaB to DNA) stages of the NF-kappaB activation cascade. A model is presented for possible interactions between DP-B and NF-kappaB proteins, which could lead to the inhibition of NF-kappaB binding to kappaB sites.

Comparison between warm blood and crystalloid cardioplegia during open heart surgery.

OBJECTIVE: This study was designed to compare the degree of myocardial protection afforded by warm blood and cold crystalloid cardioplegia in a group of patients undergoing elective coronary artery bypass surgery. METHODS: Seventeen patients, were randomly assigned to Group A (n=9), who received crystalloid cardioplegic solution, and Group B who received warm blood cardioplegic solution (n=8). Before the aorta was clamped, and 10 min after reperfusion, blood samples from the coronary sinus were obtained to assay alpha-tocopherol, beta-carotene, ubiquinol, and thiobarbituric acid reactive substances (TBARS). At the same intervals, biopsies from the left ventricle were obtained to determine ultrastructural alterations. RESULTS: No significant changes were observed between preischemia and reperfusion values for both blood and crystalloid groups concerning alpha-tocopherol, beta-carotene, and ubiquinol, and no differences between groups were detected. Values for TBARS in group A were 3.49+/-0.3 and 5.27+/-0.45 microM for presichemia and reperfusion samples, respectively (P<0.01). In group B values were 2.6+/-0.3 and 3.54+/-0.3 microM, respectively (P=NS). For electron microscopy studies, semiquantitative analysis showed a significant mitochondrial damage in reperfusion biopsies from group A (grades 0, 3 and 4). In group B, no significant changes were observed in mitochondrial damage between preischemia and repefusion biopsies (except for grade 0). CONCLUSION: These results indicate that blood cardioplegia affords better protection to the myocyte than crystalloid cardioplegia.

Influence of flavan-3-ols and procyanidins on UVC-mediated formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine in isolated DNA.

The flavan-3-ols (-)-epicatechin (epicatechin) and (+)-catechin (catechin) and their related oligomers (procyanidins) isolated from cocoa were assayed for their capacity to inhibit the UVC-mediated formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (oxo(8)dG) in calf thymus DNA. The above-mentioned compounds inhibited oxo(8)dG production in a concentration- and time-dependent manner. After 30 min of irradiation (30 kJ/m(2)), 0.1, 1.0, 10, and 100 microM epicatechin inhibited oxo(8)dG formation by 20, 36, 64, and 74%, respectively. For the same dose of UVC, 0.1, 1.0, 10, and 100 microM catechin inhibited oxo(8)dG formation by 1, 23, 50, and 70%, respectively. Epicatechin was more efficient than catechin with respect to inhibiting oxo(8)dG formation (IC(50) 1.7 +/- 0.7 vs 4.0 +/- 0.7 microM). Monomer, tetramer, and hexamer fractions were equally effective in inhibiting oxo(8)dG formation when assayed at 10 microM monomer equivalent concentration. At similar concentrations (1-50 microM), the inhibition of the UVC-mediated oxo(8)dG formation by flavan-3-ols and procyanidins was in the range of that of alpha-tocopherol, Trolox, ascorbate, and glutathione. These results support the concept that flavan-3-ols and their related procyanidins can protect DNA from oxidation at concentrations that can be physiologically relevant. Both epimerism and degree of oligomerization are important determinants of the antioxidant activity of flavan-3-ols and procyanidins.

Estado de las defensas antioxidantes y marcadores de estrés oxidativo en una población de Buenos Aires / State of antioxidant defenses and markers of oxidative stress in a population of Buenos Aires

Evalúa el estado antioxidante y estrés oxidativo de una población de 102 participantes y su asociación con edad, sedentarismo, tabaquismo, y arteriosclerosis. Se estudiaron los valores basales y a un subgrupo que recibió suplementación antioxidante con vitamina E, betacaroteno y vitamina C durante 30 días, al término de los cuales se efectuó una segunda determinación de las variables involucradas

Estado de las defensas antioxidantes y marcadores de estrés oxidativo en una población de Buenos Aires / State of antioxidant defenses and markers of oxidative stress in a population of Buenos Aires

Evalúa el estado antioxidante y estrés oxidativo de una población de 102 participantes y su asociación con edad, sedentarismo, tabaquismo, y arteriosclerosis. Se estudiaron los valores basales y a un subgrupo que recibió suplementación antioxidante con vitamina E, betacaroteno y vitamina C durante 30 días, al término de los cuales se efectuó una segunda determinación de las variables involucradas

Bajos niveles de defensas antioxidantes mejorados por IECA en pacientes en hemodiálisis / Low levels of antioxidants improved by angiotensin converting enzyme inhibitors in hemodialysis

Con el fin de investigar la relación entre el estado redox y la hemodiálisis (HD), en este estudio decidimos evaluar una serie de parámetros de estrés oxidativo y defensas antioxidantes en un grupo de pacients que recibían tratamiento hemodialítico crónico y un gupo control apareado por edad... Podemos concluir que: 1)en los pacientes en HD crónica existen profundas alteraciones de las defensas antioxidantes circulantes; b)que un estrés oxidativo adicional se produce durante la sesión de HD. Por otra parte, el tratamiento con IECA mejora varios componentes de las defensas entioxidantes en este grupo de pacientes. (AU)(Premio Dr. Víctor R. Miatello de la Sociedad Argentina de Nefrología 1998)

Bajos niveles de defensas antioxidantes mejorados por IECA en pacientes en hemodiálisis / Low levels of antioxidants improved by angiotensin converting enzyme inhibitors in hemodialysis

Con el fin de investigar la relación entre el estado redox y la hemodiálisis (HD), en este estudio decidimos evaluar una serie de parámetros de estrés oxidativo y defensas antioxidantes en un grupo de pacients que recibían tratamiento hemodialítico crónico y un gupo control apareado por edad... Podemos concluir que: 1)en los pacientes en HD crónica existen profundas alteraciones de las defensas antioxidantes circulantes; b)que un estrés oxidativo adicional se produce durante la sesión de HD. Por otra parte, el tratamiento con IECA mejora varios componentes de las defensas entioxidantes en este grupo de pacientes. (AU)(Premio Dr. Víctor R. Miatello de la Sociedad Argentina de Nefrología 1998)

Asociación entre altos niveles plasmáticos de vitamina E y disminución del pico enzimático y de la extensión del daño electrocardiográfico en pacientes con infarto agudo de miocardio / Relationship between high serum levels of vitamin E, heart enzyme decay and magnitude of electrocardiographic injury in patients with acute myocardial infarction

Se evaluaron 115 pacientes ingresados a la unidad de cuidados intensivos coronarios con infarto agudo de miocardio. Los pacientes se dividieron en dos grupos: el primero, H= vitamina E plasmática > 18 µM, y el restante, L= vitamina E plasmática < 18 µM. Los grupos fueron equivalentes en antecedentes, características poblacionales, factores de riesgo cardiovasculares asociados, localización del infarto agudo de miocardio, clase hemodinámica y tratamiento recibido. El número de derivaciones comprometidas (electrocardiograma de ingreso), de nuevas ondas Q (electrocardiograma de egreso) y de segmentos afectados (ecocardiograma) fue mayor en el grupo L que en el grupo H. Los niveles séricos de creatinfosfoquinasa, evaluados 24 y 48 horas después del ingreso a la unidad de cuidados intensivos coronarios, también fueron más altos en el grupo L. Estos resultados indican una asociación entre una alta concentración plasmática de vitamina E y bajos niveles séricos de creatinfosfoquinasa y menor extensión electrocardiográfica del infarto agudo de miocardio

Asociación entre altos niveles plasmáticos de vitamina E y disminución del pico enzimático y de la extensión del daño electrocardiográfico en pacientes con infarto agudo de miocardio / Relationship between high serum levels of vitamin E, heart enzyme decay and magnitude of electrocardiographic injury in patients with acute myocardial infarction

Se evaluaron 115 pacientes ingresados a la unidad de cuidados intensivos coronarios con infarto agudo de miocardio. Los pacientes se dividieron en dos grupos: el primero, H= vitamina E plasmática > 18 AM, y el restante, L= vitamina E plasmática < 18 AM. Los grupos fueron equivalentes en antecedentes, características poblacionales, factores de riesgo cardiovasculares asociados, localización del infarto agudo de miocardio, clase hemodinámica y tratamiento recibido. El número de derivaciones comprometidas (electrocardiograma de ingreso), de nuevas ondas Q (electrocardiograma de egreso) y de segmentos afectados (ecocardiograma) fue mayor en el grupo L que en el grupo H. Los niveles séricos de creatinfosfoquinasa, evaluados 24 y 48 horas después del ingreso a la unidad de cuidados intensivos coronarios, también fueron más altos en el grupo L. Estos resultados indican una asociación entre una alta concentración plasmática de vitamina E y bajos niveles séricos de creatinfosfoquinasa y menor extensión electrocardiográfica del infarto agudo de miocardio (AU)

Níveles plasmáticos de un marcador de peroxidación lipídica y de vitamina E en mujeres sanas eumenorreicas, en postmenopáusicas sanas y en primigestas que desarrollaron o no hipertensión inducida / Even plasmatic od a marker of lipid peroxidation and E vitamin in women healthy eumenorreicas, in health postmenopausal and in primigravidas that develope or not induced hypertension

Modificaciones en níveles circulantes de malondialdehido y de vitamina E se han asociaado con hipertensión inducida por embarazo, con diabetes gestacional y con parto pretérmino. Hay solo información fragmentaria aa esstos respectos

Níveles plasmáticos de un marcador de peroxidación lipídica y de vitamina E en mujeres sanas eumenorreicas, en postmenopáusicas sanas y en primigestas que desarrollaron o no hipertensión inducida / Even plasmatic od a marker of lipid peroxidation and E vitamin in women healthy eumenorreicas, in health postmenopausal and in primigravidas that develope or not induced hypertension

Modificaciones en níveles circulantes de malondialdehido y de vitamina E se han asociaado con hipertensión inducida por embarazo, con diabetes gestacional y con parto pretérmino. Hay solo información fragmentaria aa esstos respectos(AU)