Comparative effects of dietary supplementation with red grape juice and vitamin E on production of superoxide by circulating neutrophil NADPH oxidase in hemodialysis patients.

Background: Atherosclerotic cardiovascular disease is the most common cause of death among hemodialysis patients; it has been attributed to increased oxidative stress, dyslipidemia, malnutrition, and chronic inflammation. Activation of neutrophils is a well-recognized feature in dialysis patients, and superoxide-anion production by neutrophil NADPH oxidase may contribute significantly to oxidative stress.

Objective: The aim of the study was to compare the effects of dietary supplementation with concentrated red grape juice (RGJ), a source of polyphenols, and vitamin E on neutrophil NADPH oxidase activity and other cardiovascular risk factors in hemodialysis patients.

Quercetin is bioavailable from a single ingestion of grape juice.

The in vivo bioactivity of polyphenols will depend on their bioavailability. Grape juice is an important source of dietary phenolics. This paper reports results that prove that quercetin (3,3',4',5,7-pentahydroxyflavone) is bioavailable after a single ingestion of red grape juice by healthy volunteers.

Metabolic adaptation in the crew of the Hesperides on their Antarctic journey.

Aims: We studied the metabolic changes that took place in the crew of the Hesperides vessel in their 2001-2002 Antarctic journey, comparing two periods differing in diet and physical activity.

Methods And Results: Lipid profile, vitamin and hormone levels were analyzed in 17 subjects who completed the study in its two phases. In phase I the participants spent 47 days sailing with hard work and rough seas, and the diet was rich in fat and poor in fresh foods.

Concentrated red grape juice exerts antioxidant, hypolipidemic, and antiinflammatory effects in both hemodialysis patients and healthy subjects.

Background: Patients treated with hemodialysis frequently experience cardiovascular complications attributed, among other causes, to dyslipidemia, increased oxidative stress, and inflammation.

Objective: The aim of the study was to study the effects of dietary supplementation with concentrated red grape juice (RGJ), a source of polyphenols, on lipoprotein profile, antioxidant capacity, LDL oxidation, and inflammatory biomarkers.

Design: Twenty-six patients receiving hemodialysis and 15 healthy subjects were instructed to drink 100 mL RGJ/d for 14 d.

Influence of apolipoprotein E genotype on fat-soluble plasma antioxidants in Spanish children.

Background: Apolipoprotein (apo) E is a major determinant of plasma lipid concentrations, which in turn influence the plasma concentrations of various fat-soluble vitamins.

Objective: We aimed to analyze the effect of APOE genotype on fat-soluble antioxidant concentrations in children.

Design: A total of 926 healthy boys and girls aged 6-8 y were selected from 4 cities in Spain.

Liquid chromatographic method for the simultaneous determination of different lipid-soluble antioxidants in human plasma and low-density lipoproteins.

We describe a reverse phase HPLC method, employing a simple methanol:water gradient as mobile phase, for the determination of several lipophilic antioxidants, such as retinol, gamma-tocopherol, alpha-tocopherol, lycopene, alpha-carotene and beta-carotene among others, using UV detection. Additionally, this method allows the simultaneous separation of probucol, an hypocholesterolemic drug with antioxidant properties. Retinol acetate and alpha-tocopherol acetate were added to samples as internal standards.