ascorbic-acid and delta-tocopherol

Despite promising evidence from in vitro experiments and observational studies, supplementation of diets with alpha-tocopherol has not reduced the risk of cardiovascular disease and cancer in most large-scale clinical trials. One plausible explanation is that the potential health benefits of alpha-tocopherol supplements are offset by deleterious changes in the bioavailability and/or bioactivity of other nutrients. We studied the effects of supplementing diets with RRR-alpha-tocopheryl acetate (400 IU/d) on serum concentrations of gamma- and delta-tocopherol in a randomized, placebo-controlled trial in 184 adult nonsmokers. Outcomes were changes in serum concentrations of gamma- and delta-tocopherol from baseline to the end of the 2-mo experimental period. Compared with placebo, supplementation with alpha-tocopherol reduced serum gamma-tocopherol concentrations by a median change of 58% [95% CI = (51%, 66%), P < 0.0001], and reduced the number of individuals with detectable delta-tocopherol concentrations (P < 0.0001). Consistent with trial results were the results from baseline cross-sectional analyses, in which prior vitamin E supplement users had significantly lower serum gamma-tocopherol than nonusers. In view of the potential benefits of gamma- and delta-tocopherol, the efficacy of alpha-tocopherol supplementation may be reduced due to decreases in serum gamma- and delta-tocopherol levels. Additional research is clearly warranted.

Topics: Aged; alpha-Tocopherol; Ascorbic Acid; Dietary Supplements; Female; gamma-Tocopherol; Humans; Male; Middle Aged; Placebos; Tocopherols

Although freezing is the most common method used to preserve human milk, nutritional and immunological components may be lost during storage. Freeze-drying could increase the shelf life of human milk, while preserving its original characteristics. Seventy-two samples of freeze-dried human milk were stored for different periods of time, up to a maximum of 3 months, at 4 °C or 40 °C. Vitamin C, tocopherols, antioxidant capacity, and fatty acids composition were analyzed. A new HILIC-UHPLC method improving vitamin C determination was also validated. Ascorbic acid and total vitamin C concentrations significantly decreased at both temperatures, while antioxidant capacity only decreased at 40 °C. Fatty acids composition and both γ-tocopherol and δ-tocopherol contents remained unaltered. The stability after storage of freeze-dried milk was higher than that reported for frozen or fresh milk indicating that freeze-drying is a promising option to improve the preservation of human milk in banks.

Topics: Antioxidants; Ascorbic Acid; Chromatography, High Pressure Liquid; Fatty Acids; Female; Food Preservation; Food Storage; Freeze Drying; Freezing; gamma-Tocopherol; Humans; Milk, Human; Temperature; Tocopherols; Vitamins

The aim of this study was to evaluate the antioxidant substances present in the human diet with an antimutagenic protective capacity against genotoxic damage induced by exposure to X-rays in an attempt to reduce biological damage to as low a level as reasonably possible.. Ten compounds were assessed using the lymphocyte cytokinesis-block micronucleus (MN) cytome test. The compounds studied were added to human blood at 25 μM 5 min before exposure to irradiation by 2 Gy of X-rays.. The protective capacity of the antioxidant substances assessed was from highest to lowest according to the frequency of the MN generated by X-ray exposure: rosmarinic acid = carnosic acid = δ-tocopherol = l-acid ascorbic = apigenin = amifostine (P < 0.001) > green tea extract = diosmine = rutin = dimetylsulfoxide (P < 0.05) > irradiated control. The reduction in genotoxic damage with the radiation doses administered reached 58%, which represents a significant reduction in X-ray-induced chromosomal damage (P < 0.001). This degree of protection is greater than that obtained with amifostine, a radioprotective compound used in radiotherapy and which is characterised by its high toxicity.. Several antioxidant substances, common components of the human diet and lacking toxicity, offer protection from the biological harm induced by ionizing radiation. Administering these protective substances to patients before radiological exploration should be considered, even in the case of small radiation doses and regardless of the biological damage expected.

Topics: Abietanes; Amifostine; Analysis of Variance; Antimutagenic Agents; Antioxidants; Apigenin; Ascorbic Acid; Catechin; Cells, Cultured; Cinnamates; Cytokinesis; Depsides; Diet; Diosmin; DNA Damage; Female; Humans; Lymphocytes; Micronucleus Tests; Plant Extracts; Radiation-Protective Agents; Radiometry; Rosmarinic Acid; Rutin; Tocopherols; X-Rays

The physico-chemical properties of oil from Moringa oleifera seeds from India were determined in the present study. The petroleum ether extracted oil ranged from 27.83 - 45.07% on kernel basis and 15.1-28.4% on whole seed basis in 20 different clones. Leaves and pods showed a good source of vitamin C. Oleic acid (C18:1) has been found to be the major fatty acid being 78.91-85.52% as compared to olive oil, which is considered to be richest source of oleic acid. All the clones from India did not show any presence of behenic acid (C 22:0). The oil was also found to contain high levels of beta-sitosterol ranged from 42.29-47.94% stigmasterol from 13.66-16.61%, campesterol from 12.53-16.63%. The gamma- and delta-tocopherol were found to be in the range of 128.0-146.95, 51.88-63.5 and 55.23-63.84 mg/kg, respectively.

Topics: Ascorbic Acid; Cholesterol; Fatty Acids; gamma-Tocopherol; Genetic Variation; India; Moringa oleifera; Oleic Acid; Olive Oil; Phytosterols; Plant Oils; Seeds; Sitosterols; Stigmasterol; Tocopherols

The antioxidative phytochemicals in various fruits and vegetables are widely recognized for their role in scavenging free radicals, which are involved in the etiology of many chronic diseases. Colored fruits are especially considered a quality trait that correlates with their nutritional values and health benefits. The specific aim of this study was to investigate the antioxidants in the juice and freeze-dried flesh and peel of red pummelo and their ability to scavenge free radicals and compare them with those in white pummelo juice. The total phenolic content of red pummelo juice extracted by methanol (8.3 mg/mL) was found to be significantly higher than that of white pummelo juice (5.6 mg/mL). The carotenoid content of red pummelo juice was also significantly higher than that in white pummelo juice. The contents of vitamin C and delta-tocopherol in red pummelo juice were 472 and 0.35 mug/mL, respectively. The ability of the antioxidants found in red pummelo juice to scavenge radicals were found by methanol extraction to approximate that of BHA and vitamin C with a rapid rate in a kinetic model. The ability of methanol extracts of freeze-dried peel and flesh from red pummelo to scavenge these radicals was 20-40% that of BHA and vitamin C effects. Fresh red pummelo juice is an excellent source of antioxidant compounds and exhibited great efficiency in scavenging different forms of free radicals including DPPH, superoxide anion, and hydrogen peroxide radicals.

Topics: Antioxidants; Ascorbic Acid; Beverages; Carotenoids; Citrus; Food Preservation; Free Radical Scavengers; Freeze Drying; Fruit; Phenols; Tocopherols