Although the interrelation between vitamins C and E has been demonstrated on an experimental level, its impact on biomarkers in community-dwelling subjects along the trajectory of ageing has not yet been shown. The present longitudinal study investigates the determinants and interrelation of vitamins C and E plasma concentrations in 399 subjects aged ≥60 years with a median follow-up time of 12 years. Linear mixed-effects models were used to analyze the influence of age, sex, body composition, dietary intake, physical activity, smoking and supplement/drug use on plasma vitamin C, plasma α-tocopherol and α-tocopherol/total cholesterol ratio. At baseline, median plasma concentrations of vitamin C and α-tocopherol were 74 and 35 µmol/L. Absolute fat-free mass, physical activity, use of supplements, and plasma α-tocopherol were main determinants of plasma vitamin C in the course of ageing. For the α-tocopherol/total cholesterol ratio, age, use of supplements, use of lipid-modifying drugs, and plasma vitamin C were main determinants. The results reveal a stable positive interrelation between plasma concentrations of vitamins C and E along the trajectory of ageing independent of the other identified determinants. The possible regulatory mechanisms that could explain this robust positive interrelation remain to be elucidated.

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Introduction: Current evidence on the association between dietary vitamin E intake and hyperuricemia risk is limited and conflicting.

Objective: The aim of the study was to assess the association of dietary vitamin E intake with hyperuricemia in US adults.

Methods: We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey, 2009-2014. Dietary vitamin E intake was evaluated through two 24-h dietary recall interviews. Logistic regression and restricted cubic spline models were used to examine the association between dietary vitamin E intake and hyperuricemia.

Results: Overall, 12,869 participants were included. The prevalence of hyperuricemia was 19.35%. After adjustment for age, gender, BMI, race, educational level, smoking status, alcohol consumption, physical activity, total daily energy intake, total cholesterol, protein intake, glomerular filtration rate, serum Cr, use of uric acid drugs, and drug abuse, the odds ratio (95% confidence interval) of hyperuricemia for the highest tertile of dietary vitamin E intake was 0.77 (0.63-0.96) compared with that of the lowest tertile. In men, dietary vitamin E intake and hyperuricemia were negatively correlated. In stratified analyses by age (20-39, 40-59, and ≥60 years), dietary vitamin E intake was inversely associated with hyperuricemia only among participants aged ≥60 years. Dose-response analyses showed that dietary vitamin E intake was inversely associated with hyperuricemia in a nonlinear manner.

Conclusion: Dietary vitamin E intake was negatively correlated with hyperuricemia in US adults, especially among males and participants aged ≥60 years.

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Measurements of aroxyl (ArO・)-radical-scavenging rate constants (k_s^AOH) of antioxidants (AOHs) (i.e., α-, β-, γ-, δ-Tocopherol (TocH) and ubiquinol-10 (UQ₁₀H₂)) were performed in ethanol/chloroform/H₂O (50/50/1, v/v) solution, using stopped-flow spectrophotometry. k_s^AOH values were measured not only for each AOH, but also for the mixtures of two AOHs (i.e., TocH and UQ₁₀H₂). k_s^TocH values for α-, β-, γ-, δ-TocH increased 1.21, 1.28, 1.55, and 1.19 times, respectively, under the coexistence of constant concentrations of UQ₁₀H₂. Similar measurements were performed for eight vegetable oils 1 – 8, containing different concentrations of α-, β-, γ-, δ-tocopherol (TocH) and -tocotrienol (Toc-3H). k_s^Oil values of all eight vegetable oils 1 – 8 also increased 1.24 – 1.54 times under the coexistence of constant concentrations of UQ₁₀H₂. A new mechanism to explain the notable increase of k_s^AOH values under the coexistence of two kinds of phenolic AOHs was proposed. UV-vis absorption of α-, β-, γ-Toc · radicals, produced by reaction of α-, β-, γ-TocHs (or vegetable oils 1 – 8) with ArO ·, disappeared under the coexistence of TocHs (or oils) and UQ₁₀H₂, suggesting that the prooxidant reaction resulting from the presence of Toc · radicals is suppressed in the presence of UQ₁₀H₂.

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Oxidative stress is generated in biological system by several endogenous/exogenous factors like environmental-pollution/toxicity/diseases and by daily-life-stress. We previously showed that oxidative-stress impaired the activities/expressions of phase-II drug-metabolizing enzyme, sulfotransferases (SULTs). The SULT catalyzes sulfation of endogenous/exogenous compounds. Vitamin E is globally consumed by a large number of individuals for the cellular protection from oxidative stress and aging. Here, vitamin E (tocopherol; α/γ and tocotrienol; α/γ; 0, 1, 10, or 100 μM) was tested in human carcinoma cell line, HepG2 for their influences on SULTs expression/(western blotting). The effects of oxidant (glutathione-oxidized/GSSG) or reductant (glutathione-reduced/GSH, Dithiothreitol/DTT) on SULT activities were studied in rat-liver/human intestinal tissues. Results suggest, tocopherol is more inductive to monoamine-SULT (MPST) and Dehydroepiandrosterone-SULT (DHEAST) compared to that of tocotrienol (inconsistent change in PPST, phenol sulfotransferase/MPST/EST, estrogen sulfotransferase). The nuclear-factor constitutive androstane receptor (CAR) was found to be induced moderately. This study overall describes that vitamin E moderately influences SULTs expression. The induction ability of tocopherol should be judged taking into account its long-term consummation. Oxidative stress activates rat and human SULTs activities and expressions. Further studies are necessary in this regard.

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Microencapsulated α-tocopherol and wheat germ oil (WGO) were incorporated as WGO (5.0 ml) in liquid: WGO-L, encapsulated: WGO-E, encapsulated α-tocopherol as E1, E2 and E3 at 2.0, 3.0 and 4.0 g respectively in cookies and evaluated for physical, sensory and shelf life parameters. Spread ratio was decreased, whereas hardness was increased with encapsulated formulations and observed least in WGO-L (40.52 N) formulated cookies. During storage moisture content was observed increased (2.51-4.78%), vitamin E was retained in all formulations except WGO-L and was found maximum in E3 (4.45 mg/100 g) formulated cookies. Formulations brought the peroxide value to nil, free fatty acid development was very less, better antioxidant activity (41.1% maximum), total plate count was observed least in E3 (25 × 10² cfu/g) and good sensory acceptance of cookies up to 4 months of storage. The study concluded that encapsulated vitamin E elevated the antioxidant activity and consequently shelf life and nutritive value of cookies.

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Vitamin E is an essential nontoxic fat-soluble micronutrient whose effects on livestock performance and products can be attributed to its antioxidant and nonantioxidant properties. Although it is needed in small quantity in the diet, its roles in livestock production are indispensable as it is required in boosting performance, nutritional qualities, and yield of animal and animal products. The dietary or oral supplementation of vitamin E is essential in reducing lipid oxidation in muscle, egg, and dairy products as well as lowering cholesterol concentrations and improving antioxidant status of livestock. Evidence has shown that bioavailability of vitamin E-enriched animal products could serve as an invaluable nutritional benefit to consumers; especially those in regions of limited resources where vitamin E deficiencies pose a risk that may be detrimental to some cellular activities of the body and on human health. It is therefore important to redirect research on the impact of vitamin E supplementation as antioxidant on livestock performance and animal products.

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