Faster plasma vitamin E disappearance in smokers is normalized by vitamin C supplementation
Faster plasma vitamin E disappearance in smokers is normalized by vitamin C supplementation
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DOI：
10.1016/j.freeradbiomed.2005.10.051
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发表时间：
2006-02-15
影响因子：
7.4
通讯作者：
Traber, MG
中科院分区：
文献类型：
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作者：
Bruno, RS;Leonard, SW;Traber, MG
由于吸烟者氧化应激增加，维生素E的消失加速，并与血浆维生素C浓度呈负相关。因此，我们假设补充抗坏血酸（500 mg，每日2次; 2周）将使吸烟者的血浆α-和γ-生育酚消失率正常化，并进行了一项双盲，安慰剂对照，在吸烟者（n = 11）和非吸烟者（n = 13）中进行的随机交叉研究，给予单剂氘标记的α-和γ-生育酚（d（6）-kRR-α和d（2）-RRR-gamma-生育酚乙酸酯各50 mg）。在安慰剂试验中，吸烟者与不吸烟者相比，α-和γ-生育酚的消失率显著（P < 0.05）更高，半衰期更短。补充抗坏血酸使两组的血浆抗坏血酸浓度增加一倍（P < 0.0001），并使吸烟者的血浆α-和γ-生育酚（P < 0.05）的部分消失率分别降低25%和45%，但不降低非吸烟者的血浆α-和γ-生育酚（P < 0.05）。同样地，在72 It时，与安慰剂相比，吸烟者的血浆氘标记的α-和γ-生育酚浓度在抗坏血酸补充期间显著更高（P < 0.05）。补充抗坏血酸并没有显著改变（P > 0.05）最大或最大标记的α-和γ-生育酚浓度的时间。吸烟者血浆F-2 α-异前列腺素水平比非吸烟者高26%（P > 0.05），且两组均不受补充抗坏血酸的影响（P > 0.05）。总之，吸烟增加了血浆α-和γ-生育酚部分消失率，表明吸烟的氧化应激氧化生育酚，血浆抗坏血酸将α-和γ-生育酚氧基自由基还原为非氧化形式，从而减少人体维生素E的消失。(c)2005年爱思唯尔公司All rights reserved.
Vitamin E disappearance is accelerated in cigarette smokers due to their increased oxidative stress and is inversely correlated with plasma vitamin C concentrations. Therefore, we hypothesized that ascorbic acid supplementation (500 mg, twice daily; 2 weeks) Would normalize smokers' plasma alpha- and gamma-tocopherol disappearance rates and conducted a double-blind, placebo-controlled, randomized crossover investigation in smokers (n = 11) and nonsmokers (n = 13) given a single dose of deuterium-labeled alpha- and gamma-tocopherols (50 mg each d(6)-kRR-alpha and d(2)-RRR-gamma-tocopheryl acetate). During the placebo trial, smokers, compared with nonsmokers, had significantly (P < 0.05) greater alpha- and gamma-tocopherol fractional disappearance rates and shorter half-lives. Ascorbic acid supplementation doubled (P < 0.0001) plasma ascorbic acid concentrations in both groups and attenuated smokers', but not nonsmokers', plasma alpha- and gamma-tocopherol (P < 0.05) fractional disappearance rates by 25% and 45%, respectively. Likewise, smokers' plasma deuterium-labeled alpha- and gamma-tocopherol concentrations were significantly higher (P < 0.05) at 72 It during ascorbic acid supplementation compared with placebo. Ascorbic acid supplementation did not significantly change (P > 0.05) time of maximal or maximal-labeled alpha- and gamma-tocopherol concentrations. Smokers' plasma F-2 alpha-isoprostanes were similar to 26% higher than nonsmokers (P > 0.05) and were not affected by ascorbic acid Supplementation in either group (P > 0.05). In summary, cigarette smoking increased plasma alpha- and gamma-tocopherol fractional disappearance rates, suggesting that the oxidative stress from smoking oxidizes tocopherols and that plasma ascorbic acid reduces alpha- and gamma-tocopheroxyl radicals to nonoxidized forms, thereby decreasing vitamin E disappearance in humans. (c) 2005 Elsevier Inc. All rights reserved.