Mah Eunice, Pei Ruisong, Guo Yi, Ballard Kevin D, Barker Tyler, Rogers Victoria E, Parker Beth A, Taylor Alan W, Traber Maret G, Volek Jeff S, Bruno Richard S
Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA.
Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA.
Free Radic Biol Med. 2013 Dec;65:1291-1299. doi: 10.1016/j.freeradbiomed.2013.09.016. Epub 2013 Sep 27.
Oxidative stress and inflammation persist years after smoking cessation thereby limiting the restoration of vascular endothelial function (VEF). Although short-term smoking cessation improves VEF, no studies have examined co-therapy of antioxidants in combination with smoking cessation to improve VEF. We hypothesized that improvements in γ-tocopherol (γ-T) status during smoking cessation would improve VEF beyond that from smoking cessation alone by decreasing oxidative stress and proinflammatory responses. A randomized, double-blind, placebo-controlled study was conducted in otherwise healthy smokers (22 ± 1 years; mean ± SEM) who quit smoking for 7 days with placebo (n=14) or γ-T-rich supplementation (n=16; 500 mg γ-T/day). Brachial artery flow-mediated dilation (FMD), cotinine, and biomarkers of antioxidant status, oxidative stress, and inflammation were measured before and after 7 days of smoking cessation. Smoking cessation regardless of supplementation similarly decreased plasma cotinine, whereas γ-T-rich supplementation increased plasma γ-T by seven times and its urinary metabolite γ-carboxyethyl hydroxychroman by nine times (P<0.05). Smoking cessation with γ-T-rich supplementation increased FMD responses by 1.3% (P<0.05) beyond smoking cessation alone (4.1 ± 0.6% vs 2.8 ± 0.3%; mean ± SEM). Although plasma malondialdehyde decreased similarly in both groups (P<0.05), plasma oxidized LDL and urinary F2-isoprostanes were unaffected by smoking cessation or γ-T-rich supplementation. Plasma TNF-α and myeloperoxidase decreased (P<0.05) only in those receiving γ-T-rich supplements and these were inversely related to FMD (P<0.05; R=-0.46 and -0.37, respectively). These findings demonstrate that short-term γ-T-rich supplementation in combination with smoking cessation improved VEF beyond that from smoking cessation alone in young smokers, probably by decreasing the proinflammatory mediators TNF-α and myeloperoxidase.
戒烟多年后，氧化应激和炎症依然存在，从而限制了血管内皮功能（VEF）的恢复。尽管短期戒烟可改善VEF，但尚无研究探讨抗氧化剂与戒烟联合治疗对改善VEF的作用。我们推测，戒烟期间γ-生育酚（γ-T）状态的改善可通过降低氧化应激和促炎反应，使VEF的改善程度超过单纯戒烟。本研究对健康吸烟者（22±1岁；均值±标准误）进行了一项随机、双盲、安慰剂对照试验，这些吸烟者使用安慰剂（n=14）或富含γ-T的补充剂（n=16；500mgγ-T/天）戒烟7天。在戒烟7天前后，测量肱动脉血流介导的舒张功能（FMD）、可替宁以及抗氧化状态、氧化应激和炎症的生物标志物。无论是否补充，戒烟均同样降低了血浆可替宁水平，而富含γ-T的补充剂使血浆γ-T增加了7倍，其尿液代谢产物γ-羧乙基羟基色满增加了9倍（P<0.05）。与单纯戒烟相比，富含γ-T的补充剂联合戒烟使FMD反应增加了1.3%（P<0.05）（分别为4.1±0.6%和2.8±0.3%；均值±标准误）。尽管两组血浆丙二醛均同样降低（P<0.05），但血浆氧化型低密度脂蛋白和尿液F2-异前列腺素不受戒烟或富含γ-T的补充剂影响。仅在接受富含γ-T补充剂的人群中，血浆肿瘤坏死因子-α（TNF-α）和髓过氧化物酶降低（P<0.05），且这些指标与FMD呈负相关（P<0.05；相关系数分别为-0.46和-0.37）。这些研究结果表明，在年轻吸烟者中，短期富含γ-T的补充剂联合戒烟改善VEF的程度超过单纯戒烟，这可能是通过降低促炎介质TNF-α和髓过氧化物酶实现的。
