Department of Public Health Sciences, Penn State Hershey Cancer Institute, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA.
Nutr Cancer. 2011;63(3):367-75. doi: 10.1080/01635581.2011.535967.
Selenium deficiency has been linked with increased cancer risk and, in some studies, selenium supplementation was protective against certain cancers. Previous studies have suggested that selenium chemoprevention may involve reduced oxidative stress through enhanced glutathione (GSH). Our objectives were to examine the relationships between selenium and GSH in the blood and the modifying effects of race and sex in free-living adults and individuals supplemented with selenium. Plasma selenium concentrations and free and bound GSH concentrations and γ-glutamyl cysteine ligase (GCL) activity in the blood were measured in 336 healthy adults (161 Blacks, 175 Whites). Plasma selenium and blood GSH were also measured in 36 healthy men from our previously conducted placebo-controlled trial of selenium-enriched yeast (247 μg/day for 9 mo). In free-living adults, selenium concentrations were associated with increased blood GSH concentration and GCL activity (P < 0.05). Further, selenium was significantly higher in Whites than in Blacks (P < 0.01). After 9 mo of supplementation, plasma selenium increased 114% in Whites and 50% in Blacks (P < 0.05), and blood GSH increased 35% in Whites (P < 0.05) but was unchanged in Blacks. These results indicate a direct association between selenium and GSH in the blood of both free-living and selenium-supplemented individuals, with race being an important modifying factor.
硒缺乏与癌症风险增加有关，在一些研究中，硒补充剂对某些癌症具有保护作用。先前的研究表明，硒的化学预防作用可能涉及通过增强谷胱甘肽 (GSH) 来减少氧化应激。我们的目的是在自由生活的成年人和补充硒的个体中，研究血液中硒与 GSH 之间的关系，以及种族和性别对其的修饰作用。在 336 名健康成年人（161 名黑人，175 名白人）中测量了血浆硒浓度以及血液中的游离和结合 GSH 浓度和 γ-谷氨酰半胱氨酸连接酶 (GCL) 活性。我们之前进行的富硒酵母安慰剂对照试验（247μg/天，持续 9 个月）中还测量了 36 名健康男性的血浆硒浓度和血液 GSH。在自由生活的成年人中，硒浓度与血液 GSH 浓度和 GCL 活性增加相关（P < 0.05）。此外，白人的硒浓度明显高于黑人（P < 0.01）。补充 9 个月后，白人的血浆硒增加了 114%，黑人增加了 50%（P < 0.05），而白人的血液 GSH 增加了 35%（P < 0.05），但黑人没有变化。这些结果表明，在自由生活和补充硒的个体的血液中，硒与 GSH 之间存在直接关联，而种族是一个重要的修饰因素。
