Richie John P, Das Arun, Calcagnotto Ana M, Sinha Raghu, Neidig Wanda, Liao Jiangang, Lengerich Eugene J, Berg Arthur, Hartman Terryl J, Ciccarella Amy, Baker Aaron, Kaag Matthew G, Goodin Susan, DiPaola Robert S, El-Bayoumy Karam
Departments of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
Cancer Prev Res (Phila). 2014 Aug;7(8):796-804. doi: 10.1158/1940-6207.CAPR-14-0042. Epub 2014 Jun 17.
Epidemiologic and laboratory studies indicate that dietary selenium protects against prostate cancer. Results from clinical trials suggest that selenium-enriched yeast (SY) but not selenomethionine (SeMet) may be effective at reducing prostate cancer risk. Our objectives were to directly compare for the first time the effects of SeMet and SY on prostate cancer relevant biomarkers in men. We performed a randomized double blind, placebo-controlled trial of SY (200 or 285 μg/day) and SeMet (200 μg/day) administered for 9 months in 69 healthy men. Primary endpoints included blood levels of selenium-containing compounds and oxidative stress biomarkers [urine 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α) and blood glutathione (GSH)]. Secondary endpoints included plasma glucose and PSA levels. Compliance was high in all groups (>95%). Plasma selenium levels were increased 93%, 54%, and 86% after 9 months in SeMet and low- and high-dose SY groups, respectively, and returned to baseline levels after a 3-month washout (P < 0.05). Levels of 8-OHdG and 8-iso-PGF2α were decreased 34% and 28%, respectively, after 9 months in the high-dose SY group (P < 0.05). These decreases were greatest in individuals with low baseline plasma levels of selenium (<127 ng/mL). No changes in serum PSA or blood glucose and GSH were observed. Overall, we showed for the first time, reductions in biomarkers of oxidative stress following supplementation with SY but not SeMet in healthy men. These findings suggest that selenium-containing compounds other than SeMet may account for the decrease in oxidative stress.
流行病学和实验室研究表明，膳食中的硒可预防前列腺癌。临床试验结果表明，富硒酵母（SY）而非硒代蛋氨酸（SeMet）可能对降低前列腺癌风险有效。我们的目标是首次直接比较SeMet和SY对男性前列腺癌相关生物标志物的影响。我们对69名健康男性进行了一项随机双盲、安慰剂对照试验，给予SY（200或285微克/天）和SeMet（200微克/天），为期9个月。主要终点包括含硒化合物的血液水平和氧化应激生物标志物[尿8-羟基-2'-脱氧鸟苷（8-OHdG）、8-异前列腺素-F2α（8-异-PGF2α）和血液谷胱甘肽（GSH）]。次要终点包括血浆葡萄糖和PSA水平。所有组的依从性都很高（>95%）。在SeMet组以及低剂量和高剂量SY组中，9个月后血浆硒水平分别升高了93%、54%和86%，在3个月的洗脱期后恢复到基线水平（P<0.05）。高剂量SY组9个月后8-OHdG和8-异-PGF2α水平分别下降了34%和28%（P<0.05）。这些下降在基线血浆硒水平低（<127纳克/毫升）的个体中最为明显。未观察到血清PSA、血糖和GSH的变化。总体而言，我们首次表明，健康男性补充SY而非SeMet后氧化应激生物标志物有所降低。这些发现表明，除SeMet外的含硒化合物可能是氧化应激降低的原因。
