American Journal of Clinical Nutrition, 2010, 91(4):976-84.

Disposition of soy isoflavones in normal human breast tissue

Selin Bolca, Herman Depypere, et al

Laboratory of Microbial Ecology and Technology, Faculty of Bioscience Engineering and the Laboratory of Experimental Cancer Research, Department of Experimental Cancer Research, Radiotherapy and Nuclear Medicine, Ghent University Hospital, Ghent, Belgium; et al

BACKGROUND: Despite decades of research on the relation between soy and breast cancer, questions regarding the absorption, metabolism, and distribution of isoflavones in breast tissue largely remain unanswered.

OBJECTIVE: We evaluated the potential health effects of isoflavone consumption on normal breast tissue; isoflavone concentrations, metabolites, and biodistribution were investigated and compared with 17beta-estradiol exposure.

DESIGN: In this dietary intervention study, healthy women were randomly allocated to a soy milk (n = 11; 16.98-mg genistein and 5.40-mg daidzein aglycone equivalents per dose), soy supplement (n = 10; 5.27-mg genistein and 17.56-mg daidzein aglycone equivalents per dose), or control (n = 10) group. After a run-in period > or = 4 d, 3 doses of soy milk or soy supplements were taken daily for 5 d before an esthetic breast reduction. Blood and breast biopsies were collected during surgery and analyzed with liquid chromatography-tandem mass spectrometry.

RESULTS: After soy administration, genistein and total daidzein concentrations, which were expressed as aglycone equivalents, ranged from 135.1 to 2831 nmol/L and 105.1 to 1397 nmol/L, respectively, in hydrolyzed serum and from 92.33 to 493.8 pmol/g and 22.15 to 770.8 pmol/g, respectively, in hydrolyzed breast tissue. The major metabolites identified in nonhydrolyzed samples were genistein-7-O-glucuronide and daidzein-7-O-glucuronide, with an overall glucuronidation of 98%. Total isoflavones showed a breast adipose/glandular tissue distribution of 40:60, and their mean (+/-SEM) derived 17beta-estradiol equivalents toward estrogen receptor beta were 21 +/- 4-fold and 40 +/- 10-fold higher than the 17beta-estradiol concentrations in adipose (0.283 +/- 0.089 pmol/g, P < 0.001) and glandular (0.246 +/- 0.091 pmol/g, P = 0.001) fractions, respectively.

CONCLUSION: After intake of soy milk and soy supplements, isoflavones reach exposure levels in breast tissue at which potential health effects may occur.

美国《美国临床营养学杂志》，2010年4月

大豆异黄酮在正常人体乳腺组织中的分布

瑟林 伯卡， 赫尔曼 迪派尔等

比利时根特医科大学放射治疗和核医学院实验癌症研究部生物工程和实验癌症研究实验系微生物生态学和技术实验室等

背景︰ 尽管已经进行了几十年大豆与乳腺癌关系的研究，关于异黄酮的吸收、 代谢、 和在乳腺癌组织中的分布问题很大程度上仍然没有答案。

目的︰ 我们评估了异黄酮对正常乳腺组织潜在的健康影响。探究异黄酮的浓度、 代谢产物、 和体内分布并与相比 17beta-雌二醇相比较。

设计︰ 在这项饮食干预研究中，健康的妇女被随机分配到豆浆 (n = 11; 每剂量16.98 mg金雀异黄素和 5.40mg大豆黄酮苷元)，大豆补充剂(n = 10; 每剂量5.27 mg金雀异黄素和 17.56 mg大豆黄酮苷元)，或对照组 (n = 10) 。在一个超过或等于 4 天的磨合期以后，在美学标准乳房缩小之前每日服用三种剂量的豆浆或大豆补充剂共5天。在手术过程中收集血液和乳腺的活体组织并且用液相色谱-串联质谱分析。