Dietary lignins are precursors of mammalian lignans in rats
Dietary lignins are precursors of mammalian lignans in rats
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DOI：
10.1093/jn/134.1.120
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发表时间：
2004-01-01
影响因子：
4.2
通讯作者：
Scalbert, A
中科院分区：
文献类型：
--
作者：
Begum, AN;Nicolle, C;Scalbert, A
哺乳动物木脂素肠内酯 (ENL) 和肠二醇常见于人类血浆和尿液中，是植物雌激素，可能有助于预防乳腺癌和冠心病。它们是通过结肠微生物群将膳食前体（例如开环异落叶松树脂醇和马泰树脂醇木脂素）转化而形成的。本文首次报道了木质素（结构上与木脂素相关的细胞壁聚合物）作为哺乳动物木脂素前体的鉴定。在研究 1 中，给大鼠喂食黑麦或麦麸（15% 饮食）5 天。比较了未经处理的麸皮和用溶剂提取以去除木脂素的麸皮。 ENL 是通过时间分辨荧光免疫测定法对收集 24 小时的尿液样本进行估计的。当从黑麦麸皮中去除木酚素时，ENL 尿排泄量从 18.6 减少到 5.3 nmol/d (n = 8; P < 0.001)；当从麦麸中去除木脂素时，ENL 尿排泄量从 30.5 nmol/d 减少到 6.2 nmol/d (P < 0.001)。这些结果表明，嵌入细胞壁并在溶剂提取过程中保留在麸皮中的木质素占谷物麸皮形成的 ENL 的 26-32%。在研究 2 中，给大鼠喂食氘化合成木质素（0.2% 饮食）和麦麸（15%）3 天。通过 LC-串联 MS 检测尿液中的氘化 ENL（20 nmol/d），清楚地证实了木质素转化为哺乳动物木脂素。需要更多的研究来确定人类饮食中木质素的生物利用度。
The mammalian lignans enterolactone (ENL) and enterodiol, commonly found in human plasma and urine, are phytoestrogens that may contribute to the prevention of breast cancer and coronary heart disease. They are formed by the conversion of dietary precursors such as secoisolariciresinol and matairesinol lignans by the colonic microflora. The identification of lignins, cell-wall polymers structurally related to lignans, as precursors of mammalian lignans is reported here for the first time. In study 1, rats were fed rye or wheat bran (15% diet) for 5 d. Untreated brans and brans extracted with solvents to remove lignans were compared. ENL was estimated in urine samples collected for 24 h by time-resolved fluoroimmunoassay. ENL urinary excretion was reduced from 18.6 to 5.3 nmol/d (n = 8; P < 0.001) when lignans were removed from rye bran and from 30.5 to 6.2 nmol/d (P < 0.001) when they were removed from wheat bran. These results suggest that lignins, embedded in the cell wall and retained in the bran during solvent extraction, account for 26-32% of the ENL formed from cereal brans. In study 2, rats were fed a deuterated synthetic lignin (0.2% diet) together with wheat bran (15%) for 3 d. The detection of deuterated ENL by LC-tandem MS in urine (20 nmol/d) clearly confirms the conversion of lignin into mammalian lignans. More research is warranted to determine the bioavailability of lignins in the human diet.