Gu Liwei, House Suzanne E, Rooney Lloyd, Prior Ronald L
Arkansas Children's Nutrition Center, Agricultural Research Service, U.S. Department of Agriculture, 1212 Marshall Street, Little Rock, Arkansas 72202, USA.
J Agric Food Chem. 2007 Jun 27;55(13):5326-34. doi: 10.1021/jf070100p. Epub 2007 May 31.
Sorghum bran is concentrated with procyanidins (predominately polymers), which may be beneficial for health in humans; however, the bioavailability of procyanidins is not well-understood. Female Sprague-Dawley rats were fed an AIN93G diet containing 0, 5, 10, 20, or 40% Hi-tannin sorghum bran (n = 5-7 for each group) for 50 days. Sorghum bran contained 23.3 mg/g of procyanidins. The urinary excretions of catechin, epicatechin, methylated catechins, and phenolic acids were analyzed using liquid chromatography-tandem mass spectrometry. Sorghum bran dose dependently increased the urinary excretion of catechin (0-2.2 nmol/day) and 3'-O-methylcatechin (0-9.5 nmol/day). Their serum concentrations also increased with dose (range of 0-14 nM for 3'-O-methylcatechin). Among the 14 phenolic acids analyzed, 3,4-dihydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, and 4-hydroxyphenylacetic acid dominated in the serum (1.8-8 micromol/L). In the urine, 3-methoxy-4-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, and 3-hydroxyphenylpropionic acid dominated and their excretion increased significantly with the level of sorghum bran in the diet. The summed phenolic acid excretion was 0.8 micromol/day in the control group and increased to 23 micromol/day for 40% sorghum bran group. The hippuric acid excretion ranged from 2.2 to 16.2 micromol/day and peaked in the 10% sorghum bran group. On the basis of chromic oxide, a nonabsorbable marker, total procyanidins and polymers disappeared progressively, and significant degradation occurred in the cecum and colon. Catechins and procyanidins in sorghum were bioavailable; however, bacteria-derived phenolic acids were the predominant metabolites of procyanidins. Procyanidins degraded in the gastrointestinal tract. Depolymerization was not observed.
高粱麸富含原花青素（主要是聚合物），这可能对人体健康有益；然而，原花青素的生物利用度尚未得到充分了解。将雌性斯普拉格-道利大鼠喂食含有0%、5%、10%、20%或40%高单宁高粱麸的AIN93G饮食（每组n = 5 - 7），持续50天。高粱麸含有23.3毫克/克的原花青素。使用液相色谱-串联质谱法分析儿茶素、表儿茶素、甲基化儿茶素和酚酸的尿排泄量。高粱麸剂量依赖性地增加了儿茶素（0 - 2.2纳摩尔/天）和3'-O-甲基儿茶素（0 - 9.5纳摩尔/天）的尿排泄量。它们的血清浓度也随剂量增加（3'-O-甲基儿茶素的范围为0 - 14纳摩尔）。在所分析的14种酚酸中，3,4-二羟基苯甲酸、3-甲氧基-4-羟基苯甲酸和4-羟基苯乙酸在血清中占主导地位（1.8 - 8微摩尔/升）。在尿液中，3-甲氧基-4-羟基苯乙酸、3-羟基苯乙酸和3-羟基苯丙酸占主导地位，并且它们的排泄量随着饮食中高粱麸水平的增加而显著增加。对照组酚酸排泄总量为0.8微摩尔/天，40%高粱麸组增加到23微摩尔/天。马尿酸排泄量在2.2至16.2微摩尔/天之间，在10%高粱麸组达到峰值。基于氧化铬（一种不可吸收的标记物），总原花青素和聚合物逐渐消失，并且在盲肠和结肠中发生了显著降解。高粱中的儿茶素和原花青素具有生物利用度；然而，细菌衍生的酚酸是原花青素的主要代谢产物。原花青素在胃肠道中降解。未观察到解聚现象。
