Bioavailability of [2-14C]Quercetin-4′-glucoside in Rats
Bioavailability of [2-14C]Quercetin-4′-glucoside in Rats
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DOI：
10.1021/jf802754s
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发表时间：
2008-12-24
影响因子：
6.1
通讯作者：
Crozier, Alan
中科院分区：
文献类型：
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作者：
Mullen, William;Rouanet, Jean-Max;Crozier, Alan
[2-C-14]通过管饲法向饲养在代谢笼中的大鼠喂食槲皮素-4 '-葡萄糖苷（4 mg/kg体重）。在随后的72小时内，通过具有在线放射性和MS 2检测的高效液相色谱法监测身体组织、血浆、粪便和尿液中的放射性标记产物。摄入后1小时和6小时，而在小肠中，黄酮醇葡萄糖苷转化为葡糖苷酸和甲基化和硫酸化的槲皮素衍生物，但只有微量的这些代谢产物经尿液排泄。在进入盲肠和结肠时，黄酮醇代谢物下降，因为它们被结肠微生物菌群转化为酚酸，主要是3-羟基苯乙酸和3，4-二羟基苯乙酸。粪便主要含有3-羟基苯乙酸。摄入后0-12和0-24 h采集的尿液中含有放射性标记的马尿酸和3-羟基苯乙酸。在24-48和48-72 h尿样中，14 C-马尿酸显著下降，同时标记苯甲酸增加。尽管在72小时内尿液中的标记回收率为69%，但血浆中的放射性蓄积极轻微，同样，在胃肠道外的身体组织中检测到极少量放射性。这反映在摄入后72 h，96%的摄入放射性在粪便、尿液和笼洗液（包括尿液和粪便的混合物）中回收。该研究表明，当它通过胃肠道时，几乎所有的[2-C-14]槲皮素-4 '-葡萄糖苷都转化为酚酸，这些化合物在以前的模型动物系统的黄酮醇生物利用度研究中没有监测到，其中一些使用了非常高剂量的糖苷配基槲皮素（500 mg/kg体重），这不是正常的饮食成分。
[2-C-14]Quercetin-4'-glucoside (4 mg/kg body weight) was fed by gavage to rats housed in metabolic cages, and over. an ensuing 72 h period, radiolabeled products in body tissues, plasma, feces, and urine were monitored by high-performance liquid chromatography with online radioactivity and MS2 detection. One and 6 h after ingestion, while in the small intestine, the flavonol glucoside was converted to glucuronide and methylated and sulfated derivatives of quercetin, but only trace amounts of these metabolites were excreted in urine. On entering the cecum and the colon, the flavonol metabolites declined as they were converted to phenolic acids, principally 3-hydroxyphenylacetic acid and 3,4-dihydroxyphenylacetic acid, by the colonic microflora. Feces contained mainly 3-hydroxyphenylacetic acid. Urine collected 0-12 and 0-24 h after ingestion contained radiolabeled hippuric acid and 3-hydroxyphenylacetic acid. 14 C-Hippuric acid declined markedly in the 24-48 and 48-72 h urine samples, and there was a concomitant increase in labeled benzoic acid. There was minimal accumulation of radioactivity in plasma, despite a 69% recovery of label in urine over the 72 h period, and likewise, very little radioactivity was detected in body tissues out with the gastrointestinal tract. This is reflected in the fact that 72 h after ingestion 96% of the ingested radioactivity was recovered in feces, urine, and the cage washes, which comprise a mixture of urine and feces. The study reveals that as it passes through the gastrointestinal tract, almost all of the of [2-C-14]quercetin-4'-glucoside is converted to phenolic acids, compounds not monitored in previous flavonol bioavailability studies with model animal systems, some of which have used exceedingly high doses of the aglycone quercetin (500 mg/kg body weight), which is not a normal dietary component.