QUERCETIN METABOLITES IN PLASMA OF RATS FED DIETS CONTAINING RUTIN OR QUERCETIN
QUERCETIN METABOLITES IN PLASMA OF RATS FED DIETS CONTAINING RUTIN OR QUERCETIN
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DOI：
10.1093/jn/125.7.1911
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发表时间：
1995-07-01
影响因子：
4.2
通讯作者：
REMESY, C
中科院分区：
文献类型：
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作者：
MANACH, C;MORAND, C;REMESY, C
研究了槲皮素和芦丁饲料对大鼠黄酮醇的生物利用度和血浆转运的影响。Wistar大鼠饲喂以下纯化饲料之一10 d：对照；16.4或8.2 mmol芦丁/kg日粮；或16.4、8.2或4.1 mmol槲皮素/kg日粮。测定血浆、回肠、盲肠内容物和粪便中的黄酮醇浓度。槲皮素和芦丁含量分别为16.4 mmol /kg时，循环黄酮醇浓度均为115 μ mol/L。给予槲皮素或芦丁后，盲肠内容物中槲皮素的浓度相近。通过高效液相色谱分析和β -葡萄糖醛酸酶/磺化酶处理，血浆黄酮醇被鉴定为偶联槲皮素本身，或者是比槲皮素极性低的苷元的偶联形式（丰度是槲皮素的4.5倍）。喂食槲皮素或芦丁的大鼠血浆呈绿色/黄色，吸光度峰值分别为411 nm，而纯芦丁或槲皮素溶液的吸光度峰值分别为363 nm或375 nm。当纯槲皮素存在于白蛋白中或添加到血浆组分中时，获得了这种带I吸收的位移。黄酮类化合物在白蛋白存在下的显色特性高度依赖于c环上C-2/C-3双键的存在，并受b环羟基化程度的影响。白蛋白和槲皮素之间的分子间键的存在得到了体外吸光度和荧光研究的支持。加入人白蛋白后，荧光强度和槲皮素吸光度的位移随白蛋白/槲皮素摩尔比的增加而增加。0.5 μ mol/L槲皮素可有效抑制Cu2+催化氧化人LDL或大鼠VLDL+LDL生成共轭二烯。这些结果表明，黄酮醇在大鼠血浆中以不可忽略浓度的共轭代谢产物的形式被回收，这些黄酮醇可能是具有多种生物效应的抗氧化微量营养素。
We studied the bioavailability and the plasma transport of flavonols in rats fed quercetin or rutin diets. Wistar rats were fed one of the following purified diets for 10 d: control; 16.4 or 8.2 mmol rutin/kg diet; or 16.4, 8.2 or 4.1 mmol quercetin/kg diet. Flavonol concentrations were determined in plasma, ileal and cecal contents, and feces. In rats fed diets containing 16.4 mmol quercetin or rutin/kg, the concentration of circulating flavonols was similar to 115 mu mol/L. Quercetin or rutin administration resulted in similar concentrations of quercetin in cecal contents. By HPLC analysis and beta-glucuronidase/sulfatase treatment, plasma flavonols have been identified as conjugated quercetin itself, or a conjugated form (4.5-fold as abundant) of an aglycone less polar than quercetin. Rats fed quercetin or rutin diets had a green/yellow-colored plasma that exhibited a peak absorbance at 411 nm, vs. 363 or 375 nm for pure rutin or quercetin solutions, respectively. This shift of band I absorption was obtained when pure quercetin was in the presence of albumin or added to a plasma fraction. The bathochromic properties of flavonoids in the presence of albumin are highly dependent on the presence of the C-2/C-3 double bond on the C-ring and are influenced by the degree of B-ring hydroxylation. The existence of intermolecular bonds between albumin and quercetin is supported by in vitro absorbance and fluorescence studies. With human albumin, the fluorescence intensity and the shift of quercetin absorbance increased in parallel to the albumin/quercetin molar ratio. Conjugated diene formation, resulting from Cu2+-catalyzed oxidation of human LDL or rat VLDL+LDL was effectively inhibited in vitro by 0.5 mu mol/L quercetin. These results show that dietary flavonols are recovered in rat plasma as conjugated metabolites in non-negligible concentrations, and that these flavonols may be interesting antioxidant micronutrients with a variety of biological effects.