Absorption, bioavailability, and metabolism of flavonoids
Absorption, bioavailability, and metabolism of flavonoids
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DOI：
10.3109/13880200490893492
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发表时间：
2004-01-01
影响因子：
3.8
通讯作者：
Hollman, PCH
中科院分区：
文献类型：
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作者：
Hollman, PCH
为了揭示膳食类黄酮在疾病预防中的潜在作用的作用机制，关键是要知道决定它们从食物中释放的因素，它们的吸收程度以及它们在生物体中的命运。对黄酮类化合物的吸收、代谢和生物利用度的研究将回答这些问题。类黄酮醇，槲皮素作为主要的膳食黄酮醇，是第一个被研究，和其他类黄酮亚类的信息正在出现。大多数类黄酮，除了儿茶素的子类，存在于植物中结合糖作为β-糖苷。这种结构特征决定了类黄酮是否可以从小肠吸收，或者在吸收发生之前必须进入结肠。一般来说，但也有例外，葡萄糖苷是唯一可以从小肠吸收的糖苷。小肠的吸收比结肠更有效，并将导致更高的血浆值。从小肠吸收后，类黄酮与葡萄糖醛酸或硫酸盐结合，或可能发生O-甲基化。在吸收时发生在小肠中的缀合反应是非常有效的。结果，除了儿茶素外，血浆或尿液中没有发现游离的类黄酮苷元。正常饮食引起的血浆浓度将小于1 μ M。不能从小肠吸收的黄酮类化合物，以及随胆汁分泌的吸收的黄酮类化合物，将在结肠中被微生物降解，这将破坏黄酮类化合物的环结构。所得的酚酸已部分表征。这些酚酸可以被吸收，并已在血浆和尿液中进行了测量。未来的研究将需要解决组织分布，细胞摄取和细胞代谢。
To unravel mechanisms of action of dietary flavonoids in their potential role in disease prevention, it is crucial to know the factors that determine their release from foods, their extent of absorption, and their fate in the organism. Research on absorption, metabolism, and bioavailability of flavonoids will answer these questions. The subclass, flavonols, with quercetin as the major dietary flavonol, was the first to be studied, and information on other subclasses of flavonoids is emerging. Most flavonoids, except for the subclass of catechins, are present in plants bound to sugars as beta-glycosides. This structural feature determines whether the flavonoid can be absorbed from the small intestine or has to go to the colon before absorption can occur. Generally, but exceptions have been described, glucosides are the only glycosides that can be absorbed from the small intestine. Absorption from the small intestine is more efficient than from the colon and will lead to higher plasma values. After absorption from the small intestine, flavonoids are conjugated with glucuronic acid or sulfate or O-methylation may occur. The conjugation reactions, which occur in the small intestine upon absorption, are very efficient. As a result, no free flavonoid aglycones can be found in plasma or urine, except for catechins. Plasma concentrations due to a normal diet will be less than 1 muM. Flavonoids that cannot be absorbed from the small intestine, and absorbed flavonoids secreted with bile, will be degraded in the colon by microorganisms, which will break down the flavonoid ring structure. The resulting phenolic acids have partly been characterised. These phenolic acids can be absorbed and have been measured in plasma and urine. Future research will need to address tissue distribution, cellular uptake, and cellular metabolism.