Absorption and Function of Dietary Carotenoids
Absorption and Function of Dietary Carotenoids
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DOI：
10.1159/000212738
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发表时间：
2009-01-01
期刊：
影响因子：
--
通讯作者：
Nagao, Akihiko
中科院分区：
文献类型：
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作者：
Nagao, Akihiko
类胡萝卜素是一种具有高度疏水性的色素，颜色为黄色至红色，其主要膳食来源是水果和蔬菜。它们具有作为维生素A前体的基本生理功能，并且还具有与预防退行性疾病相关的抗氧化、抗癌、免疫增强和抗肥胖活性。类胡萝卜素从食物基质中的释放、在消化道内的分散以及在混合胶束中的增溶是类胡萝卜素生物可利用性的重要步骤。溶解的类胡萝卜素通过简单的扩散和/或转运蛋白介导的过程被小肠上皮细胞吸收，然后作为乳糜微粒分泌到淋巴中。积累在组织中的类胡萝卜素被认为通过酶促裂解和/或在共轭双键处与活性氧物质的化学氧化代谢成小分子。叶黄素的羟基可被氧化代谢为羰基。具有共轭双键长链的类胡萝卜素物理淬灭单线态氧和双氧自由基，特别是在低氧压下，因此它们被认为作为亲脂性抗氧化剂用于人类健康。除了抗氧化活性外，每种类胡萝卜素还具有特征性功能，如细胞周期抑制、诱导细胞分化和凋亡以及增强间隙连接通讯。然而，这些生物学作用的详细机制尚未完全揭示，值得进一步研究。版权所有（C）2009 S. Karger AG，巴塞尔
Carotenoids are highly hydrophobic pigments with yellow to red color and their major dietary sources are fruits and vegetables. They have an essential physiological function as a vitamin A precursor and also have antioxidant, anticancer, immune enhancement and antiobesity activities related to prevention of degenerative diseases. The release of carotenoids from food matrix, their dispersion within the digestive tract, and their solubilization in mixed micelles are important steps for carotenoid bioaccessibility. Solubilized carotenoids are taken up by epithelial cells of the small intestine by simple diffusion and/or transporter-mediated processes and then secreted to lymph as chylomicron. Carotenoids accumulated in tissues are thought to be metabolized to small molecules by enzymatic cleavage and/or chemical oxidation with active oxygen species at conjugated double bonds. The hydroxyl group of xanthophylls can be oxidatively metabolized to carbonyl group. Carotenoids with long chain of conjugated double bonds physically quench singlet oxygen and scavenge oxygen radicals, particularly under low oxygen pressure, and thereby they have been thought to work as lipophilic antioxidants for human health. In addition to antioxidant activities, each carotenoid has characteristic functions such as cell cycle inhibition, induction of cell differentiation and apoptosis, and enhancement of gap-junctional communication. However, the detailed mechanisms of these biological actions have not been fully revealed yet and deserve future studies. Copyright (C) 2009 S. Karger AG, Basel