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Mechanism for the protection of oxidative stress in digestive tract by phytic acid

植酸保护消化道氧化应激的机制

基本信息

批准号：
11660127
负责人：
TERAO Junji
金额：
$ 1.92万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11660127/
关键词：
Phytic acid Chelating effect Antioxdant activity Colon cancer Oxidative stress Phytase intestinal mucosa fatly acid composition リポソーム

项目摘要

Phytic acid (IP_6) is capable of chelating iron ion and thereby blocking the generation of reactive oxygen radical via Fenton reaction. Some evidences suggest that the consumption of diets rich in phytic acid protect intestinal epithelial cells against iron ion-induced oxidative damage. During digestion, phytic acid is dephosphorylated yielding lower phosphorylated forms of inositol phosphate (IP_5〜IP_1). In this study, we evaluated the antioxidant properties of its hydrolysis products. Their ability to chelate iron ion decreased with the decrease in the number of phosphate groups on inositol structure. However, IP_2 showed a unique ability to prevent iron ion- induced deoxyribose degradation and IP3, as similarly to IP6, showed strong inhibitory effect against iron ion-induced oxidation of large intestinal mucosa homogenate. Interestingly, addition of vitamin E into liposomal suspension greatly incressed IP3 antioxidant activity, suggesting a synergistic antioxidant effect. Moreover, oral administration of IP6 protected large intestinal mucosa against iron ion-induced lipid peroxidation. These observations indicate an important antioxidant function for phytic acid hydrolysis products and suggest that their synergistic effect with vitamin E is an essential factor in the prevention of oxidative damage occurring in large intestinal mucosa.

植酸（IP_6）能螯合铁离子，从而阻断芬顿反应产生活性氧自由基。有证据表明，富含植酸的饮食可以保护肠上皮细胞免受铁离子诱导的氧化损伤。在消化过程中，植酸被脱磷酸化，产生较低磷酸化形式的肌醇磷酸（IP_5 → IP_1）。在这项研究中，我们评估了其水解产物的抗氧化性能。它们螯合铁离子的能力随着肌醇结构上磷酸基团数目的减少而降低。而IP_2对铁离子诱导的脱氧核糖降解有独特的抑制作用，IP_3对铁离子诱导的大肠粘膜匀浆氧化有较强的抑制作用，与IP_6相似。有趣的是，添加维生素E到脂质体悬浮液中大大增加了IP3的抗氧化活性，表明协同抗氧化作用。此外，口服IP6保护大肠粘膜免受铁离子诱导的脂质过氧化。这些观察表明植酸水解产物具有重要的抗氧化功能，并表明它们与维生素E的协同作用是预防大肠粘膜发生氧化损伤的重要因素。