2000 Fiscal Year Final Research Report Summary
Mechanism for the protection of oxidative stress in digestive tract by phytic acid
| Project/Area Number |
11660127
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
食品科学・栄養科学
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| Research Institution | The University of Tokushima |
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Principal Investigator |
TERAO Junji The Univ.Tokushima Dept.Nutrition, Professor, 医学部, 教授 (60093275)
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| Co-Investigator(Kenkyū-buntansha) |
BANDO Noriko The Univ.Tokushima Dept.Nutrition, Researcher, 医学部, 教務員 (40116851)
MUROTA Kaeko The Univ.Tokushima Dept.Nutrition, Research Associate, 医学部, 助手 (40294681)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Phytic acid / Chelating effect / Antioxdant activity / Colon cancer / Oxidative stress / Phytase / intestinal mucosa / fatly acid composition |
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| Research Abstract |
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.
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