1999 Fiscal Year Final Research Report Summary
Molecular basis for establishing the environment in digestive tract by food components
| Project/Area Number |
10460052
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | HOKKAIDO UNIVERSITY |
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Principal Investigator |
KAWABATA Jun Hokkaido Univ., Grad. School of Agr., Asso. Pro., 大学院・農学研究科, 助教授 (60142197)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIZUKA Satoshi Hokkaido Univ., Grad. School of Agr., Inst., 大学院・農学研究科, 助手 (00271627)
KURIHARA Hideyuki Hokkaido Univ., Grad. School of Fis., Asso. Pro., 大学院・水産学研究科, 助教授 (40234570)
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| Project Period (FY) |
1998 – 1999
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| Keywords | maltase / α-amylase / ellagitannin / β-glucuronidase / seafood / nucleic acid / aberrant crypt / intrarectal injection |
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| Research Abstract |
As the inhibitory principles against rat intestinal maltase, two ellagitannins, eugeniin and casuarictin, were isolated from the methanolic extracts of Clove buds. Structure-activity relationship study of the isolates together with synthetic pentagalloylglucose (PGG), which showed the highest activity , revealed that the inhibitory activity depended on the number of uncoupled galloyl residues in the molecule. These tannins also inhibited maltase expressed on a human carcinoma cell line, Caco-2. On the other hand, the acetone extracts of roselle tea, dried flower buds of Hibiscus sabdariffa, possessed an inhibitory activity against porcine pancreatic α-amylase. The active compound was identified as hibiscus acid.
Inhibitory potencies of the extracts of seafood and algae against Escherichia coli β-glucuronidase were investigated by the colorimetric method in vitro. Among them, the extracts of dried bonito (katsuobushi), the brown alga Hizikia fusiformis, and the red alga Chondria crassica
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ulis showed the inhibitory activity. The inhibitor obtained from dried bonito was disclosed to be inosinic acid. Among nucleic acid-related compounds, adenylic acid and adenosine triphosphate also inhibited the β-glucuronidase. The inhibitor obtained from H. fusiformis was identified to be a mixture of free fatty acids. Isolation and structural elucidation of the inhibitor of C. crassicaulis is now in progress.
Direct effect of molecules on the formation of aberrant crypt foci (ACF) induced by 1,2-dimethylhydrazine using the intrarectal injection was investigated. Butyric acid or deoxycholic acid (and the derivatives) was used as the test molecule. Intrarectal injection of butyric acid showed a protective effect on the ACF formation at 20 mM. On the other hand, intrarectal injection of deoxycholic acid significantly promoted the size of ACF. These results suggest that the intrarectal injection with experimental animal is useful model to assess the effect of such molecules on the early phase of carcinogenesis. Less
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