| Project/Area Number |
14560095
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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 | Gifu University |
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Principal Investigator |
NAGAOKA Satoshi Gifu University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (50202221)
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| Co-Investigator(Kenkyū-buntansha) |
SEISHIMA Misturu Gifu University, Faculty of Medicine, Professor, 医学部, 教授 (10171315)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | cholesterol / β-lactoglobulin / mouse / CYP7A1 / HMG-CoAreductase / HepG2 / bile acid / milk / 遺伝子 / コレステロール輸送担体 |
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| Research Abstract |
Generally, animal proteins known as casein and else are considered to cause atherosclerosis in comparison with vegetable proteins. However, we have shown bovine milk whey protein which is animal protein and its major constituent protein β-lactoglobulin and β-lactoglobulin tryptic hydrolysate (LTH) reduce the serum cholesterol level compared with casein and its tryptic hydrolysate. Moreover, we identified the novel hypocholesterolemic peptides derived from LTH by screening using Caco-2 cells and animal studies. These are four kinds of peptides including IIAEK (Ile-Ile-Ala-Glu-Lys). In this report, we investigate the actions of a novel hypocholesterolemic peptide IIAEK derived from (3 -lactoglobulin in vivo or in vitro. The present study in mice suggests that IIAEK tends to decrease liver cholesterol level and cholesterol pool, and has influence to gene expression in liver The expression of the CYP7A1 known as rate-limiting enzyme of bile acids biosynthesis is dramatically down-regulated And expression of the HMG-CoA reductase known as rate-limiting enzyme of cholesterol biosynthesis or LDL-receptor is also down-regulated However, CYP7A1 mRNA level was significantly increased by IIAEK in HepG2 cells. Moreover, IIAEK activated CYP7A1 gene transcription measured by luciferase assay in HepG2 cells. We speculate that IIAEK accelerates cholesterol degradation in HepG2 cells.
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