| Project/Area Number |
16K21534
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Eating habits
Food science
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| Research Institution | Shujitsu University |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
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| Keywords | 糖尿病 / 米タンパク加水分解物 / DPP-4 / 酸化ストレス / 生理活性 / 食品 |
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| Outline of Final Research Achievements |
In this study, anti-diabetic activities of rice-derived protein hydrolysates (RPH) were evaluated. RPH showed an inhibitory activity (IC50 = 1.5 ± 0.1 mg/mL) toward dipeptidylpeptidase-IV (DPP-4) that metabolizes the insulinotropic hormone, glucagon-like peptide-1. Further, we identified that the dipeptides Ile-Pro, Met-Pro, Val-Pro, and Leu-Pro from the RPH are involved in the inhibitory activity against DPP-4. Pancreatic beta-cell dysfunction is a major feature of type 2 diabetes. Previous studies have demonstrated that high glucose can increase the accumulation of intracellular reactive oxygen species (ROS) that results in oxidative stress to the beta-cells. Glutathione, the most abundant intracellular antioxidant, protects cells against ROS induced oxidative stress. We demonstrated that RPH showed increasing effect of the intracellular glutathione levels and the protective effect against oxidative stress.
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| Academic Significance and Societal Importance of the Research Achievements |
2型糖尿病は、膵β細胞からのインスリン分泌障害により発症・進展する疾患であり、膵β細胞の機能低下は2型糖尿病の発症に直結すると考えられている。本研究により、米タンパク加水分解物は日本においても新たな糖尿病治療ターゲットとなっているDPP-4阻害作用があることを明らかとした。また、米由来タンパク加水分解物は膵β細胞内グルタチオンを上昇させることにより、酸化ストレスによる細胞傷害抑制効果があることを見出した。以上の結果から、米由来タンパク加水分解物はDPP-4阻害作用によるインスリン量の調節とβ細胞保護作用により、糖尿病予防に対して相乗的な効果が期待できる。
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