Studies on the molecular mechanisms of the effects of ingested phytochemicals on the reactive oxygen species-generating system of cells in the intestinal tract

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K02329
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 08030:Family and consumer sciences, and culture and living-related
• Research Institution: Shokei Junior College
• Principal Investigator: Kikuchi Hidehiko 尚絅大学短期大学部, その他部局等, 教授 (10301384)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: フィトケミカル / 腸管細胞 / マクロファージ / 活性酸素 / 自然免疫 / Nox2 / ウロリチンA / L-テアニン

Outline of Final Research Achievements

In this study, I mainly focused on the macrophage Nox2 (gp91-phox) as a superoxide-generating system of cells in the intestinal tract. Retinoic acid induces differentiation of human monoblast U937 cells to macrophage-like cells, which induces superoxide-generating ability. To know the effects of phytochemicals on the retinoic acid-induced superoxide-generating ability, U937 cells were grown with retinoic acid in the presence or absence of various phytochemicals. As a result, chalcones, sulforaphane, urolithin A, 3', 4'-dihydroxyflavones and L-theanine enhanced the gene expression of gp91-phox, resulting in up-regulation of the retinoic acid-induced superoxide-generating ability of U937 cells. These data suggested that these phytochemicals can bring about enhancement of the superoxide-generating ability of leukocytes, resulting in up-regulation of innate immune response.

Free Research Field

生化学　分子栄養学

Academic Significance and Societal Importance of the Research Achievements

食品中に含まれる植物性生理活性物質（フィトケミカル）は多彩な生物活性を有し、疾病の予防や治療を通じて人間の健康維持に寄与することが期待されている。本研究では、食品成分と直接接する機会が多い消化管の中で活性酸素産生能を有する腸管細胞、特にマクロファージに着目して、フィトケミカルがマクロファージの活性酸素産生能に及ぼす影響を解析した。その結果、カルコン類、スルフォラファン、ウロリチンA、3',4'-ジヒドロキシフラボンやL-テアニンがマクロファージの活性酸素産生能を亢進することが明らかとなった。これらの研究成果は、上記フィトケミカルが免疫力（自然免疫）を増強する可能性を強く示唆するものである。