Elucidation of chemical structure of pectin for anti-inflammatory activity and its protective mechanism against inflammatory diseases

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K21075
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Eating habits; Food science
• Research Institution: Gifu University
• Principal Investigator: KITAGUCHI Kohji 岐阜大学, 応用生物科学部, 助教 (50508372)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 食物繊維 / 炎症 / 腸管免疫 / マクロファージ

Outline of Final Research Achievements

Dietary fiber intake has been reported to decrease the risk of developing inflammatory diseases. This anti-inflammatory effect is at least partially due to fermentation of dietary fiber by the colonic microbiota. In addition it has been suggested that pectin, a water-soluble dietary, directly influence host cells and thereby modulate inflammatory responses. However, the underlying mechanism by which pectin exerts its protective effect against inflammatory diseases remains unknown. IL-6 secretion from TLR-activated RAW264.7 cells was suppressed by pretreatment with pectin. This suppression was observed even with degraded pectin pretreatment but not with polygalacturonic acid, as the principal constituent of the pectin backbone. Furthermore, we found that pectin-administered mice showed attenuation of LPS-induced inflammatory responses and reduced levels of inflammatory cytokine in Peyer’s patches. These results suggest that pectin suppresses TLR signaling by its side chains.

Free Research Field

食品免疫学

Academic Significance and Societal Importance of the Research Achievements

近年，生活習慣病のみならず，がんや神経変性疾患などの 基盤病態として，免疫系細胞の過剰な活性化と慢性的な炎症応答の持続が指摘されている。本研究成果より，ペクチンを摂取することで，腸管免疫系を介して過剰な免疫細胞の活性化や炎症を制御でき，炎症が関与する様々な慢性疾患や生活習慣病の予防や治療に応用できる可能性が示された。また本研究により，ペクチン分子内の抗炎症活性の発現に必要な化学構造が推定できた。この活性成分のみを濃縮・添加することにより，少量の摂取で充分にペクチンの抗炎症機能を発揮できる新たな機能性食品を創出できる可能性が考えられる。