In situ visualization of intestinal absorption processes of polyphenols by using MALDI-MS imaging

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05534
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38050:Food sciences-related
• Research Institution: Kyushu University
• Principal Investigator: Tanaka Mitsuru 九州大学, 五感応用デバイス研究開発センター, 准教授 (70584209)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: MS イメージング / 腸管吸収 / ポリフェノール / 代謝 / MALDI-MS

Outline of Final Research Achievements

In the present study, MALDI-MS imaging was used as a visualization technique to investigate the intestinal absorption of polyphenols. Nifedipine/phytic acid-aided MALDI-MS imaging was performed to visualize theaflavin-3’-O-gallate (TF3’G) and epicatechin-3-O-gallate (ECG) in the rat jejunum. Non-absorbable TF3’G was successfully visualized at the apical region, whereas absorbable ECG was detected throughout the rat jejunum. MALDI-MS imaging was also performed to determine the transport routes of the target metabolites. The inhibitor aided-intestinal MALDI-MS imaging visualized the behavior in which TF3’G and ECG were incorporated into intestinal tissues, followed by efflux back to the apical compartment. In addition, MALDI-MS imaging analyses suggested that TF3’G was resistant to phase II metabolism during the influx/efflux processes, whereas ECG was susceptible to methylation and sulphation reactions.

Free Research Field

食品分析

Academic Significance and Societal Importance of the Research Achievements

これまでの食品成分の吸収性評価は、摂取した成分の血中移行性の評価に終始しているものがほとんどで、実際の吸収を制御する腸管での動態や代謝物を考慮した解析にはほとんど至れていない。対して、本研究にて構築したラット腸管 in situ MALDI-MS イメージング法は、腸管組織での成分の透過過程、並びに、一連の代謝物を可視化することが可能な方法である。すなわち、本法はこれまではブラックボックスとされてきた腸管での吸収動態を可視化という直截的な手法で評価可能であり、生体利用性の解明を基盤とした食機能研究の遂行に極めて有用な評価法であると考えられる。