The Alzheimer's disease prevention and treatment by nutritional increase in endogenous neuro-protective mediator, kynurenic acid in brain

2015 Fiscal Year Final Research Report

• Project/Area Number: 25750068
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Eating habits
• Research Institution: National Center for Geriatrics and Gerontology
• Principal Investigator: OKUNO Alato 国立研究開発法人国立長寿医療研究センター, ラジオアイソトープ管理室, 研究員 (50623980)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: トリプトファン / キヌレン酸 / キノリン酸

Outline of Final Research Achievements

Tryptophan (Trp) metabolism within the mammalian brain mainly occurs through the kynurenine pathway, where both the endogenous neuro-protective mediator, kynurenic acid (KYNA) and the endogenous excitatory neurotoxin, quinolinic acid (QA) are generated. Increase in KYNA/QA ratio in the brain is thought to be neuro-protective against some neurodegenerative diseases. To examine the possible effect of Trp intake on the change of the KYNA/QA ration in the brain, 0, 0.5, 1.0, 2.0, 5.0% Trp supplementation to 20% casein diet were fed to 20 weeks old C57BL6/J male mice for 28 weeks. As a result, the 1-5% Trp supplementation caused a decrease in the KYNA/QA ratio in brain. Furthermore, a systemic inflammation (a 5-fold increase in plasma level of IFN-γ). These results suggest that a simple Trp supplementation to AD patients worsens rather than suppresses neural degeneration by decrease in the KYNA/QA ratio and by increase in systemic inflammation.

Free Research Field

基礎栄養学