Study on the mechanism by which beta-carotene increases skeletal muscle mass

2015 Fiscal Year Final Research Report

• Project/Area Number: 26660117
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Food science
• Research Institution: Osaka Prefecture University
• Principal Investigator: Yamaji Ryoichi 大阪府立大学, 生命環境科学研究科(系), 教授 (00244666)
• Co-Investigator(Kenkyū-buntansha): IWATA AKIRA 大阪府立大学, 総合リハビリテーション学部, 准教授 (90382241)
• Co-Investigator(Renkei-kenkyūsha): Adachi Tetsuya 湊川短期大学, 人間生活学科, 教授 (60345014)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: β-カロテン / 骨格筋 / ビタミンA / レチノイン酸受容体 / BCMO1 / 機能性食品成分

Outline of Final Research Achievements

Skeletal muscle plays a critical role in mobility and glucose and lipid metabolism. Food components effective for maintenance or enhancement of muscle mass are expected to contribute to prevention of decreased mobility and increased risk of metabolic diseases. Dietary beta-carotene increased the ratio of soleus muscle mass/body weight in mice. The cross-sectional area in soleus muscle fibers was increased. In soleus muscle of beta-carotene group, twitch force tended to be increased and tetanic force was increased, whereas specific force remains unchanged. beta-Carotene enhanced protein synthesis, but decreased ubiquitin conjugates. BCMO1 converts beta-carotene to retinal. However, beta-carotene enhanced retinoic acid receptor (RAR) transactivation in BCMO1-knockdown cells and increased soleus muscle mass in BCMO1-knockout mice. These results indicate that dietary beta-carotene induces functional hypertrophy in soleus muscle and suggest that beta-carotene transactivates RAR as a ligand.

Free Research Field

農学