Kudo Naoto, Arai Yasunori, Suhara Yoshitomo, Ishii Takeshi, Nakayama Tsutomu, Osakabe Naomi
Department of Bio-science and Engineering, Shibaura Institute of Technology, 307 Fukasaku, Munumaku, Saitama, 337-8570, Japan.
Department of Food and Nutritional Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan.
PLoS One. 2015 Sep 16;10(9):e0137809. doi: 10.1371/journal.pone.0137809. eCollection 2015.
Theaflavins are polyphenols found in black tea, whose physiological activities are not well understood. This study on mice evaluated the influence of a single oral administration of theaflavins on energy metabolism by monitoring the initial metabolic changess in skeletal muscle and brown adipose tissue (BAT). Oxygen consumption (VO2) and energy expenditure (EE) were increased significantly in mice treated with theaflavin rich fraction (TF) compared with the group administered vehicle alone. There was no difference in locomotor activity. Fasting mice were euthanized under anesthesia before and 2 and 5, 20-hr after treatment with TF or vehicle. The mRNA levels of uncoupling protein-1 (UCP-1) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in BAT were increased significantly 2-hr after administration ofTF. The levels of UCP-3 and PGC-1α in the gastrocnemius muscle were increased significantly 2 and 5-hr after administration of TF. The concentration of phosphorylated AMP-activated protein kinase (AMPK) 1α was also increased significantly in the gastrocnemius 2 and 5-hr after treatment with TF. These results indicate that TF significantly enhances systemic energy expenditure, as evidenced by an increase in expression of metabolic genes.
茶黄素是红茶中含有的多酚类物质，其生理活性尚未得到充分了解。这项针对小鼠的研究通过监测骨骼肌和棕色脂肪组织（BAT）的初始代谢变化，评估了单次口服茶黄素对能量代谢的影响。与仅给予赋形剂的组相比，用富含茶黄素的组分（TF）处理的小鼠的耗氧量（VO2）和能量消耗（EE）显著增加。运动活性没有差异。在给予TF或赋形剂处理前以及处理后2、5、20小时，将禁食小鼠在麻醉下安乐死。给予TF后2小时，BAT中解偶联蛋白-1（UCP-1）和过氧化物酶体增殖物激活受体γ共激活因子-1α（PGC-1α）的mRNA水平显著增加。给予TF后2小时和5小时，腓肠肌中UCP-3和PGC-1α的水平显著增加。用TF处理后2小时和5小时，腓肠肌中磷酸化的AMP激活蛋白激酶（AMPK）1α的浓度也显著增加。这些结果表明，TF显著提高了全身能量消耗，代谢基因表达的增加证明了这一点。
