Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, Hunan, China.
National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Centre of Utilisation of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, Hunan, China.
J Agric Food Chem. 2021 Jul 28;69(29):8144-8159. doi: 10.1021/acs.jafc.1c02892. Epub 2021 Jul 14.
Drinking tea has been proven to have a positive biological effect in regulating human glucose and lipid metabolism and preventing type 2 diabetes (T2D). Skeletal muscle (SkM) is responsible for 70% of the sugar metabolism in the human body, and its dysfunction is an important factor leading to the development of obesity, T2D, and muscle diseases. As one of the four known theaflavins (TFs) in black tea, the biological role of theaflavin (TF1) in regulating SkM metabolism has not been reported. In this study, mature myotubes induced by C2C12 cells in vitro were used as models. The results showed that TF1 (20 μM) promoted mitochondrial abundance and glucose absorption in myotubes by activating the CaMKK2-AMPK signaling axis via Ca influx. Moreover, it promoted the expression of slow muscle fiber marker genes (Myh7, Myl2, Tnnt1, and Tnnc1) and PGC-1α/SIRT1, as well as enhanced the oxidative phosphorylation capacity of myotubes. In conclusion, this study preliminarily clarified the potential role of TF1 in regulating SkM glucose absorption as well as promoting SkM mitochondrial biosynthesis and slow muscle fiber formation. It has potential research and application values for the prevention/alleviation of SkM-related T2D and Ca-related skeletal muscle diseases through diet.
饮茶已被证明具有调节人体葡萄糖和脂质代谢、预防 2 型糖尿病（T2D）的积极生物学效应。骨骼肌（SkM）负责人体 70%的糖代谢，其功能障碍是导致肥胖、T2D 和肌肉疾病发展的重要因素。茶黄素（TFs）是红茶中四种已知茶黄素之一，其在调节 SkM 代谢中的生物学作用尚未报道。在这项研究中，使用体外 C2C12 细胞诱导的成熟肌管作为模型。结果表明，TF1（20 μM）通过 Ca2+内流激活 CaMKK2-AMPK 信号通路，促进肌管中线粒体的丰度和葡萄糖的吸收。此外，它还促进了慢肌纤维标记基因（Myh7、Myl2、Tnnt1 和 Tnnc1）和 PGC-1α/SIRT1 的表达，并增强了肌管的氧化磷酸化能力。总之，本研究初步阐明了 TF1 调节 SkM 葡萄糖吸收以及促进 SkM 线粒体生物合成和慢肌纤维形成的潜在作用。通过饮食预防/缓解与 SkM 相关的 T2D 和与 Ca 相关的骨骼肌肉疾病具有潜在的研究和应用价值。
