Zheng Wenya, Hemker Marie L, Xie Mingyong, Soukup Sebastian T, Diel Patrick
Institute of Cardiovascular Research and Sports Medicine, Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Germany.
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China.
Planta Med. 2018 Sep;84(14):1022-1029. doi: 10.1055/a-0598-4812. Epub 2018 Apr 12.
Isoflavones have been reported to stimulate muscle growth. The aim of this study was to examine anabolic activity and associated molecular mechanisms of a soy extract (SoyEx), isoflavone aglycones, and a mixture simulating the composition of SoyEx in C2C12 myotubes. C2C12 cells were differentiated into myotubes. The effects of SoyEx, genistein, daidzein, glycitein, and the mixture of genistein-daidzein-glycitein (Mix) on myotube diameter and number were determined. In addition, the expression of genes and proteins associated with anabolic activity was analyzed. Treatment with SoyEx, genistein, and Mix led to a significant increase of myotube diameter and an increase of the number of myotubes per area compared to the control cell. The increase of diameter by SoyEx was antagonized by an antiestrogen, not by an antiandrogen. Furthermore, gene expressions of insulin growth factor (IGF)-1 and its receptor (IGF-1R), as well as protein expression of myosin heavy chain (MHC), were significantly increased by SoyEx, genistein, and Mix. The effects induced by genistein and Mix were comparable to SoyEx. In conclusion, SoyEx displays an anabolic activity in C2C12 myotubes by binding to ER and modulating IGF-1 and MHC expression. Our studies with isoflavone aglycones and Mix indicate that the isoflavone aglycone with the highest anabolic bioactivity in SoyEx is genistein.
据报道，异黄酮可刺激肌肉生长。本研究旨在检测大豆提取物（SoyEx）、异黄酮苷元以及一种模拟SoyEx成分的混合物在C2C12肌管中的合成代谢活性及相关分子机制。将C2C12细胞分化为肌管。测定了SoyEx、染料木黄酮、大豆苷元、黄豆黄素以及染料木黄酮 - 大豆苷元 - 黄豆黄素混合物（Mix）对肌管直径和数量的影响。此外，还分析了与合成代谢活性相关的基因和蛋白质表达。与对照细胞相比，用SoyEx、染料木黄酮和Mix处理导致肌管直径显著增加，且每单位面积的肌管数量增加。SoyEx引起的直径增加可被抗雌激素拮抗，而非抗雄激素。此外，SoyEx、染料木黄酮和Mix显著增加了胰岛素生长因子（IGF）-1及其受体（IGF-1R）的基因表达，以及肌球蛋白重链（MHC）的蛋白质表达。染料木黄酮和Mix诱导的效应与SoyEx相当。总之，SoyEx通过与雌激素受体结合并调节IGF-1和MHC表达，在C2C12肌管中表现出合成代谢活性。我们对异黄酮苷元和Mix的研究表明，SoyEx中具有最高合成代谢生物活性的异黄酮苷元是染料木黄酮。
