SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, 603 203, India.
Department of Biotechnology, Anna University, BIT Campus, Tiruchirappalli, Tamil Nadu, 620 024, India.
Mol Biol Rep. 2020 Sep;47(9):6727-6740. doi: 10.1007/s11033-020-05728-5. Epub 2020 Aug 18.
Understanding the mechanism by which the exogenous biomolecule modulates the GLUT-4 signalling cascade along with the information on glucose metabolism is essential for finding solutions to increasing cases of diabetes and metabolic disease. This study aimed at investigating the effect of hamamelitannin on glycogen synthesis in an insulin resistance model using L6 myotubes. Glucose uptake was determined using 2-deoxy-D-[1-H] glucose and glycogen synthesis were also estimated in L6 myotubes. The expression levels of key genes and proteins involved in the insulin-signaling pathway were determined using real-time PCR and western blot techniques. The cells treated with various concentrations of hamamelitannin (20 µM to 100 µM) for 24 h showed that, the exposure of hamamelitannin was not cytotoxic to L6 myotubes. Further the 2-deoxy-D-[1-H] glucose uptake assay was carried out in the presence of wortmannin and Genistein inhibitor for studying the GLUT-4 dependent cell surface recruitment. Hamamelitannin exhibited anti-diabetic activity by displaying a significant increase in glucose uptake (125.1%) and glycogen storage (8.7 mM) in a dose-dependent manner. The optimum concentration evincing maximum activity was found to be 100 µm. In addition, the expression of key genes and proteins involved in the insulin signaling pathway was studied to be upregulated by hamamelitannin treatment. Western blot analysis confirmed the translocation of GLUT-4 protein from an intracellular pool to the plasma membrane. Therefore, it can be conceived that hamamelitannin exhibited an insulinomimetic effect by enhancing the glucose uptake and its further conversion into glycogen by regulating glucose metabolism.
了解外源性生物分子如何调节 GLUT-4 信号级联以及葡萄糖代谢的信息对于找到解决糖尿病和代谢疾病病例增加的方法至关重要。本研究旨在使用 L6 肌管研究金缕梅单宁对胰岛素抵抗模型中糖原合成的影响。使用 2-脱氧-D-[1-H]葡萄糖测定葡萄糖摄取，并用 L6 肌管测定糖原合成。使用实时 PCR 和 Western blot 技术测定参与胰岛素信号通路的关键基因和蛋白的表达水平。用不同浓度的金缕梅单宁（20µM 至 100µM）处理细胞 24 小时，结果表明金缕梅单宁对 L6 肌管没有细胞毒性。进一步在wortmannin 和 Genistein 抑制剂存在下进行 2-脱氧-D-[1-H]葡萄糖摄取测定，以研究 GLUT-4 依赖的细胞表面募集。金缕梅单宁通过以剂量依赖的方式显著增加葡萄糖摄取（125.1%）和糖原储存（8.7mM）表现出抗糖尿病活性。表现出最大活性的最佳浓度被发现为 100µm。此外，还研究了参与胰岛素信号通路的关键基因和蛋白的表达，发现金缕梅单宁处理后这些基因和蛋白的表达上调。Western blot 分析证实 GLUT-4 蛋白从细胞内池易位到质膜。因此，可以设想金缕梅单宁通过增强葡萄糖摄取及其通过调节葡萄糖代谢进一步转化为糖原来发挥胰岛素样作用。
