College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan.
Phytother Res. 2012 Aug;26(8):1173-7. doi: 10.1002/ptr.3709. Epub 2012 Jan 4.
Previous studies have shown that Cordyceps militaris (CM) has a hypoglycemic effect, but the actual mechanism remains unclear. This study explored the hypoglycemic mechanism of aqueous extracts of CM in normal Wistar rats. First, the optimal dose of CM for lowering plasma glucose and insulin secretion was tested. Further, atropine and hemicholinium-3 (HC-3) were injected and a western blot was used to investigate insulin signaling. It was found that 10 mg/kg CM extracts had a stronger hypoglycemic effect than a higher dose (100 mg/kg); therefore, a dose of 10 mg/kg was used in subsequent experiments. In normal rats, CM extracts decreased plasma glucose by 21.0% and induced additional insulin secretion by 54.5% after 30 min. When atropine or HC-3 was injected, CM induced a hypoglycemic effect, but the enhancement of insulin secretion was blocked. By western blotting, significant increases in the insulin receptor substrate 1 (IRS-1) and glucose transporter 4 (GLUT-4) were observed after CM feeding. However, the elevation of these signaling proteins was abolished by atropine or HC-3. Taken together, these findings indicate that CM can lower plasma glucose via the stimulation of insulin secretion and cholinergic activation involved in the hypoglycemic mechanism of normal Wistar rats.
先前的研究表明，蛹虫草（CM）具有降血糖作用，但实际机制尚不清楚。本研究旨在探讨 CM 水提物在正常 Wistar 大鼠中的降血糖机制。首先，测试了 CM 降低血浆葡萄糖和胰岛素分泌的最佳剂量。然后，注射阿托品和血卟啉-3（HC-3），并进行 Western blot 分析以研究胰岛素信号。结果发现，10mg/kg CM 提取物比高剂量（100mg/kg）具有更强的降血糖作用；因此，在后续实验中使用 10mg/kg 的剂量。在正常大鼠中，CM 提取物可在 30 分钟内使血浆葡萄糖降低 21.0%，并额外诱导胰岛素分泌增加 54.5%。当注射阿托品或 HC-3 时，CM 可诱导低血糖，但会阻断胰岛素分泌的增强。通过 Western blot 分析，发现 CM 喂养后胰岛素受体底物 1（IRS-1）和葡萄糖转运蛋白 4（GLUT-4）明显增加。然而，这些信号蛋白的升高被阿托品或 HC-3 所抑制。综上所述，这些结果表明 CM 可通过刺激胰岛素分泌和参与正常 Wistar 大鼠降血糖机制的胆碱能激活来降低血浆葡萄糖。
