Pharmacy Department, Faculty of Technology and Engineering, Kalabhavan, The M.S. University of Baroda, Vadodara 390 001, Gujarat, India.
Phytomedicine. 2011 Sep 15;18(12):1045-52. doi: 10.1016/j.phymed.2011.05.006. Epub 2011 Jun 12.
The stem of Tinospora cordifolia (TC) is widely used in the therapy of diabetes in traditional folk medicine of India. In the present study, isoquinoline alkaloid rich fraction (AFTC) derived from stem of TC and three alkaloids viz., palmatine, jatrorrhizine and magnoflorine were evaluated for insulin-mimicking and insulin-releasing effect in vitro and in vivo. Their effect on hepatic gluconeogenesis was examined in rat hepatocytes. Insulin releasing effect was detected in vitro using rat pancreatic β-cell line, RINm5F. Furthermore, effects of AFTC and isolated alkaloids on serum glucose and insulin level were studied in fasted and glucose challenged normal rats. AFTC significantly decreased gluconeogenesis in rat hepatocytes as insulin did and it increases insulin secretion in RINm5F cells similar to tolbutamide. In acute 30 min test in vitro, AFTC, palmatine, jatrorrhizine and magnoflorine stimulated insulin secretion from the RINm5F cell line. As in vivo results, administration of AFTC (50, 100, and 200 mg/kg), palmatine, jatrorrhizine and magnoflorine (10, 20 and 40 mg/kg each) orally significantly decreased fasting serum glucose, and suppressed the increase of blood glucose levels after 2 g/kg glucose loading in normal rats. In vivo study further justified their insulin secreting potential by raising the serum insulin level in glucose fed rats. These results demonstrate the alkaloid present in TC contributed for antihyperglycemic activity. AFTC may have hypoglycemic effects via mechanisms of insulin releasing and insulin-mimicking activity and thus improves postprandial hyperglycemia.
三叶鬼针草的茎在印度传统民间医学中被广泛用于糖尿病的治疗。在本研究中，从三叶鬼针草的茎中提取的富含异喹啉生物碱的部分（AFTC）和三种生物碱，即黄连碱、药根碱和木兰碱，被评估了其在体外和体内的胰岛素模拟和胰岛素释放作用。它们在大鼠肝细胞中的肝糖异生作用也被检测到。胰岛素释放作用在体外使用大鼠胰岛β细胞系 RINm5F 进行检测。此外，还研究了 AFTC 和分离的生物碱对禁食和葡萄糖挑战的正常大鼠血清葡萄糖和胰岛素水平的影响。AFTC 可显著降低大鼠肝细胞中的糖异生，如胰岛素一样，它还可增加 RINm5F 细胞中的胰岛素分泌，类似于甲苯磺丁脲。在体外 30 分钟急性试验中，AFTC、黄连碱、药根碱和木兰碱刺激 RINm5F 细胞系的胰岛素分泌。与体内结果一致，AFTC（50、100 和 200mg/kg）、黄连碱、药根碱和木兰碱（10、20 和 40mg/kg 各）口服给药可显著降低正常大鼠的空腹血清葡萄糖水平，并抑制 2g/kg 葡萄糖负荷后血糖水平的升高。体内研究通过提高葡萄糖喂养大鼠的血清胰岛素水平进一步证明了它们的胰岛素分泌潜力。这些结果表明，TC 中存在的生物碱有助于抗高血糖活性。AFTC 可能通过释放胰岛素和模拟胰岛素的作用来发挥降血糖作用，从而改善餐后高血糖。
