Abudula Reziwanggu, Jeppesen Per Bendix, Rolfsen Stig Eric D, Xiao Jianzhong, Hermansen Kjeld
Department of Endocrinology and Metabolism, Aarhus University Hospital, Denmark.
Metabolism. 2004 Oct;53(10):1378-81. doi: 10.1016/j.metabol.2004.04.014.
Extracts of leaves of the plant Stevia rebaudiana Bertoni (SrB), have been used for many years in traditional treatment of diabetes in South America. Stevia leaves contain diterpene glycosides, stevioside and rebaudioside A being the most abundant. Recently, it was demonstrated that stevioside stimulates the insulin secretion both in vitro and in vivo. Subsequently, we wanted to elucidate the influence of rebaudioside A on the insulin release from mouse islets using static incubations, as well as perifusion experiments. Rebaudioside A (10(-16) to 10(-6) mol/L) dose-dependently stimulated the insulin secretion in the presence of 16.7 mmol/L glucose (P < .05). The stimulation of insulin release occurs at a concentration of 10(-14) mol/L rebaudioside A, and maximal insulin response was obtained at 10(-10) mol/L (P < .01). Rebaudioside A stimulates insulin secretion in a glucose-dependent manner (3.3 to 16.7 mmol/L) and only potentiated insulin secretion at glucose > 6.6 mmol/L. The effect of rebaudioside A is critically dependent on the presence of extracellular Ca2+, ie, rebaudioside A-induced insulin stimulation at high glucose disappears in the absence of extracellular Ca2+. In conclusion, rebaudioside A possesses insulinotropic effects and may serve a potential role as treatment in type 2 diabetes mellitus.
甜叶菊（Stevia rebaudiana Bertoni，SrB）叶提取物在南美洲用于传统糖尿病治疗已有多年。甜叶菊叶含有二萜糖苷，其中甜菊糖苷和莱鲍迪苷A含量最为丰富。最近有研究表明，甜菊糖苷在体外和体内均能刺激胰岛素分泌。随后，我们希望通过静态孵育以及灌流实验来阐明莱鲍迪苷A对小鼠胰岛胰岛素释放的影响。在16.7 mmol/L葡萄糖存在的情况下，莱鲍迪苷A（10^(-16)至10^(-6) mol/L）呈剂量依赖性地刺激胰岛素分泌（P <.05）。在莱鲍迪苷A浓度为10^(-14) mol/L时出现胰岛素释放刺激，在10^(-10) mol/L时获得最大胰岛素反应（P <.01）。莱鲍迪苷A以葡萄糖依赖性方式刺激胰岛素分泌（3.3至16.7 mmol/L），且仅在葡萄糖> 6.6 mmol/L时增强胰岛素分泌。莱鲍迪苷A的作用严重依赖于细胞外Ca2+的存在，即，在没有细胞外Ca2+的情况下，高葡萄糖时莱鲍迪苷A诱导的胰岛素刺激消失。总之，莱鲍迪苷A具有促胰岛素分泌作用，可能在2型糖尿病治疗中发挥潜在作用。
