玉竹对STZ诱导的1型糖尿病小鼠的降糖作用

目的:探讨玉竹对链脲佐菌素(STZ)诱导的1型糖尿病小鼠的降糖作用及其可能的作用机制。方法:采用多次小剂量STZ(mlD-STZ)腹腔注射的方法建立1型糖尿病小鼠模型。玉竹提取物8,4,2g/kg剂量组分别按相应剂量用玉竹提取物灌胃,糖尿病模型组和正常对照组用蒸馏水灌胃0.2ml/只,1次/d,共4周。每周剪尾取血1次,用快速血糖仪监测血糖变化。四周后将小鼠处死取胰腺做HE染色,光镜下观察胰腺病理学改变;采用酶联免疫分析(ELISA)法检测小鼠脾细胞上清液中IFN-γ和IL-4水平。结果:与糖尿病模型组相比,玉竹提取物8g/kg和4g/kg剂量组小鼠血糖明显降低(P<0.01)、胰岛炎程度明显缓解、脾细胞上清液中IFN-γ水平和IFN-γ/IL-4比值明显降低(P<0.05～0.01),而2g/kg剂量组小鼠上述指标变化不明显;各组小鼠脾细胞上清液中IL-4水平差异无统计学意义。结论:玉竹提取物能明显降低STZ诱导的1型糖尿病小鼠的血糖,其降糖机制可能与抑制1型糖尿病小鼠Th1细胞的极化程度,减轻细胞免疫功能对胰岛β细胞的破坏有关。

Hypoglycemic effect study on streptozotocin induced type 1 diabetes in mice by Polygonatum odoratum

Objective: To study the hypoglycemic effect and mechanisms of Extract from Polygonatum odoratum(E-PAOA) on type 1 diabetes mellitus induced by Streptozotocin(STZ) in mice.Methods: A mouse model of type 1 diabetes mellitus was established by intraperitoneal injections of multiple low dose STZ(mlD-STZ).The mice in E-PAOA 8,4,2g/kg group were given E-PAOA by intragastric administration at dose of 8,4,2g/kg respectively once a day for 4 weeks,while the mice in normal control group and diabetes control group were given distilled water 0.2 ml by intragastric administration once a day for 4 weeks.During fasting blood glucose levels were measured once a week on blood samples taken from the tail tip using a blood glucose meter.Four weeks later,mice were sacrificed and the pancreas were removed and stained with haematoxylin-eosin.IFN-γand IL-4 production of splenic cell were assayed by enzyme-linked immunosorbent assay(ELISA).Results: The blood glucose levels decreased significantly(P <0.01),the degree of insulitis were alleviated and IFN-γproduction of splenic cell and the ratio of IFN-γ/IL-4 reduced significantly(P <0.05～0.01) in E-PAOA 8g/kg and 4g/kg group as compared with diabetes control group,while those changed without significant difference in E-PAOA 2g/kg group.No significant difference among groups was observed in the IL-4 production of splenic cell.Conclusion: E-PAOA can significantly decrease the blood glucose levels of T1DM induced by STZ in mice,and which may be associated with the alleviation of the destruction of pancreatic β-cells by inhibiting Th1 polarization of splenocytes and cellular immunity in STZ-induced T1DM mice.