乌饭树叶黄酮对糖尿病小鼠胰岛形态和功能的影响

Effects of Vaccinium bracteatum Thunb.leaves flavonoids on islet morphology and function in diabetic mice

目的:探讨乌饭树叶黄酮对链脲佐菌素诱导的糖尿病小鼠的胰岛形态和功能的影响。方法:采用昆明小鼠作为研究对象,以静脉注射链脲佐菌素致小鼠体内诱导形成糖尿病模型。造模成功后将糖尿病小鼠随机分为模型对照组、二甲双胍对照组、80 mg·kg^-1·d^-1和160 mg·kg^-1·d^-1乌饭树叶黄酮组,另设有空白对照组。随后各组小鼠连续给予相应药物14 d。末次给药后,各组小鼠经过夜禁食,测其空腹血糖水平,而后收集小鼠血清和胰腺标本。ELISA法检测血清胰岛素;胰腺组织制备匀浆用于超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)的活性和丙二醛(malondialdehyde,MDA)含量;测定胰腺组织中肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)和白细胞介素6(interleukin 6,IL-6)水平;并以HE染色及透射电镜观察胰岛组织病理学和超微结构变化。结果:与模型组相比较,糖尿病小鼠经乌饭树叶黄酮干预后空腹血糖有不同程度下降(P<0.05);乌饭树叶黄酮受试组的血清胰岛素含量明显比模型对照组高(P<0.05);与模型对照组比较,乌饭树叶黄酮组的胰腺组织中SOD和GSH-Px活性显著升高,MDA含量则明显下降,与此同时,炎症因子TNF-α和IL-6也明显下降。糖尿病小鼠的胰腺组织病理形态学和超微机构改变也在经乌饭树叶黄酮干预后有所改善。结论:乌饭树叶黄酮可降低糖尿病小鼠血糖,该作用可能与其能改善糖尿病小鼠血脂代谢和胰腺组织的氧化应激状态进而减少炎症反应有关。

OBJECTIVE To investigate the effect of Vaccinium bracteatum Thunb.leaves flavonoids on islet morphology and function in streptozotocin-induced diabetic mice.METHODS Kunming mice were used to induce diabetes in vivo by intravenous injection of streptozotocin.After the model was successfully established,diabetic mice were randomly divided into model control group,metformin control group,80 mg·kg^-1·d^-1 and 160 mg·kg^-1·d^-1 folium flavone groups,and another blank control group was set.Subsequently,mice in each group were given the corresponding drugs for 14 consecutive days.After overnight fasting,fasting blood glucose levels were measured,and serum and pancreas samples were collected from mice in each group.Serum insulin was measured by ELISA;homogenates were prepared from pancreatic tissues for the activity of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)and malondialdehyde(MDA)content;tumor necrosis factor-α(TNF-α)and interleukin 6(IL-6)levels in pancreatic tissues were measured;and histopathological and ultrastructural changes in islets were observed by HE staining and transmission electron microscopy.RESULTS Compared with model control group,fasting blood glucose was decreased in mice treated with Vaccinium bracteatum Thunb.leaves flavonoids,as well as blood lipid level.Serum level of insulin was increased.The SOD and GSH-Px activities were up-regulated by Vaccinium bracteatum Thunb.leaves flavonoids,while the MDA content was significantly decreased,at the same time,the inflammatory factors TNF-α and IL-6 were also significantly decreased.Pancreatic histomorphological and ultrastructural changes in diabetic mice were also improved after intervention with flavonoids from the leaves of P.acuminata.CONCLUSION Vaccinium bracteatum Thunb.leaves flavonoids could reduce blood glucose in diabetic mice,which may be related to the improvement of blood lipid metabolism and oxidative stress status of pancreatic tissue in diabetic mice,resulting in inflammation response reduction.