番石榴叶总三萜对2型糖尿病大鼠肾损伤的保护作用

目的:探讨番石榴叶总三萜(TTPGL)对2型糖尿病大鼠肾脏病变的影响。方法:采用高糖高脂饮食加腹腔注射小剂量链脲佐菌素(STZ,35 mg/kg)方法建立2型糖尿病大鼠模型。将造模成功的糖尿病大鼠随机分为5组:糖尿病模型组,番石榴叶总三萜低、中、高剂量组,罗格列酮阳性对照组;另取12只正常大鼠作为正常对照组。给药组灌胃给药1次/d,连续给药6 w。取血清测定大鼠空腹血糖(FPG)、空腹血清胰岛素(FINS)、血清肌酐(Cr)、血清尿素氮(BUN)。另取肾组织,进行常规HE染色进行病理组织学切片。结果:与正常对照组比较,糖尿病模型组空腹血糖显著升高、胰岛素水平及胰岛素敏感指数下降;血清肌酐及尿素氮水平升高;肾脏病理形态学显示:肾小球内皮及系膜细胞增生,毛细血管腔变窄,基底膜增厚,肾小球肿大、肾小囊变窄,肾小管水肿等。与糖尿病模型组比较,TTPGL中、高剂量组大鼠的空腹血糖显著降低,血清胰岛素水平及胰岛素敏感指数显著升高(P0.01或P0.05);同时,TTPGL给药组大鼠血清肌酐、尿素氮含量显著降低,肾脏病理形态学损伤明显改善(P0.01或P0.05)。结论:番石榴叶总三萜能显著降低2型糖尿病大鼠的血糖水平,提高胰岛素敏感指数,并对糖尿病肾损伤具有明显的保护作用。

Nephro-protective effects of total triterpenoids from Psidium guajava leaves on type 2 diabetic rats

Objective:To investigate the nephro-protective effects of total triterpenoids from Psidium guajava leaves(TTPGL) on type 2 diabetic rats.Methods:Diabetic rats were induced by intraperitoneal injection of streptozotocin(STZ,35 mg/kg) and a high-fat diet.Diabetic rats were divided into five groups:diabetic model control,low-dose TTPGL-treated(60 mg/kg,L-TTPGL),medium-dose TTPGL-treated(120 mg/kg,M-TTPGL),high-dose TTPGL-treated(240 mg/kg,H-TTPGL)and rosiglitazone-treated(3 mg/kg,RSG).The rats received daily treatment for six weeks.At the end of the period,the levels of fasting blood glucose(FPG),fasting insulin(FINS),creatinine(Cr) and blood urea nitrogen(BUN) in serum were measured.Kidneys for histopathological evaluation were stained with Hematoxylin and Eosin(HE).Results:Compared with normal control group,the level of FPG was increased,the insulin and insulin sensitivity index were decreased in the model group;The levels of BUN and Cr were increased with histopathological changes related to diabetic nephropathy in the kidney,which were the glomerular endothelium and mesangial cell proliferation,capillary narrowed,the base-membrane incrassation,glomerular swelling,cysts narrowed and tubules edema.Compared with the model group,the levels of FPG were decreased,serum insulin and insulin sensitivity index were increased significantly in M-TTPGL and H-TTPGL groups(P<0.01or P<0.05);The levels of BUN and Cr were decreased significantly(P<0.01or P<0.05) and the renal structural damages were improved significantly.Conclusion:TTPGL could decrease the level of blood glucose of diabetic rat effectively,increase the insulin sensitivity index and protect renal lesions in diabetic rats.