新化合物结构蜕皮甾酮衍生物TAPA降糖作用与机制的初步研究

Preliminary Study on Effects and Mechanism of New Ecdysterone Derivative TAPA on Reducing Blood Glucose

目的:评价新化合物结构蜕皮甾酮衍生物TAPA的体内降糖作用,并对其作用机制从细胞水平上进行初步研究。方法:取大鼠随机分为正常对照组、模型组、TAPA-1(1 mg/kg)组、TAPA-5(5 mg/kg)组、TAPA-25(25 mg/kg)组和罗格列酮(2 mg/kg)组,每组10只,除正常对照组外其余各组大鼠建立2型糖尿病模型,后4组即为给药组,每日灌胃1次,连续给药28 d,给药期间每周测定大鼠摄食量、体质量、饮水量及随机血糖水平,末次给药5 h后灌胃葡萄糖测定2 h内的血糖浓度,计算血糖-时间曲线下面积(AUC)考察糖耐量。建立胰岛素抵抗肝癌细胞Hep G2,采用3H-d-葡萄糖掺入实验评价在1×10-9、1×10-7mol/L胰岛素环境下,1×10-5mol/L的TAPA和罗格列酮分别对Hep G2细胞和胰岛素抵抗Hep G2细胞的葡萄糖掺入率。取胰岛β细胞瘤细胞系3(βTC3)细胞,随机分为空白对照组、TAPA-Ⅰ(1×10-10mol/L)组、TAPA-Ⅱ(1×10-8mol/L)组、TAPA-Ⅲ(1×10-6mol/L)组和格列齐特(1×10-5mol/L)组,给药孵育24 h后测定各组细胞液中胰岛素含量。结果:与正常对照组比较,给药组大鼠的摄食量、体质量、饮水量均无明显变化;与模型组比较,给药组大鼠血糖水平在给药结束时均明显降低、糖耐量均降低(P<0.05),且降糖效果、糖耐量与TAPA剂量和给药时间均呈正相关。TAPA和罗格列酮对Hep G2细胞的葡萄糖掺入率无明显影响,能明显提高对胰岛素抵抗Hep G2细胞的葡萄糖掺入率(P<0.01)。与空白对照组比较,TAPA各剂量组βTC3细胞的胰岛素释放量无明显变化,格列齐特组βTC3细胞的胰岛素释放量明显增加(P<0.01)。结论:TAPA可降低2型糖尿病模型大鼠的血糖水平和糖耐量,体外试验认为其可增加胰岛素敏感性,但不促进胰岛素分泌。

OBJECTIVE： To evaluate the effects of new ecdysterone derivative TAPA on reducing blood glucose, and to study the mechanism preliminarily based on cell study. METHODS： Rats were randomly divided into normal control group, model group, TAPA-1（1 mg/kg）group, TAPA-5（5 mg/kg）group, TAPA-25（25 mg/kg）group and rosiglitazone （2 mg/kg） group with 10 rats in each group. Type 2 diabete model was established in those groups except for normal control group. The latter 4 groups were given relevant medicines intragastrically for consecutive 28 d. Food intake, body weight, water intake and random blood glucose were determined every week; 2 h blood glucose concentration was determined following intragastric administration of glucose 5 h after last administration to calculate AUC for investigation glucose tolerance. Insulin-resistant HepG2 cells were established, and effects of TAPA and rosiglitazone 1×10^-5 mol/L on incorporation rate of glucose in insulin-resistant He pG2 cells were evaluated by 5H-d-glucose incorporation test under the condition of 1×10^-9 mol/L and 1×10^-7 mol/L insulin. Islet 13 cell tumor cell line 3 （βTC3） were randomly divided into blank control group, TAPA- Ⅰ （1×10^-10 mol/L）group, TAPA-Ⅱ （1×10^-8 mol/L）group, TAPA-Ⅲ （1×10^-6 mol/L） group and gliclazide （1×10^-5 mol/L） group. The content of insulin in cell was determined 24 h after incubation. RESULTS ： Compared with normal control group, food intake, body weight and water intake of medication groups had no significant change; compared with model group, the level of blood glucose in medication group was decreased significantly at the end of administration, and glucose tolerance was also decreased （P〈0.05）. Hypoglycemic effect and glucose tolerance were positively correlated with TAPA dose and administration medication. TAPA and rosiglitazone had no significant effect on the incorporation rate of glucose in HepG2 cells, but significantly improved that of insulin-resistant HepG2 cells （P〈0.01）. Compared with blank control group, TAPA groups did not present any great effects on the secretion of insulin in βTC3 cells, and the secretion of insulin in β TC3 cells was increased significantly in gliclazide groups （P〈0.01）. CONCLUSIONS： TAPA can decrease blood glucose in type 2 diabetes model rats and improve glucose tolerance; it also increases insulin sensitivity but dose not increase insulin secretion in vitro.