五子降糖方对T2DM大鼠血糖、C-P及DPP-4活性影响的实验研究

Experimental study of effect of Wuzi Jiangtang Formula on glucose and C-P of T2DM mice and DPP-4 activity

关键词:  二肽基肽酶Ⅳ(DPP-4)  五子降糖方  2型糖尿病(T2DM)  GK大鼠

Key words:  DPP-4  Wuzi Jiangtang Formula  Type 2 diabetes mellitus  GK rat

摘要:

[目的] 探讨五子降糖方对二肽基肽酶Ⅳ（DPP-4）活性的影响，研究其发挥降糖作用的可能机制。[方法] 选取SPF级雄性GK大鼠，适应性喂养1周后给予高脂饲料，连续喂养4周，测定血糖，以随机血糖>11.1 mmol/L或餐后2 h血糖（2 h PG）>16.7 mmol/L为成模标准，将成模2型糖尿病（T2DM）大鼠随机分为模型组、二甲双胍组（0.1 g/kg）、五子降糖方低、中、高剂量组（3.5、7.0、14 g/kg，折合生药量），同时另选Wstar大鼠为正常组，正常组与模型组灌胃等体积纯净水，灌胃前测定空腹血糖（FBG），灌胃后4周、8周测定FBG及2 h PG，8周后处死动物，检测血清C肽（C-P）水平；采用发色底物法建立DPP-4抑制剂体外筛选模型，分别应用五子降糖方及其组方的各味单药菟丝子、女贞子、紫苏子、莱菔子、车前子水提物对DPP-4抑制剂体外筛选模型进行干预，以磷酸西格列汀片作为阳性对照药，测定A值，计算DPP-4抑制率，比较IC₅₀差异。[结果] 五子降糖方可降低T2DM大鼠FBG及2 h PG，增高血清C-P水平；对DPP-4抑制作用，五子降糖方IC₅₀为（6 667.754±2 119.759） mg/L，其组成药物中莱菔子IC₅₀为（382.554±7.750） mg/L，菟丝子IC₅₀为（843.391±135.230） mg/L。[结论] 五子降糖方可以降低T2DM FBG及2 h PG，改善胰岛β细胞功能，作用机制可能与DPP-4抑制作用有关，其中莱菔子、菟丝子可能是本方发挥DPP-4抑制作用的主要药物。

Abstract:

[Objective] To investigate the effect of Wuzi Jiangtang Formula on the effect of DPP-4,and study the possible mechanism of its hypoglycemic effect.[Methods] Select SPF male GK rats,the rat model of T2DM was established by feeding high fat for 4 weeks after adaptive feeding 1 week,detect blood glucose,FBG>11.1 mmol/L or 2 hPG>16.7 mmol/L was considered succeed model.And the T2DM rats were randomly divided into model group,metformin group,Wuzi Jiangtang Formula groups with high,medium and low dose respectively,normal group.The normal group and model group were administered intragastrically with pure water.Other groups were administered intragastrically with corresponding drugs for 8 weeks.The level of FBG was detected at the beginning of treatment,and at the ends of the 4th and 8th week.The rats were sacrificed after 8 weeks.The level of C-P were detected;Establish vitro screening model of DPP-4 inhibitor,and screen Wuzi Jiangtang Formula and its component drugs,which including Tusizi,Nvzhenzi,Suzi,Laifuzi and Chenqinzi.Select the Sitagliptin Phosphate Tablets as positive control drug.Then determine the absorbance (A),calculate the inhibition rate,and compare the difference of IC₅₀.[Results] Wuzi jiangtang Formula can reduce the level FBG,2 hPG and C-P;IC₅₀ of Wuzi jiangtang Formula is (6 667.754±2 119.759) mg/L,IC₅₀ of Laifuzi is (382.554±7.749 6) mg/L,inhibition of DPP-4,IC₅₀ of Tusizi is (843.391±135.23) mg/L.The inhibitory effect of DPP-4 of Cheqianzi,Suzi and Nvzhenzi is less than 10%.[Conclusion] Wuzi Jiangtang Formula can reduce the level FBG and 2 h PG,improve the islet β cell function.The inhibitory effect on DPP-4 is the possible mechanism,and Laifuzi,Tusizi are probably the main drugs play an important role in the inhibition of DPP-4.