The mechanism of total saponins from Medicago polymorpha on glycometabolism in type 2 diabetic rats / 重庆医学

ABSTRACT

Objective To explore the effect of total saponins from Medicago polymorpha (TSMP) on glucose metabolism in type 2 diabetes mellitus (T2DM) rats and its possible mechanism.Methods T2DM rats were established by feeding with fat diets and intraperitoneally injecting with STZ 30 mg/kg.The rats were divided into control group,model group,metformin group (0.2 g/kg),TSMP high dose group (1.4 g/kg) and TSMP low dose group (0.7 g/kg),which were administrated for four weeks.At the end of administration,blood samples were collected to determine insulin resistance index (IRI),levels of fasting blood glucose (FBG),glycosylated hemoglobin (HbAlc),hepatic glycogen,interleukin (IL)-1 β,tumor necrosis factor (TNF)-α,free fatty acids (FFA) and Leptin,and activities of pyruvate kinase (PK),hexokinase (HK),glucose-6-phosphatase (G-6-Pase),fructose-1,6-bisphosphatase and glucokinase (GK).Western blot was used to detect the expression levels of G-6-Pase and phosphoenolpyruvate carboxykinase (PEPCK) proteins.Results Compared withthe model group,high dose (1.4 g/kg) TSMP decreased IRI,levels of FBG,HbA1 c,IL-1β,TNF-α,FFA and Leptin,and activities of G-6-Pase and fructose-1,6-bisphosphatase in T2DM rats (P＜ 0.05),while increased level of hepatic glycogen,and activities of PK,HK and GK (P＜0.05).Moreover,high dose (1.4 g/kg) TSMP down-regulated expression levels of G-6-Pase and PEPCK protein in liver tissues.Conclusion Chronic administration of TSMP can improved glucose homeostasis in T2DM rats,which might be related to promoting utilization of glucose,and alleviating inflammatory and insulin resistance.