Study On Anti-hyperglycemic Activity And Mechanism In Experimental Type ⅠDiabetic Mouses Of Water Extract From Echinops Iatifolius Tausch

Diabetes is the third largest disease after cancer and cardiovascular disease affect human health, its morbidity number showed a trend of rising year by year. Therefore, it is very important to find a conveniency and effectivity drugs to control the blood sugar and complication of diabetes. Echinops latifolius Tausch has many pharmacological activities, folk have a tradition of using Echinops latifolius Tausch to treatment the diabetes, but has no related research reports at home and abroad. In this research, as the object in type I diabetes mice the hypoglycemic effects of water extract from Echinops latifolius Tausch(WET) were observed, then determine the hypoglycemic effective components of WET and the molecular mechanism, in order to provide reference for the development of new drugs of hypoglycemic.1. The hypoglycemic effect of WET in the foundation of successfully constructed type I diabetic mice model used intravenous injection of1%alloxan method. The results showed that WET could significantly reduced the fasting blood glucose, improved oral glucose tolerance, elevated liver glycogen and serum insulin levels on diabetic mice, the effects of body weight and glucagon was not significant. The fasting glucose oral tolerance, glycogen, insulin, glucagon, and the weight of healthy mice were not affected. Determined that the WET have hypoglycemic effect on type I diabetic mice, but don’t affective in healthy mice.2. To determine the hypoglycemic active ingredients of WET, the hypoglycemic substances of WET may contain were identified at first, the results showed WET contained polysaccharides, water extraction and alcohol precipitation were used to obtained the Echinops latifolius Tausch crued polysaccharide(ETCP), and compared the hypoglycemic effect to the remaining ingredients ETX. The results showed that ETCP could significantly reduced the fasting blood glucose in diabetic mice. Using papain to remove the protein of ETCP and optimized the deproteinized process, in the condition of reaction time is2.6h, pH is6.0, temperature is64℃, the protein removal and polysaccharide retention rats were56.57%and98.16%after optimized. Then get a neutral polysaccharide ETPA and two acidic polysaccharides ETPB, ETPC. After elution fractionation the deproteinized polysaccharide (ETP) using DEAE-52. The three polysaccharides were elution fractionation by Sephadex-G200, determined that the ETPA contains two kinds of polysaccharide:ETPA1, ETPA2, and the molecular weight of ETPA1, ETPA2, ETPB and ETPC are uniform. Compared the hypoglycemic effect of ETPA, ETPB and ETPC, the result showed that ETPB has a significant hypoglycemic activity. Determined that the hypoglycemic main component of WET is ETPB.3. Determination of fasting blood glucose, body weight, the oral glucose tolerance, glycogen, serum insulin and glucagon levels of type I diabetic mice after administration ETPB, and the PDX-1, IRS-2, Fas, caspase-3, GK, GLUT2gene of pancreas and GK, G-6-P gene of liver were determined using real-time PCR method to study the molecular mechanism of hypoglycemic effect on type I diabetic mice by ETPB. The results showed that ETPB could reduce fasting blood glucose, gain weight, improve oral glucose tolerance, increased glycogen and serum insulin levels, had no effect on glucagon in diabetic mice. Real-time PCR results showed that, ETPB could increase pancreatic PDX-1, IRS-2, Fas, caspase-3, GK, GLUT2, and liver GK gene expression, had no effect on the liver G-6-P gene. Speculate that the hypoglycemic molecular mechanism of ETPB is by upregulation of the PDX-1, IRS-2gene expression of pancreas and increase of the regeneration of islet3cells, while reduced apoptosis related factors Fas, caspase-3gene expression to inhibited islet3cells apoptosis, promoting islet β cells GK, GLUT2gene expression increased serum insulin, while promoting the gene expression of liver GK to improve glucose metabolism ability of the liver, experimental studies have proved this conclusion.The whole study showed that, WET has a good hypoglycemic function, and the ETPB is the main component of hypoglycemic. Its possible mechanisms include increase the islet β cells regenerative, inhibited islet β cells apoptosis, increased serum insulin, improve glucose metabolism ability of the liver. But the structure of ETPB remains to be further clear, and its hypoglycemic mechanism need to further research, for Echinops latifolius Tausch as a hypoglycemic drug development provide more sufficient data.