| Purpose:To study the influence of astragulus polysaccharide on the endoplasmic reticulum stress of islet and apoptosis-related proteins and gens of the Bcl-2 and Bax expression in type 2 diabetes mellitus rats.Materials and methods:1. Select eighty SD male rats, the average weight is about 220 g.The computer random number method elected fifteen as the control group, with a normal diet; and the remaining 65 rats were fed high-fat diet with a self-made four weeks then modeling,after modeling eligibility screening in diabetic rats and retained 37. The 37 rats were divided into astragalus polysaccharide group, metformin group and model group. The control group and the untreated group: normal saline 10ml/kg orally once a day;astragalus polysaccharide group: 400mg/kg astragalus polysaccharide orally, once daily;metformin group: 100mg/kg metformin hydrochloride orally, every day once.2. General situation observed in rats before and after treatment, including body weight,behavior,color. Four weeks after the treatment, fasting 14 hours, after weighing with10% chloral hydrate(0.35ml/100g) intraperitoneal injection anesthesia,the separation of the inferior vena cava blood sampling, serum was separated and placed in-20℃refrigerator tested rats fasting serum insulin(FINS),glycosylated hemoglobin(GHb).Aseptically removed pancreas,and saved in liquid nitrogen, RT-PCR and Western blot determination of pancreatic expression of Bcl-2,Bax,CHOP gene and protein; islet morphology HE staining.3. All measurement data were expressed as”( X ±s)”,group were compared using the paire t test the two group were compared using independent samples t test,count data using chi-square test,analysis of variance were used for independent samples,P<0.05 had significant different.All data were statiscally analyzed with SPASS 17.0 statistical software.Results:1.Experimental data show that the weight of the model group,metformin group and APS group was reduced than the blank group(P<0.01);after treatment,metformin group and APS group in rats increased body weight compared with the model group(P<0.01).2. The screening T2 DM rats model with high fat diet for four weeks combined with low dose STZ induced, compared with the blank group, model group,APS group and metformin group FPG,FINS increased significantly(P<0.05), which suggests the model is successful. After treatment of four weeks, FPG,FINS of model group,APS group and metformin group were significantly decreased(P<0.05);metformin group was significantly lower than the APS group(P<0.05).3. Glycated hemoglobin levels: model group, APS group and metformin group were significantly higher than control group(P<0.01); The glycated hemoglobin level in astragalus polysaccharide group and metformin group were distinguished lower than in the model group(P<0.01),metformin group was significantly lower than that of Astragalus polysaccharide group(P<0.01).4. The expression of apoptosis-related proteins and genes of the Bcl-2 and Bax: model group than the control group decreased expression of Bcl-2,Bax expression increased,there was a significant difference(P<0.01);metformin group and astragalus polysaccharide group compared with the model group Bcl-2 expression was increased,Bax expression were reduced,there was a significant difference(P<0.01),metformin group compared astragalus polysaccharide group slightly increased Bcl-2 and Bax expression,the difference were not statistically significant(P>0.05).5. CHOP protein and genes levels: model CHOP group than the control group was significantly increased(P<0.01); Astragalus polysaccharide group and metformin group compared with the model group CHOP significantly lower(P<0.01); but there was no significant difference in astragalus polysaccharide group and metformin group(P>0.05).6. Islet morphology: light microscope you can see the model rats islet atrophy, less rounded contours, irregular edges, reduce the number of islet and sparse and uneven distribution within the islet vacuoles; astragalus polysaccharide group with metformin rats were increased number of islet, the distribution of relatively dense and metformin group was better than astragalus polysaccharide group.Conclusion:Astragalus polysaccharide can significantly reduce glycated hemoglobin levels in diabetic rats, down CHOP expression, increased expression of Bcl-2, Bax expression reduce, reduce endoplasmic reticulum stress levels, improve the function of islet morphology, thereby inhibiting or delaying the islet apoptosis. |
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