| Objectives To investigate the effect of Shi jinmo herbal-pair formula(SJMHPF)on the apoptosis of islet cells in type 2 diabetes mellitus(T2DM)rats and the mechanism of apoptosis.Methods The rat model of type 2 diabetes was constructed by 5% sugar water and high-fat diet with small dose of streptozotocin(STZ)intraperitoneal injection.50 Wistar rats were purchased and 6 were randomly selected to be fed with normal maintenance feed as the control group.The other rats were fed 5% sugar water and high-fat diet for 28 days.Rats were intraperitoneally injected with STZ(35mg/kg)according to their body weight,and rats in the control group were intraperitoneally injected with citrate-sodium citrate buffer.After 72 hours,fasting blood glucose(FBG)?11.1mmol/L and postprandial blood glucose(PBG)?16.7mmol/L were measured with a blood glucose meter as the mold forming standard.In the end,33 rats were moulded,8 rats were not moulded,and 3 rats died.3 rats with postprandial blood glucose ?30.0mmol/L were excluded,and the remaining 30 rats were used for therapeutic observation.The modeled rats were randomly divided into 5 groups: model group(n=6,saline lavage),metformin group(n=6,metformin lavage,100mg/kg/day),SJMHPF low dose group(SJMHPF(L),n=6,SJMHPF lavage,crude drug dose of 5.8g/kg/day),SJMHPF medium dose group(SJMHPF(M),n=6,SJMHPF lavage,crude drug dose of 11.6g/kg/day)and SJMHPF high dose group(SJMHPF(H),n=6,SJMHPF lavage,crude drug dose of 23.2g/kg/day),the control group also lavage the same volume of normal saline.The general condition of rats in each group was observed during the administration of normal feed,and the weight and blood glucose of rats were measured weekly from the first day of administration(fasting blood glucose and OGTT were measured at 2,4,6 and 8 weeks).The OGTT area under curve was calculated by comparing the fasting blood glucose before and after administration with the blood glucose level 2 hours after meal.After administration,blood was collected from the abdominal aorta and centrifuged serum to determine glycosylated serum protein,glycosylated hemoglobin and c-peptide.Insulin resistance index was calculated and pancreatic tissue was stained with HE.Subsequently,oxidative stress-related indicators(MDA,T-SOD,CAT,GSH-PX)of pancreatic tissue were detected.The expression of caspase-3 protein in pancreatic tissue was detected by immunohistochemistry,and the protein levels of Bcl-2,Bax,Cleaved Caspase-3 and Caspase-7 were detected by Western Blot.Results 1 Rats in the model group lost weight,had more water,more diet,more urine,soft or loose stools,messy body hair,poor spirits,and less tired activity;normal rats increased weight,diet,drinking,The urine output is normal,the stool is spindle-shaped,the texture is hard,the whole body is smooth,and the spirit is active;compared with the model group,the above-mentioned conditions of the rats in the metformin group and SJMHPF groups have improved.2 FBG,OGTT-AUC,GSP,HbA1 c and insulin resistance index increased in the model group,while c-peptide level decreased.Compared with the model group,the FBG,OGTT-AUC,GSP,HbA1 c and insulin resistance index of the rats in the drug formulation group were decreased,and the c-peptide level was increased.3 HE staining of pancreatic tissue showed that SJMHPF improved the morphological structure of pancreatic tissue compared with the model group.4 The levels of MDA in the pancreatic tissue of the model group increased,while the levels of T-SOD,CAT and GSH-PX decreased.Compared with the model group,the levels of MDA in the pancreatic tissue of rats in the SJMHPF group were decreased and the levels of T-SOD,CAT and GSH-PX were increased.5 According to the immunohistochemical results,the average optical density of the model group was significantly increased,and the average optical density of each group was decreased compared with that of the model group,indicating that SJMHPF could reduce the expression of Caspase-3.Western Blot analysis showed that in the model group,the expression of Bcl-2 decreased,while the expression of Bax,Cleaved Caspase-3 and Caspase-7 increased.Compared with the model group,SJMHPF increased the expression of Bcl-2 and decreased the expression levels of Bax,Cleaved Caspase-3 and Caspase-7.Conclusions 1 Shi jinmo herbal-pair formula could down-regulate the blood glucose level in T2 DM rats,enhance the tolerance to glucose load in OGTT,and improve the disorder of glucose metabolism,abnormal glucose tolerance and damage of islet cells.2 Shi jinmo herbal-pair formula can improve the tissue structure of pancreas.3 Shi jinmo herbal-pair formula can improve the oxidative stress level of pancreatic tissue in T2 DM rats.4 Shi jinmo herbal-pair formula can improve the blood glucose and oxidative stress levels,possibly by regulating the Bcl-2/Bax-Caspase-3 signaling pathway to inhibit the apoptosis of islet cells.Figure 10;Table 3;Reference 130. |
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