Animals ; Diabetes Mellitus, Experimental/drug therapy* ; Fibrosis/prevention & control* ; Hyperglycemia/prevention & control* ; Hypoglycemic Agents/pharmacology* ; Inflammation/prevention & control* ; Male ; Rats ; Rats, Sprague-Dawley ; Stilbenes/pharmacology*

The study aimed to investigate the intervening role of Didang decoction (DDD) at different times in macrovascular endothelial defense function, focusing on its effects on the AMP-activated protein kinase (AMPK) signaling pathway. The effects of DDD on mitochondrial energy metabolism were also investigated in rat aortic endothelial cells (RAECs). Type 2 diabetes were induced in rats by streptozotocin (STZ) combined with high fat diet. Rats were randomly divided into non-intervention group, metformin group, simvastatin group, and early-, middle-, late-stage DDD groups. Normal rats were used as control. All the rats received 12 weeks of intervention or control treatment. Western blots were used to detect the expression of AMP-activated protein kinase α1 (AMPKα1) and peroxisome proliferator-activated receptor 1α (PGC-1α). Changes in the intracellular AMP and ATP levels were detected with ELISA. Real-time-PCR was used to detect the mRNA level of caspase-3, endothelial nitric oxide synthase (eNOS), and Bcl-2. Compared to the diabetic non-intervention group, a significant increase in the expression of AMPKα1 and PGC-1α were observed in the early-stage, middle-stage DDD groups and simvastatin group (P < 0.05). The levels of Bcl-2, eNOS, and ATP were significantly increased (P < 0.05), while the level of AMP and caspase-3 were decreased (P < 0.05) in the early-stage DDD group and simvastatin group. Early intervention with DDD enhances mitochondrial energy metabolism by regulating the AMPK signaling pathway and therefore may play a role in strengthening the defense function of large vascular endothelial cells and postpone the development of macrovascular diseases in diabetes.
AMP-Activated Protein Kinases ; metabolism ; Adenosine Triphosphate ; metabolism ; Animals ; Aorta ; drug effects ; metabolism ; Cardiovascular Diseases ; metabolism ; prevention & control ; Caspase 3 ; metabolism ; Diabetes Mellitus, Experimental ; complications ; drug therapy ; metabolism ; Diabetes Mellitus, Type 2 ; complications ; drug therapy ; metabolism ; Diptera ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Endothelial Cells ; drug effects ; metabolism ; Endothelium, Vascular ; drug effects ; metabolism ; Energy Metabolism ; drug effects ; Leeches ; Mitochondria ; drug effects ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; metabolism ; Phytotherapy ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Prunus persica ; Rats, Sprague-Dawley ; Rheum ; Signal Transduction

OBJECTIVETo investigate the impact of 1, 25-(OH)2D3 on left ventricular hypertrophy (LVH) in type 2 diabetic rats.

METHODSType 2 diabetic mellitus (DM) model rats were established by intraperitoneally injecting with 30 mg/kg streptozotocin. After 8 weeks, 19 male rats were identified as diabetic with left ventricular hypertrophy (LVH) by ultrasound examination, and randomly assigned into three groups: untreated (DM-LVH, n=7), treated with insulin (DM-LVH+INS, n=6), and treated with 1, 25-(OH)2D3 (DM-LVH+VD, n=6). Healthy male rats were used as the controls group (n=6). The fasting blood glucose and the insulin level were determined weekly. The left ventricular mass index, myocardial collagen content, collagen volume fraction, and 1, 25-(OH)2D3-receptor level were determined by 4 weeks later.

RESULTSIn the DM-LVH model group, the insulin level was significantly decreased compared with the non-diabetic control group (P<0.05), whereas the blood glucose, left ventricular mass index, myocardial collagen content, collagen volume fraction, and 1, 25-(OH)2D3-receptor expression were significantly increased (all P<0.05). In the DM-LVH+INS and DM-LVH+VD groups, the insulin levels were significantly increased compared with the DM-LVH model group (P<0.05), whereas the other parameters were significantly decreased (all P<0.05).

CONCLUSION1, 25-(OH)2D3 could reverse LVH in diabetic rats and that the mechanism may involve stimulating insulin secretion and reducing blood glucose via direct up-regulation of 1, 25-(OH)2D3-receptor expression.

Animals ; Blood Glucose ; analysis ; Calcitriol ; therapeutic use ; Diabetes Mellitus, Experimental ; blood ; complications ; Diabetes Mellitus, Type 2 ; blood ; complications ; Hypertrophy, Left Ventricular ; prevention & control ; Insulin ; blood ; Male ; Rats ; Rats, Wistar ; Receptors, Calcitriol ; analysis ; Streptozocin

OBJECTIVEThe beneficial effects of silymarin have been extensively studied in the context of inflammation and cancer treatment, yet much less is known about its therapeutic effect on diabetes. The present study was aimed to investigate the cytoprotective activity of silymarin against diabetes-induced cardiomyocyte apoptosis.

METHODSRats were randomly divided into: control group, untreated diabetes group and diabetes group treated with silymarin (120 mg/kg•d) for 10 d. Rats were sacrificed, and the cardiac muscle specimens and blood samples were collected. The immunoreactivity of caspase-3 and Bcl-2 in the cardiomyocytes was measured. Total proteins, glucose, insulin, creatinine, AST, ALT, cholesterol, and triglycerides levels were estimated.

RESULTSUnlike the treated diabetes group, cardiomyocyte apoptosis increased in the untreated rats, as evidenced by enhanced caspase-3 and declined Bcl-2 activities. The levels of glucose, creatinine, AST, ALT, cholesterol, and triglycerides declined in the treated rats. The declined levels of insulin were enhanced again after treatment of diabetic rats with silymarin, reflecting a restoration of the pancreatic β-cells activity.

CONCLUSIONThe findings of this study are of great importance, which confirmed for the first time that treatment of diabetic subjects with silymarin may protect cardiomyocytes against apoptosis and promote survival-restoration of the pancreatic β-cells.

Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Blood Glucose ; Cholesterol ; blood ; Creatinine ; blood ; Diabetes Mellitus, Experimental ; complications ; Diabetic Cardiomyopathies ; prevention & control ; Heart ; drug effects ; Immunohistochemistry ; Insulin ; blood ; Male ; Myocardium ; pathology ; Myocytes, Cardiac ; drug effects ; Rats ; Silymarin ; pharmacology ; Triglycerides ; blood

OBJECTIVETo investigate the influence of total flavonoids of epimedium (TFE) on the streptozocin (STZ)-induced kidney injury in diabetic rats and discuss the possible mechanism.

METHODSDiabetes was produced by a single injection of streptozocin (40 mg/kg, iv) in male SD rats. The rats were randomly divided into three groups (n = 10): control group, model group and TFE group (100 mg/kg, ig). Animals were sacrificed 12 weeks later. The level of blood glucose, blood urea nitrogen (BUN) and creatinine (Cr) as well as the renal index were determined. Detect the specific biochemical of renal tissue: superoxide dismutase (SOD), malondialdehyde (MDA). Use masson staining to observe the morphology of the renal tissue. Immunohistochemistry was employed to determine the protein levels of transforming growth factor-beta1 (TGF-beta1).

RESULTSCompared to control group, the enhancement of blood glucose, renal index, BUN and Cr was found in model group, which was significantly attenuated by treatment with TFE. Meanwhile, elevated MDA level in renal tissue as well as decreased SOD activities in renal tissue were significantly remitted by TFE. Furthermore, TFE decreased the expression of TGF-beta1.

CONCLUSIONTFE can evidently relieve renal damage in rats with diabetic nephropathy induced by STZ, which might be related to antioxidation and modulating the expression of TGF-beta1 protein.

Animals ; Diabetes Mellitus, Experimental ; metabolism ; Diabetic Nephropathies ; metabolism ; prevention & control ; Epimedium ; chemistry ; Flavonoids ; pharmacology ; Kidney ; drug effects ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the protective effect and mechanism of Shenqi Compound on diabetic angiopathy modeled rats.

METHODSTotally 18 SD rats were randomized into 3 groups, i.e., the normal control group, the diabetic mellitus (DM) group, and Shenqi Compound group, 6 in each group. The DM rat model was established by feeding high-fat diet (to induce hyperlipidemia) +intraperitoneal injection of small dose streptozotocin (STZ). Shenqi Compound was given to rats in the Shenqi Compound group at the daily dose of 2 g/kg. Equal volume of normal saline was given to rats in the model group and the normal control group by gastrogavage. All treatment was lasted for 12 weeks. Then 2-D and ultrasonic integrated backscatter technique were used to evaluate structural and functional changes of abdominal aorta in the progression of diabetic macroangiopathy. The fibrosis degree of the aorta vessel and myocardium capillaries were observed by using HE and Masson trichrome staining. The tension of the aortic vascular ring was determined. The transforming growth factor beta (TGF-beta) mRNA expression was detected by real time PCR (RT-PCR). The protein expression of TGF-beta, collagen I, collagen III, connective tissue growth factor (CTGF), and phosphorylation P38 MAPK were detected by Western blot.

RESULTSCompared with the normal control group, abdominal aortic systolic inner diameter, diastolic inner diameter, Peterson elastic modulus, stiffness index, and backscatter integral significantly increased; the rangeability of integral backscatter and the extension coefficient of cross section significantly decreased in the DM group (all P < 0.05). After 12 weeks aforesaid indices were obviously improved in the Shenqi Compound group (P < 0.05). Results of HE and Masson staining showed that the fibrosis degree of the aorta vessel and myocardium capillaries was obviously alleviated in rats of the Shenqi Compound group (P < 0.05). Results of the aortic vascular ring tension showed that acetylcholine induced vasodilatation and maximum diastolic percent were obviously elevated in the Shenqi Compound group (P < 0.05). Compared with the normal control group, the mRNA expression of TGF-beta, and the protein expression of TGF-beta, collagen I, and collagen III, and phosphorylation of P38 MAPK all significantly increased in the DM group (P < 0.05). Compared with the DM group, the mRNA expression of TGF-beta, and the protein expression of TGF-beta, collagen I, and collagen III, and phosphorylation of P38 MAPK all decreased (P < 0.05).

CONCLUSIONSShenqi Compound could effectively improve the arterial function in diabetic marcoangiopathy and microvascular dysfunction. The mechanism might be due to the down-regulating the expression of TGF-beta, and further suppressing the phosphorylation of P38 MAPK, reducing the synthesis of collagen I and collagen III, therefore, ameliorating arterial and myocardial interstitial fibrosis.

Animals ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Angiopathies ; prevention & control ; Drugs, Chinese Herbal ; pharmacology ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism

BACKGROUNDDiabetic cardiovascular complication is a major cause of mortality in type 2 diabetic patients. Hyperglycemia markedly increases the risk of cardiovascular disease. Endothelial dysfunction is common in type 2 diabetes mellitus (DM) and is an early indicator of diabetic vascular disease. Therefore, it is necessary to identify the effect of different hypoglycemic agents on vascular endothelium. The aim of the study was to examine and compare the effects of metformin and gliquidone on atherosclerotic lesions in streptozotocin-induced diabetic rats.

METHODSForty male Sprague-Dawley rats (age, 8 weeks; weight, 180-200 g) were included in this study and fed with a normal chow diet for 1 week. Rats (n = 10) served as the normal control group (NC group) were fed with a normal chow for another 2 weeks and received an injection of saline. The rest 30 rats fed with a high-fat diet for 2 weeks and injected streptozotocin were randomly assigned to three groups (n = 10 rats per group) as follow: type 2 DM group (DM group), DM + gliquidone group (GLI group) and DM + metformin group (MET group). Five weeks later, all rats were fasted overnight and taken tail blood samples for biochemical determinations. Then rats in the NC and DM groups were administrated with normal saline, while rats in the MET and GLI groups were administrated with metformin (100 mg/kg) or gliquidone (10 mg/kg), respectively. All medicines were given via intragastric administration for 8 weeks. After 16 weeks, plasma triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) were measured. The aortic arch was isolated from diabetic rats and was assessed by pathological sectioning using H&E staining.

RESULTSMetformin treatment prevented weight gain ((315.80 ± 52.16) g vs. (318.70 ± 68.48) g, P = 0.773), improved plasma TG, HDL-C and LDL-C levels (P = 0.006, 0.003, 0.001, respectively, all P < 0.05). However, gliquidone showed no significant effects on plasma TG and TC levels (P = 0.819, 0.053, respectively). LDL-C and HDL-C in the GLI group changed ((0.46 ± 0.10) mmol/L vs. (0.36 ± 0.14) mmol/L, P = 0.007; (0.99 ± 0.27) mmol/L vs. (1.11 ± 0.18) mmol/L, P = 0.049). Both metformin and gliquidone treatment lowered blood glucose levels (P = 0.001, 0.004, respectively, P < 0.05). Under light microscopy, no changes were observed in the aortic wall structure of each layer; the intima was smooth and the membrane elastic fibers were normal in the NC group. In the DM group, the aortic wall structure was unclear, the intima was thickened with irregular intima, and membrane elastic fibers collapsed. The aortic intima in the MET and GLI groups was smoother compared with the DM group, but the endothelial structure of the MET group was closer to that of the NC group.

CONCLUSIONSBoth metformin and gliquidone have anti-atherosclerotic effects. But the endothelial structure of the MET group was closer to that of the NC group. Metformin and gliquidone therapy can reduce serum level of LDL-C and increase level of HDL-C, whereas gliquidone therapy did not lose weight and decrease serum level of TG. These data may have important implications for the treatment of patients with type 2 DM.

Animals ; Aorta ; drug effects ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Angiopathies ; prevention & control ; Hypoglycemic Agents ; therapeutic use ; Male ; Metformin ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sulfonylurea Compounds ; therapeutic use

This study is to evaluate the anti-diabetic effects of the alpha-glucosidase inhibitor valibose in a streptozotocin (STZ)-induced type 1 diabetes rat model. Diabetes was induced by a single dose of STZ (58 mg x kg(-1), ip) in SD rats, rats with elevated fasting blood glucose levels (250-450 mg x dL(-1)) were selected and divided into five groups (n = 10 in each). Another ten normal SD rats were chosen as normal group. Valibose mixed with the high sucrose diets (0.4, 1.0 and 2.5 mg 100 g(-1) diets) or acarbose (30 mg x 100 g(-1) diets) was administrated in the diabetic rats for about 5 weeks. In all groups, fasting and postprandial plasma glucose, plasma lipids, glycosylated serum protein, N-acetyl-beta-D-glucosaminidase (NAG), creatinine (Cre), blood urea nitrogen (BUN) and urine sugar levels were determined during the treatment. At the end of the experiment, the morphological alterations in kidney were evaluated by hematoxylin-eosin (HE) staining. After 3-weeks administration, valibose significantly decreased postprandial and fasting blood glucose, urine glucose, and reduced the levels of serum fructosamine. Valibose also decreased plasma triglyceride and cholesterol levels after 4 weeks treatment. These results indicated that valibose ameliorated metabolic disturbance of glucose and lipids in STZ-induced diabetic rats. In addition, valibose markedly reduced level of serum NAG and BUN, and decreased the weight index of kidney. HE staining showed reduced kidney pathological changes after valibose treatment. The findings of the present study indicate that valibose may be a novel alpha-glucosidase inhibitor for the prevention from hyperglycemia in STZ-induced type 1 diabetes rats. And valibose might have a potential role for protecting against diabetic nephropathy during hyperglycemia.
Acetylglucosaminidase ; blood ; Animals ; Blood Glucose ; metabolism ; Blood Urea Nitrogen ; Cholesterol ; blood ; Creatinine ; blood ; Cyclohexanols ; pharmacology ; Diabetes Mellitus, Experimental ; blood ; pathology ; Diabetic Nephropathies ; prevention & control ; Enzyme Inhibitors ; pharmacology ; Fructosamine ; blood ; Glycoside Hydrolase Inhibitors ; Hyperglycemia ; prevention & control ; Hypoglycemic Agents ; pharmacology ; Kidney ; pathology ; Male ; Rats ; Rats, Sprague-Dawley ; Triglycerides ; blood ; Weight Gain ; drug effects

Cytokines activate several inflammatory signals that mediate beta-cell destruction. We recently determined that SPA0355 is a strong anti-inflammatory compound, thus reporting its efficacy in protecting beta cells from various insults. The effects of SPA0355 on beta-cell survival were studied in RINm5F cells and primary islets. The protective effects of this compound on the development of type 1 diabetes were evaluated in non-obese diabetic (NOD) mice. SPA0355 completely prevented cytokine-induced nitric oxide synthase (iNOS) expression and cytotoxicity in RINm5F cells and isolated islets. The molecular mechanism of SPA0355 inhibition of iNOS expression involves the inhibition of nuclear factor kappaB and Janus kinase signal transducer and activator of transcription pathways. The protective effects of SPA0355 against cytokine toxicity were further demonstrated by normal insulin secretion and absence of apoptosis of cytokine-treated islets. In experiments with NOD mice, the occurrence of diabetes was efficiently reduced when the mice were treated with SPA0355. Therefore, SPA0355 might be a valuable treatment option that delays the destruction of pancreatic beta cells in type 1 diabetes.
Animals ; Apoptosis ; Benzoxazines/pharmacology/*therapeutic use ; Cell Line ; Cell Survival ; Cells, Cultured ; Diabetes Mellitus, Experimental/*prevention & control ; Insulin-Secreting Cells/*drug effects/metabolism ; Janus Kinases/genetics/metabolism ; Mice ; Mice, Inbred NOD ; NF-kappa B/genetics/metabolism ; Nitric Oxide Synthase Type II/genetics/metabolism ; Rats ; Thiourea/*analogs & derivatives/pharmacology/therapeutic use

To evaluate the effect of chlorogenic acid (CGA), a polyphenol abundant in coffee, on retinal vascular leakage in the rat model of diabetic retinopathy, Sprague-Dawley rats were divided into four groups: controls, streptozotocin-induced diabetic rats, and diabetic rats treated with 10 and 20 mg/kg chlorogenic acid intraperitoneally daily for 14 days, respectively. Blood-retinal barrier (BRB) breakdown was evaluated using FITC-dextran. Vascular endothelial growth factor (VEGF) distribution and expression level was evaluated with immunohistochemistry and Western blot analysis. Expression of tight junction proteins, occludin and claudin-5, and zonula occludens protein, ZO-1 was also evaluated with immunohistochemistry and Western blot analysis. BRB breakdown and increased vascular leakage was found in diabetic rats, with increased VEGF expression and down-regulation of occludin, claudin-5, and ZO-1. CGA treatment effectively preserved the expression of occludin, and decreased VEGF levels, leading to less BRB breakdown and less vascular leakage. CGA may have a preventive role in BRB breakdown in diabetic retinopathy by preserving tight junction protein levels and low VEGF levels.
Animals ; Blood-Retinal Barrier/*drug effects ; Chlorogenic Acid/metabolism/*pharmacology ; Claudin-5/metabolism ; Dextrans/chemistry ; Diabetes Mellitus, Experimental/complications/metabolism/*pathology ; Diabetic Retinopathy/etiology/prevention & control ; Down-Regulation ; Fluorescein-5-isothiocyanate/chemistry ; Male ; Occludin/metabolism ; Rats ; Rats, Sprague-Dawley ; Retina/*metabolism ; Tight Junction Proteins/metabolism ; Vascular Endothelial Growth Factor A/metabolism ; Zonula Occludens-1 Protein/metabolism