OBJECTIVE: To investigate the effect of Tongmai Hypoglycemic Capsule (THC) on myocardium injury in diabetic cardiomyopathy (DCM) rats. METHODS: A total of 24 Sprague Dawley rats were fed for 4 weeks with high-fat and high-sugar food and then injected with streptozotocin intraperitoneally for the establishment of the DCM model. In addition, 6 rats with normal diets were used as the control group. After modeling, 24 DCM rats were randomly divided into the model, L-THC, M-THC, and H-THC groups by computer generated random numbers, and 0, 0.16, 0.32, 0.64 g/kg of THC were adopted respectively by gavage, with 6 rats in each group. After 12 weeks of THC administration, echocardiography, histopathological staining, biochemical analysis, and Western blot were used to detect the changes in myocardial structure, oxidative stress (OS), biochemical indexes, protein expressions of myocardial fibrosis, and nuclear factor erythroid 2-related faactor 2 (Nrf2) element, respectively. RESULTS: Treatment with THC significantly decreased cardiac markers such as creatine kinase, lactate dehydrogenase, and creatine kinase-MB, etc., (P<0.01); enhanced cardiac function indicators including heart rate, ejection fraction, cardiac output, interventricular septal thickness at diastole, and others (P<0.05 or P<0.01); decreased levels of biochemical indicators such as fasting blood glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, aspartate transaminase, (P<0.05 or P<0.01); and decreased the levels of myocardial fibrosis markers α-smooth muscle actin (α-SMA), and collagen I (Col-1) protein (P<0.01), improved myocardial morphology and the status of myocardial interstitial fibrosis. THC significantly reduced malondialdehyde levels in model rats (P<0.01), increased levels of catalase, superoxide dismutase, and glutathione (P<0.01), and significantly increased the expression of Nrf2, NAD(P)H:quinone oxidoreductase 1, heme oxygenase-1, and superoxide dismutase 2 proteins in the left ventricle of rats (P<0.01). CONCLUSION THC activates the Nrf2 signaling pathway and plays a protective role in reducing OS injury and cardiac fibrosis in DCM rats.
Animals ; Diabetic Cardiomyopathies/physiopathology* ; Oxidative Stress/drug effects* ; Drugs, Chinese Herbal/therapeutic use* ; Rats, Sprague-Dawley ; Myocardium/metabolism* ; Fibrosis ; Male ; Capsules ; Hypoglycemic Agents/therapeutic use* ; NF-E2-Related Factor 2/metabolism* ; Rats ; Diabetes Mellitus, Experimental/drug therapy*

Humans ; Glucagon-Like Peptide-1 Receptor/agonists* ; Diabetic Cardiomyopathies/drug therapy* ; Diabetes Mellitus, Type 2

Diabetic cardiomyopathy( DCM) is one of the major cardiovascular complications of diabetes mellitus. Based on the clinical efficacy of Danzhi Jiangtang Capsules( DJC) in the prevention and treatment of diabetes and its cardiovascular complications,both in vivo and in vitro methods were adopted to investigate its effect and underlying mechanism of protecting myocardial injury induced by diabetes. The type 2 diabetic rats were prepared by feeding high-energy food combined with streptozotin( STZ) injection,and the effects of DJC were observed by blood sugar,blood lipid,hemodynamic index,cardiac weight index and the change of cardiac pathological morphology. The protein expressions of TLR4,MyD88 and NF-κB p65 in myocardial tissue were detected and the possible mechanism was preliminarily analyzed. Besides this,DJC containing serum was prepared,H9 c2 cardiomyocyte induced by high sugar were studied to investigate the mechanism of TLR4/MyD88/NF-κB signaling pathway regulating cardiomyocyte injury and the therapeutic effect of DJC. The results demonstrated that fasting blood sugar,glycosylated hemoglobin,total cholesterol and glycerol triglyceride were significantly reduced( P<0. 01,P<0. 05). Cardiac weight index,left ventricle weight index,LVEDP and the protein expressions of TLR4,MyD88 and NF-κB p65 were significantly reduced( P<0. 01,P<0. 05). LVSP,+dp/dtmaxand-dp/dtmaxincreased significantly( P<0. 01,P< 0. 05). Moreover,the pathological damage of myocardial tissue in rats improved significantly. Meanwhile,the protein expressions of TLR4,MyD88 and NF-κB p65 in cardiomyocytes induced by high sugar were significantly inhibited( P<0. 01).It showed that DJC were effective in preventing and treating myocardial injury induced by diabetes and its mechanism may be related to the over-expression of TLR4/MyD88/NF-κB signaling pathway induced by high sugar.
Animals ; Blood Glucose ; Capsules ; Diabetes Mellitus, Experimental/complications* ; Diabetic Cardiomyopathies/drug therapy* ; Drugs, Chinese Herbal/therapeutic use* ; Myeloid Differentiation Factor 88/metabolism* ; NF-kappa B/metabolism* ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Toll-Like Receptor 4/metabolism*

To explore the protective effect of naringin(Nar) on the injury of myocardium tissues induced by streptozotocin(STZ) in diabetic rats and the relationship with oxidative stress and endoplasmic reticulum stress(ERS)， the male SD rats were intraperitoneally injected with streptozotocin(STZ， 60 mg·kg⁻¹) to establish the diabetic rat model and then randomly divided into the type 1 diabetic rat group(T1DR)， the low-dose Nar group(Nar25)， the middle-dose Nar group(Nar50) and the high-dose Nar group(Nar100). The normal rats were designed as control group(Con). Nar25， Nar50， Nar100 groups were orally administered with Nar at the doses of 25.0， 50.0， 100.0 mg·kg⁻¹ per day， respectively， while the normal group and the T1DR group were orally administered with saline. At the 8th week after treatment， fasting plasma glucose and heart mass index were measured. The pathological changes in myocardial tissues were observed by microscope. The cardiac malondialdehyde(MDA) level and superoxide dismutase(SOD) activities were measured. The gene and protein expressions of glucose-regulated protein 78(GRP78)， C/EBP homologous protein(CHOP)， cysteinyl aspartate-specific proteinase 12(caspase 12) were detected by qRT-PCR and Western blot. According to the results， compared with control group， the myocardial structure was damaged， the content of MDA was increased， while the activities of SOD were decreased(<0.05) in T1DR group. GRP78， CHOP and caspase 12 mRNA and protein expressions were increased significantly in T1DR group(<0.05， <0.01). Compared with T1DR group， myocardial structure damage was alleviated in Nar treatment group. The content of MDA was decreased， while the activities of SOD were increased significantly. The mRNA and protein expressions of GRP78， CHOP and caspase 12 were increased， especially in middle and high-dose groups(<0.05， <0.01). After treatment with Nar for 8 weeks， myocardial structure damage was obviously alleviated in Nar treatment groups. The content of MDA was decreased， while the activities of SOD were increased significantly in myocardial tissues. The mRNA and protein expressions of GRP78， CHOP and caspase 12 were increased， especially in middle and high-dose groups(<0.05， <0.01). The findings suggest that Nar may protect myocardium in diabetic rats by reducing mitochondrial oxidative stress injuries and inhibiting the ERS-mediated cell apoptosis pathway.
Animals ; Apoptosis ; Cardiotonic Agents ; pharmacology ; Caspase 12 ; metabolism ; Diabetes Mellitus, Experimental ; Diabetic Cardiomyopathies ; drug therapy ; Endoplasmic Reticulum Stress ; drug effects ; Flavanones ; pharmacology ; Heat-Shock Proteins ; metabolism ; Male ; Malondialdehyde ; metabolism ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; Transcription Factor CHOP ; metabolism

OBJECTIVE: To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyopathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy. METHODS: Sixty Sprague-Dawley (SD) rats were randomly divided into six groups: a normal control group (NC), an obesity group (OB), a diabetic cardiomyopathy group (DCM), a tea polyphenol group (TP), an obesity tea polyphenol treatment group (OB-TP), and a diabetic cardiomyopathy tea polyphenol treatment group (DCM-TP). After successful modeling, serum glucose, cholesterol, and triglyceride levels were determined; cardiac structure and function were inspected by ultrasonic cardiography; myocardial pathology was examined by staining with hematoxylin-eosin; transmission electron microscopy was used to observe the morphology and quantity of autophagosomes; and expression levels of autophagy-related proteins LC3-II, SQSTM1/p62, and Beclin-1 were determined by Western blotting. RESULTS: Compared to the NC group, the OB group had normal blood glucose and a high level of blood lipids; both blood glucose and lipids were increased in the DCM group; ultrasonic cardiograms showed that the fraction shortening was reduced in the DCM group. However, these were improved significantly in the DCM-TP group. Hematoxylin-eosin staining showed disordered cardiomyocytes and hypertrophy in the DCM group; however, no differences were found among the remaining groups. Transmission electron microscopy revealed that the numbers of autophagosomes in the DCM and OB-TP groups were obviously increased compared to the NC and OB groups; the number of autophagosomes in the DCM-TP group was reduced. Western blotting showed that the expression of LC3-II/I and Beclin-1 increased obviously, whereas the expression of SQSTM1/p62 was decreased in the DCM and OB-TP groups (P<0.05). CONCLUSIONS Tea polyphenols had an effect on diabetic cardiomyopathy in rat cardiac function and may alter the levels of autophagy to improve glucose and lipid metabolism in diabetes.
Animals ; Autophagy ; drug effects ; Beclin-1 ; analysis ; Blood Glucose ; analysis ; Body Weight ; Diabetic Cardiomyopathies ; drug therapy ; pathology ; physiopathology ; Lipids ; blood ; Male ; Myocardium ; pathology ; Polyphenols ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Tea ; chemistry

Diabetic cardiomyopathy (DCM) is characterized by left ventricular hypertrophy, myocardial fibrosis and diastolic dysfunction, which are uncorrelated with underlying coronary artery disease or hypertension. As an important metabolic organelle, mitochondria directly involve the process of cell growth, proliferation, signal transduction, apoptosis and so on. Recent studies have demonstrated a close correlation between the mitochondrial dysfunction and the pathogenesis of diabetic cardiomyopathy. The underlying effects of mitochondrial dysfunction in the progress of diabetic cardiomyopathy involve disturbed metabolism, oxidative stress, defective calcium handling, mitochondrial uncoupling, apoptosis, imbalance of mitochondrial quality control and regulation of MicroRNAs. Traditional Chinese medicines have been widely applied in clinic. Nowadays, more and more herbs of extracts of traditional Chinese medicines have been proved to ameliorate diabetic myocardial injury. Because the improvement of mitochondrial dysfunction has emerged as a promising therapeutic strategy, this review summarizes these effects of mitochondrial dysfunction in diabetic cardiomyopathy, and discusses the intervention studies of traditional Chinese medicine in the field, in expectation to provide new ideas for DCM prevention and treatment.
Diabetic Cardiomyopathies ; drug therapy ; pathology ; Drugs, Chinese Herbal ; therapeutic use ; Humans ; Medicine, Chinese Traditional ; Mitochondria ; pathology ; Myocardium

OBJECTIVETo investigate the effects of hydrogen sulfide (H₂S) on oxidative stress and endoplasmic reticulum stress (ERS) in a rat model of diabetic cardiomyopathy (DCM).

METHODSThirty male SD rats were randomly divided into control group, diabetes group and treatment group( n = 10). Intraperitoneal injection of streptozotocin was utilized to establish a rat model of DCM. The rats with DCM in treatment group were intraperitoneally injected with NaHS solution. After treated for 12 weeks, the hearts isolated from rats were perfused on a langendorff apparatus. The ventricular hemodynamic parameters were measured. The ultrastructures of myocardium were observed using electron microscopy. The content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in myocardial tissue were determined by spectrophotometry. The expressions of C/EBP homologous protein( CHOP), glucose-regulated protein 78 (GRP78) and Caspase 12 at mRNA level in myocardium were detected using RT-PCR.

RESULTSCompared with control group, the cardiac function and myocardial ultrastructure were damaged obviously in diabetic rats. In myocardial tissue, the content of MDA was increased, while the activities of SOD and GSH-Px were decreased. CHOP, GRP78 and Caspase 12 mRNA expressions were increased significantly. Compared with diabetes group, cardiac function and myocardial ultrastructure damage were improved in treatment group. The content of MDA was decreased, while the activities of SOD and GSH-Px were increased significantly. The mRNA levels of CHOP, GRP78 and Caspase 12 were increased.

CONCLUSIONH2S can protect myocardium in diabetic rats, maybe it is related to reduce oxidative stress damage and inhibition of the ERS-induced apoptosis pathway.

Animals ; Apoptosis ; Caspase 12 ; metabolism ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Cardiomyopathies ; drug therapy ; Endoplasmic Reticulum Stress ; Glutathione Peroxidase ; metabolism ; Heat-Shock Proteins ; metabolism ; Hydrogen Sulfide ; pharmacology ; Male ; Malondialdehyde ; metabolism ; Myocardium ; ultrastructure ; Oxidative Stress ; Rats ; Streptozocin ; Superoxide Dismutase ; metabolism ; Transcription Factor CHOP ; metabolism

This article aimed at exploring the effects and protective mechanism of β-CM7 on renin angiotensin system (RAS) in diabetic rats myocardial tissue. We divided 32 male SD rats into 4 groups: control group, diabetic model control group, insulin (3.7x10(-8) mol/d) treatment group and β-CM7 (7.5x10(-8) mol/d) treatment group. After 30 days, all rats were decapitated and myocardical tissues were collected immediately. After injection, β-CM7 could decrease the content of Ang II, increase the content of Angl-7. And β-CM7 could improve the mRNA of AT1 receptor and Mas receptor. β-CM7 also could improve the mRNA of ACE and ACE2, enhance the activity of ACE and ACE2. These data confirmed tli β-CM7 could activate ACE2-Angl-7-Mas axis, negative passage in RAS, to inhibit the expression ACE mnRiJA and protein in rat myocardium, alleviate the myocardial tissue damage induced by Ang II. The effect of β-CM7 on inhibiting myocardium damage might be related to ACE/ACE2 passageway.
Angiotensin II ; metabolism ; Animals ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Cardiomyopathies ; drug therapy ; Endorphins ; pharmacology ; Male ; Myocardium ; metabolism ; pathology ; Peptide Fragments ; pharmacology ; Peptidyl-Dipeptidase A ; metabolism ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Receptor, Angiotensin, Type 1 ; metabolism ; Receptors, G-Protein-Coupled ; metabolism ; Renin-Angiotensin System

OBJECTIVEOver the last few decades, diabetic cardiomyopathy has been identified as a significant contributor in cardiac morbidity. However, the mechanisms of diabetic cardiomyopathy have not been clarified.

METHODSIn the present study, a diabetic rat model was induced by the intraperitoneal injection of streptozotocin. The myocardial CD147 expression and extent of glycosylation, as well as thematrixmetalloproteinases(MMPs) expression and activity, were observed in the diabetic and synchronous rats.

RESULTSThe results showed that CD147 located on sarcolemma of cardiomyocytes. The myocardial CD147 expression and glycosylation were significantly increased in the diabetic rats as compared with the control. Expression of MMP-2 protein, MMP-2 and MMP-9 activity were also increased in left ventricular myocardium in the diabetic rats. Tamoxifen only inhibited the enhanced expression of myocardial CD147 in the diabetic rats, but not in synchronous control rats. Tamoxifen inhibited glycosylation of myocardial CD147 in both diabetic and control rats. The inhibition of tamoxifen on CD147 glycosylation was stronger than on the expression in the myocardium. The extent of myocardial CD147glycosylation was positively related toMMP-2 and MMP-9 activity. Tamoxifen induced an inhibition of myocardial MMP-2 and MMP-9 activity in the control and diabetic rats.

CONCLUSIONThese results indicate that myocardial CD147 expression, especially the extent of glycosylation, regulates MMP-2 and MMP-9 activity, then accelerates cardiac pathological remodeling inducing diabetic cardiomyopathy. Tamoxifen inhibits myocardial CD147 glycosylation and further depress the activity of MMPs. Therefore, tamoxifen may protect the diabetic rats against diabetic myocardium.

Animals ; Basigin ; metabolism ; Diabetes Mellitus, Experimental ; complications ; Diabetic Cardiomyopathies ; drug therapy ; Glycosylation ; Heart ; drug effects ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Myocardium ; metabolism ; Myocytes, Cardiac ; cytology ; Rats ; Sarcolemma ; metabolism ; Tamoxifen ; pharmacology

To observe the preventive effect of polydatin on diabetic myocardial hypertrophy in mice and discuss its and mechanism. The diabetic model was induced with low dose STZ (40 mg x kg(-1) x d(-1) x 5 d, ip) for five days in mice. The myocardial hypertrophy was determined by hypertrophy indexes (LVHI, left ventricular/right ventricle and septum), left ventricular/body weight (LV/BW), the histological examination and the mRNA expression of atrial natriuretic factor(ANF). The fast blood glucose(FBG), serum insulin and plasma hemoglobin A1c ( HbA1c) levels were detected, and then HOMA insulin resistance index ( HOMA. IR) was calculated. The mRNA and protein expressions were measured by qRT-PCR and western blotting, respectively. According to the results, the FBG of the model group exceeded 11.1 mmol x L(-1), with notable decrease in BW and significant increase in insulin, HbA1c and HOME. IR, suggesting the successful establishment and stability of the diabetic model. The increases in LVHI, LV/BW, cell surface and ANF mRNA indicated a myocardial hypertrophy in diabetic mice. Meanwhile, the model group showed decrease in mRNA and protein expressions of PPARβ and significant increase in NF-κB p65, COX-2 and iNOS expressions. After the preventation with PD (50, 100 mg x kg(-1) x d(-1)), diabetic mice showed increase in BW, reduction in the levels of FBG, insulin and HbA1 c, relief in insulin resistance and significant recovery in hypertrophy indexes, indicating PD has the protective effect in diabetic myocardial hypertrophy. Meanwhile, PD up-regulated the expression of PPARβ, inhibited the expressions of NF-κB p65, COX-2 and iNOS, demonstrating that PD's protective effect may be related to the activation of PPARβ and the inhibition of NF-κB, COX-2 and iNOS signaling pathways.
Animals ; Diabetes Mellitus, Experimental ; complications ; Diabetic Cardiomyopathies ; drug therapy ; genetics ; metabolism ; Drugs, Chinese Herbal ; administration & dosage ; Glucosides ; administration & dosage ; Humans ; Hypertrophy ; drug therapy ; genetics ; metabolism ; Insulin ; metabolism ; Male ; Mice ; NF-kappa B ; genetics ; metabolism ; Signal Transduction ; Stilbenes ; administration & dosage