Influence of Tangshenfang on diabetic liver injury and the expression of SIRT1 and PGC-1α in the liver tissue

AIM: To observe the effect of Tangshenfang (TS) on the liver protection and the levels of silent information regulator 1 (SIRT1) and peroxisom proliferator-activated receptor γ coactivator-1α (PGC-1α) in the liver tissue. METHODS: The rat model of diabetes mellitus (DM) was established by intravenous injection of streptozotocin (STZ;30 mg/kg) after having the high fat/high glucose diets for 1 month. The diabetic rats were randomly divided into DM group, DM with high-dose TS (TS^Hi) group, medium-dose TS (TS^Med) group and low-dose TS (TS^Low)group. The normal rats were served as control group. There were 8 rats in each group. After treatment with TS for 12 weeks, the serum biochemical indices including fasting blood glucose (FBG), triglyceride (TG), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were tested. Fasting insulin (FINS) was also detected by radioimmunoassay, and homeostatic model assessment for insulin resistance (HOMA-IR) was calculated. The serum levels of tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) were measured by ELISA. The activity of SOD and content of MDA in the liver tissues were measured by the methods of hydroxylamine and thiobarbituric acid. The liver pathological changes were observed under light microscope with HE and Masson staining. The protein expression of SIRT1and PGC-1α in the liver tissues was determined by Western blot. RESULTS: In DM group, serum FBG, TG, ALT, AST, FINS, HOMA-IR, TNF-α and IL-1 were obviously increased compared with the control group (P<0.01). The fatty changes, local necrosis, inflammation and fibrosis in the liver tissues were observed. The content of MDA in liver increased, while the activity of SOD decreased markedly. The protein expression of SIRT1 and PGC-1α was decreased (P<0.05). In TS treatment groups, all these changes in DM rats were markedly reversed by TS, and the protein expression of SIRT1 and PGC-1α in the liver tissues was markedly increased. CONCLUSION: TS may protect the rats from diabetic liver injury by increasing the expression of SIRT1 and PGC-1α, and thereby improving insulin resistance and oxidative stress.     

Changes of cardiac function,RAGE expression and calcium dysregulation in type 2 diabetic rats

AIM: To investigate the changes of cardiac structure and function in rats with type 2 diabetic mellitus (T2DM), and to explore the mechanisms underlying diabetic cardiomyopathy. METHODS: The cardiac structure and function were measured by echocardiography in Zucker diabetic fatty (ZDF) rats and their control Zucker lean (ZL) rats. The size of the cardiomyocytes was determined by wheat germ agglutinin staining. The protein expression of atrial natriuretic peptide (ANP), β-myosin heavy chain (β-MHC), receptor for advanced glycation end products (RAGE), L-type cal-cium channel α1C subunit (Ca_V1.2) and Orai1 was assessed by Western blot. RESULTS: Compared with the ZL control rats, the thickness of left ventricular wall, ejection fraction (EF), fractional shortening (FS) and the sizes of cardiomyocytes were significantly increased, and diastolic function was decreased in the ZDF rats (P<0.05). The protein expression of β-MHC, ANP, RAGE and Orai1 was increased, while the expression of Ca_V1.2 was decreased in ZDF rats (P<0.05). CONCLUSION: T2DM rats show the prominent features including cardiomyocyte hypertrophy, ventricular hypertrophy and compensatory enhancement of cardiac function, and the Ca²⁺ handling and increase in RAGE expression may play important roles in the processes.     

Role of PPARα/PGC-1α in doxorubicin induced mouse dilated cardio-myopathy

AIM: To investigate the changes of peroxisome proliferator-activated receptors (PPAR)α/peroxisome proliferator activated receptor coactivator 1 alpha (PGC-1α) in doxorubicin (DOX) induced dilated cardiomyopathy (DCM) and its effect on the energy metabolism and myocardial function in mice. METHODS: Forty mice were randomly divided into 4 groups: control group, DOX group, PPARα inhibitor group and PPARα agonist group. The DCM model was established by injection of DOX. The protein levels of PPARα/PGC-1α were detected. The PPARα inhibitor and PPARα agonist were used 2 weeks beforeinjection of DOX. The contents of adenine acid and phosphocreatine (Pcr) in the mitochondria were measured by high-performance liquid chromatography (HPLC). The ANT activity was analyzed by the atractyloside-inhibitor stop technique. The changes of the echocardiography and hemodynamics were also observed. RESULTS: DOX induced DCM model was successfully established. The protein levels of PPARα and PGC-1α in control group were significantly higher than those in DOX group (P<0.05). Both of the high-energy phosphate contents and the transport activity of ANT were decreased in DOX group (P<0.05), and the hemodynamic parameters were disordered (P<0.01). Compared with DOX group, PPARα inhibitor pre-treatment significantly reduced the PPARα/PGC-1α expression. Meanwhile, high-energy phosphate contents in the mitochondria and the ANT transport activity of the mitochondria decreased, as well as the left ventricular function (P<0.05). On the other hand, PPARα agonist significantly increased the expression of PPARα and PGC-1α, and improved the transport activity of ANT. In addition, the hemodynamic parameters were ameliorated, but the high-energy phosphate contents of the mitochondria did not significantly change. CONCLUSION: PPARα/PGC-1α plays an important role in the regulation of ANT transport activity in dilated cardiomyopathy induced by DOX, and the activation of PPARα/PGC-1α has protective effects on the DCM induced by DOX.     

Protective role of carnosine on cardiac dysfunction in type 1 diabetes mellitus rat model

AIM:To explore the effects of carnosine (CAR) on cardiac dysfunction in type 1 diabetic mellitus rats and the underlying mechanism. METHODS:The SD rats were randomly divided into 4 groups:control (C) group, control+carnosine (C+CAR) group, diabetes mellitus (DM) group and diabetes mellitus+carnosine (DM+CAR) group (n=10). The rats were sacrificed after 12 weeks. The cardiac function was assessed by ventricular cannulation. The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were assessed by ELISA. The mRNA levels of tumor necrosis factor α(TNF-α), interleukin-1β(IL-1β) and IL-6 were measured by real-time PCR. The distribution of connexin 43 (Cx43) was examined by immunofluorescence. The protein levels of Cx43 and protein kinase C (PKC) were determined by Western blot. RESULTS:Compared with the C group, the left ventricular end diastolic pressure (LVEDP) was increased whereas the left ventricular pressure maximum rise/fall velocity (±dp/dt_max) was decreased in the DM group (P<0.01). The activity of SOD decreased while the MDA increased in the left ventricular tissues (P<0.01). The mRNA levels of TNF-α, IL-1β and IL-6 were increased (P<0.01). The Cx43 distribution was irregular. The protein levels of phosphorylated Cx43 and PKCε were elevated (P<0.01). Compared with the DM group, the cardiac function of LVEDP and ±dp/dt_max in DM+CAR group was ameliorated (P<0.01), with increased SOD activity and decreased MDA content (P<0.05). The mRNA levels of TNF-α, IL-1β and IL-6 were reduced (P<0.01). The Cx43 distribution was improved and the protein levels of phosphorylated Cx43 and PKCε were decreased (P<0.01). CONCLUSION:CAR treatment can improve the cardiac function by its anti-oxidative and anti-inflammation effects and suppression of Cx43 abnormalities through PKCε in DM rats.     

Influence of 8-week swimming on peripheral neuropathy in type 2 diabetic rats

AIM: To explore the influence of long-term swimming on peripheral neuropathy in type 2 diabetic rats. METHODS: Male Wistar rats were fed with a high-fat and high-fructose diet, and injected with streptozocin to establish a model of type 2 diabetes mellitus. The rats were randomly divided into 4 groups: blank control group (C group), exercise control group (CE group), diabetes mellitus group (DM group) and diabetes mellitus+exercise group (DME group). The rats in CE group and DME group received 8-week swimming training (6 d/week). The training time was 20, 30 and 45 min in the first 3 d,respectively, and then it increased to 60 min a day. Eight weeks later, the motor nerve conduction velocity (MNCV) and the levels of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and C-reactive protein (CRP) in sciatic nerve tissues of the rats were measured. The morphological changes of the sciatic nerve were also observed under light microscope. RESULTS: Compared with DM group, 8-week swimming obviously accelerated the MNCV (P<0.05), decreased the levels of TNF-α, IL-6 and CRP in DME group (but no significant difference, P>0.05). The obvious nerve injury in DM group was observed. However, the pathological change of the sciatic nerve in DME group was relieved. CONCLUSION: Eight-week swimming training significantly accelerates the MNCV, attenuates the nerve injury in diabetic rats and has protective effect on peripheral nerve, which may be correlated with relieving the inflammatory reaction.     

Effect of blood glucose control on expression of Smad7 and renal fibrosis in diabetic rats

AIM： To verify the hypothesis that treatment with insulin to control the blood glucose (BG) may relieve or slow down the development of diabetic nephropathy (DN) in diabetic rats by increasing the expression of Smad7. METHODS：The diabetic rat model was established by tail-vein injection of streptozotocin. Sixteen rats were divided into 2 groups. Eight of these animals in diabetes mellitus (DM) group had no treatment. The remaining eight of them in insulin treatment (INS) group were injected with insulin. After 13 weeks, the rats in INS group were given individual treatment with insulin to let the blood glucose level keep within 4 to 7 mmol/L. Meanwhile, 8 rats were used for normal control (NC group). After 16 weeks, the rats were sacrificed to detect the relevant biochemical parameters, and to observe the histophathological changes of the kidney and pancreas. In addition, immunohistochemical staining and Western blotting were employed to detect the protein expression of transforming growth factor β1 (TGF-β1), Smad ubiquitin regulatory factor 2 (Smurf2), Smad7, E-cadherin, α-sooth muscle actin (α-SMA), fibronectin (FN) and collagen I. RESULTS：Compared with NC group, the body weight was significantly reduced in DM group, whereas the body weight in INS group increased gradually. Compared with NC group, the levels of 24 h urine protein (24 h UP), BG and triglyceride (TG) were remarkably increased in DM group. Pathological detection on pancreas indicated that the islet was destroyed. The levels of TGF-β1, Smurf2, α-SMA, FN and collagenⅠ in the kidneys were increased in DM group, and the expression of Smad7 and E-cadherin, which were mainly located in renal tubular epithelial cells, was significantly reduced. Compared with DM group, the levels of 24 h UP and BG were significantly reduced in INS group, and the alleviated renal fibrosis was observed under light microscope. In addition, the protein levels of TGF-β1, Smurf2, α-SMA, FN and collagenⅠ in INS group were decreased compared with DM group, and the expression of Smad7 and E-cadherin was increased significantly. CONCLUSION：Target glucose control with insulin treatment restores the protein expression of Smad7 in the kidney of diabetic rats, reduces the accumulation of extracellular matrix and slows down DN progress. The decrease in TGF-β1 and Smurf2 expression, and the attenuation of Smad7 ubiquitination in renal tissues are the crucial parts in this process.     

Protective effect of pyrrolidine dithiocarbamate on cardiac muscles in diabetic rats

AIM: To investigate the effect of pyrrolidine dithiocarbamate (PDTC) on reducing blood glucose level and its protective effect on cardiac muscles in diabetic rats.METHODS: Thirty-seven male Wistar rats were randomly divided into normal control (NC) group and the high-fat diet (HFD) group. After 8 weeks of feeding, the rats in high-fat diet group were given a single dose of streptozotocin (STZ, 27 mg/kg) by intraperitoneal injection to induce type 2 diabetes. The diabetic rats were randomly divided into diabetes mellitus (DM) group and PDTC treatment(PDTC) group. The rats in PDTC group were intraperitoneally injected with PDTC (50 mg/kg) once daily. The rats in NC group and DM group were injected with equivalent volume of saline in the same way. After 1-week treatment, the level of blood glucose was measured, and all animals were killed. The concentration of malondialdehyde (MDA) and the activity of superoxide dismutases (SOD) and glutathione peroxidase (GSH-Px) were determined using commercial kits. The ultrastructural changes of the cardiac tissues were observed under transmission electron microscope. The expression of inducible nitric oxide synthase(iNOS) and content of nitrotyrosine was examined by the method of immunohistochemistry.RESULTS: The levels of blood glucose and MDA were significantly higher, while the activity of SOD and GSH-Px was lower in DM group than those in NC group (P<0.01). Treatment with PDTC markedly decreased the blood glucose and MDA content, and increased the activity of SOD and GSH-Px. Severe degeneration, necrosis, mitochondrial damage and inflammatory cell infiltration were found in the cardiac tissues in DM group. Treatment with PDTC markedly attenuated mitochondrial damage. The expression of iNOS and content of nitrotyrosine in cardiac tissues were significantly higher in DM group than those in NC group, and those were reduced after administration of PDTC.CONCLUSION: High glucose induces oxidative stress, increases the expression of iNOS and content of nitrotyrosine, and impairs the structure and function of myocardium. PDTC reduces blood glucose level, decreases the expression of iNOS and content of nitrotyrosine, and delays or attenuates the development of diabetic cardiomyopathy in diabetic rats.     

Effects of resveratrol on levels of ceramide via regulating miRNA-122 in treating non-alcoholic fatty liver disease

AIM: To observe the therapeutical effects of resveratrol on non-alcoholic fatty liver disease and its potential mechanism. METHODS: Male C57BL/6J mice were fed with high-fat and high-cholesterol diet to established non alcoholic fatty liver disease model, and were administrated with resveratrol at doses of 80 mg/kg and 160 mg/kg. After 4-week treatment, the blood sample was collected for determination of total cholesterol (TC) and triglyceride (TG). The liver tissues were harvested for measuring the liver lipid content. The histopathological examination were conducted with hematoxylin and eosin staining. The ceramide levels in the liver tissues were detected by HPLC-MS. The microRNA (mi-RNA)-122 levels in the liver tissues were detected by real-time PCR. The protein levels of serine palmitoyltransferase (SPT) were determined by Western blot. The HepG2 cells were cultured and divided into 5 groups:control group, model group (induced by 0.25 mmol/L oleic acid), model+resveratrol group (treated with 5 μmol/L resveratrol), miRNA-122 siRNA group and resveratrol+miRNA-122 siRNA group. Except control group, the cells in other groups were stimulated with oleic acid and incubated with respective drugs simultaneously for 24 h. The levels of TC, TG and ceramide in the cells of each group were measured. The protein levels of SPT in each group were determined by Western blot. RESULTS: In non-alcoholic fatty liver disease mice, resveratrol dose-dependently reduced the serum TC and TG levels, decreased the lipid deposition, the ceramide level and the SPT protein level, and increased the level of miRNA-122 in the liver tissues. In the in vitro study, compared with model group, resveratrol reduced the serum TC and TG levels, decreased the ceramide level, reduced the SPT protein level. Compared with control group, the levels of TC, TG and ceramide, and the protein expression of SPT were increased in miRNA-122 siRNA group. Compared with miRNA-122 siRNA group, no statistical difference of TC, TG, ceramide and protein expression of SPT in resveratrol combined miRNA-122 siRNA group was observed. CONCLUSION: Resveratrol significantly reduces lipid accumulation by reduction of miRNA-122 and ceramide levels, and decrease in SPT protein levels in the liver.     

Over-expression of PGC-1α reverses mitochondrial function reduction and apoptosis in OGD/R-induced neurons

AIM: To investigate the effect of over-expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) on mitochondrial morphology and cell apoptosis in the cortical neurons with oxygen glucose deprivation/reoxygenation (OGD/R). METHODS: The whole gene sequence of PGC-1α was obtained from the cerebral cortex of C57BL/6 mice by RT-PCR and cloned into the eukaryotic expression vector pEGFP-N1. The pEGFP-N1-PGC-1α was identified by PCR, and transfected into cortical neurons. The level of PGC-1α expression was identified by Western blot. The cortical neurons transfected with pEGFP-N1 and pEGFP-N1-PGC-1α vectors were treated with OGD/R. The mitochondrial mass, reactive oxygen species (ROS) and ATP production, cell apoptosis and changes of cleaved caspase-3 were detected by MitoTracker Red staining, flow cytometry, ATP metabolic assay kit and TUNEL. RESULTS: Over-expression of PGC-1α inhibited the decrease in mitochondrial biogenesis capacity and the ROS formation of OGD/R neurons (P<0.05), enhanced the ability of ATP synthesis (P<0.01), inhibited neuronal apoptosis (P<0.01) and decreased the activation of caspase-3 (P<0.01). CONCLUSION: PGC-1α over-expression inhibits neuronal apoptosis with OGD/R treatment by promoting mitochondrial biogenesis, inhibiting the production of ROS and maintaining mitochondrial function. PGC-1α may be used as a target for the development of cerebral ischemia/reperfusion injury drugs.     

Effect of curcumin derivative B06 on liver from type 2 diabetic rats

AIM:To observe the protective effect of curcumin derivative B06 on the liver from the rats with hyperlipidemia and type 2 diabetes mellitus. METHODS:Male Sprague-Dawley rats (n=35) were divided randomly into 5 groups: normal control group, high-fat group, high-fat+B06-treated group, diabetic group and diabetic +B06-treated group. After fed with a high-fat diet for 4 weeks, the rats in the later 2 groups were injected with streptozotocin intraperitoneally to induce type 2 diabetes mellitus. The rats in B06-treated groups were given B06 by gavage at a dose of 0.2 mg· kg-1·d-1 for 8 weeks. After the treatment, the morphology of the liver was observed under light and transmission electron microscopes. The protein expression of AMP-activated protein kinase α (AMPKα) and phosphorylated AMPK α (p-AMPKα) was detected by Western blotting. RESULTS:Fatty degeneration, hepatocellular necrosis, inflammatory cell infiltration and hyperplasia of fibrous tissue were observed in the liver from the rats in high-fat group and diabetic group,and were relieved after B06 treatment. The protein expression of p-AMPKα was decreased in the liver of the rats in diabetic group and high-fat group, and it was increased in the liver of the high-fat and diabetic rats in B06-treated group. CONCLUSION:Curcumin derivative B06 exerts a protective effect on the liver in type 2 diabetic rats, and the increased expression of p-AMPKα may be involved in the mechanism of protection.     

Effects of pyrrolidine dithiocarbamate on synthesis of hepatic glycogen in diabetic rats

AIM: To determine the effect of pyrrolidine dithiocarbamate on hepatic glycogen synthesis and its mechanism in diabetic rats. METHODS: Male Wistar rats were randomly divided into normal diet group and high-fat diet group. After 8 weeks of feeding, the rats in high-fat diet group were injected intraperitoneally with a single dose of streptozotocin (27 mg/kg) to induce type 2 diabetes. The diabetes rats were randomly divided into 3 groups: diabetes mellitus group (DM), PDTC-treated group (DM+PDTC) and insulin-treated group (DM+INS). The rats in PDTC-treated group were injected with PDTC (50 mg/kg) intraperitoneally daily. At the same time, the rats in normal diet group, DM group and insulin-treated group were injected with equivalent volume of saline in the same way. The rats in insulin-treated group were injected with insulin (1 U/kg) 1 h before killed. After the treatment was taken for 1 week, the levels of blood glucose were measured, then the animals in all groups were killed. The liver glycogen content was detected, and the levels of GSK-3β and Akt phosphorylation in the liver tissues were analyzed by Western blotting. RESULTS: The blood glucose level and liver glycogen content were significantly higher, and the levels of GSK-3β and Akt phosphorylation were lower in DM group than those in normal-diet group (P<0.01). Compared with DM group, the glycogen content, the phosphorylation of Akt and GSK-3β in the liver tissues in DM+PDTC group and DM+INS group increased significantly (P<0.01), and the blood glucose levels decreased (P<0.01). CONCLUSION: PDTC increases the synthesis of liver glycogen and decreases the level of blood glucose by regulating the activity of Akt and GSK-3β in the liver.     

Effect of insulin combined with selenium on myocardial remodeling in diabetic rats

AIM: To investigate the effects of insulin combined with selenium on myocardial remodeling in streptozotocin (STZ)-induced diabetic rats.METHODS: The animal model of diabetic cardiomyopathy was induced by intraperitoneal injection of STZ (50 mg/kg) in rats. The level of blood glucose was estimated using One Touch SureStep blood glucose meter. Hemoglobin A1c level was detected by microcolumn assay. Triglyceride and total cholesterol were measured by enzymatic method. Collagen content in the myocardium was determined by Mallory staining. The expression of tumor necrosis factor α (TNF-α) in the serum and myocardium was observed by the methods of ELISA and immunohistochemistry, respectively.RESULTS: Compared with control group, the animals in model group showed metabolic disorders of glucose and lipid, and the cardiac function declined significantly (P<0.01).The myocardial cells showed disorder of distribution, filament breakage and collagen hyperplasia,and serum and myocardial TNF-α levels were significantly elevated.Insulin in combination with selenium significantly decreased the levels of blood glucose and lipid, and markedly inhibited the expression of TNF-α in the serum and myocardium than those in the rats administered with insulin alone (P<0.01).CONCLUSION: Combination of insulin and selenium significantly improves the structure and function of the heart by down-regulation of TNF-α.     

Effects of curcumin analogue L6H4 on myocardial tissue of type 2 diabetic rats

AIM: To explore the effects of curcumin analogue L6H4 on the myocardial tissue of type 2 diabetic rats and its mechanism. METHODS: Male Sprague-Dawley rats were randomly divided into normal control (NC) group, high-fat (HF) group, high-fat treatment (FT) group, diabetes mellitus (DM) group and diabetes treatment (DT) group.The rats in the latter 4 groups were fed high-fat diet for 4 weeks, then the rats in DM groups and DT groups were intraperitoneally injected with streptozotocin (STZ) to induce type 2 diabetes, while the rats in FT group and DT group were given L6H4. The blood glucose and lipid levels were detected by biochemical method, and serum adiponectin (APN) levels were detected by ELISA. The serum insulin levels were measured by radioimmunoassay and homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. The morphological changes of myocardium were observed by Masson staining and electron microscopy. The protein expression of adiponectin receptor 1 (AdipoR1) and transforming growth factor β1(TGF-β1) in myocardial tissue were determined by immunohistochemistry. The protein expression of adipoR1 was also detected by Western blot for verification. RESULTS: Compared with NC group, the blood glucose, lipids, insulin, HOMA-IR and TGF-β1 were increased in HF and DM group, but they were decreased after treated with L6H4. Compared with NC group, the concentration of serum APN were decreased and the expression of AdipoR1 in the myocardium were weakened in HF group and DM group, and they increased after treated with L6H4. The myocardial fibrosis was obvious in HF group and DM group, the mitochondria in cardiomyocytes expanded, and the cristae disordered, partial disappeared. These lesions were significantly reduced after L6H4 treatment. CONCLUSION: L6H4 exerts a protective effect on the heart in type 2 diabetic rats. The increased concentration of serum APN, the enhanced expression of AdipoR1, and the expression of TGF-β1 inhibited by APN may be involved in the mechanism of protection.     

Effect of RYR1 gene expression knock-down by siRNA on mitochondria in C2C12 cells

AIM: To investigate the effect of ryanodine receptor 1 (RYR1) down-regulation on mitochondria in mouse myoblast C2C12 cell line and to explore the possible mechanism. METHODS: The expression of RYR1 in the C2C12 cells was knocked down by the targeted small interfering RNA (siRNA). The mitochondrial number and morpholo-gical changes were evaluated by transmission electron microscopy and the stereoscopic analysis. Real-time PCR and Western blot were used to determine the mRNA and protein levels of mitofusin 2 (Mfn2), peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) and extracellular signal-regulated kinase 1/2 (ERK1/2), respectively. RESULTS: The expression of RYR1 was significantly down-regulated by siRNA transfection (P<0.01), with fragmentized mitochondria in the C2C12 cells in knock-down (KD) group. Although no statistical difference of the mitochondrial number was observed, the mitochondria area and circumference were significantly lowered in KD group (P<0.05). In KD group, the mRNA and protein expression of Mfn2 was significantly reduced (P<0.01). The mRNA level of PGC-1α was also reduced (P<0.01), but no significant change at protein level was observed. No change of ERK1/2 expression and phosphorylated ERK1/2 level was detected. CONCLUSION: Knock-down of RYR1 expression leads to morphological changes of mitochondria, and down-regulation of Mfn2 expression may be involved in the underlying mechanism. While PGC-1α and ERK1/2-associated oxidative stress pathway may not play an important role in the process.     

Protective effects of Zhenwu decoction on kidney injury of diabetic rats induced by streptozotocin

AIM：To investigate the effects of Zhenwu decoction (ZWD) on the expression of α-smooth muscle actin (α-SMA) and NF-κB in diabetic nephropathy (DN) rats. METHODS：Diabetic rat model was induced by intrape-ritoneal injection of streptozotocin (STZ), and the animals were randomly divided into STZ group (n=22) and STZ+ZWD group (n=23). The normal rats served as control (n=16). All rats were sacrificed on 8 weeks after modeling. Biochemical assay and pathological observation (HE staining and transmission electron microscopy) were used to evaluate the effects of Zhenwu decoction on the renal function and pathological morphology. The body weight, renal index, blood glucose, total urinary protein in 24 h, and superoxide dismutase (SOD), malondialdehyde (MDA),inducible nitric oxide synthase (iNOS) were determined as well. Western blotting was used to observe the effects of Zhenwu decoction on the expression of α-SMA and NF-κB in diabetic nephropathy (DN) rats. RESULTS：Compared with normal group, the renal index, blood glucose concentration, total urinary protein in 24 h, blood urea nitrogen (BUN), serum creatinine (SCr) and MDA were significantly higher and body weight was lower in DN rats (P<0. 05). Pathological examination of the kidneys in DN group showed glomerular hypertrophy, glomerular basement membrane thickening, tubular epithelial cell degeneration, mesangial matrix proliferation, protein cast formation in some renal tubules. The protein expression levels of α-SMA and NF-κB were markedly increased (P<0.05). After ZWD treatment, the level of renal index, total urinary protein in 24 h, BUN, SCr and the expression of α-SMA and NF-κB at the protein level were significantly decreased (P<0.05). The renal histological injury in ZWD group was significantly ameliorated. CONCLUSION：Zhenwu decoction might protect kidney against STZ-induced injury via decreasing the expression of α-SMA and NF-κB.     

Effect of acarbose on the aortic collagen nonenzymatic glycosylation in diabetic rats

AIM: To observe the effect of α-glucosindase inhibitor, acarbose on the aortic collagen nonenzymatic glycosylation in streptozotocin-induced diabetic rats . METHODS: The treated group (DM+A) was given acarbose (1 mg·kg^-1). The aortic collagen and its AGEs concentration were measured at the scheduled periods (1, 3 and 6 months ). RESULTS: During the observed period , the aortic collagen and its AGEs concentration were higher than that of control group in a time-dependent manner (P＜0.01 ), but decreased in acarbose-treated rats as compared with untreated group (P＜0.01 ). CONCLUTION:Acarbose can prevent the aortic vascular collagen nonenzymatic glycosylation in diabetic rats.     

Effects of Aconiti tuber polysaccharides on hypercholesterolemia and hepatic cholesterol 7α-hydroxylase expression in rats

AIM: To investigate the effects of polysaccharides isolated from Aconiti tuber (Fuzi polysaccharides,FPS) on the prevention of hypercholesterolemia induced by high-cholesterol diet and the expression of hepatic cholesterol 7α-hydroxylase (cytochrome P450 7α-1, CYP7α-1) in rats.METHODS: Fifty male Wistar rats were randomly divided into 3 groups. The rats were fed with normal diet (control group), high-cholesterol diet (HC group) or high-cholesterol diet plus FPS (224, 448 or 896 mg·kg^-1·d^-1, FPS group) for 2 weeks. The serum lipid level, body weight, food-intake and fecal amount were measured at week 2. The pathological changes of the liver were observed with HE staining. The mRNA expression of hydroxy methylglutaryl coenzyme A (HMG-CoA) reductase and CYP7α-1, the protein level of CYP7α-1, and fecal bile acid were also detected at week 2.RESULTS: FPS significantly inhibited high-cholesterol diet-induced elevation of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) (P<0.05). HE staining showed that FPS attenuated fatty degeneration in liver. Real-time PCR analysis showed that FPS significantly up-regulated the mRNA expression of CYP7α-1, but down-regulated the mRNA expression of HMG-CoA reductase (P<0.01). The protein level of CYP7α-1 was higher in FPS group than that in HC group (P<0.01). The level of fecal bile acid in HC-treated rats was higher than that in the control rats, and FPS stimulated the excretion of fecal bile acid (P<0.05).CONCLUSION: FPS significantly reduces serum cholesterol levels, which is associated with the up-regulation of hepatic CYP7α-1 expression and down-regulation of hepatic HMG-CoA reductase expression.