Effect of rhynchophylline on TGF-β1/Smad pathway for processing ventricular remodeling in spontaneously hypertensive rats

AIM: To investigate the effect of rhynchophylline (Rhy) on blood pressure, cardiac hypertrophy and myocardial fibrosis in spontaneously hypertensive rats (SHR). METHODS: Spontaneously hypertensive rats were randomly divided into model group, high dose (10 mg·kg^-1·d^-1) and low dose (2.5 mg·kg^-1·d^-1) group of rhynchophylline, captopril group (17.5 mg·kg^-1·d^-1). Wistar-Kyoto rats were used as normal control. Respectively, systolic blood pressure was measured by tail cuff every 2 weeks. After 10 weeks, heart weight index and left ventricular weight index were calculated. The myocardial hydroxyproline and plasma angiotensin Ⅱ were detected. Moreover, basic myocardial histopathological changes and myocardial collagen fibres were observed by HE staining and Masson staining, respectively. The protein expression of TGF-β₁ and Smad3 in the myocardium was measured by the methods of immunohistochemistry and Western blot. RESULTS: Compared with SHR model group, Rhy significantly reduced blood pressure (P<0.05), the levels of HYP in the myocardium (P<0.05) and the levels of AngⅡ in the plasma (P<0.01). The pathological damages of the myocardial tissues and collagen deposition were attenuated. The protein expression of TGF-β₁ and Smad3 was significantly reduced by the treatment with Rhy (P<0.01). CONCLUSION: Rhynchophylline reduces blood pressure and adjusts to improve ventricular remodeling of SHR. The mechanism may be involved in the TGF-β₁/Smad pathway and reducing AngⅡ content.     

Ginsenoside Rh1 attenuates unilateral ureteral obstruction-induced renal interstitial fibrosis in rats

AIM:To observe the effects of ginsenoside Rh1 (G-Rh1) on unilateral ureteral obstruction (UUO)-induced renal interstitial fibrosis and to investigate the underlying mechanisms. METHODS:Male Sprague-Dawley (SD) rats (n=40) were divided into the following 4 groups:UUO-operated group (UUO group), sham-operated group (sham group), UUO-operated plus a low dose (50 mg·kg^-1·d^-1) of G-Rh1 treatment (low G-Rh1 group) and UUO-operated plus a high dose (100 mg·kg^-1·d^-1) of G-Rh1 treatment group (high G-Rh1 group). The G-Rh1 treatment was carried out by gastric gavage from the next day after the UUO operation once a day for 2 weeks (14 d). Immediately after the final dose of G-Rh1, 24 h urine was collected for the urine protein test, and then the rats were euthanized. The blood was collected for the blood urea nitrogen (BUN) and serum creatinine (SCr) assays, and the kidney was removed for pathological and biochemical evaluations. RESULTS:The levels of 24 h urine protein did not show any significant diffe-rence among the groups, while significantly increased levels of BUN and SCr in UUO group were observed (P<0.05), which was prevented by the treatment with G-Rh1 at both doses in a dose-dependent manner. Pathological evaluation showed the renal tissue damage was obvious in UUO group, which was improved by the treatment with G-Rh1 at both doses. Immunohistochemcial analysis exhibited that UUO increased renal interstitial transforming growth factor-β₁ (TGF-β₁) expression, which was also inhibited by the treatment with G-Rh1 at both doses(P<0.05). Significantly increased protein expression of renal interstitial collagen type I, α-smooth muscle actin (α-SMA) and connective tissue growth factor (CTGF) in UUO group was detected, which was suppressed by the treatment with G-Rh1 at both doses. CONCLUSION:G-Rh1 improves UUO-induced renal dysfunction and attenuates interstitial fibrosis, which is mediated via modulation of TGF-β₁-related pro-fibrogenic signaling pathway.     

Effect of leonurine on expression of miR-1 in rats with myocardial fibrosis induced by isoproterenol

AIM: To investigate effect of leonurine on the expression of microRNA-1 (miR-1) in rats with myocardial fibrosis induced by isoproterenol (ISO). METHODS: SD rats (n=10) were used as normal control group, and 80 rats were given ISO by intraperitoneal injection daily for 2 weeks to establish the model of myocardial fibrosis. The model rats were randomly divided into 5 groups:model group, low-dose (7.5 mg·kg^-1·d^-1) leonurine group, middle-dose (15 mg·kg^-1·d^-1) leonurine group, high-dose (30 mg·kg^-1·d^-1) leonurine group and p38 mitogen-activated protein kinase (p38 MAPK) inhibitor (0.3 mg·kg^-1·d^-1) group. After the treatment for 2 weeks, the ultrastructure of left ventricular myocardial tissues was observed under electron microscope. Masson staining was used to detect collagen fibrosis, and the expression of collagen I and collagen Ⅲ was determined by the method of immunohistochemistry. The contents of endothelin-1 (ET-1) and angiotensin Ⅱ (Ang Ⅱ) were measured by ELISA. The expression of miR-1 and ET-1 mRNA was detected by real-time PCR, and the protein expression of p38 MAPK, β-myosin heavy chain (MHC) and α-MHC was determined by Western blot. RESULTS: Compared with model group, the ultrastructure of left ventricular myocardial tissues in high-dose leonurine group was attenuated, and the expression of miR-1 and the protein expression of α-MHC in left ventricular myocardial tissues of high-dose leonurine group were increased (P<0.05). Collagen volume fraction, collagen I, collagen Ⅲ, the ratio of collagen Ⅰ/collagen Ⅲ, the contents of ET-1 and Ang Ⅱ, the mRNA expression of ET-1, and the protein expression of p38 MAPK and β-MHC in high-dose leonurine group were lower than those in model group (P<0.05). CONCLUSION: Leonurine attenuates myocardial fibrosis in the rats induced by ISO, and it is potentially associated with affecting the expression of miR-1, and inhibiting ET-1/p38 MAPK signaling pathway.     

Role of TGF-β1/Smad signaling in angiotensin Ⅱ mediated down-regulation of connexin 43

AIM: To analyze the alterations of angiotensin Ⅱ (Ang Ⅱ), connexin 43 (Cx43), angiotenisin Ⅱ receptor type 1 (AT1) and signaling molecules in the TGF-β1/Smad pathway in different regions of the left ventricular heart tissue for exploring whether Ang Ⅱ regulates Cx43 expression via the TGF-β1/Smad signaling pathway in myocardial infarction (MI) rats. METHODS: MI was induced in 20 male Sprague-Dawley rats by the left anterior descending coronary artery ligation. The rats were then randomized into 2 groups. In the losartan group, 20 mg·kg^-1·d^-1 of losartan were administered for 2 weeks. Heart functions were assessed after surgery and 2 weeks later again following the above treatments. All the rats were sacrificed and relevant molecules, including Ang Ⅱ, AT1, and Cx43 were determined thereafter in diffe-rent areas of the left ventricle. TGF-β1 and its downstream signaling molecules, including Smad 2, Smad 3 and Smad 7, were also detected. RESULTS: In losartan group, both left ventricular internal dimension diastole (LVIDd) and left ventricular internal dimension systole (LVIDs) were smaller, with diminished interventricular septal thickness (IVSd) and left ventricular posterior wall depth (LVPWd) and distinct improvement of left ventricular ejection fraction (LVEF) (P<0.05). Losartan therapy exhibited a reduction of Ang Ⅱ in the infarct zone and the border zone in the cardiac tissues. AT1 was obviously attenuated in the infarct zone with an enhanced expression of Cx43, which was also elevated in the border zone and none infarct zone. TGF-β1, Smad 2 and Smad 3 were decreased in different zones of the left ventricle, while Smad 7, in contrary to the above factors, presented a converse alteration.CONCLUSION: The activation of Ang Ⅱ provokes downregulation of Cx43 through TGF-β1/Smad signaling pathway in MI rats.     

Rebamipide repairs injury of small intestinal epithelial barrier induced by aspirin in mice

AIM: To investigate whether rebamipide repairs the small intestinal epithelial barrier in aspirin-induced small intestinal injury (SⅡ) in mice and its mechanism.METHODS: Small intestinal injury was induced by aspirin (200 mg·kg^-1·d^-1 for 5 d) in BALB/c mice. Based on the treatment with aspirin and/or rebamipide (320 mg·kg^-1·d^-1), the mice were divided into 4 groups (n=18 in each group). The living mice in each group (n=6) were sacrificed via cervical dislocation method at day 0, day 5, and day 10. The structure and function of intestinal barrier and the levels of the signaling pathway factors were measured by transmission electron microscopy, immunohistochemistry, qPCR, and Western blot.RESULTS: Tight junctions between intestinal epithelial cells improved significantly after reba-mipide treatment. The expression of ZO-1 and occludin in the injured small intestine showed a gradually increasing trend after rebamipide administration (P<0.05). There was a decreased trend of D-lactate level in rebamipide-treated SⅡ mice (P<0.05). The expression of cyolooxygenase-2 (COX-2), β-catenin, and c-Myc, and prostaglandin E₂ concentration in small intestinal tissues were significantly increased in rebamipide treatment group (P<0.05). However, down-regulated COX-1 expression in the SⅡ mice was sustained at a low level after rebamipide administration.CONCLUSION: Rebami-pide repairs the injury of small intestinal mucosa and improves the structure and function of small intestinal barrier in aspirin-induced SⅡ mice by up-regulating the expression of COX-2.     

Role of bradykinin in the therapeutic effect of enalapril on left ventricular hypertrophy and cardiac function after myocardial infarction in rats

AIM:To investigate the influences of bradykinin(BK)on left ventricular hypertrophy and cardiac function in angiotensin-converting enzyme inhibitor(ACEI) therapy in rats after myocardial infarction.METHODS:The effects of enalapril (500 μg·kg^-1·d^-1), enalapril (500 μg·kg^-1·d^-1)with BKB₂ receptor antagonist (Hoe-140 500 μg·kg^-1·d^-1), losartan(3 mg·kg^-1·d^-1) on left ventricular end-diastolic pressure (LVEDP), maximum positive left ventricular pressure change (+dp/dt_max) and LVW/BW as well as V(m)n of noinfarcted area were examined after 4 weeks treatment in rats after myocardial infarction.RESULTS:The values of LVEDP, LVW/BW and V(m)n of three treatment groups were higher than that of untreated MI group (P＜0.05),but the +dp/dt_max of three treatment groups were not significantly different compared with the untreated MI group. In addition, no significant difference in MAP was observed among the three treatment groups, but the LVW/BW and V(m)n of enalapril+Hoe-140-treated group were higher than that of enalapril-treated group (P＜0.05) .CONCLUSION:Enalapril can prevent left ventricular hypertrophy and improve cardiac function independent of blood pressure after myocardial infarction, which is partly due to the inhibition of BK degradation.     

Renoprotective effect of L-carnitine on streptozotocin-induced diabetic nephropathy in rats

AIM: To investigate whether L-carnitine (LC) treatment confers renoprotection in a rat model of streptozotocin (STZ)-induced diabetic nephropathy (DN). METHODS: Diabetic animal model was established by intraperitoneal injection of STZ (65 mg/kg) in Sprague-Dawley rats. Diabetic rats were treated with LC (50 mg·kg^-1·d^-1 or 200 mg·kg^-1·d^-1 intravenously) daily for 12 weeks. The effects of LC on STZ-induced DN were evaluated by assessing renal function, urinary protein excretion, histopathological changes, macrophage infiltration, the expression of proinflammatory and prosclerotic cytokines, and the expression of nuclear factor-κB (NF-κB) and apoptosis-related gene. RESULTS: LC administration significantly decreased glomerulosclerosis, preserved the number of podocytes, and reduced macrophage infiltration. These changes were accompanied by improvements in urinary protein excretion and renal dysfunction. LC treatment suppressed the expression of proinflammatory and prosclerotic cytokines, and these changes were paralleled by significant attenuation of NF-κB and apoptosis-related gene expression. CONCLUSION: LC has a renoprotective effect against STZ-induced DN in rats.     

Cyclosporin A induces myocardial fibrosis and affects expression of matrix metalloproteinases and their inhibitors in rats

AIM: To investigate the changes of matrix metalloproteinases (MMP2 and MMP9) and tissue inhibitor of metalloproteinases (TIMP2 and TIMP1) in the myocardial fibrosis induced by cyclosporin A (CsA), and to explore the underlying mechanism. METHODS: Female Wistar rats (n=64, 6~8 weeks old) weighing (200±25) g were randomly divided into 4 groups[control, low dose of CsA (5 mg·kg^-1·d^-1), medium dose of CsA (12.5 mg·kg^-1·d^-1) and high dose of CsA (25 mg·kg^-1·d^-1)]. The rats were intraperitoneally injected with saline and different doses of CsA, respectively. CsA was continuously administered for 1, 2 and 3 weeks, and then the animals were killed to collect samples. HE staining was used to observe the morphological structure of myocardium. Masson staining was used to observe the deposition of myocardial collagen and the degree of myocardial fibrosis. The protein expression levels of MMP2, MMP9, TIMP2 and TIMP1 were determined by immunohistochemistry and Western blot. RESULTS: HE staining showed that CsA induced cardiomyocyte edema, eosinophilic changes in the cytoplasm, fine granular and vacuolar changes in cardiomyocytes, disappearance of myocardial striae, nuclear condensation, and myocardial focal necrosis and fibrosis. Masson staining showed that the degree of myocardial interstitial fibrosis was getting worse with the increase in the duration and doses of CsA exposure. The results of immunohistochemistry and Western blot showed that the expression of MMP2 in CsA groups was significantly increased in the process of CsA-induced myocardial fibrosis. In each CsA dose group, MMP2 was highly expressed at the first week, and the expression was gradually decreased over time. In contrast, the expression of TIMP2 was increased gradually in a time-and dose-dependent manner (P<0.05). Compared with control group, MMP9 expression level was low at the first week, increased at the second week, and decreased at the third week (P<0.05). Compared with control group, the expression of TIMP1 was dose-dependently increased (P<0.05). CONCLUSION: CsA induces myocardial injury and interstitial fibrosis in rats in a dose-and time-dependent manner. CsA-induced myocardial fibrosis is associated with changes of MMPs and TIMPs, and is affected by the imbalance of MMPs/TIMPs.     

Effects of flavonoids isolated from Scutellaria stem and leaf on expression of NMDAR and VEGF in chronic cerebral ischemia rats

AIM: To study the effects of flavonoids isolated from Scutellaria stem and leaf (SSF) on the expression of N-methyl-D-aspartate receptor (NMDAR) and vascular endothelial growth factor (VEGF) in chronic cerebral ischemia rats. METHODS: The model of chronic cerebral ischemia was established by bilateral carotid artery occlusion for 2 months in female SD rats. The effects of SSF on mRNA expression of NMDAR in hippocampus and VEGF in cerebral cortex were evaluated by the method of RT-PCR. RESULTS: Compared with the sham group, the expression of NMDAR1, NMDAR2A and NMDAR2B in hippocampus and VEGF in cerebral cortex were significantly increased (P<0.01). However, the cerebral ischemia rats daily and orally administered with SSF at doses of 17.5 mg·kg^-1·d^-1, 35 mg·kg^-1·d^-1 and 70 mg·kg^-1·d^-1 for 38 days appeared that the mRNA expression of NMDAR1, NMDAR2A and NMDAR2B in hippocampus was obviously reduced (P<0.05), and the mRNA content of VEGF in the cortex (P<0.05) was increased. CONCLUSION: SSF decreases the expression of NMDAR in hippocampus, increases the expression of VEGF in cerebral cortex of cerebral ischemia rats, suggesting that the neuroprotective effect of SSF may be exerted by influencing the production of NMDAR and VEGF in the brain.     

Effects of Zuogui pill-medicated serum on proliferation and differentiation of MC3T3-E1 cells via ERK/TGF-β/Smads signaling cascade

AIM:To study the effects of Zuogui pill(ZG)-medicated serum on the proliferation and differentiation of MC3T3-E1 cells via ERK/TGF-β/Smads signaling pathway. METHODS:Using Premarin(conjugated estrogens tablets) as a positive control, the SD female rats were fed with high-, medium- or low-dose of ZG suspension. ZG-medicated serum was separated from abdominal aortic blood 7 d after feeding of ZG. MTT assay was applied to test the effect of ZG-medicated serum on the viability of MC3T3-E1 cells. The production of alkaline phosphatase(ALP) was detected by a modified calcium and cobalt dyeing method. The calcified nodules were observed by the method of alizarin red staining. The levels of core binding factor α1(Cbfα1) and collagen type I(Col I) protein were analyzed by Western blotting. The mRNA expression of TGF-β₁, Smad4 and Smad2 was measured by real-time RT-PCR. RESULTS:ZG-medicated serum promoted the proliferation of MC3T3-E1 cells in a dose-and time-dependent manner. Compared with other groups, treatment with 15% ZG(low dose) for 48 h increased the proliferation of MC3T3-E1 cells significantly. The protein levels of ALP, Cbfα1 and Col I,the calcified nodules, and the mRNA expression of TGF-β₁, Smad4 and Smad2 in MC3T3-E1 cells were all significantly increased after treatment with ZG-medicated serum. After the addition of PD98059(a specific blocker of ERK1/2 signaling pathway), all those were down-regulated except for mRNA expression of TGF-β₁. CONCLUSION:ZG regulates MC3T3-E1 cell proliferation and differentiation via the intervention of ERK/TGF-β/Smads signaling cascade, which may be one of the mechanisms that ZG effectively prevents and treats osteoporosis.     

Effects of ginsenoside Rh1 on expression of inflammatory factors in mouse asthma model

AIM: To observe the effects of ginsenoside Rh1 on the levels of inflammatory factors in serum and bronchoalveolar lavage fluid (BALF), and the pathological changes of the lung tissues in an experimentally induced mouse asthma model. METHODS: Male BALB/c mice (n=40) were divided into 4 groups:normal control group, asthma mo-del group, and low-dose (40 mg·kg^-1·d^-1) and high-dose (80 mg·kg^-1·d^-1) ginsenoside Rh1 groups. The bronchial asthma mouse model was established by the method of ovalbumin induction and excitation, and during the excitation period, the mice were daily treated with ginsenoside Rh1 for 2 weeks. At 24 h after the final dose of ginsenoside Rh1, the mice were sacrificed. The number of eosinophils (EOS) and the concentrations of interleukin (IL)-4, IL-5 and interferon (IFN)-γ in BALF were determined. The levels of IgG and IgE in serum were measured, and the expression of transforming growth factor (TGF)-β1 and the pathological changes in lung tissues were evaluated. RESULTS: Ginsenoside Rh1 inhibited the increases in the number of EOS and the concentrations of IL-4, IL-5, IFN-γ and IgE, reversed the increased expression of TGF-β1, and improved the pathological changes of the lung tissues in asthmatic mice. CONCLUSION: Ginsenoside Rh1 improves the immuno-inflammatory profile and pathological changes in the experimentally induced mouse asthma model, implying its potential therapeutic effect on asthma.     

Effect of rosuvastatin combined with irbesartan on remodeling of myocardial hypertrophy in rats

AIM: To evaluate the effect of rosuvastatin combined with irbesartan on the remodeling of myocardial hypertrophy in the rats. METHODS: Male SD rats(n=50) were randomly divided into control group, model group, rosuvastatin group, irbesartan group and combination group. The model of myocardial hypertrophy was established by subcutaneous injection of isoproterenol at dose of 2.5 mg/kg for 14 d. From the first day of modeling, the rats in control group and model group received intragastrical saline, and the rats in rosuvastatin group, irbesartan group and combination group were treated with rosuvastatin(4 mg·kg^-1·d^-1), irbesartan(15 mg·kg^-1·d^-1) and rosuvastatin(4 mg·kg^-1·d^-1)+ irbesartan(15 mg·kg^-1·d^-1), respectively. The interventions continued for 4 weeks. After the interventions, the cardiac mass index and left ventricular mass index of the SD rats were measured. Besides, the degree of myocardial hypertrophy was observed with HE staining. The mRNA expression of hypertrophy-related factors, such as ANF, β-MHC and AT1R was determined by RT-PCR, and the protein expression of AT1R was determined by Western blot. RESULTS: Compared with control group, the cardiac mass index, left ventricular mass index, as well as the mRNA expression of ANF and β-MHC in model group were significantly increased(P<0.05). Compared with model group, the above factors in rosuvastatin group and irbesartan group were decreased(P<0.05), and the factors in combination group were lower than those in rosuvastatin group and irbesartan group(P<0.05). In addition, the expression of AT1R at mRNA and protein levels in rosuvastatin group and irbesartan group was lower than that in model group(P<0.05), while the expression AT1R at mRNA and protein levels in combination group was lower than that in rosuvastatin group and irbesartan group(P<0.05). CONCLUSION: Rosuvastatin and irbesartan are equally effective drugs to resist the formation of myocardial hypertrophy by decreasing the expression of AT1R. Moreover, combination of the 2 drugs is more effective to improve the degree of myocardial hypertrophy than the 2 drugs alone.     

Effects of folic acid on antioxidant enzyme,nitric oxide synthase and nitric oxide in ovariectomized rats

AIM: To observe the effects of folic acid (FA) on antioxidant enzyme, nitric oxide synthase (NOS) and nitric oxide (NO) in ovariectomized (OVX) rats.METHODS: Forty three-month-old female SD rats were randomly divided into 5 groups: sham group, OVX group, diethylstilbestrol group (0.03 mg·kg^-1·d^-1), low-dose FA group (5 mg·kg^-1·d^-1) and high-dose FA group (20 mg·kg^-1·d^-1). Gastric gavage started 1 week after operation and lasted for 10 weeks. The rats in sham group and OVX group were given distilled water instead of FA as controls. At the end of the 10th week, the L₅ vertebra and right femur were removed for determination of bone mineral density (BMD). The bone homogenates were made using the L₃ and L₄ vertebrae. The levels of the total antioxidant capacity (TAC), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), NOS and NO were detected in plasma and bone homogenates.RESULTS: Compared with sham group, the BMD levels in L₅ vertebra and right femur and the levels of GSH-Px and NO in the plasma were all decreased. The levels of TAC, GSH-Px, NOS and NO in the bone homogenates were also decreased, while the MDA concentration was increased in OVX group (all P < 0.01). Compared with OVX group, the levels of TAC, GSH-Px, NOS, NO and BMD of the L₅ vertebra and right femur were all increased, while the MDA concentration was decreased in high-dose FA group (all P < 0.01). CONCLUSION: In female SD rats, ovariectomy leads to a significant reduction of antioxidant enzyme, NOS and NO levels. Oxidative stress is possibly involved in the development of osteoporosis. Protection against osteoporosis by high-dose FA may be linked to improvement of antioxidant enzyme activity, the levels of NOS and NO as well as a reduction of oxidative stress in ovariectomized rats.     

Effects of metformin on pressure overload-induced cardiac hypertrophy in rats

AIM: To study the effects of metformin on the pressure overload-induced cardiac hypertrophy in rats. METHODS: Transverse aortic constriction (TAC) model of rat was made through laparotomy. One week after TAC surgery, the rats were randomly divided into 5 groups (n=8 in each group) and were administered with the corresponding drugs orally every day for 8 weeks: sham group (sham surgery, administered with 2 mL distilled water); TAC group (TAC rats, administered with 2 mL distilled water); metformin (MET) group (TAC rats, administered with MET at dose of 300 mg·kg^-1·d^-1); MN group [TAC rats, administered with MET at dose of 300 mg·kg^-1·d^-1 plus NOS inhibitor, N^G-nitro-L-arginine methyl ester (L-NAME) 50 mg·kg^-1·d^-1] and L-NAME group (TAC rats, administered with L-NAME at dose of 50 mg·kg^-1·d^-1). After treated for 8 weeks, the echocardiography, hemodynamics, the ratio of heart weight to body weight (HW/BW) and histological examination of the heart were performed. The levels of myocardial AMP-activated protein kinase subunit α (AMPKα), p-AMPKα Thr172, endothelial nitric oxide synthase (eNOS) and p-eNOS Ser1177 were detected by Western blotting. Plasma and myocardial nitric oxide (NO) were detected biochemically. RESULTS: After 8 weeks treatment, the wall thickness of left ventricle, the heart weight/body weight ratio (HW/BW), and the left ventricular myocardial perivascular fibrosis and myocardial interstitial fibrosis of the animals in TAC group were significantly increased as compared to those in sham rats. Treatment with MET for 8 weeks significantly attenuated left ventricular hypertrophy and improved cardiac function in TAC rats. These effects of MET were mostly abolished by L-NAME. Molecular biology and biochemical testing revealed that the levels of left ventricular myocardial p-AMPKα Thr172 and p-eNOS Ser1177, as well as the levels of myocardial and serum NO were significantly increased in MET group. CONCLUSION: Long-term MET treatment significantly inhibits the cardiac hypertrophy and the myocardial fibrosis and improves the cardiac functions in pressure-overload rats. The anti-hypertrophic effects of MET may be mediated via activation of AMPK-eNOS signaling pathway.     

VPA alleviates bleomycin-induced pulmonary fibrosis in rats

AIM: To investigate the effect of sodium valproate (VPA) on bleomycin-induced pulmonary fibrosis (PF) and its mechanism. METHODS: SD rats (n=42) were randomly divided into model group and treatment group. Bleomycin at dose of 5 mg/kg was intratracheally injected to establish a rat PF model. The rats in treatment group were given normal saline (NS, 0.5 mL/d), VPA (300 mg·kg^-1·d^-1) or dexamethasone (DEX, 0.6 mg·kg^-1·d^-1) via intraperitoneal injection from the 14th day to the 28th day after modeling. The rats in model group were sacrificed on 0 d, 14 day and 28 d after modeling . The rats in treatment group were killed at 14th day after treatment. The effects of VPA on PF were evaluated by HE and Masson staining. The hydroxyproline (HYP) content in the rat lung tissues was detected, and the expression of α-smooth muscle actin (α-SMA) and E-cadherin was determined by Western blotting. RESULTS: HE staining showed that the alveolar structure and interstitial morphology in VPA group were better than those in NS group and DEX group. The level of collagen in VPA group was significantly lower than that in DEX group and NS group by determining the HYP content and Masson staining. VPA reduced the expression of α-SMA, a mesenchymal marker protein of PF, while increased the expression of epithelial marker protein E-cadherin. CONCLUSION: VPA reduces collagen content and distribution, and up-regulates the expression of the epithelial marker protein E-cadherin, while down-regulates mesenchymal marker protein α-SMA, thereby preventing the rat lung tissues from bleomycin-induced PF.     

Effects of grape seed procyanidin on vascular remodeling in renovascular hypertensive rats

AIM: To study the effect of grape seed procyanidin (GSP) on vascular remodeling in renovascular hypertensive (RH) rats. METHODS: The RH rat model was established by two-kidney one-clip method. Two weeks after operation, 28 rats were selected according to the increased tail systolic pressure above 130 mmHg and randomly divided into 4 groups (n=7): RH model group, low GSP treatment group (50 mg·kg^-1·d^-1),high GSP treatment group (200 mg·kg^-1·d^-1) and captopril treatment group (30 mg·kg^-1·d^-1). Meanwhile, 7 rats with sham operation served as controls. Tail systolic pressure, medial thickness (MT), luminal diameter (LD), and the ratio of MT to LD in thoracic aortic wall were determined 6 weeks after treatment. Masson staining and ELISA were used to detect the content of collagen and angiotensin II (Ang II) in aortic tissues. The protein expression of tumor necrosis factor α (TNF-α) in abdominal aortic tissues was determined by Western blotting. RESULTS: Compared with control group, the tail systolic pressure, MT, MT/LD, the content of collagen and the protein expression of TNF-α in aorta were significantly increased in RH model group, but LD decreased. Treatment with GSP and captopril reduced the raised parameters, and increased the LD in RH model rats. These effects were more notable in high GSP treatment group, and equal to captopril treatment group. CONCLUSION: GSP treatment significantly decreases tail systolic pressure in RH rats, and effectively attenuates arterial vascular remodeling by decreasing the content of AngII and reducing the protein expression of TNF-α in aorta.     

Effects of valsartan alone or in combination with benazepril on blood pressure and left ventricular hypertrophy in spontaneously hypertensive rats

AIM:To evaluate the effects of different doses of valsartan alone or with concomitant be-nazepril on blood pressure,left ventricular hypertrophy,RAASfunction and endoxi nlevel in spontaneously hy-pertensive rats(SHR).METHODS:Thirty SHR(fourteen-week-old,male)were divi ded into five groups(six rats in each group):SHR control group:fed with normal saline;benazepril group:fed with 1 mg·kg^-1·d^-1benazepril);low dose valsartan group:fed with 8 mg·kg^-1·d^-1valsartan;high dose valsartan group:fed with 24 mg·kg^-1·d^-1valsartan;combination drug therapy group:fed with valsartan(8 mg·kg^-1·d^-1)and benazepril(1 mg·kg^-1·d^-1),all for 8 weeks.WKY control group(n=6):fed with normal saline for 8 weeks.RESULTS:SBP,LVM/BW,TDMof SHR were remarkably lower than those of control after drug i n-tervene,and effect on SBP was most remarkable in high dose valsartan group and i nthe combi nation drug ther-apy group;effect on LVM/BW,TDM were most remarkable in combination drug therapy group.Renin activi-ties in plasma and myocardiumwere remarkably i ncreased in drug i ntervene groups.The levels of AngⅡi nplasma and myocardiumwere remarkably increased in two different dose of valsartan treati ng group,and thelarger dose of valsartan were,the higher levels of AngⅡin plasma and myocardium were;decreased in be-nazepril treati ng group and combination drug therapy group.Na⁺-K⁺-ATPase activities in myocardi umwere remarkably i ncreased and the level of endoxi n i n myocardium were remarkably decreased as SBP de-creased after drug intervene.CONCLUSION:Different dose of valsartan alone or combi ned with benazeprilcan decrease SBP of SHR,have the effect of inhibiti ng progression of ventricular hypertrophy.The effect ofcombination drug therapy group was most remarkable among five groups and can avoi d the si de effect of highAngⅡin plasma and myocardiumduri ng long-termuse of valsartan alone.     

Effects of metformin combined with Ge Xia Zhu Yu decoction on TLR4/NF-κB signaling pathway in rats with polycystic ovary and insulin resis-tance

AIM: To study the effect of metformin (Met) combinated with Ge Xia Zhu Yu decoction on Toll-like receptor-4 (TLR-4)/nuclear factor-κB (NF-κB) signaling pathway in the rats with polycystic ovary syndrome (PCOS) and insulin resistance induced by dehydroepiandrosterone, and to explore the mechanisms. METHODS: PCOS rats (after induced by dehydroepiandrosterone, n=110) were randomly divided into 3 groups:model group (30 rats), Met treatment group (40 rats) and Met combinated with Ge Xia Zhu Yu decoction treatment (combination) group (40 rats). The rats in model group were given the same volume of 0.9% sodium chloride daily by gavage. The rats in Met group were given Met (270 mg·kg^-1·d^-1) by gavage. The rats in combination group were given Met (270 mg·kg^-1·d^-1) and Ge Xia Zhu Yu decoction (34.5 mg·kg^-1·d^-1) by gavage. All rats were continuously intervened for 28 d. After the intervention, blood glucose[fasting plasma glucose (FPG) and 2-hour postprandial blood glucose (2hPBG)] was measured. The mRNA expression levels of follicular epithelial NF-κB, TLR-4 and oxidized low-density lipoprotein (ox-LDL) were detected by RT-PCR. The serum levels of inflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) were also detected by ELISA. RESULTS: After the intervention, FPG, 2hPBG, and serum levels of IL-6, TNF-α and CRP in Met group and combination group were lower than those in model group (P<0.05), and those in combination group were lower than those in Met group (P<0.05). Meanwhile, the mRNA expression levels of follicular epithelial NF-κB, TLR-4 and ox-LDL in Met group and combination group were lower than those in model group (P<0.05), and those in combination group were lower than those in Met group (P<0.05). CONCLUSION: Treatment with Met combined with Ge Xia Zhu Yu decoction improves insulin resistance in PCOS rats by decreasing the levels of inflammatory factors in serum and epithelial cells of ovary and inhibiting the expression of NF-κB, TLR-4 and ox-LDL in epithelial tissue of ovary.     

Effects of PI3K/PKB signaling pathway on expression of osteopontin in human hepatic stellate cells induced by transforming growth factor-β1

AIM: To investigate the regulatory effects of phosphatylinositol 3-kinase/protein kinase B (PI3K/PKB) signaling pathway on the expression of osteopontin (OPN) in transforming growth factor-β₁ (TGF-β₁)-induced human hepatic stellate cells. METHODS: Human hepatic stellate cell line LX-2 was cultured in DMEM and stimulated by TGF-β₁ at the final concentration of 2.5, 5, 10 and 20 μg/L for 24 h or at final concentration of 10 μg/L for 12 h, 24 h and 48 h. LX-2 cells were pretreated with wortmannin, a specific inhibitor of PI3K/PKB signaling pathway, at final concentration of 0.1 μmol/L for 1 h, followed by incubation with TGF-β₁ at final concentration of 10 μg/L for 24 h. The cells were collected. The expression of OPN was detected by real-time PCR and Western blotting. RESULTS: In LX-2 cells, the expression of OPN was apparently elevated when incubated with TGF-β₁. With the increase in TGF-β₁ concentration or the extension of incubation hours, the expression of OPN was increased gradually in a dose-and time-dependent manner with certain limits. LX-2 cells pretreated with wortmannin and incubated with TGF-β₁ had a significant decrease in the OPN expression as compared with control group (P<0.01). CONCLUSION: The expression of OPN in TGF-β₁-induced LX-2 cells is regulated by the PI3K/PKB signaling pathway.     

Effect of methylene blue on T-lymphocyte subsets and oxidative stress in rat thymus with paraquat poisoning

AIM: To illustrate the effect of methylene blue(MB) on T-lymphocyte subsets and oxidative stress of the thymus in rats with paraquat(PQ) poisoning.METHODS: Male SD rats(n=40) were randomly assigned to 4 groups: normal group, control group, low-dose(2 mg·kg^-1·d^-1) MB group and high-dose(4 mg·kg^-1·d^-1) MB group. After 72 h, the pathological morphological changes of the thymus were observed under microscope with HE staining. The SOD activity and MDA content were measured by colorimetry method. The expression of Bcl-2, Bax, CD4 and CD8 was determined by immunohistochemical method.RESULTS: In MB group, the thymus tissue showed good corticomedullary demarcation. MDA content decreased and SOD activity increased, indicating that the ability of antioxidation enhanced. Bcl-2 and Bax expression was down-regulated, Bcl-2/Bax ratio increased, and CD4 positive cells increased.CONCLUSION: MB protects against oxidative damage induced by PQ, and regulates the distribution of T-lymphocyte subsets in the cortex and medulla, thus relieving the persistent body damage.