The effects of Radix Angelica Sinensis and Radix Hedysari ultrafiltration extract on X-irradiation-induced myocardial fibrosis in rats.

Radix Angelica Sinensis and Radix Hedysari are traditional Chinese medicines that are used for preventing and treating various diseases. This study aimed to investigate the effect and possible underlying mechanisms of Radix Angelica Sinensis and Radix Hedysari ultrafiltration extract (RAS-RH) on X-irradiation-induced cardiac fibrosis in rats. Our data demonstrated that (a) a single dose of total body irradiation (TBI) at 8 Gy resulted in cardiac fibrosis, whereas the control hearts exhibited less collagen and fibrosis. RAS-RH mitigated these morphological injuries. (b) TBI resulted in an increase in the serum levels of transforming growth factor ß1 (TGF-ß1) and troponin-I (TnI). RAS-RH inhibited the release of TBI-induced serum TGF-ß1 and the TnI levels. (c) TBI inhibited the apoptosis of primary rat cardiac fibroblasts, whereas RAS-RH induced the apoptosis of primary rat cardiac fibroblasts after X- irradiation. (d) TBI resulted in an increase in the expression of osteopontin (OPN), c-fos, c-jun, miRNA-21 and collagen1α (COL1α) in primary rat cardiac fibroblasts, and RAS-RH mitigated the TBI-induced increased expression of OPN, c-jun, miRNA-21 and COL1α. In conclusion, these results demonstrate that RAS-RH exerts antifibrotic effects possibly through inducing the apoptosis of fibroblasts, inhibiting the release of serum TGF-ß1, reducing the levels of serum TnI and reducing the expression of OPN, c-jun, miRNA-21 and COL1α. Therefore, RAS-RH may potentially be developed as a medical countermeasure for the mitigation of radiation-induced myocardial fibrosis.

Astragalosideâ £ against cardiac fibrosis by inhibiting TRPM7 channel.

BACKGROUND: Astragaloside Ⅳ (ASG-Ⅳ, (Fig. 1) is the most active component of Chinese sp. Astragalus membranaceus Bunge (Fabaceae) that has showed antioxidant, antiapoptotic and antiviral activities among others. It is reported to play an important role in cardiac fibrosis (CF), but the mechanism remains unclear. PURPOSE: To investigate the mechanism of ASG-Ⅳ on inhibiting myocardial fibrosis induced by hypoxia. STUDY DESIGN: We studied the relationship between anti-fibrotic effect of ASG-Ⅳ and transient receptor potential cation channel, subfamily M, member 7 (TRPM7) by in vivo and in vitro experiments. METHODS: In vivo, CF was induced by subcutaneous isoproterenol (ISO) for 10 days. Rat hearts were resected for histological experiment and reverse transcription real-time quantitative poly merase chain reaction (RT-qPCR). In vitro, molecular and cellular biology technologies were used to confirm the anti-fibrosis effect underlying mechanism of ASG-Ⅳ. RESULTS: Histological findings and the collagen volume fraction showed that ASG-Ⅳ decreased fibrosis in heart tissues. Hypoxia could stimulate the proliferation and differentiation of cardiac fibroblast which indicated that the degree of fibrosis was increased significantly. Anoxic treatment could also obviously up-regulate the expression of TRPM7 protein and current. ASG-Ⅳ groups showed the opposite results. Knock-down TRPM7 experiment further confirmed the role of TRPM7 channel in hypoxia-induced cardiac fibrosis. CONCLUSION: Our results suggest that the inhibition of hypoxia-induced CF in vivo and in vitro by ASG-IV is associated with reduction of the expression of TRPM7. The moderate inhibition of the TRPM7 channel may be a new strategy for treating cardiac fibrosis.

Ameliorative effects of Xue-Fu-Zhu-Yu decoction, Tian-Ma-Gou-Teng-Yin and Wen-Dan decoction on myocardial fibrosis in a hypertensive rat mode.

BACKGROUND: Xue-Fu-Zhu-Yu decoction (XFZYD), Tian-Ma-Gou-Teng-Yin (TMGTY) and Wen-Dan decoction (WDD) are Chinese herbal formulas used to treat hypertension and cardiovascular diseases in traditional Chinese medicine (TCM). The goal of our study is to determine if XFZYD, TMGTY or WDD treatment ameliorated myocardial fibrosis in spontaneously hypertensive rats (SHRs) and to identify the mechanisms underlying any beneficial effects observed during the courses of the investigation. METHODS: Forty-five 12-week-old male spontaneously hypertensive rats and five age-matched male Wistar-Kyoto control rats were studied for 16 weeks. Each day 6 g∙kg(-1) or 12 g∙kg(-1) of XFZYD, TMGTY or WDD was orally administered at the indicated dose, and the systolic blood pressure (SBP) of all rats was measured using the tail-cuff method. Collagen levels were measured via hydroxyproline content assays and histological examination. Transforming growth factor beta-1 (TGF-ß1) protein levels were determined via immunhistochemical and Western blot analysis. TGF-ß1 mRNA levels were assessed using real-time reverse transcription polymerase chain reaction. RESULTS: Systolic blood pressure was unaffected, but collagen and TGF-ß1 levels in SHRs treated with captopril and XFZYD (12 g∙kg(-1)) were significantly reduced when compared with untreated control SHRs. Administration of 12 g∙kg(-1) XFZYD increased myocardial cell protection and decreased TGF-ß1 mRNA and protein expression when compared with the other SHR treatment groups. CONCLUSIONS: XFZYD treatment demonstrated a superior ability to reverse myocardial fibrosis when compared with WDD or TMGTY treatment in SHRs. XFZYD also decreased TGF-ß1 mRNA and protein expression, suggesting that the TGF-ß1 signaling pathway plays a role in the therapeutic effects of XFZYD treatment.

Continuing treatment with Salvia miltiorrhiza injection attenuates myocardial fibrosis in chronic iron-overloaded mice.

Iron overload cardiomyopathy results from iron accumulation in the myocardium that is closely linked to iron-mediated myocardial fibrosis. Salvia miltiorrhiza (SM, also known as Danshen), a traditional Chinese medicinal herb, has been widely used for hundreds of years to treat cardiovascular diseases. Here, we investigated the effect and potential mechanism of SM on myocardial fibrosis induced by chronic iron overload (CIO) in mice. Kunming male mice (8 weeks old) were randomized to six groups of 10 animals each: control (CONT), CIO, low-dose SM (L-SM), high-dose SM (H-SM), verapamil (VRP) and deferoxamine (DFO) groups. Normal saline was injected in the CONT group. Mice in the other five groups were treated with iron dextran at 50 mg/kg per day intraperitoneally for 7 weeks, and those in the latter four groups also received corresponding daily treatments, including 3 g/kg or 6 g/kg of SM, 100 mg/kg of VRP, or 100 mg/kg of DFO. The iron deposition was estimated histologically using Prussian blue staining. Myocardial fibrosis was determined by Masson's trichrome staining and hydroxyproline (Hyp) quantitative assay. Superoxide dismutase (SOD) activity, malondialdehyde (MDA) content and protein expression levels of type I collagen (COL I), type I collagen (COL III), transforming growth factor-ß1 (TGF-ß1) and matrix metalloproteinase-9 (MMP-9) were analyzed to investigate the mechanisms underlying the effects of SM against iron-overloaded fibrosis. Treatment of chronic iron-overloaded mice with SM dose-dependently reduced iron deposition levels, fibrotic area percentage, Hyp content, expression levels of COL I and COL III, as well as upregulated the expression of TGF- ß1 and MMP-9 proteins in the heart. Moreover, SM treatment decreased MDA content and increased SOD activity. In conclusion, SM exerted activities against cardiac fibrosis induced by CIO, which may be attributed to its inhibition of iron deposition, as well as collagen metabolism and oxidative stress.

[Intervention effect of quercetin on inflammatory secretion of cardiac fibroblasts].

To establish neonatal rat cardiac fibroblast inflammatory secretion model by using LPS 100 microg x L(-1) combined with ATP 5 mmol x L(-1), in order to study the inhibitory effect of quercetin on the secretion of inflammatory factors TNF-alpha, IL-1beta and IL-6 of cardiac fibroblasts, further investigate the effect of quercetin on the protein expression of p-NF-kappaB p65 (S276) and p-Akt (S473) by western blot, and discuss the inhibitory effect of quercetin on the inflammatory secretion of cardiac fibroblasts. According to the findings, quercetin with the concentrations between 51.74 micromol x L(-1) and 827.81 micromol x L(-1) had no significant effect on the activity of cardiac fibroblasts. Quercetin with the concentrations of 82.78, 41.39, 20.70 micromol x L(-1) could notably inhibit the increase of TNF-alpha and IL-1beta induced by LPS 100 microg x L(-1) for 3 h and then ATP 5 mmol x L(-1) for 36 h (P < 0.01 or P < 0.05). Quercetin with the concentrations of 82.78, 41.39 micromol x L(-1) could notably inhibit the increase of IL-6 induced LPS 100 microg x L(-1) for 3 h and then ATP 5 mmol x L(-1) for 36 h (P < 0.05), without any notable effect of quercetin with the concentration of 20.70 micromol x L(-1). Quercetin with the concentrations of 82.78, 41.39, 20. 70 micromol x L(-1) could notably inhibit the NF-kappaB p65 (S276) activation induced by LPS 100 microg x L(-1) for 3 h and then ATP 5 mmol x L(-1) for 15 min, with the most significant effect in 20.70 micromol x L(-1). Quercetin with the concentrations of 82.78, 41.39, 20.70 micromol x L(-1) could notably inhibit the increase of p-Akt(473) expression induced by LPS 100 microg x L(-1) for 3 h and then ATP 5 mmol x L(-1) for 240 min (P < 0.05). Therefore, this study believes that quercetin could attenuate the secretion of inflammatory factors TNF-alpha, IL-1beta and IL-6 of cardiac fibroblasts by inhibiting the activation of NF-kappaB p65 (S276) and Akt (473).

[Inhibitory effect and mechanism of procyanidin from vaccinium on isoprenaline-induced myocardial fibrosis in rats].

OBJECTIVE: To detect the effect and mechanism of procyanidin foom vaccinium (PC) on myocardial fibrosis in rats. METHOD: The myocardial fibrosis model in rats was built by subcutaneous injection of 5 mg x kg(-1) x d(-1) of isoprenaline (Iso) for 7 days in vivo while intragastrically administrating PC 100, 200 and 400 mg x kg(-1) x d(-1) for 14 days. Following the model was established, myocardial indexes (heart weight/body weight, HW/BW and left ventricalar weight/body weight, LVW/BW) were measured. Besides, angiotensin II and I , III collagen quantification levels in blood serum were determined respectively by ELISA. The change in the content of nitric oxide (NO) in blood serum was determined with colorimetry. The content of malondialdehyde (MDA) in left ventricle was assayed with spectrophotometry. The contents of lactate dehydrogenase (LDH) and creatine kinase (CK) in blood serum were detected with automatic biochemistry analyzer. RESULT: Compared with the control group, the myocardial indexes, the contents of I , III collagen quantification, angiotensin II in blood serum and malondialdehyde in left ventricle were markedly increased and the content of nitric oxide in blood serum was decreased, the contents of lactate dehydrogenase and creatine kinase in blood serum were markedly increased in Iso model group (P<0.05 or P<0.01). Compared with the model group, the myocardial indexes were decreased, the contents of I , III collagen quantification, angiotensin II in blood serum were reduced in PC 200 and 400 mg x kg(-1) x d(-1) groups (P<0.05 or P<0.01). The content of nitric oxide in blood serum was increased, the content of malondialdehyde in left ventricle was markedly decreased, the contents of lactate dehydrogenase and creatine kinase in blood serum were markedly decreased in PC three groups (P<0.05 or P<0.01). CONCLUSION: PC could inhibit collagen synthesis by decreasing angiotensin II level and increasing the content of nitric oxide and antioxidation, and thereby inhibiting myocardial fibrosis and protect myocardium in rats.

Cardoguard, an Ayurvedic antihypertensive formulation, prevents cardiac remodeling in spontaneously hypertensive rats by inhibition of ERK and PKCε signaling pathways.

Ayurveda is an Indian system of medicine. Despite clinical efficacy, lack of scientific validation has limited the effective use of Ayurvedic drugs. Cardoguard is an Ayurvedic antihypertensive drug formulated by Nagarjuna Herbal Concentrates Ltd., Kerala, India. Left ventricular hypertrophy (LVH) is a modifiable risk factor, and regression of LVH reduces the propensity for adverse cardiovascular events. This study was taken up with the objective of evaluating the efficacy of Cardoguard in the prevention of cardiac remodeling. Cardoguard was administered orally to 2-month-old spontaneously hypertensive rats for 4 months at a dose of 5 mg·day(-1). The dose corresponds to the therapeutic dose calculated on the basis of body surface area. Lower hypertrophy index, decrease in cardiomyocyte area, and reduction of interstitial fibrosis in treated spontaneously hypertensive rats indicate amelioration of cardiac hypertrophy by Cardoguard. Cardiac output increased in response to treatment. Immunostaining for the phosphorylated components of major signaling pathways associated with hypertrophy suggests that prevention of LVH by Cardoguard is possibly mediated through inhibition of extracellular signal-regulated kinases and protein kinase C-ε signaling pathways. Reduced expression of 3-nitrotyrosine in response to the treatment suggests that prevention of cardiac remodeling by Cardoguard is mediated by reduction of oxidative stress.

Coenzyme Q10 attenuates diastolic dysfunction, cardiomyocyte hypertrophy and cardiac fibrosis in the db/db mouse model of type 2 diabetes.

AIMS/HYPOTHESIS: An increase in the production of reactive oxygen species is commonly thought to contribute to the development of diabetic cardiomyopathy. This study aimed to assess whether administration of the antioxidant coenzyme Q(10) would protect the diabetic heart against dysfunction and remodelling, using the db/db mouse model of type 2 diabetes. Furthermore, we aimed to compare the efficacy of coenzyme Q(10) to that of the ACE inhibitor ramipril. METHODS: Six-week-old non-diabetic db/+ mice and diabetic db/db mice received either normal drinking water or water supplemented with coenzyme Q(10) for 10 weeks. Endpoint cardiac function was assessed by echocardiography and catheterisation. Ventricular tissue was collected for histology, gene expression and protein analysis. RESULTS: Untreated db/db diabetic mice exhibited hyperglycaemia, accompanied by diastolic dysfunction and adverse structural remodelling, including cardiomyocyte hypertrophy, myocardial fibrosis and increased apoptosis. Systemic lipid peroxidation and myocardial superoxide generation were also elevated in db/db mice. Coenzyme Q(10) and ramipril treatment reduced superoxide generation, ameliorated diastolic dysfunction and reduced cardiomyocyte hypertrophy and fibrosis in db/db mice. Phosphorylation of Akt, although depressed in untreated db/db mice, was restored with coenzyme Q(10) administration. We postulate that preservation of cardioprotective Akt signalling may be a mechanism by which coenzyme Q(10)-treated db/db mice are protected from pathological cardiac hypertrophy. CONCLUSIONS/INTERPRETATION: These data demonstrate that coenzyme Q(10) attenuates oxidative stress and left ventricular diastolic dysfunction and remodelling in the diabetic heart. Addition of coenzyme Q(10) to the current therapy used in diabetic patients with diastolic dysfunction warrants further investigation.

Salutary effects of Corydalis yanhusuo extract on cardiac hypertrophy due to pressure overload in rats.

We have evaluated the effects of an alcohol extract from the rhizome of Corydalis yanhusuo W. T. (CY), a well-known traditional Chinese medicinal herb, on pressure-overloaded cardiac hypertrophy induced by transverse abdominal aorta constriction (TAAC) in rats. Rats were given vehicle or CY extract (200 or 50 mg kg(-1) per day) from the second week after induction of pressure overload, for a period of 7 weeks. Haemodynamic parameters, relative heart weight and myocyte cross-sectional area were measured in each group. We also estimated left ventricular (LV) collagen volume fraction (CVF) using Masson trichrome staining, and type I collagen expression by Western blot assay. Chronic TAAC caused notable cardiac hypertrophy and heart dysfunction. Significant collagen deposition and greater type I collagen expression were found in model control rats. These changes were not significantly reversed after treatment with 50 mg kg(-1) CY, whereas 200 mgkg(-1) significantly improved heart function and prevented cardiac hypertrophy, with parallel reductions in myocardial fibrosis, as evidenced by reduced LV CVF and reduced levels of type I collagen. In conclusion, chronic treatment of rats with CY extract attenuated development of cardiac hypertrophy.

Salacia oblonga improves cardiac fibrosis and inhibits postprandial hyperglycemia in obese Zucker rats.

Diabetes has a markedly greater incidence of cardiovascular disease than the non-diabetic population. The heart shows a slowly developing increase in fibrosis in diabetes. Extended cardiac fibrosis results in increased myocardial stiffness, causing ventricular dysfunction and, ultimately, heart failure. Reversal of fibrosis may improve organ function survival. Postprandial hyperglycemia plays an important role in the development of type 2 diabetes and cardiovascular complications, and has been proposed as an independent risk factor for cardiovascular diseases. Salacia oblonga (S.O.) is traditionally used in the prevention and treatment of diabetes. We investigated the effects of its water extract on cardiac fibrosis and hyperglycemia in a genetic model of type 2 diabetes, the obese Zucker rat (OZR). Chronic administration of the extract markedly improved interstitial and perivascular fibrosis in the hearts of the OZR. It also reduced plasma glucose levels in non-fasted OZR, whereas it had little effect in the fasted animals, suggesting inhibition of postprandial hyperglycemia in type 2 diabetic animals, which might play a role in improvement of the cardiac complications of OZR. Furthermore, S.O. markedly suppressed the overexpression of mRNAs encoding transforming growth factor betas 1 and 3 in the OZR heart, which may be an important part of the overall molecular mechanisms. S.O. dose-dependently inhibited the increase of plasma glucose in sucrose-, but not in glucose-loaded mice. S.O. demonstrated a strong inhibition of alpha-glucosidase activity in vitro, which is suggested to contribute to the improvement of postprandial hyperglycemia.

Development of test systems for the discovery of selective human aldosterone synthase (CYP11B2) and 11beta-hydroxylase (CYP11B1) inhibitors. Discovery of a new lead compound for the therapy of congestive heart failure, myocardial fibrosis and hypertension.

Two key players in adrenal steroid hormone biosynthesis are the human mitochondrial cytochrome P450 enzymes CYP11B1 and CYP11B2 that catalyze the final steps in the biosynthesis of cortisol and aldosterone, respectively. Overproduction of both hormones contributes to a number of severe diseases, as illustrated by the association of elevated aldosterone levels with hypertension and higher mortality in congestive heart failure, and by Cushing's syndrome as the clinical correlate of chronic hypercortisolism. Thus, CYP11B1 and CYP11B2 comprise new targets for drug treatment and selective inhibitors of both enzymes are of high pharmacological interest. To facilitate the search for such compounds, we have established novel test procedures using recombinant fission yeast strains that stably express these enzymes. The aim of this study was to compare the inhibition profiles displayed by these enzymes in established mammalian cell culture test systems to those obtained with the new fission yeast assays, and to evaluate the usefulness of the Schizosaccharomyces pombe strains as screening systems for the identification of novel lead compounds. Using these test systems, we were able to identify a new and very selective CYP11B2 inhibitor (SIAS-1) that displayed no detectable interference with CYP11B1 activity.

Arteriolar wall thickening, capillary rarefaction and interstitial fibrosis in the heart of rats with renal failure:the effects of ramipril, nifedipine and moxonidine.

In experimental renal failure, increased intramyocardial arteriolar wall thickness, reduced myocardial capillary density, and increased cardiac interstitium are found. The extent to which such alterations can be modified by therapeutic interventions has not been investigated to date. The purpose of this study was to examine the effects of Ramipril, Nifedipine and Moxonidine on these structural changes. Sham-operated and subtotally nephrectomized (SNX) 300-g male Sprague-Dawley rats (N = 7 to 11) were left untreated (N = 9) or treated with Ramipril (0.5 mg/kg body wt per day; N = 7), Nifedipine (30 mg/kg body wt per day; N = 9), or Moxonidine (10 mg/kg body wt per day; N = 8) for 8 wk. After perfusion fixation, heart and aorta were examined by stereological techniques. Aortic wall thickness was significantly higher in SNX than in sham-operated control rats and was similarly lowered by all three interventions. In contrast, the wall thickness of intramyocardial arterioles was significantly higher in SNX; this was prevented by Ramipril and Nifedipine, but not by Moxonidine. Intramyocardial capillary length density (Lv) was significantly lower and interstitial volume density (Vv) significantly higher in untreated SNX. Reduction of capillary length density was completely prevented by Moxonidine and in part by Ramipril. The increase in cardiac interstitial volume density was completely prevented by Ramipril and was partially prevented by Moxonidine or Nifedipine treatment. The following conclusions can be drawn from the results: (1) all agents normalize aortic wall thickness, but only calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors prevent intramyocardial arteriolar wall thickening: (2) intramyocardial arteriolar wall thickening, capillary rarefaction, and expansion of the cardiac interstitium are seen in SNX even after lowering the blood pressure to subnormal levels; i.e., changes in systemic blood pressure cannot completely explain the altered vascular structure in renal failure; (3) the effects of Ramipril, Nifedipine, and Moxonidine on cardiovascular structures in experimental renal failure are not completely accounted for by their hemodynamic actions.