Similar to spironolactone, oxymatrine is protective in aldosterone-induced cardiomyocyte injury via inhibition of calpain and apoptosis-inducing factor signaling

Compound Kushen injection attenuates angiotensin II‑mediated heart failure by inhibiting the PI3K/Akt pathway

Compound Kushen injection (CKI) is a type of traditional Chinese medicine that has previously been studied for the treatment of various types of cancer. Previous studies have reported that CKI regulates cell apoptosis by downregulating the PI3K/Akt pathway. The present study aimed to determine whether CKI alleviates heart failure (HF) by attenuating cardiomyocyte apoptosis via the inhibition of the PI3K/Akt pathway. Angiotensin II (Ang II) was used to elicit HF, and osmotic minipumps with either Ang II (2 µg/kg/day) or phosphate‑buffered saline (PBS; 200 µl) were subcutaneously implanted into 6‑week‑old male C57BL/6 mice for 3 weeks. In addition, PBS or CKI (25 mg/kg/day) were subcutaneously infused once a day for 3 weeks. Echocardiography was used to examine hemodynamics. The myocardial injury biomarkers, cardiac troponin I and N‑terminal (NT)‑pro hormone B‑type natriuretic peptide, were assessed using enzyme‑linked immunosorbent assay. Transmission electron microscopy was used to determine the morphology of the myocardium. The rate of apoptosis was detected using TUNEL staining and flow cytometry (FCM), and the expression levels of apoptosis‑related proteins were measured using western blot (WB) analysis. Moreover, H9C2 cells were treated with CKI (2 mg/ml) or LY294002 (an inhibitor of the PI3K/Akt pathway; 25 µmol/l) in combination with Ang II (1 µmol/l) for 48 h. Cell Counting Kit‑8 assay, FCM and WB analysis were performed in the H9C2 cells to examine cell viability, cell cycle distribution and representative signaling proteins. It was found that CKI promoted healthy cardiac function, reduced myocardial structural damage and reduced the rate of cardiomyocyte apoptosis. CKI markedly attenuated the expression of apoptosis‑related proteins in the PI3K/Akt pathway. The results of the in vitro experiments indicated that CKI promoted cardiomyocyte proliferation and inhibited apoptosis, similar to LY294002. On the whole, the present study demonstrates that CKI reduces cardiomyocyte apoptosis, promotes healthy cardiac function and attenuates Ang II‑mediated HF. These ameliorative effects may be associated with the inhibition of the PI3K/Akt pathway.

Calpain-Mediated Mitochondrial Damage: An Emerging Mechanism Contributing to Cardiac Disease

Calpains belong to the family of calcium-dependent cysteine proteases expressed ubiquitously in mammals and many other organisms. Activation of calpain is observed in diseased hearts and is implicated in cardiac cell death, hypertrophy, fibrosis, and inflammation. However, the underlying mechanisms remain incompletely understood. Recent studies have revealed that calpains target and impair mitochondria in cardiac disease. The objective of this review is to discuss the role of calpains in mediating mitochondrial damage and the underlying mechanisms, and to evaluate whether targeted inhibition of mitochondrial calpain is a potential strategy in treating cardiac disease. We expect to describe the wealth of new evidence surrounding calpain-mediated mitochondrial damage to facilitate future mechanistic studies and therapy development for cardiac disease.

Oxymatrine pretreatment protects H9c2 cardiomyocytes from hypoxia/reoxygenation injury by modulating the PI3K/Akt pathway

Ischemia-reperfusion (I/R) plays an important role in myocardial damage, which has been widely recognized as a key procedure in the cardiovascular disease. A hypoxia/reoxygenation (H/R) model was established using H9c2 cardiomyocytes to investigate the possible positive effect of oxymatrine (OMT), an alkaloid originating from the traditional Chinese herb Sophora flavescens Aiton, on cardiomyocytes exposed to H/R injury and the underlying molecular mechanisms. Cell viability was measured using the MTT assay, lactate dehydrogenase release measurements and hematoxylin and eosin staining. Oxidative stress was detected by measuring cellular malondialdehyde (MDA) content, as well as superoxide dismutase (SOD) and catalase (CAT) activities. Apoptosis was detected using TUNEL staining and flow cytometric analysis, and the underlying mechanism was investigated using reverse transcription-quantitative PCR and western blot analyses. The results revealed that OMT increased the viability of H9c2 cardiomyocytes exposed to H/R. The OMT pretreatment decreased the production of MDA by reactive oxygen species and increased the activities of SOD and CAT. Furthermore, the OMT pretreatment reduced the expression of Bax and caspase-3, while inducing Bcl-2 expression. In addition, the protective effect of OMT was shown to be associated with the PI3K/Akt signaling pathway, and the PI3K inhibitor LY294002 attenuated the effects of OMT on the H9c2 cardiomyocytes exposed to H/R. These findings indicate that OMT could be a potential therapeutic candidate for the treatment of myocardial ischemia/reperfusion injury.

A Review of Plant Extracts and Plant-Derived Natural Compounds in the Prevention/Treatment of Neonatal Hypoxic-Ischemic Brain Injury

Neonatal hypoxic-ischemic (HI) brain injury is one of the major drawbacks of mortality and causes significant short/long-term neurological dysfunction in newborn infants worldwide. To date, due to multifunctional complex mechanisms of brain injury, there is no well-established effective strategy to completely provide neuroprotection. Although therapeutic hypothermia is the proven treatment for hypoxic-ischemic encephalopathy (HIE), it does not completely chang outcomes in severe forms of HIE. Therefore, there is a critical need for reviewing the effective therapeutic strategies to explore the protective agents and methods. In recent years, it is widely believed that there are neuroprotective possibilities of natural compounds extracted from plants against HIE. These natural agents with the anti-inflammatory, anti-oxidative, anti-apoptotic, and neurofunctional regulatory properties exhibit preventive or therapeutic effects against experimental neonatal HI brain damage. In this study, it was aimed to review the literature in scientific databases that investigate the neuroprotective effects of plant extracts/plant-derived compounds in experimental animal models of neonatal HI brain damage and their possible underlying molecular mechanisms of action.

Oxymatrine exerts a protective effect in myocardial ischemia/reperfusion‑induced acute lung injury by inhibiting autophagy in diabetic rats

Oxymatrine (OMT) is the primary active component of Sophora flavescens Ait., and is widely used for the treatment of diabetic complications. The present study aimed to investigate the effects of OMT on acute lung injury (ALI) in diabetic rats subjected to myocardial ischemia/reperfusion (I/R). ALI in a myocardial I/R model was established in streptozocin‑induced diabetic rats. Enzyme‑linked immunosorbent assays were used to evaluate the levels of creatine kinase isoenzyme MB and lactate dehydrogenase, and the inflammatory response was assessed via leukocyte counts and the levels of tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and IL‑8 in the bronchoalveolar lavage (BAL) fluid. Hematoxylin and eosin staining was used to determine pathological changes to the lung tissue, and the autophagy‑related proteins LC‑3II/LC‑3I, Beclin‑1, autophagy protein 5 (Atg5) and p62 were detected by western blotting. Diabetic rats subjected to myocardial I/R showed increased levels of ALI with a higher lung injury score and WET/DRY ratio, and lower partial pressure of oxygen. This was accompanied by aberrant autophagy, indicated by an increased LC‑3II/LC‑3I ratio, decreased p62 expression levels, increased Atg5 and beclin‑1 expression levels, decreased superoxide dismutase activity and increased 15‑F2t‑isoprostane formation in lung tissues, as well as increased levels of leukocytes, TNF‑α, IL‑6 and IL‑8 in the BAL fluid. Administration of the autophagy inducer rapamycin significantly accelerated these alterations, while the autophagy inhibitor 3‑Methyladenine exerted the opposite effects. These results indicated that diabetic lungs are more vulnerable to myocardial I/R, which was associated with aberrant autophagy. Furthermore, oxymatrine was observed to reverse and alleviate ALI in diabetic rats with myocardial I/R in a concentration‑dependent manner, the mechanism of which may be associated with the inhibition of autophagy.

Combination of oxymatrine and diammonium glycyrrhizinate significantly mitigates mice allergic contact dermatitis induced by dinitrofluorobenzene

This study investigated the safety and effect of oxymatrine (OMT) and/or diammonium glycyrrhizinate (DG) on allergic contact dermatitis (ACD) induced by 1-fluoro-2,4-dinitrofluorobenzene (DNFB) in ICR mice. Mice were topically smeared with vehicle (control) or DNFB on their ear and skin to induce ACD. The mice were randomized and injected with saline as the model, treated intraperitoneally with dexamethasone (DEX), 45 or 90 mg·kg−1 OMT and/or DG daily beginning one day post the first smearing for two weeks. The body weights, the severity of ear and skin inflammation, the levels of serum IgE, IL-4, and IFNγ, creatinine and urea as well as plasma sodium and potassium in individual mice were measured. In comparison with the control group, the model group did not change the body weights, but developed severe skin and ear inflammation with increased ear thickness, accompanied by many inflammatory infiltrates in the lesions and high levels of serum IgE, IL-4, and IFNγ. Combination of OMT and DG prevented the OMT- or DG-altered body weights in mice. While treatment with either OMT or DG moderately reduced the skin and ear inflammation, their thickness and inflammatory infiltrates, combination of OMT and DG further significantly increased their anti-inflammatory effects in mice. A similar pattern of inhibitory effect on the levels of serum IgE, IL-4, and IFNγ was observed in the different groups of mice. Combination of OMT and DG also prevented the OMT-, DG-, or DEX-altered plasma sodium or potassium levels in mice. Therefore, combination of OMT and DG significantly increased anti-inflammatory effects on ACD induced by DNFB in mice and attenuated DG- or OMT-related adverse effects.

Impact statement

Diammonium glycyrrhizinate (DG) and oxymatrine (OMT) have similar anti-inflammatory, anti-allergic, anti-tumor, immunomodulatory, and other pharmacological properties. Our previous study has shown that when DG and OMT are combined, DG can attenuate both high-dose (347.44 mg·kg−1) and regular-dose (90 mg·kg−1) OMT-induced mortality and adverse effects (such as body weight loss and hyponatremia). Furthermore, OMT can similarly attenuate the adverse effects (such as body weight gain, hypernatremia, and hypokalemia) induced by regular dose (90 mg·kg−1) of DG. Accordingly, we tested whether combination of OMT and DG would increase anti-inflammatory activities and reduce their adverse effect in a mouse model of allergic contact dermatitis (ACD) induced by 1-fluoro-2,4-dinitrofluorobenzene (DNFB). Our findings indicated that combination of OMT and DG significantly increased anti-inflammatory effects on ACD induced by DNFB in ICR mice and attenuated adverse effects of DG or OMT alone.

Relation of the renin-angiotensin-aldosterone system with potential cardiac injury and remodelling: the SABPA study

Purpose: The renin-angiotensin-aldosterone system (RAAS) plays an important role in maintaining hemodynamic homeostasis. Ethnic disparities exist regarding RAAS activity due to sympathetic activity and sodium-water retention, however the implications thereof on cardiac damage is unknown. This study investigated the associations of cardiac troponin T (cTnT), N-terminal pro-brain natriuretic peptide (NTproBNP) and subclinical LVH with components of the RAAS (renin, aldosterone and aldosterone-to-renin ratio (ARR)) and copeptin in a black and white South African cohort.Materials and methods: The study population consisted of 305 participants (black = 139, white = 166) aged 20-62 years. Serum cTnT, NTproBNP, Cornell product, components of the RAAS (active renin, aldosterone and ARR) and copeptin were determined.Results: The black group had lower renin (p < 0.001) and higher ARR (p < 0.001), cTnT (p = 0.015) and Cornell product compared to whites (all p < 0.001). NTproBNP and copeptin were similar between the groups. After forward stepwise adjustments for multiple confounders, inverse associations of cTnT with renin (β = -0.17, p = 0.018) and aldosterone (β = -0.14, p = 0.048) as well as an inverse association between NTproBNP and aldosterone (β = -0.25, p < 0.001) were observed in the white population only. In the black group cTnT associated positively with renin (β = 0.16, p = 0.040) and copeptin (β = 0.21, p = 0.020) and inversely with ARR (β = -0.15, p = 0.047). Additionally, NTproBNP associated positively with copeptin (β = 0.18, p = 0.045). No correlations were observed between the RAAS and Cornell product in any of the groups.Conclusions: Our findings suggest that RAAS, together with cardiac stress may function differently in cardiac damage and remodelling in the two ethnic groups; which may influence treatment in clinical practice.

Inhibitory Effects of Oxymatrine on Transdifferentiation of Neonatal Rat Cardiac Fibroblasts to Myofibroblasts Induced by Aldosterone via Keap1/Nrf2 Signaling Pathways In Vitro

Background

Oxymatrine (OMT), a quinolizidine alkaloid derived from the traditional Chinese herb Radix Sophorae flavescentis, has widely reported pharmacological efficacy in treating cardiovascular dysfunction-related diseases. However, the underlying mechanism has been unclear. Here, we investigated the potential inhibitory effects and mechanism of OMT on transdifferentiation of cardiac fibroblast to myofibroblasts induced by aldosterone in vitro.

Material/Methods

The cardiac fibroblasts (CFBs) proliferation and migration capacity were evaluated by MTT assay, cell cycle assay, and scratch analysis, respectively. The protein expression of the Nrf2/Keap1 signal pathway, FN, Collagen I, Collagen III, α-SMA, CTGF, and mineralocorticoid receptor (MR) protein was detected by Western blot analysis. The mRNA expression of Nrf2 was detected by qRT-PCR. Immunofluorescence staining was used to observe the expression of α-SMA protein. Nrf2 siRNA was used to explore the role of Nrf2 in OMT-treated CFBs. GSH, SOD, and MDA levels and hydroxyproline content were measured by colorimetric assay with commercial kits. The DCFH-DA fluorescent probe was used to assess cellular ROS levels.

Results

OMT and Curcumin (an Nrf2 agonist) attenuated aldosterone (ALD)-induced proliferation and migration in CFBs, as well as the fibrosis-associated protein expression levels. Moreover, OMT activated Nrf2 and promoted the nucleus translocation of Nrf2. OMT alleviated the elevated levels of α-SMA, Collagen I, Collagen III, and CTGF, which were abrogated by the Nrf2 siRNA transfection. We also found that OMT decreased oxidative stress levels.

Conclusions

Our results confirm that OMT alleviates transdifferentiation of cardiac fibroblasts to myofibroblasts induced by aldosterone via activating the Nrf2/Keap1 pathway in vitro.

Oxymatrine ameliorates diabetes-induced aortic endothelial dysfunction via the regulation of eNOS and NOX4

AIM

Oxymatrine (OMT) is the major quinolizidine alkaloid extracted from the root of Sophora flavescens Ait (the Chinese herb Kushen) and exhibits diverse pharmacological actions. In this study, we investigated the effects of OMT on diabetes-associated aortic endothelial dysfunction in a rat model of diabetes and its mechanisms.

METHODS

Male Sprague-Dawley rats were randomly divided into five groups: control, diabetic rats, diabetic rats treated with OMT (60, 120 mg/kg per day, by gavage), and diabetic rats treated with metformin (20 mg/kg per day, by gavage). The serum fasting blood glucose, insulin, total cholesterol, triglyceride, and nitric oxide (NO) levels were determined with commercial kits. Biochemical indices reflecting oxidative stress, such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were analyzed with commercial kits. Mitochondrial reactive oxygen species 2',7'-dichlorofluorescein diacetate (DCFH-DA) was measured by fluorescence microscopy. Histological analyses were conducted to observe morphological changes. Western blot analysis was applied to detect the expression levels of eNOS and NOX4. Reverse transcription polymerase chain reaction was used to detect the expressions of eNOS and NOX4 messenger RNA (mRNA).

RESULTS

The diabetic rats exhibited markedly reduced body weight and increased plasma glucose levels. Moreover, the diabetic rats showed oxidative stress (significantly increased MDA and decreased SOD, CAT, GSH-Px, and serum NO levels). Hyperglycemia caused significant endothelial injury and dysfunction, including vasodilative and histologic changes in the diabetic rats. The expressions of phospho-eNOS protein and mRNA were significantly decreased, while the NOX4 protein expression was increased in the aortas of the diabetic rats. All of these diabetes-induced effects were reversed by OMT in the diabetic rats.

CONCLUSION

The OMT treatment ameliorates diabetic endothelial dysfunction through enhanced NO bioavailability by upregulating eNOS expression and downregulating expression of NOX4.

Oxymatrine exhibits anti-tumor activity in gastric cancer through inhibition of IL-21R-mediated JAK2/STAT3 pathway

Oxymatrine (OMT) as a type of alkaloids collected from Sophora flavescens Ait exerts some biological functions including anticancer properties. Here, we investigated the therapeutic effects of OMT in gastric cancer cells (HGC 27 and AGS). As a result, the exposure of gastric cancer (GC) cells to OMT contributed to the suppression of cell proliferation and invasion. Interleukin 21 receptor (IL-21R) was identified to be differentially expressed between OMT treatment group (4 mg/mL) and control group (0 mg/mL), and knockdown of IL-21R repressed cell proliferation and invasion via inactivation of the JAK2/STAT3 pathway. The rescue experiment showed that IL-21R overexpression attenuated the anti-tumor effects of OMT through activation of the JAK2/STAT3 pathway. Moreover, the expression of IL-21R was significantly upregulated in GC samples compared with the adjacent normal tissues and associated with overall survival (OS) and tumor recurrence of GC patients. Taken together, in this study, we evaluated the anti-tumor effects of OMT on GC by investigating proliferation and invasion ability changes, and our findings show that OMT exhibits effects via regulation of JAK/STAT signaling pathway. Through the mechanism study, we may enlighten the potential therapeutic target for treatment of GC.

Oxymatrine Inhibits Transforming Growth Factor β1 (TGF-β1)-Induced Cardiac Fibroblast-to-Myofibroblast Transformation (FMT) by Mediating the Notch Signaling Pathway In Vitro

Background

Oxymatrine, a component extracted from the traditional Chinese herb Sophora japonica (Sophora flavescens Ait.), has various pharmacological effects, especially on the cardiovascular system. However, its cardiac protection effects and the underlying mechanism are still poorly understood. In the present study, we investigated the inhibitory effect and mechanism of oxymatrine on cardiac fibrosis induced by TGF-β1.

Material/Methods

Cardiac fibroblasts were isolated and purified from neonatal rats. Immunocytochemical staining was used to identify the cells. MTT assay and immunofluorescence staining were used to assess cardiac fibroblasts proliferation and myofibroblasts transformation. Hematoxylin-eosin staining was performed to evaluate morphological changes of cardiac fibroblasts. The secretion of type I and III collagen was assessed by staining with picrosirius red and the hydroxyproline content was determined by colorimetric assay. Cardiac fibroblast migration was examined by scratch assay and DNA content was detected to analyze cell cycle distribution using flow cytometry. Western blot analysis was used to detect the protein expressions of Notch pathway-associated protein in cardiac fibroblasts.

Results

Oxymatrine and Notch signaling pathway inhibitor DAPT could attenuated TGF-β1 induced the capacity of proliferation and migration increased in cardiac fibroblasts, as well as the secretion of collagen and hydroxyproline colorimetric content in medium. TGF-β1 induced the biomarker α-SMA of fibroblast-to-myofibroblast transformation (FMT), which was inhibited by oxymatrine and DAPT. Western blotting confirmed that oxymatrine blocked the activation of Notch induced by TGF-β1.

Conclusions

Oxymatrine is a potential inhibitor FMT induced by TGF-β1, which is at least in part mediated via inhibition of Notch signaling.

Mitochondria-Targeting Small Molecules Effectively Prevent Cardiotoxicity Induced by Doxorubicin

Doxorubicin (Dox) is a chemotherapeutic agent widely used for the treatment of numerous cancers. However, the clinical use of Dox is limited by its unwanted cardiotoxicity. Mitochondrial dysfunction has been associated with Dox-induced cardiotoxicity. To mitigate Dox-related cardiotoxicity, considerable successful examples of a variety of small molecules that target mitochondria to modulate Dox-induced cardiotoxicity have appeared in recent years. Here, we review the related literatures and discuss the evidence showing that mitochondria-targeting small molecules are promising cardioprotective agents against Dox-induced cardiac events.

AIFM1 mutation presenting with fatal encephalomyopathy and mitochondrial disease in an infant

Apoptosis-inducing factor mitochondrion-associated 1 (AIFM1), encoded by the gene AIFM1, has roles in electron transport, apoptosis, ferredoxin metabolism, reactive oxygen species generation, and immune system regulation. Here we describe a patient with a novel AIFM1 variant presenting unusually early in life with mitochondrial disease, rapid deterioration, and death. Autopsy, at the age of 4 mo, revealed features of mitochondrial encephalopathy, myopathy, and involvement of peripheral nerves with axonal degeneration. In addition, there was microvesicular steatosis in the liver, thymic noninvolution, follicular bronchiolitis, and pulmonary arterial medial hypertrophy. This report adds to the clinical and pathological spectrum of disease related to AIFM1 mutations and provides insights into the role of AIFM1 in cellular function.

The synergy of diammonium glycyrrhizinate remarkably reduces the toxicity of oxymatrine in ICR mice

Most traditional Chinese medicine prescription dosages are imprecise. This study analyzes the toxicities and adverse effects of a combination the active ingredients of licorice and Kushen medicine: oxymatrine (OMT) and diammonium glycyrrhizinate (DG). The median lethal dose (LD₅₀) and mortality were analyzed in single-dose OMT (or DG) intraperitoneally injected mice with or without combination DG (or OMT). Body weight changes as well as levels of serum sodium and potassium, alanine transaminase (ALT), aspartate transaminase (AST), creatinine, and urea were measured in mice treated with a daily dose of OMT and/or DG for 14days. This study showed that the LD₅₀ of OMT for males and females were 347.44 and 429.15mg/kg, respectively. The LD₅₀ of DG were 525.10 and 997.26mg/kg for males and females, respectively. DG significantly decreased the mice LD₅₀-induced mortality of the OMT, however OMT did not succeed in reducing the LD₅₀-induced mortality rate of DG. The combination of OMT and DG obviously attenuated the changes of the body weight, serum sodium, and potassium induced by DG or OMT alone. These results suggested that toxicity and adverse effects of the OMT was significantly attenuated by DG. The OMT neutralized the adverse effects of the DG, but not the toxicity.

Metuzumab enhanced chemosensitivity and apoptosis in non-small cell lung carcinoma

Targeted therapeutics is used as an alternative treatment of non-small cell lung cancer (NSCLC); however, treatment effect is far from being satisfactory, and therefore identification of new targets is needed. We have previously shown that metuzumab inhibit tumor growth in vivo. The present study was performed to investigate the anti-tumor efficacy of metuzumab combined with gemcitabine and cisplatin (GP), paclitaxel and cisplatin (TP) or navelbine and cisplatin (NP) regimens in multiple NSCLC cell lines. Our results demonstrate that, in comparison to single agent metuzumab or GP treated cells, metuzumab combined with GP display inhibitory effects on tumor growth. Furthermore, we found that metuzumab elevated the sensitivity of cell lines to gemcitabine, which was identified by MTT assay. Flow cytometric analysis showed that metuzumab combined with gemcitabine (GEM) treatment led to an obvious G1 arrest and an elevated apoptosis in A549, NCI-H460 and NCI-H520 cells. Western blot analysis also demonstrated a significantly reduced level of cyclin D1, Bcl-2, and an obviously increase level of Bax and full-length caspase-3 in A549, NCI-H460 and NCI-H520 cells treated with metuzumab/gemcitabine combination in comparison with single agent treated cells. In addition, metuzumab/gemcitabine treated A549, NCI-H460 and NCI-H520 cells also demonstrated a significantly increase in deoxycytidine kinase (dCK) protein level compared with single agent metuzumab or gemcitabine treated cells. Xenograft models also demonstrated that this metuzumab/gemcitabine combination led to upregulation of dCK. Taken together, the mechanisms of metuzumab combined with GP repress tumor growth were that the combined treatment significantly inhibited the tumor cell proliferation, apoptosis and cell cycle in vitro and in vivo and at least partially by induction of dCK expression. Our results suggested that metuzumab could significantly enhance chemosensitivity of human NSCLC cells to gemcitabine. Metuzumab/gemcitabine combination treatment may be a potentially useful therapeutic regimen for NSCLC patients.

Inhibitory effects of oxymatrine on TGF‑β1‑induced proliferation and abnormal differentiation in rat cardiac fibroblasts via the p38MAPK and ERK1/2 signaling pathways

Interstitial fibrosis serves a causal role in the development of heart failure following acute and chronic myocardial infarction, and anti-fibrotic therapy represents a promising strategy to mitigate this pathological process. Oxymatrine (OMT) exerts a number of pharmacological effects on the cardiovascular system, but its anti-cardiovascular disease mechanisms remain unclear. The purpose of the present study was to investigate the effect of OMT administration on transforming growth factor (TGF)-β1-induced cardiac fibroblast (CFB) proliferation and abnormal differentiation, and to elucidate the underlying mechanisms. Primary CFBs were isolated from neonatal rats and used for experimental treatments. TGF-β1 stimulation in CFBs resulted in increased proliferation, increased α-smooth muscle actin (SMA) and type I and type III collagen expression, and increased p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK)1/2 phosphorylation. Treatment with OMT and SB431542 (a TGF-β1 receptor inhibitor) attenuated the proliferation and abnormal differentiation of CFBs induced by TGF-β1, and decreased p38MAPK and ERK1/2 phosphorylation. In addition, treatment with SB203580 (a p38MAPK inhibitor) or PD98059 (an ERK1/2 inhibitor), but not by SP600125 (a c-jun N-terminal kinase1/2/3 inhibitor), inhibited the TGF-β1 stimulated CFB proliferation, as well as the elevation of α-SMA and the deposition of type I and type III collagen, suggesting that ERK1/2 and p38MAPK signaling may be important in the in the process of myocardial fibrosis. In conclusion, the present study revealed that OMT treatment inhibited CFB proliferation and the CFB-myofibroblast transition induced by TGF-β1, at least in part through inhibition of ERK1/2 and p38MAPK signaling.

Anti-exudation effects of sodium ferulate and oxymatrine combination via modulation of aquaporin 1

The present study aimed to investigate the anti-exudative effects of sodium ferulate combined with oxymatrine in a mouse model of acetic acid-induced peritonitis. Furthermore, the underlying mechanisms were explored by determining the effects of these drugs on the volume and aquaporin 1 (AQP1) expression in vascular endothelial cells on omentum majus and human umbilical vein endothelial cells (HUVEC). Treatment with sodium ferulate combined with oxymatrine was shown to significantly inhibit acetic acid-induced vascular permeability in the peritonitis model mice and furthermore to significantly decrease the optical density of Evans blue, the leukocyte number and the levels of interleukin-6, C-reactive protein and interferon-γ in peritoneal lavage fluid. Pathological analysis of the omentum majus revealed that sodium ferulate and oxymatrine combination treatment significantly alleviated vascular endothelial cell edema and capillary loss. In vitro, flow cytometry revealed that the volume of HUVECs was significantly reduced in the drug treatment groups, as reflected in the forward scatter value. The optical density of AQP1 on the membrane of the vascular endothelial cells on omentum majus and HUVECs were significantly increased in the drug treatment groups compared with the model group. These results indicated that sodium ferulate and oxymatrine combination treatment possessed prominent anti-exudative effects and that the underlying mechanisms are likely to include the improvement of vascular endothelial cellular edema, possibly by upregulation of AQP1 expression on their membrane, which requires further exploration.

Danshensu attenuates aldosterone-induced cardiomyocytes injury through interfering p53 pathway

Heart failure, characterized by impaired systolic and/or diastolic function, is a common cardiovascular disease. The loss of cardiomyocytes due to various factors, including through necrosis or apoptosis can result in heart failure. Previous studies have indicated that excessive aldosterone (ALD) serves an essential role in the process of heart failure, and the heart is also one of the direct targets of ALD, which can provoke hypertrophy and the apoptosis of cardiomyocytes. The aim of the present study was to investigate the protective effect of danshensu (DSS) on ALD‑induced cardiomyocytes injury. The present results demonstrated that DSS increased cell viability and decreased the leakage of lactate dehydrogenase in cardiomyocytes exposed to ALD. In addition, DSS decreased the apoptotic rate of ALD‑stimulated cells. Further research indicated that DSS‑ and cellular tumor antigen p53 (p53)‑alone or combination treatment was able to decrease the expression levels of apoptosis regulator BAX and caspase‑3, and increase the expression of apoptosis regulator B‑cell lymphoma (Bcl)‑2 in ALD‑stimulated cardiomyocytes. Taken together, the results of the present study suggest that DSS inhibits the harmful effects of ALD on cardiomyocytes via interfering with the p53 signaling pathway. These results provide novel evidence for the potential protective effects of DSS.

Oxymatrine provides protection against Coxsackievirus B3-induced myocarditis in BALB/c mice

Oxymatrine is the primary pharmacological component of Sophora flavescens Ait. In the present study, we investigated the protective effect of oxymatrine against Coxsackievirus B3-induced myocarditis in mice. Coxsackievirus B3-infected HeLa cells were treated with oxymatrine and the viral titer, as well as the degree of cellular proliferation were determined. Additionally, BALB/c mice were infected with Coxsackievirus B3 and received differing concentrations of oxymatrine. On days 5 and 12 following treatment, mice were sacrificed, and serum lactate dehydrogenase, creatine kinase-MB isozyme, and tumor necrosis factor-α levels were quantified. The heart index and degree of myocardial tissue inflammation were also assessed. On day 5, the Coxsackievirus B3 TCID₅₀ values of the heart tissue, and the expression of NTR, IFN-γ, and TNF-α genes in the myocardial tissue were measured. Our results showed that oxymatrine exhibits potent antiviral effects on Coxsackievirus B3 as 50% inhibition was achieved at a concentration as low as 0.238 mg/mL. Oxymatrine markedly reduced the viral titer and inhibited cardiac myocyte pathology exhibited in viral myocarditis. Furthermore, oxymatrine treatment reduced the expression of Coxsackievirus B3 NTR and mouse TNF-α genes compared to the controls. Therefore, our findings indicate that oxymatrine is a promising potent antiviral agent against Coxsackievirus B3-induced myocarditis.

Oxymatrine inhibits aldosterone-induced rat cardiac fibroblast proliferation and differentiation by attenuating smad-2,-3 and-4 expression: an in vitro study

BACKGROUND

We previously demonstrated oxymatrine, an alkaloid from the Chinese medicine radix Sophorae flavescentis, ameliorates hemodynamic disturbances and cardiac fibrosis; however, the underlying mechanisms are unclear. Here, we investigated the effect and mechanism of action of oxymatrine on aldosterone-induced cardiac fibroblast to myofibroblast differentiation in vitro.

METHODS

Cardiac fibroblasts were isolated purified from neonatal Sprague Dawley rats. The optimal concentration of aldosterone to stimulate cardiac fibroblast proliferation was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cardiac fibroblasts were pretreated with 7.57 × 10(-4) mol/L or 3.78 × 10(-4) mol/L oxymatrine or without oxymatrine for 2 h, and then coincubated with 1 × 10(-8) mol/L aldosterone for 48 h. The MTT assay and Masson staining were used to detect the cardiac fibroblast proliferation and myofibroblast differentiation. The secretion of type I and III collagen was measured by commercial ELISA kits, and the hydroxyproline content was determined by the colorimetric assay. Western blotting assayed the Smad-2, Smad-3, and Smad-4 protein expression in cardiac fibroblasts.

RESULTS

The present results confirmed that aldosterone induced cardiac fibroblast to myofibroblast proliferation and differentiation. The MTT assay and Masson staining indicated oxymatrine significantly inhibited aldosterone-induced cardiac fibroblast proliferation and myofibroblast differentiation. Oxymatrine significantly inhibited aldosterone-induced secretion of type I and III collagen, as indicated by commercial ELISA kits, and aldosterone-induced increase in hydroxyproline content, as indicated by a colorimetric assay. Western blotting revealed oxymatrine attenuated aldosterone-induced Smad-2, Smad-3, and Smad-4 expression in cardiac fibroblasts.

CONCLUSION

Oxymatrine can inhibit cardiac fibroblast proliferation and differentiation into myofibroblasts via a mechanism linked to attenuation of the Smad signaling pathway.

Rapid effects of aldosterone in primary cultures of cardiomyocytes - do they suggest the existence of a membrane-bound receptor?

Aldosterone acts on its target tissue through a classical mechanism or through the rapid pathway through a putative membrane-bound receptor. Our goal here was to better understand the molecular and biochemical rapid mechanisms responsible for aldosterone-induced cardiomyocyte hypertrophy. We have evaluated the hypertrophic process through the levels of ANP, which was confirmed by the analysis of the superficial area of cardiomyocytes. Aldosterone increased the levels of ANP and the cellular area of the cardiomyocytes; spironolactone reduced the aldosterone-increased ANP level and cellular area of cardiomyocytes. Aldosterone or spironolactone alone did not increase the level of cyclic 3',5'-adenosine monophosphate (cAMP), but aldosterone plus spironolactone led to increased cAMP level; the treatment with aldosterone + spironolactone + BAPTA-AM reduced the levels of cAMP. These data suggest that aldosterone-induced cAMP increase is independent of mineralocorticoid receptor (MR) and dependent on Ca(2+). Next, we have evaluated the role of A-kinase anchor proteins (AKAP) in the aldosterone-induced hypertrophic response. We have found that St-Ht31 (AKAP inhibitor) reduced the increased level of ANP which was induced by aldosterone; in addition, we have found an increase on protein kinase C (PKC) and extracellular signal-regulated kinase 5 (ERK5) activity when cells were treated with aldosterone alone, spironolactone alone and with a combination of both. Our data suggest that PKC could be responsible for ERK5 aldosterone-induced phosphorylation. Our study suggests that the aldosterone through its rapid effects promotes a hypertrophic response in cardiomyocytes that is controlled by an AKAP, being dependent on ERK5 and PKC, but not on cAMP/cAMP-dependent protein kinase signaling pathways. Lastly, we provide evidence that the targeting of AKAPs could be relevant in patients with aldosterone-induced cardiac hypertrophy and heart failure.

Oxymatrine and cancer therapy

Oxymatrine is a kind of alkaloid extracted from traditional Chinese herb Sophora flavescens Ait. It has been proved to exert various biological activities such as anti-angiogenesis, proliferation-inhibiting, apoptosis-promoting, analgesic-strengthening, and anti-metastasis. The biological activities are related with inhibition of angiogenesis-associated factors, regulation of related signaling pathway and protein expression, synergistic effects with chemotherapy drug, cell cycle arrest and inhibition of voltage-activated K+ channel. In this review, we summarize the recent investigations of oxymatrine in cancer therapy so as to provide references for further study and clinical therapy.

Reduced apoptosis after acute myocardial infarction by simvastatin

To observe the effect of simvastatin in patients with acute myocardial infarction in rabbits against myocardial apoptosis, and to explore its possible mechanism. Male New Zealand white rabbits were randomized into three groups, including the myocardial infarction group (12 rabbits), the simvastatin treatment group (15 rabbits), and the sham group (12 rabbits). In the simvastatin treatment and myocardial infarction groups, the rabbits received myocardial infarction surgeries. While in the sham group, loose knots were tied in the left anterior descending coronary artery branches. The simvastatin treatment group was given simvastatin by oral gavage 24 h after surgery. Parameters, which included left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left ventricular ejection fraction, and left ventricular mass index, were recorded in these three groups. Edge myocardial infarction and myocardial cell apoptosis were analyzed using TUNEL assay, and Bcl-2, Bax, and Caspase-3 protein levels were detected by Western blot. Acute myocardial infarction model was successfully established in rabbits by ligation of the left anterior descending coronary artery. Compared with the myocardial infarction group, left ventricular end-diastolic diameter (LVEDD) and left ventricular end systolic diameter (LVESD) were significantly reduced and left ventricular ejection fraction (LVEF) increased in the simvastatin treatment group. Compared with the sham group, LVEDD and LVESD were significantly increased and LVEF decreased in the simvastatin treatment group. All the differences were statistically significant (P < 0.05). Left ventricular mass index in the simvastatin treatment group was statistically lower than the myocardial infarction group. Compared with the sham group, left ventricular mass index in both the simvastatin treatment and myocardial infarction groups was significantly increased. The differences of the above comparisons were statistically significant (P < 0.05). Compared with the sham group, the apoptosis rate of the myocardial infarction group and the simvastatin treatment groups was significantly increased as shown by TUNEL assay, however, the apoptosis rate of the simvastatin treatment group was significantly lower than that of the myocardial infarction group. All the differences among above comparisons were statistically significant (P < 0.05). Bcl-2 levels significantly increased in the simvastatin treatment group compared with the myocardial infarction group, but Bcl-2 levels in both groups were significantly lower than the sham group. However, Bax protein levels showed inverse expression with Bcl-2. Meanwhile, Caspase-3 protein expression showed similar trend with Bcl-2. Simvastatin can improve cardiac function after myocardial infarction and reduce apoptosis of myocardial cells, possibly by decreasing Bax and Caspase-3 expression and increasing the expression level of Bcl-2.

Oxymatrine attenuated hypoxic-ischemic brain damage in neonatal rats via improving antioxidant enzyme activities and inhibiting cell death

Oxymatrine (OMT), an active constituent of Chinese herb Sophora flavescens Ait, has been proved to possess anti-tumor, anti-oxidant, anti-inflammatory, and anti-apoptotic activities. Previous study has demonstrated that OMT had protective roles on multiple in vitro and in vivo brain injury models including regulation of apoptosis-related proteins caspase-3, Bax and Bcl-2. In this study, we investigated whether this protective effect could apply to neonatal hypoxic-ischemic brain damage. Seven-day-old Sprague-Dawley rats were treated with the left carotid artery ligation followed by exposure to 8% oxygen (balanced with nitrogen) for 2.5 h at 37 °C. In sham group rats, neither ligation nor hypoxia was performed. After two successive days intraperitoneal injection with OMT (30, 60 and 120 mg/kg), Nimodipine (1 mg/kg), and saline, brain infarct volume was estimated, histomorphology changes were performed by hematoxylin-eosin (HE) staining as well as electron microscopy. In addition, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC), as well as production of malondialdehyde (MDA) were assayed in ipsilateral hemisphere homogenates to evaluate the redox status after hypoxic-ischemic. Expression of apoptosis-related proteins Caspase-3, Bax and Bcl-2 in brain were analyzed by western-blot analysis and immunofluorescence. Administration of OMT significantly decreased brain infarct volume and the percentage of injured cells, and ameliorated histopathology and morphological injury as well. Furthermore, OMT obviously increased the activities of SOD, GSH-Px, CAT and T-AOC, and decreased MDA content. Western-blot analysis showed a marked decrease in Caspase-3 expression and increase in the ratio of Bcl-2/Bax after OMT (120 mg/kg) post-treatment as compared with hypoxic-ischemic group. These results suggest that OMT exerts a neuroprotective effect against hypoxic-ischemic brain damage in neonatal rats, which is likely to be mediated through increasing anti-oxidant enzyme activities and inhibiting cell death.

Role of endogenous PDGF-BB in cultured cardiomyocytes exposed to hypoxia

Platelet-derived growth factor-BB (PDGF-BB) plays a critical role in cell proliferation, angiogenesis and fibrosis. However, its exact role in cardiomyocytes exposed to hypoxia is not well known. This study was therefore designed to detect whether PDGF-BB expression was changed in a hypoxic condition, then the possible role of endogenous PDGF-BB in cardiomyocytes was explored, with interference RNA in a lentiviral vector ex vivo. The results showed that cultured cardiomyocytes exhibited an optimal proliferation from 3 to 10 days. However, LDH level was significantly increased but the heart rhythm was not altered in cardiomyocytes exposed to hypoxia for 24 hours. PDGF-BB expression was substantially upregulated in hypoxic cardiomyocytes. In order to know the role of PDGF-BB, we performed PDGF-BB knockdown in cultured cardiomyocytes. The number of apoptotic cells and the level of LDH were significantly increased but the beat rhythm was reduced in cardiomyocytes with PDGF-BB knockdown. These findings suggest that endogenous PDGF-BB exerts a crucial protective effect to cultured cardiomyocytes exposed to hypoxia.