A Novel Polysaccharide From Chuanminshen violaceum and Its Protective Effect Against Myocardial Injury
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ABSTRACT: We isolated and purified a novel polysaccharide from the root of Chuanminshen violaceum, namely, Chuanminshen violaceumis polysaccharide (CVP) and confirmed its structure and molecular weight. Furthermore, in vivo experiment, CVP’s protective effect against myocardial ischemia-reperfusion (I/R) injury in mice was evidenced by significantly reducing I/R-induced myocardial infarction (MI) size, decreasing the secretion of heart damage biomarkers, and improving cardiac function. Then, the myocardial anoxia/reoxygenation (A/R) injury model was established to mimic reperfusion injury. Noticeably, ferroptosis was the major death manner for A/R-damaged H9c2 cells. Meanwhile, CVP significantly inhibited ferroptosis by decreasing intracellular Fe2+ level, enhancing GPX4 expression, and suppressing lipid peroxidation to confront A/R injury. In conclusion, CVP, with a clear structure, ameliorated I/R injury by inhibiting ferroptosis.
Project description:Er-Xian decoction (EXD), a formula of Chinese medicine, is often used to treat menopausal syndrome in China. The aim of the present study was to explore the potential cardioprotective mechanism of EXD against myocardial injury in an ovariectomy-induced menopausal rat model.We divided the female Wistar rats into ovariectomy group and sham operation group (SHAM group). The ovariectomized (OVX) rats received treatment of vehicle (OVX group), EXD (EXD group) or 17?-estradiol (E2 group). After 12-week of treatment, the level of estradiol in serum was detected using an electrochemiluminescence immunoassay, and electrophysiologic changes in myocardial action potentials (AP) were evaluated using intracellular microelectrode technique. Changes in the histopathology of the left ventricle and the ultrastructure of the cardiomyocytes were observed by hematoxylin and eosin (HE) staining and transmission electronmicroscopy to assess myocardial injury. Microarrays were applied for the evaluation of gene expression profiles in ventricular muscle of the OVX and EXD rats. Further pathway analyses of the differential expression genes were carried out using the Kyoto Encyclopedia of Genes and Genomes (KEGG). And real-time quantitative RT-PCR (qRT-PCR) was used for verification of the key findings.The results from electrophysiological and histomorphological observations demonstrated that EXD had a substantial myocardial protective effect. The EXD-treated rats, in comparison with the OVX rats, demonstrated up-regulated expression of 28 genes yet down-regulated expression of 157 genes in the ventricular muscle. The qRT-PCR assay validated all selected differential expression genes. The KEGG pathway analysis showed that the down-regulated genes were relevant to cardiomyopathy and myocardial contractility. EXD could decrease the mRNA expressions of cardiac myosin (Myh7, Myl2) and integrin (Itgb5) in the ventricular myocardium.EXD had a protective effect against myocardial injury in OVX rats, and this cardioprotective effect may be associated with modulation of the expression of cardiac myosin or integrin at the mRNA level.
Project description:This study aimed to novelly design and synthesize an amide derivative as a potential substitute of celastrol (CLT). We constituted the compound celastrol-glucosamine (CLG) by conjugating 1-(2-aminoethoxy)-2-glucosamine to celastrol (CLT) and confirmed its chemical structure by 1H NMR, 13C NMR, and LC-MS/MS. Then, the potential efficacy of the CLG was investigated on renal ischemia-reperfusion injury animal models. The results demonstrated that the decorated compound CLG could completely reverse the disease progression as same as CLT. Furthermore, the toxicity of CLG was also fully evaluated in rat blood, liver, kidney, heart, spleen, lung, and reproductive system. Compared to the performance of CLT on normal organs, CLG could remarkably maintain high safety and significantly reduce the side effects. Taken together, the CLG could keep the same efficacy as CLT while processing lower toxicity in vivo.
Project description:Electroacupuncture (EA) can help reduce infarct size and injury resulting from myocardial ischemia/reperfusion (I/R); however, the underlying molecular mechanism remains unknown. We previously reported that STAT5 plays a critical role in the cardioprotective effect of remote ischemic preconditioning (RIPC). Here, we assessed the effects of electroacupuncture pretreatment (EAP) on myocardial I/R injury in the presence and/or absence of Stat5 in mice and investigated whether EAP exerts its cardioprotective effects in a STAT5-dependent manner. Adult Stat5 fl/fl and Stat5-cKO mice were exposed to EAP at Neiguan (PC6) for 7 days before the induction of I/R injury by left anterior descending (LAD) coronary artery ligation. The myocardial infarct size (IS), area at risk, and apoptotic rate of cardiomyocytes were detected. RT-qPCR and western blotting were used to measure gene and protein expression, respectively, in homogenized heart tissues. RNA-seq was used to identify candidate genes and pathways. Our results showed that EAP decreased IS and the rate of cardiomyocyte apoptosis. We further found that STAT5 was activated by EAP in Stat5 fl/fl mice but not in Stat5-cKO mice, whereas the opposite was observed for STAT3. Following EAP, the levels of the antiapoptotic proteins Bcl-xL, Bcl-2, and p-AKT were increased in the presence of Stat5, while that of interleukin 10 (IL-10) was increased in both Stat5 fl/fl and Stat5-cKO. The gene expression profile in heart tissues was different between Stat5 fl/fl and the Stat5-cKO mice with EAP. Importantly, the top 30 DEGs under EAP in the Stat5-cKO mice were enriched in the IL-6/STAT3 signaling pathway. Our results revealed for the first time that the protective effect of EAP following myocardial I/R injury was attributable to, but not dependent on, STAT5. Additionally, we found that EAP could activate STAT3 signaling in the absence of the Stat5 gene, and could also activate antiapoptotic, survival, and anti-inflammatory signaling pathways.
Project description:BackgroundRed ginseng (RG) was widely used as traditional Chinese medicine (TCM) or dietary supplement. However, few researches had been reported on the red ginseng polysaccharide (RGP).MethodsIn this study, a novel heteropolysaccharide named RGP1-1 was fractionated sequentially by DEAE-52 column and Sephadex G-100 gel column. The primary structure of RGP1-1, including glycosyl linkages, molecular weight, monosaccharide composition, morphology and physicochemical property were conducted by nuclear magnetic resonance (NMR), gas chromatography-mass spectrometer (GC-MS), atomic force microscope (AFM), scanning electron microscope (SEM), differential scanning calorimetry-thermogravimetric analysis (DSC-TG) and so on. The effect of RGP1-1 in preventing and treating myocardial ischemia was evaluated by an animal model isoprenaline (ISO) induced mice.ResultsRGP1-1, with a homogeneous molecular weight of 5655 Da, was composed of Glc and Gal in the ratio of 94.26:4.92. The methylation and NMR analysis indicated the backbone was composed of → 1)-Glcp-(4 → and → 1)-Galp-(4 →, branched partially at O-4 with α-D-Glcp-(1 → residue. Morphology and physicochemical property analysis revealed a triple-helical conformation, flaky and irregular spherical structure with molecule aggregations and stable thermal properties of RGP1-1. And it contained 6.82 mV zeta potential, 117.4 nm partical size and polymerization phenomenon. Furthermore, RGP1-1 possessed strong antioxidant activity in vitro and in vivo, RGP1-1 could decrease cardiomyocyte apoptosis and myocardium fibrosis of mice in histopathology and it could decrease significantly the serum levels of cardiac troponin (cTnI), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), malondialdehyde (MDA). Western blot analysis showed that RGP1-1 can increase the expression of main protein Nuclear factor E2-related factor 2(Nrf2), NAD(P)H:quinone oxidoreductase 1 (NQO1), heme oxygenase-1(HO-1) and kelch-like ECH-associated protein1(keap1) in oxidative stress injure progress, and therefore regulate the pathway of Nrf2/HO-1.ConclusionThe above findings indicated that RGP1-1 had an improving effect on ISO-induced myocardial ischemia injury in mice, as novel natural antioxidant and heart-protecting drugs.
Project description:Septicemia is associated with excessive inflammation, oxidative stress and apoptosis, causing myocardial injury that results in high mortality and disability rates worldwide. The abnormal expression of multiple microRNAs (miRNAs/miRs) is associated with more severe sepsis‑induced myocardial injury (SIMI) and miR‑335 has been shown to protect cardiomyocytes from oxidative stress. The present study aimed to investigate the role of miR‑335 in SIMI. An SIMI model was established by cecal ligation and puncture (CLP) in mice. An miRNA‑335 precursor (pre‑miR‑335) was transfected to accelerate miR‑335 expression and an miR‑335 inhibitor (anti‑miR‑335) was used to inhibit miR‑335 expression. CLP or sham surgery was performed on pre‑miR‑335, anti‑miR‑335 and wild‑type mice and miR‑335 expression was determined by reverse transcription‑quantitative PCR. Inflammatory factors (TNF‑α, IL‑6 and IL‑10) and troponin (cTNI), brain natriuretic peptide (BNP), creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) were assessed using commercial kits. Apoptosis was detected by flow cytometry and cardiac function was assessed using a Langendorff isolated cardiac perfusion system. miR‑335 expression was upregulated and an elevation in inflammatory factors and cTNI, BNP, CK, LDH and AST was observed. Compared with the wild‑type control group, pre‑miR‑335 mice treated with CLP exhibited significantly reduced left ventricular development pressure, maximum pressure increased reduction rates, as well as decreased levels of TNF‑α, IL‑6 and IL‑10, myocardial injury and apoptosis; by contrast, these features were amplified in CLP‑treated anti‑miR‑335 mice. In conclusion, the upregulation of miR‑335 exerted ameliorative effects on myocardial injury following sepsis and may indicate a novel therapeutic intervention for SIMI.
Project description:Oxidative and nitrative stress is a well-known phenomenon in cisplatin-induced nephrotoxicity. The purpose of this work is to study the role of two metalloporphyrins (FeTMPyP and MnTBAP), water soluble complexes, in cisplatin-induced renal damage and their ability to scavenge peroxynitrite. In cisplatin-induced nephropathy study in mice, renal nitrative stress was evident by the increase in protein nitration. Cisplatin-induced nephrotoxicity was also evident by the histological damage from the loss of the proximal tubular brush border, blebbing of apical membranes, tubular epithelial cell detachment from the basement membrane, or intra-luminal aggregation of cells and proteins and by the increase in blood urea nitrogen and serum creatinine. Cisplatin-induced apoptosis and cell death as shown by Caspase 3 assessments, TUNEL staining and DNA fragmentation Cisplatin-induced nitrative stress, apoptosis and nephrotoxicity were attenuated by both metalloporphyrins. Heme oxygenase (HO-1) also plays a critical role in metalloporphyrin-mediated protection of cisplatin-induced nephrotoxicity. It is evident that nitrative stress plays a critical role in cisplatin-induced nephrotoxicity in mice. Our data suggest that peroxynitrite is involved, at least in part, in cisplatin-induced nephrotoxicity and protein nitration and cisplatin-induced nephrotoxicity can be prevented with the use of metalloporphyrins.
Project description:1 We examined whether edaravone (Eda), a clinically available radical scavenger, directly protects cardiomyocytes from ischemia/reperfusion (I/R) injury, and whether the timing of its application is critical for protection. 2 Cardioprotective effects of edaravone were tested in the modified cell-pelleting model of ischemia and under exogenous oxidative stress (hydrogen peroxide: H2O2) in isolated adult rabbit ventricular cells. Cell death and reactive oxygen species (ROS) generation were detected using propidium iodide (PI) and DCFH-DA, respectively. These parameters were evaluated objectively using flow cytometory. 3 Hypoxia and reoxygenation aggravated the proportion of dead cells from 32.2+/-1.8% (Baseline) to 51.3+/-2.7% (Control). When 15 microm edaravone was applied either throughout the entire experiment (Through) or only at reoxygenation (Reox), cell death was significantly reduced to 39.9+/-1.8% (P<0.01 vs Control) and 43.3+/-2.5% (P<0.05 vs Control), respectively. In contrast, when edaravone was applied 10 min after reoxygenation, its protective effect disappeared. Cardioprotection by edaravone was more remarkable than that afforded by other free radical scavengers, such as ascorbate and superoxide dismutase (SOD). There is a positive correlation between the cardioprotective effect of edaravone and the extent of ROS reduction. 4 Edaravone blunted the H2O2-induced changes in electrical properties, and significantly prolonged the time to contracture induced by H2O2 in single ventricular myocytes. 5 Taken together, edaravone directly protects cardiomyocytes from I/R injury by attenuating ROS production, even when applied at the time of reoxygenation, suggesting that edaravone could be a potent cardioprotective therapeutic agent against hypoxia-reoxygenation injury.
Project description:An iridoid glycoside, agnucastoside C (ACC) was isolated from the leaves of Moringa oliefera and its cardio protective potential was investigated in adult rats by examining the effects of this test compound, ACC at 30 mg/kg for 14 days in isoproterenol (100 mg/kg)-induced myocardial injury. Isoproterenol (ISO) administration induced the myocardial injury as evidenced by the altered ECG pattern with ST-segment elevation and an increase in the levels of cardiac injury markers including troponin-I, creatine kinase-MB, alanine transaminase, aspartate transaminase, lactate dehydrogenase; inflammatory markers, interleukine-6 and tumor necrosis factor. In this group, there was also an increase in cardiac lipid peroxidation and a decrease in cellular antioxidants. However, pretreatment with ACC maintained the normal ECG pattern and nearly normal levels of all the cardiac markers in ISO-induced animals. Electron microscopic and histological studies also showed marked reduction in ISO-induced cardiac damages including infarct size by ACC. Analysis by 2-DE revealed the involvement of 19 different cardiac proteins, associated with energy metabolism, oxidative stress and maintenance of cytoskeleton. The expression of those proteins were altered by ISO, but maintained in ACC pretreated rats. Our findings reveal the potential of isolated ACC in the prevention of myocardial damage.
Project description:Coronary heart disease is a major cause of death in the western world. Although essential for successful recovery, reperfusion of ischemic myocardium is inevitably associated with reperfusion injury. To investigate a potential protective role of ADAMTS13, a protease cleaving von Willebrand factor multimers, during myocardial ischemia/reperfusion, we used a mouse model of acute myocardial infarction. We found that Adamts13(-/-) mice developed larger myocardial infarctions than wild-type control mice, whereas treatment of wild-type mice with recombinant human ADAMTS13 (rhADAMTS13) led to smaller infarctions. The protective effect of ADAMTS13 was further confirmed by a significant reduction of cardiac troponin-I release and less myocardial apoptosis in mice that received rhADAMTS13 compared with controls. Platelets adherent to the blood vessel wall were observed in few areas in the heart samples from mice treated with vehicle and were not detected in samples from mice treated with rhADAMTS13. However, we observed a 9-fold reduction in number of neutrophils infiltrating ischemic myocardium in mice that were treated with rhADAMTS13, suggesting a potent anti-inflammatory effect of ADAMTS13 during heart injury. Our data show that ADAMTS13 reduces myocardial ischemia/reperfusion injury in mice and indicate that rhADAMTS13 could be of therapeutic value to limit myocardial ischemia/reperfusion injury.
Project description:BackgroundOur previous studies suggested that deoxyschizandrin (DSD) and schisantherin A (STA) may have cardioprotective effects, but information in this regard is lacking. Therefore, we explored the protective role of DSD and STA in myocardial ischemia-reperfusion (I/R) injury.Methodology/principal findingsAnesthetized male rats were treated once with DSD and STA (each 40 µmol/kg) through the tail vein after 45 min of ischemia, followed by 2-h reperfusion. Cardiac function, infarct size, biochemical markers, histopathology and apoptosis were measured and mRNA expression of gp91 (phox) in myocardial tissue assessed by RT-PCR. Neonatal rat cardiomyocytes were pretreated with DSD and STA and then damaged by H2O2. Cell apoptosis was tested by a flow cytometric assay. Compared with the I/R group: (i) DSD and STA could significantly reduce the abnormalities of LVSP, LVEDP, ±dp/dtmax and arrhythmias, thereby showing their protective roles in cardiac function; (ii) DSD and STA could significantly attenuate the infarct size and MDA release while increasing SOD activity, suggesting a role in reducing myocardial injury; (iii) tissue morphology and myocardial textual analysis revealed that DSD and STA mitigated changes in myocardial histopathology; (iv) DSD and STA decreased apoptosis (33.56±2.58% to 10.28±2.80% and 10.98±1.99%, respectively) and caspase-3 activity in the myocardium (0.62±0.02 OD/mg to 0.38±0.02 OD/mg and 0.32±0.02 OD/mg, respectively), showing their protective effects upon cardiomyocytes; and (v) DSD and STA had similar protective effects on I/R injury as those seen with the positive control metoprolol. In vitro, DSD and STA could significantly decrease the apoptosis of neonatal cardiomyocytes.Conclusions/significanceThese data suggest that DSD and STA can protect against myocardial I/R injury. The underlining mechanism may be related to their role in inhibiting cardiomyocyte apoptosis.