Cardioprotective effects of Guanxinshutong (GXST) against myocardial ischemia/ reperfusion injury in rats

Rapid identification, quantitation, and antioxidant activity evaluation of the components in Guanxin Shutong capsule with liquid chromatography and mass spectrometry

Guanxin Shutong capsule (GSC) is a traditional Chinese medicinal prescription used in the treatment of coronary heart disease (CHD) and angina pectoris in clinic. However, the chemical profile of GSC is still uncovered, which hindered the progress of pharmacological study and clinical application. Herein, high performance liquid chromatography (HPLC) together with high resolution mass spectrometry (HR-MS) techniques were employed to analyze the quality consistency and to identify chemical components in GSC. As a result, a total of 111 compounds were tentatively annotated. Quantitative analysis based on HPLC-ultraviolet detection (UV) was performed for 6 main components and fingerprints of 10 different batches of GSC were established. The developed method was validated for linearity, precision, repeatability, stability, and recovery. The quality evaluation and similarity analysis of the 10 batches were also performed. Furthermore, in vitro antioxidant activity assays demonstrated that GSC exhibited potential DPPH and hydroxyl radical scavenging capacities. Especially, salvianolic acids showed the strongest free radical scavenging capacities, which might be the main component for quality control of GSC.

Effect Produced by a Cyclooctyne Derivative on Both Infarct Area and Left Ventricular Pressure via Calcium Channel Activation

BACKGROUND

There are reports which indicate that some cyclooctyne derivatives may exert changes in cardiovascular system; however, its molecular mechanism is not very clear.

OBJECTIVE

The aim of this study was to evaluate the biological activity of four cyclooctyne derivatives (compounds 1: to 4: ) produced on infarct area and left ventricular pressure.

METHODS

Biological activity produced by cyclooctyne derivatives on infarct area was determinate using an ischemia/reperfusion injury model. In addition, to characterize the molecular mechanism of this effect, the following strategies were carried out as follows; i) biological activity produced by cyclooctyne derivative (compound 4: ) on either perfusion pressure or left ventricular pressure was evaluated using an isolated rat heart; ii) theoretical interaction of cyclooctyne derivative with calcium channel (1t0j protein surface) using a docking model.

RESULTS

The results showed that cyclooctyne derivative (compound 4: ) decrease infarct area of in a dose-dependent manner compared with compound 1: to 3: . Besides, this cyclooctyne derivative increase both perfusion pressure and left ventricular pressure which was inhibited by nifedipine. Other theoretical data suggests that cyclooctyne derivative could interact with some aminoacid residues (Met₈₃, Ile₈₅, Ser₈₆, Leu₁₀₈, Glu₁₁₄) involved in 1t0j protein surface.

CONCLUSIONS

All these data indicate that cyclooctyne derivative increase left ventricular pressure via calcium channel activation and this phenomenon could be translated as a decrease of infarct area.

Simvastatin Improves Myocardial Ischemia Reperfusion Injury through KLF-Regulated Alleviation of Inflammation

Objective. To clarify the protective effect of simvastatin on myocardial ischemia reperfusion injury (MIRI) and the underlying mechanism. Materials and Methods. The MIRI model in rats was firstly constructed. Twenty-four male rats were randomly assigned into the sham group, ischemia-reperfusion (I/R) group, and simvastatin group, with 8 rats in each group. Contents of superoxide dismutase (SOD) and malondialdehyde (MDA), as well as serum levels of CK and inflammatory factors, in rats were determined by the enzyme-linked immunosorbent assay (ELISA). Lactate dehydrogenase (LDH) activity in the three groups was examined. Through flow cytometry and Cell Counting Kit-8 (CCK-8) assay, apoptosis and viability in each group were detected, respectively. Relative levels of HMGB1, Kruppel-like factor 2 (KLF2), eNOS, and thrombomodulin (TM) were finally determined. Results. Simvastatin treatment markedly enhanced SOD activity and reduced contents of MDA, LDH, and creatine kinase (CK) in MIRI rats. The increased apoptosis and decreased viability following MIRI were partially reversed by simvastatin treatment. Besides, MIRI resulted in the upregulation of inflammatory factors and chemokines. Their elevations were abolished by simvastatin. In MIRI rats, simvastatin upregulated KLF2 and p-eNOS. Conclusions. Simvastatin protects inflammatory response at post-MIRI through upregulating KLF2, thus improving cardiac function.

The effect of Guanxin Shutong capsule on alleviating the myocardial fibrosis in heart failure rats

ETHNOPHARMACOLOGICAL RELEVANCE

Guanxin Shutong (GXST) capsule is a renowned traditional Chinese medicine widely used for the treatment of cardiovascular diseases in the clinic. However, no pharmacological experimental studies of GXST has been reported on the treatment of pressure overload-induced heart failure. This study aimed to investigate the effects of GXST capsule on ameliorating myocardial fibrosis conditions in pressure overload-induced heart failure rats.

MATERIAL AND METHODS

Rats were randomly divided into 6 groups: Normal group, Model group, GXST-treated group at a dose of 0.5 g/kg, 1 g/kg, 2 g/kg, respectively, and digoxin positive control group at a dose of 1 mg/kg. After 4 weeks of administration, cardiac function was evaluated by echocardiography. Cardiac injury and fibrotic conditions were evaluated by H&E staining, Masson staining, and Sirius Red staining. Myocardial fibrosis was evaluated by immunohistochemistry staining and Western blot.

RESULTS

GXST significantly inhibited cardiac fibrosis, reduced the excessive deposition of collagen, and finally improved cardiac function. GXST reversed ventricular remodeling might be through the TGF-β/Smad3 pathway.

CONCLUSION

GXST capsule demonstrated a strong anti-fibrosis effect in heart failure rats by inhibiting the TGF-β/Smad3 signaling pathway.

Investigation of the Multi-Target Mechanism of Guanxin-Shutong Capsule in Cerebrovascular Diseases: A Systems Pharmacology and Experimental Assessment

Guanxin-Shutong capsule (GXSTC), a combination of Mongolian medicines and traditional herbs, has been clinically proven to be effective in treating cerebrovascular diseases (CBVDs). However, the underlying pharmacological mechanisms of GXSTC in CBVDs remain largely unknown. In this study, a combination of systems pharmacology and experimental assessment approach was used to investigate the bioactive components, core targets, and possible mechanisms of GXSTC in the treatment of CBVDs. A total of 15 main components within GXSTC were identified using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD) and a literature research. Fifty-five common genes were obtained by matching 252 potential genes of GXSTC with 462 CBVD-related genes. Seven core components in GXSTC and 12 core genes of GXSTC on CBVDs were further determined using the protein-protein interaction (PPI) and component-target-pathway (C-T-P) network analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis results predicted that the molecular mechanisms of GXSTC on CBVDs were mainly associated with the regulation of the vascular endothelial function, inflammatory response, and neuronal apoptosis. Molecular docking results suggested that almost all of core component-targets have an excellent binding activity (affinity < −5 kcal/mol). More importantly, in middle cerebral artery occlusion (MCAO) -injured rats, GXSTC significantly improved the neurological function, reduced the infarct volume, and decreased the percentage of impaired neurons in a dose-dependent manner. Western blotting results indicated that GXSTC markedly upregulated the expression of vascular endothelial growth factor A (VEGFA) and endothelial nitric oxide synthase (eNOS), while downregulating the expression of cyclooxygenase-2 (COX-2) and transcription factor AP-1 (c-Jun) in MCAO-injured rats. These findings confirmed our prediction that GXSTC exerts a multi-target synergetic mechanism in CBVDs by maintaining vascular endothelial function, inhibiting neuronal apoptosis and inflammatory processes. The results of this study may provide a theoretical basis for GXSTC research and the clinical application of GXSTC in CBVDs.

Study of the Mechanism of Action of Guanxin Shutong Capsules in the Treatment of Coronary Heart Disease Based on Metabolomics

Background: Guan-Xin-Shu-Tong capsule (GXSTC) is a traditional Chinese medicine (TCM) that has been used to treat coronary heart disease (CHD) for many years in China. However, the holistic mechanism of GXSTC against CHD is still unclear. Therefore, the purpose of this paper was to systematically explore the mechanism of action GXSTC in the treatment of CHD rats using a metabolomics strategy.

Methods: A CHD model was induced by ligation of the left anterior descending coronary artery (LAD). In each group, echocardiography was performed; the contents of creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate transaminase (AST) in serum were determined; and the myocardial infarct size was measured. The metabolites in plasma were analyzed by UHPLC-MS/MS-based untargeted metabolomics. Then, multivariate statistical analysis was performed to screen potential biomarkers associated with the GXSTC treatment in the LAD-induced rat CHD model. Finally, the MetaboAnalyst 4.0 platform was used for metabolic pathway enrichment analysis.

Results: GXSTC was able to regulate the contents of CK, LDH and AST; restore impaired cardiac function; and significantly reduce the myocardial infarction area in model rats. Twenty-two biomarkers and nine metabolic pathways of GXSTC in the treatment of CHD were identified through UHPLC-MS/MS-based untargeted metabolomics analysis.

Conclusion: GXSTC regulates metabolic disorders of endogenous components in LAD-induced CHD rats. The anti-CHD mechanism of GXSTC is mainly related to the regulation of amino acid, lipid and hormonal metabolism. This study provides an overall view of the mechanism underlying the action of GXSTC against CHD.

Effect of Guanxin V in animal model of acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI) is the most serious and lethal manifestation of coronary heart disease worldwide, presenting extremely high disability and mortality. Our previous studies have shown that Guanxin V (GXV) could significantly improve the cardiac function and the blood flow dynamics, and reduce serum levels of inflammatory factors in AMI rats, thus triggering ventricular remodeling (VR) at post-AMI.

METHODS

An in vivo AMI model was established in Syrian hamsters by performing the ligation of the left anterior descending coronary artery. Syrian hamsters were randomly divided into four groups, namely Sham operation group (n = 12), AMI group (n = 12), GXV group (GXV 6 g/Kg/d, n = 12), and Tranilast group (Tra 105 mg/Kg/d, n = 12). Drug intervention was conducted for consecutive 8 weeks. Relative biological indicators were measured in the 4th and 8th week, respectively.

RESULTS

Cardiac functions were improved, and the infarcted size and heart weight index were limited in Syrian hamsters of GXV and Tra groups compared with those in AMI group. Furthermore, GXV was able to decrease the number of mast cells and chymase level in Syrian hamsters with AMI. Administration of GXV remarkably inactivated the renin-angiotension-aldosterone system, and alleviated myocardial fibrosis and cardiomyocyte apoptosis, thus slowing down VR at post-AMI.

CONCLUSION

GXV slows down the process of VR at post-AMI by reducing chymase level and mast cells number, as well as inactivating the reninangiotension-aldosterone system..

Effects of Guanxinshutong Capsules as Complementary Treatment in Patients With Chronic Heart Failure: Study Protocol for a Randomized Controlled Trial

Chronic heart failure (CHF) is a common cardiovascular disease with high mortality and a poor prognosis, which places heavy burdens upon society and families. Traditional Chinese medicine (TCM) has been used extensively as complementary treatment for CHF. Guanxinshutong (GXST) capsules are used commonly for the treatment of coronary heart disease (CHD). Experimental research and small-sample clinical trials have shown that GXST can attenuate CHF. However, the effects of GXST as complementary medicine in CHF treatment lack high-quality clinical evidence. We have designed a multicenter, randomized, double-blind, placebo-controlled clinical trial that explores the efficacy and safety of using GXST compared with placebo for patients with CHF with reduced left ventricular ejection fraction (LVEF). A total of 480 participants will be assigned randomly to the GXST group or placebo group at a 2:1 ratio. GXST and placebo will be added to standard treatment for 12 weeks, and then followed up for another 40 weeks. The primary outcome is the improvement value of 6-min walk distance, and the secondary outcomes include plasma levels of N-terminal pro-B-type natriuretic peptide, New York Heart Association classification, Minnesota Living with Heart Failure Questionnaire scores, echocardiographic parameters, and clinical endpoint events. Adverse events will be monitored throughout the trial. Data will be analyzed following a predefined statistical analysis plan. This study will show the effects of the specific use of GXST in CHF patients with reduced LVEF. The Research Ethics Committee of the Second Affiliated Hospital of Zhejiang Chinese Medical University has approved this study (2019-Y-003-02). Written informed consent of patients will be required. This trial is registered in the Chinese Clinical Trial Registry (ChiCTR1900023877). Our results will be disseminated to the public through peer-reviewed journals, academic conferences, and the Internet.

Guanxinshutong Alleviates Atherosclerosis by Suppressing Oxidative Stress and Proinflammation in ApoE-/- Mice

Atherosclerosis (AS) is a chronic progressive disease related to dyslipidemia, inflammation, and oxidative stress. Guanxinshutong capsule (GXST), a traditional Chinese medicine, has been widely used in treating coronary atherosclerotic heart disease, while its mechanism actions on AS are still not to be well addressed. Our present study is aimed to examine the effect of GXST on AS and elucidate the multitarget mechanisms of GXST on AS. Network pharmacology analysis was employed to screen the multitarget mechanisms of GXST on AS. ApoE^−/− mice were used to validate these effects. Circulating lipid profile and oxidative stress-related factors were measured by the Elisa kit. Furthermore, the aortic trunk and aortic root were excised for oil red O staining, histopathological and immunohistochemical analysis. We first discovered that GXST was clued to exert synergistically antiatherosclerosis properties including lipid-lowering, anti-inflammation, and antioxidation through the computational prediction based on a network pharmacology simulation. Next, the validation experiments in atherosclerosis mice provided evidence that GXST significantly reduced atherosclerotic lesions, increased collagen deposition, and attenuated LV remodeling to some extent. Mechanistically, GXST modulated lipid profile, downregulated the level of inflammatory cytokines and NF-κBp65. GXST also reduced the activity of oxidative parameter MDA and upregulated the activities of antioxidant enzymes (SOD and GSH) compared with the AS model group. In conclusion, GXST intervention might attenuate atherosclerosis by mechanisms involving reducing lipid deposition, modulating oxidative stress and inflammatory responses, but a larger controlled trial is necessary for confirmation.

Guanxinshutong capsule ameliorates cardiac function and architecture following myocardial injury by modulating ventricular remodeling in rats

Guanxinshutong capsule (GXST), which consists of five traditional Chinese medicines, has been used for a long time in China for the treatment of cardiovascular diseases, such as coronary artery disease and myocardial infarction. However, the effects on GXST on myocardial injury (MI) have not been studied in detail. In these experiments, we found that GXST administration decreased MI-associated ventricular remodeling (VR) with a reduction in interventricular septal thickness in diastole (IVSd), left ventricular posterior wall diameter in systole (LVPWs), and left ventricular posterior wall diameter in diastole (LVPWd) to ameliorate cardiac function and architecture, as measured by echocardiography. Furthermore, histological analysis showed that GXST could ameliorate pathological alterations in the myocardium. And Sirius red staining, wheat germ agglutinin staining and inflammation-related immunohistochemistry results showed that GXST ameliorated the fibrosis areas, cardiac hypertrophy and inflammation (IL-6 and TNF-α). In addition, GXST upregulated intercellular junction proteins (N-cad and Cx-43) and downregulated the angiogenesis-related proteins (PDGF and VEGFA), myocardial fibrosis-related proteins (TGF-β1), and matrix metalloproteinase (MMP-2 and MMP-9). We also found that GXST medium-dose group (1 g/kg/d) dosage was the most efficacious. In conclusion, GXST protected cardiac tissues against MI by reducing VR, thus indicating the potential application of GXST in the treatment of MI.

Adeno-associated Virus 9-mediated Small RNA Interference of TLR4 Alleviates Myocardial Ischemia and Reperfusion Injury by Inhibition of the NF-κB and MAPK Signaling Pathways in Rats

BACKGROUND

Despite intensive investigation, effective therapeutic procedures for myocardial I/R injury are still in demand.

OBJECTIVE

To explore the effect of adeno-associated virus 9 (AAV9)-mediated small interfering RNA targeting TLR4 in the treatment of myocardial ischemia and reperfusion (I/R) injury and its influence on the NF-κB and MAPK signaling pathways.

METHODS

Rats were divided into 3 groups, namely, the sham, AAV9-siRNA control, and AAV9-TLR4 siRNA groups. siRNA solution or normal saline was injected through the tail vain. The rat myocardial I/R injury model was then established. HE staining and TUNEL staining were applied to compare the pathological changes in cardiomyocytes in the three groups. Immunohistochemical staining and western blotting were utilized to detect TLR4 expression under siRNA interference. Serum inflammatory factor (IL-1β, TNF-α) expression was determined by an ELISA commercial kit. Key proteins in the MAPK (p38, JNK 1/2) and NF-κB (p65) signaling pathways were determined to identify the TLR4 siRNA functional mechanism.

RESULTS

Fluorescence microscopic images of the myocardium indicated that AAV9- mediated siRNA was efficiently transfected into the myocardium, and the infarcted size after I/R injury was decreased by AAV9-TLR4 siRNA when compared with negative control rats (P<0.05). TLR4 protein expression was significantly decreased by siRNA interference (P<0.001). Apoptosis-related factor BCL-2 expression was increased in the TLR4 gene silencing group, whereas Bax expression was decreased. The Bax/BCL-2 ratio was also decreased, demonstrating a protective effect for cardiomyocytes. Inflammatory factors were lower in the TLR4 gene silencing group than in the siRNA control group (P<0.001). The MAPK and NF-κB signaling pathways were activated in myocardial I/R injury; however, the primary proteins in these two signaling pathways were downregulated upon interference of TLR4 siRNA, with significant differences (P<0.05).

CONCLUSION

AAV9-TLR4 siRNA has a positive effect on myocardial I/R injury by inhibiting the MAPK and NF-κB signaling pathways and can be used as a potential therapeutic method for myocardial I/R injury.

Efficacy and safety of oral Guanxinshutong capsules in patients with stable angina pectoris in China: a prospective, multicenter, double-blind, placebo-controlled, randomized clinical trial

BACKGROUND

To assess the efficacy and safety of oral Guanxinshutong (GXST) capsules in Chinese patients with stable angina pectoris (SAP) in a prospective, multicenter, double-Blind, placebo-controlled, randomized clinical trial (clinicaltrials.gov Identifier: NCT02280850).

METHODS

Eligible patients were randomized 1:1 to the GXST or placebo group. Current standard antianginal treatment except for nitrate drugs was continued in both groups, who received an additional 4-week treatment of GXST capsule or placebo. Primary endpoint was the change from baseline in angina attack frequency after the 4-week treatment. Secondary endpoints included the reduction of nitroglycerin dose, score of Seatntle Agina Questionnaire, exercise tolerance test defined as time to onset of chest pain and ST-segment depression at least 1 mm greater than the resting one.

RESULTS

A total of 300 SAP patients from 12 centers in China were enrolled between January 2013 and October 2015, and they were randomly divided into the GXST group and the placebo group (150 patients in each group). Of whom, 287 patients completed the study (143 patients in the GXST group, 144 patients in the placebo group). The baseline characteristics of the two groups were comparable. After 4-week treatment with GXST capsules, the number of angina attacks and the consumption of short-acting nitrates were significantly reduced. In addition, the quality of life of patients were also substantially improved in the GXST group. No significant differences in the time of onset of angina and 1-mm ST segment depression were noted between the two groups. 7 patients (4.1%) in the GXST group and 3 patients (2.1%) in the placebo group reported at least one adverse event, respectively.

CONCLUSIONS

GXST capsules are beneficial for the treatment of SAP patients.

Screening and analysis of key active constituents in Guanxinshutong capsule using mass spectrum and integrative network pharmacology

Guanxinshutong capsule (GXSTC) is an effective and safe traditional Chinese medicine used in the treatment of cardiovascular diseases (CVDs) for many years. However, the targets of this herbal formula and the underlying molecular mechanisms of action involved in the treatment of CVDs are still unclear. In the present study, we used a systems pharmacology approach to identify the active ingredients of GXSTC and their corresponding targets in the calcium signaling pathway with respect to the treatment of CVDs. This method integrated chromatographic techniques, prediction of absorption, distribution, metabolism, and excretion, analysis using Kyoto Encyclopedia of Genes and Genomes, network construction, and pharmacological experiments. 12 active compounds and 33 targets were found to have a role in the treatment of CVDs, and four main active ingredients, including protocatechuic acid, cryptotanshinone, eugenol, and borneol were selected to verify the effect of (GXSTC) on calcium signaling system in cardiomyocyte injury induced by hypoxia and reoxygenation. The results from the present study revealed the active components and targets of GXSTC in the treatment of CVDs, providing a new perspective to enhance the understanding of the role of the calcium signaling pathway in the therapeutic effect of GXSTC.

Endogenous ornithine decarboxylase/polyamine system mediated the antagonist role of insulin/PEG-CMCS preconditioning against heart ischemia/reperfusion injury in diabetes mellitus

INTRODUCTION

Insulin has shown antioxidation and cytoprotective effects to decrease heart ischemia/reperfusion injury (HI/RI) in diabetes mellitus (DM), but the role of insulin/poly(ethylene glycol)-carboxymethyl chitosan (PEG-CMCS) on HI/RI in DM is not known. This research explored whether insulin/PEG-CMCS revealed a protective effect on HI/RI in DM through ornithine decarboxylase (ODC)/polyamine systems.

MATERIALS AND METHODS

Diabetes was induced via streptozotocin (STZ) in Sprague Dawley (SD) rats, which suffered from HI via blocking the left circumflex artery for 45 minutes, followed by 2 hours of reperfusion. α-Difluoromethylornithine-ethylglyoxal bis (guanylhydrazone) (DFMO-EGBG) and insulin/PEG-CMCS were administered to diabetic rats to explore their roles on severity of HI/RI.

RESULTS

Insulin could be fleetly and efficiently loaded via the nanocarrier PEG-CMCS at pH =6, showing efficient loading and stable release. In addition, insulin/PEG-CMCS showed significant hypoglycemic activity in diabetic rats. On the other hand, ischemia/reperfusion obviously augmented the contents of creatine kinase (CK), lactic dehydrogenase (LDH), putrescine (Pu), myocardial infarct size, and NF-κB and spermidine/spermine N'-acetyltransferase (SSAT) expressions and decreased the levels of spermine (Sp), polyamine pools (PAs), heart rate (HR), coronary blood flow (CF), left ventricular developed pressure (LVDP), and ODC expression, compared with Sham. Administration of insulin and insulin/PEG-CMCS both reduced the contents of CK, LDH, Pu, myocardial infarct size, and NF-κB and SSAT expressions and increased the levels of Sp, PAs, HR, CF, LVDP, and ODC expression, while insulin/PEG-CMCS significantly indicated the protective results, and DFMO-EGBG showed the opposite effects.

CONCLUSION

The research showed that insulin/PEG-CMCS could play a protective effect on HR/RI in diabetic rats via its antioxidative, antiapoptotic, and anti-inflammatory roles and modulating ODC/polyamine systems.

Advancements in pharmacotherapy for angina

Angina pectoris is the most prevalent symptomatic manifestation of ischemic heart disease, frequently leads to a poor quality of life, and is a major cause of medical resource consumption. Since the early descriptions of nitrite and nitrate in the 19th century, there has been considerable advancement in the pharmacologic management of angina. Areas covered: Management of chronic angina is often challenging for clinicians. Despite introduction of several pharmacological agents in last few decades, a significant proportion of patients continue to experience symptoms (i.e., refractory angina) with subsequent disability. For the purpose of this review, we searched PubMed and Cochrane databases from inception to August 2016 for the most clinically relevant publications that guide current practice in angina therapy and its development. In this article, we briefly review the pathophysiology of angina and mechanism-based classification of current therapy. This is followed by evidence-based insight into the traditional and novel pharmacotherapeutic agents, highlighting their clinical usefulness. Expert opinion: Considering the wide array of available therapies with different mechanism efficacy and limiting factors, a personalized approach is essential, particularly for patients with refractory angina. Ongoing research with novel pharmacologic modalities is likely to provide new options for management of angina.

Effects and mechanisms of compound Chinese medicine and major ingredients on microcirculatory dysfunction and organ injury induced by ischemia/reperfusion

Microcirculation dysfunction and organ injury after ischemia and reperfusion (I/R) result from a complex pathologic process consisting of multiple links, with metabolism impairment in the ischemia phase and oxidative stress in the reperfusion phase as initiators, and any treatment targeting a single link is insufficient to cope with this. Compound Chinese medicine (CCM) has been applied in clinics in China and some Asian nations for >2000years. Studies over the past decades revealed the protective and therapeutic effect of CCMs and major ingredients on I/R-induced microcirculatory dysfunction and tissue injury in the heart, brain, liver, intestine, and so on. CCM contains diverse bioactive components with potential for energy metabolism regulation; antioxidant effect; inhibiting inflammatory cytokines release; adhesion molecule expression in leukocyte, platelet, and vascular endothelial cells; and the protection of thrombosis, albumin leakage, and mast cell degranulation. This review covers the major works with respect to the effects and underlying mechanisms of CCM and its ingredients on microcirculatory dysfunction and organ injury after I/R, providing novel ideas for dealing with this threat.

Picroside II protects myocardium from ischemia/reperfusion-induced injury through inhibition of the inflammatory response

The inflammatory response is important in the pathogenesis of myocardial ischemia/reperfusion (I/R) injury. Picroside II, the primary active constituent of Picrorhizae, has been reported to protect the myocardium from I/R-induced injury, however, the exact mechanism underlying these protective effects remains unclear. The aim of the present study was to investigate the mechanism underlying the protective effects of picroside II on I/R-induced myocardial injury. Adult male Sprague-Dawley rats underwent 1 h left coronary artery occlusion followed by 3 h reperfusion. Picroside II was administered (10 mg/kg) via the tail vein 30 min prior to left coronary artery occlusion. The results revealed that pretreatment of picroside II could significantly alleviate I/R-induced myocardial injury concomitantly with a decrease in inflammatory factor production. In addition, picroside II was also able to decrease high mobility group box 1 (HMGB1) expression, and release and downregulate the expression of the receptor for advanced glycation end products (RAGE), toll-like receptor (TLR)-2 and TLR-4. Furthermore, picroside II was able to inhibit nuclear factor-κB (NF-κB) activation. The results indicated that the protective effect of picroside II on I/R-induced myocardial injury was associated, at least partly, with inhibition of the inflammatory response by suppressing the HMGB1-RAGE/TLR-2/TLR-4-NF-κB signaling pathway.

Pretreatment with low-dose gadolinium chloride attenuates myocardial ischemia/reperfusion injury in rats

AIM

We have shown that low-dose gadolinium chloride (GdCl3) abolishes arachidonic acid (AA)-induced increase of cytoplasmic Ca(2+), which is known to play a crucial role in myocardial ischemia/reperfusion (I/R) injury. The present study sought to determine whether low-dose GdCl3 pretreatment protected rat myocardium against I/R injury in vitro and in vivo.

METHODS

Cultured neonatal rat ventricular myocytes (NRVMs) were treated with GdCl3 or nifedipine, followed by exposure to anoxia/reoxygenation (A/R). Cell apoptosis was detected; the levels of related signaling molecules were assessed. SD rats were intravenously injected with GdCl3 or nifedipine. Thirty min after the administration the rats were subjected to LAD coronary artery ligation followed by reperfusion. Infarction size, the release of serum myocardial injury markers and AA were measured; cell apoptosis and related molecules were assessed.

RESULTS

In A/R-treated NRVMs, pretreatment with GdCl3 (2.5, 5, 10 μmol/L) dose-dependently inhibited caspase-3 activation, death receptor-related molecules DR5/Fas/FADD/caspase-8 expression, cytochrome c release, AA release and sustained cytoplasmic Ca(2+) increases induced by exogenous AA. In I/R-treated rats, pre-administration of GdCl3 (10 mg/kg) significantly reduced the infarct size, and the serum levels of CK-MB, cardiac troponin-I, LDH and AA. Pre-administration of GdCl3 also significantly decreased the number of apoptotic cells, caspase-3 activity, death receptor-related molecules (DR5/Fas/FADD) expression and cytochrome c release in heart tissues. The positive control drug nifedipine produced comparable cardioprotective effects in vitro and in vivo.

CONCLUSION

Pretreatment with low-dose GdCl3 significantly attenuates I/R-induced myocardial apoptosis in rats by suppressing activation of both death receptor and mitochondria-mediated pathways.