Qilong capsule prevents myocardial ischemia/reperfusion injury by inhibiting platelet activation via the platelet CD36 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Qilong capsule (QC) is developed from the traditional Chinese medicine formula Buyang Huanwu Decoction, which has been clinically used to invigorate Qi and promote blood circulation to eliminate blood stasis. Myocardial ischemia‒reperfusion injury (MIRI) can be attributed to Qi deficiency and blood stasis. However, the effects of QC on MIRI remain unclear. AIM OF THE STUDY: This study aimed to investigate the protective effect and possible mechanism of QC on platelet function in MIRI rats. MATERIALS AND METHODS: The left anterior descending artery of adult Sprague‒Dawley rats was ligated for 30 min and then reperfused for 120 min with or without QC treatment. Then, the whole blood viscosity, plasma viscosity, coagulation, platelet adhesion rate, platelet aggregation, and platelet release factors were evaluated. Platelet CD36 and its downstream signaling pathway-related proteins were detected by western blotting. Furthermore, the active components of QC and the molecular mechanism by which QC regulates platelet function were assessed via molecular docking, platelet aggregation tests in vitro and BLI analysis. RESULTS: We found that QC significantly reduced the whole blood viscosity, plasma viscosity, platelet adhesion rate, and platelet aggregation induced by ADP or AA in rats with MIRI. The inhibition of platelet activation by QC was associated with reduced levels of ß-TG, PF-4, P-selectin and PAF. Mechanistically, QC effectively attenuated the expression of platelet CD36 and thus inhibited the activation of Src, ERK5, and p38. The active components of QC apparently suppressed platelet aggregation in vitro and regulated the CD36 signaling pathway. CONCLUSIONS: QC improves MIRI-induced hemorheological disorders, which might be partly attributed to the inhibition of platelet activation via CD36-mediated platelet signaling pathways.

Roles of flavonoids in ischemic heart disease: Cardioprotective effects and mechanisms against myocardial ischemia and reperfusion injury.

BACKGROUND: Flavonoids are extensively present in fruits, vegetables, grains, and medicinal plants. Myocardial ischemia and reperfusion (MI/R) comprise a sequence of detrimental incidents following myocardial ischemia. Research indicates that flavonoids have the potential to act as cardioprotective agents against MI/R injuries. Several specific flavonoids, e.g., luteolin, hesperidin, quercetin, kaempferol, and puerarin, have demonstrated cardioprotective activities in animal models. PURPOSE: The objective of this review is to identify the cardioprotective flavonoids, investigate their mechanisms of action, and explore their application in myocardial ischemia. METHODS: A search of PubMed database and Google Scholar was conducted using keywords "myocardial ischemia" and "flavonoids". Studies published within the last 10 years reporting on the cardioprotective effects of natural flavonoids on animal models were analyzed. RESULTS: A total of 55 natural flavonoids were identified and discussed within this review. It can be summarized that flavonoids regulate the following main strategies: antioxidation, anti-inflammation, calcium modulation, mitochondrial protection, ER stress inhibition, anti-apoptosis, ferroptosis inhibition, autophagy modulation, and inhibition of adverse cardiac remodeling. Additionally, the number and position of OH, 3'4'-catechol, C2=C3, and C4=O may play a significant role in the cardioprotective activity of flavonoids. CONCLUSION: This review serves as a reference for designing a daily diet to prevent or reduce damages following ischemia and screening of flavonoids for clinical application.

Investigation of the active ingredients of Shuangshen Ningxin Fomula and the mechanism underlying their protective effects against myocardial ischemia-reperfusion injury by mass spectrometric imaging.

BACKGROUND: Traditional Chinese medicine, particularly Shuangshen Ningxin Capsule (SSNX), has been studied intensely. SSNX includes total ginseng saponins (from Panax ginseng Meyer), total phenolic acids from Salvia miltiorrhiza Bunge, and total alkaloids from Corydalis yanhusuo W. T. Wang. It has been suggested to protect against myocardial ischemia by a mechanism that has not been fully elucidated. METHODS: The composition and content of SSNX were determined by UHPLC-Q-TOFQ-TOF / MS. Then, a rat model of myocardial ischemia-reperfusion injury was established, and the protective effect of SSNX was measured. The protective mechanism was investigated using spatial metabolomics. RESULTS: We found that SSNX significantly improved left ventricular function and ameliorated pathological damages in rats with myocardial ischemia-reperfusion injury. Using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), the protective mechanism of SSNX was examined by comparing the monomer components of drugs targeted in myocardial tissue with the distribution of myocardial energy metabolism-related molecules and phospholipids. Interestingly, some lipids display inconsistent content distribution in the myocardial ischemia risk and non-risk zones. These discrepancies reflect the degree of myocardial injury in different regions. CONCLUSION: These findings suggest that SSNX protects against myocardial ischemia-reperfusion injury by correcting abnormal myocardial energy metabolism, changing the levels and distribution patterns of phospholipids, and stabilizing the structure of the myocardial cell membrane. MALDI-TOF MS can detect the spatial distribution of small molecule metabolites in the myocardium and can be used in pharmacological research.

Gram-Scale Total Synthesis of TAB with Cardioprotective Activity and the Structure-Activity Relationship of Its Analogs.

Traditional Chinese medicine has been proven to be of great significance in cardioprotective effects. Clinopodium chinense (Lamiaceae) has unique advantages in the treatment and prevention of cardiovascular diseases. Tournefolic acid B (TAB) was proven to be a potent component against myocardial ischemia reperfusion injury (MIRI) from Clinopodium chinense (Lamiaceae). This article will attempt to establish a gram-scale synthesis method of TAB and discuss the structure-activity relationship of its analogs. The total synthesis of TAB was completed in 10 steps with an overall yield of 13%. In addition, analogs were synthesized, and their cardioprotective activity was evaluated on the hypoxia/reoxygenation of H9c2 cells. Amidation of the acid position is helpful to the activity, while methylation of phenolic hydroxyl groups greatly decreased the cardioprotective activity. The easily prepared azxepin analogs also showed cardioprotective activity. Most of the clogP values calculated by Molinspiration ranged from 2.5 to 5, which is in accordance with Lipinski's rule of 5. These findings represent a novel kind of cardioprotective agent that is worthy of further study.

The plant-derived alkaloid aloperine prevents ischemia/reperfusion injury-induced sudden cardiac death.

Sudden cardiac death (SCD) remains a major cause of global mortality. In addition to modern interventions, botanical folk medicines have long been used to treat cardiovascular disease, although the efficacy and underlying mechanisms are often unresolved. Aloperine, a bioactive quinolizidine alkaloid isolated from Sophora alopecuroides plants, exhibits antioxidant, anti-inflammatory, antitumor, and vasorelaxant properties, but possible antiarrhythmic effects of aloperine in SCD are unclear. Here, we examined whether aloperine protects against ischemia and reperfusion injury-associated lethal ventricular arrhythmia and sudden cardiac death. Rats were divided into sham, control, and aloperine groups, and reperfusion-provoked ventricular arrhythmogenesis, cardiac damage markers, and signaling pathways quantified following left main coronary artery ischemia and reperfusion. In vitro studies of effects of aloperine on hERG and Kv4.3 cardiac voltage-gated potassium (Kv) channels were performed using two-electrode voltage clamp analysis of cloned channels expressed in Xenopus laevis oocytes. Aloperine pretreatment (10 mg/kg) did not affect baseline cardiac electrical stability; yet, it reduced ventricular arrhythmogenesis and susceptibility to SCD (mortality rate: control: 64.3%; aloperine: 0%) induced by reperfusion injury. Aloperine also reduced serum levels of LDH, CK-MB, α-HBDH, and cTnI post-I/R, and stimulated phosphorylation of ventricular ERK1/2 and STAT-3, which are key components of RISK and SAFE signaling pathways. Inhibition of either ERK1/2 (with U0126) or STAT-3 (with Ag490) abolished aloperine-induced anti-arrhythmic effects and ERK1/2 and STAT-3 phosphorylation. Interestingly, while aloperine (100 µM) had no effect on cloned Kv4.3 activity, aloperine (1 µM and up) negative-shifted the voltage dependence of hERG activation by ~10 mV and increased peak hERG current by 35%. Thus, aloperine exerts striking anti-arrhythmic effects against myocardial ischemia and reperfusion injury-induced severe lethal ventricular arrhythmia and sudden cardiac death via the ERK1/2/STAT-3 signaling pathway, with potential additional contribution from increased cardiac myocyte repolarization capacity via augmented hERG activity.

Dunaliella salina Alga Protects against Myocardial Ischemia/Reperfusion Injury by Attenuating TLR4 Signaling.

Myocardial ischemia/reperfusion (I/R) injury is marked by rapid increase in inflammation and not only results in myocardial apoptosis but also compromises the myocardial function. Dunaliella salina (D. salina), a halophilic unicellular microalga, has been used as a provitamin A carotenoid supplement and color additive. Several studies have reported that D. salina extract could attenuate lipopolysaccharides-induced inflammatory effects and regulate the virus-induced inflammatory response in macrophages. However, the effects of D. salina on myocardial I/R injury remain unknown. Therefore, we aimed to investigate the cardioprotection of D. salina extract in rats subjected to myocardial I/R injury that was induced by occlusion of the left anterior descending coronary artery for 1 h followed by 3 h of reperfusion. Compared with the vehicle group, the myocardial infarct size significantly decreased in rats that were pre-treated with D. salina. D. salina significantly attenuated the expressions of TLR4, COX-2 and the activity of STAT1, JAK2, IκB, NF-κB. Furthermore, D. salina significantly inhibited the activation of caspase-3 and the levels of Beclin-1, p62, LC3-I/II. This study is the first to report that the cardioprotective effects of D. salina may mediate anti-inflammatory and anti-apoptotic activities and decrease autophagy through the TLR4-mediated signaling pathway to antagonize myocardial I/R injury.

Panax ginseng against myocardial ischemia/reperfusion injury: A review of preclinical evidence and potential mechanisms.

ETHNOPHARMACOLOGICAL RELEVANCE: Panax ginseng C. A. Meyer (P. ginseng) is effective in the prevention and treatment of myocardial ischemia-reperfusion (I/R) injury. The mechanism by which P. ginseng exerts cardioprotective effects is complex. P. ginseng contains many pharmacologically active ingredients, such as molecular glycosides, polyphenols, and polysaccharides. P. ginseng and each of its active components can potentially act against myocardial I/R injury. Myocardial I/R was originally a treatment for myocardial ischemia, but it also induced irreversible damage, including oxygen-containing free radicals, calcium overload, energy metabolism disorder, mitochondrial dysfunction, inflammation, microvascular injury, autophagy, and apoptosis. AIM OF THE STUDY: This study aimed to clarify the protective effects of P. ginseng and its active ingredients against myocardial I/R injury, so as to provide experimental evidence and new insights for the research and application of P. ginseng in the field of myocardial I/R injury. MATERIALS AND METHODS: This review was based on a search of PubMed, NCBI, Embase, and Web of Science databases from their inception to February 21, 2022, using terms such as "ginseng," "ginsenosides," and "myocardial reperfusion injury." In this review, we first summarized the active ingredients of P. ginseng, including ginsenosides, ginseng polysaccharides, and phytosterols, as well as the pathophysiological mechanisms of myocardial I/R injury. Importantly, preclinical models with myocardial I/R injury and potential mechanisms of these active ingredients of P. ginseng for the prevention and treatment of myocardial disorders were generally summarized. RESULTS: P. ginseng and its active components can regulate oxidative stress related proteins, inflammatory cytokines, and apoptosis factors, while protecting the myocardium and preventing myocardial I/R injury. Therefore, P. ginseng can play a role in the prevention and treatment of myocardial I/R injury. CONCLUSIONS: P. ginseng has a certain curative effect on myocardial I/R injury. It can prevent and treat myocardial I/R injury in several ways. When ginseng exerts its effects, should be based on the theory of traditional Chinese medicine and with the help of modern medicine; the clinical efficacy of P. ginseng in preventing and treating myocardial I/R injury can be improved.

Effects of electroacupuncture with dexmedetomidine on myocardial ischemia/reperfusion injury in rats.

BACKGROUND: To investigate the protective effect of electroacupuncture combined with dexmedetomidine (EA + Dex) on oxidative stress injury in myocardial ischemia/reperfusion (I/R) rats. METHODS: A total of 50 male Sprague-Dawley (SD) rats were randomly divided into 5 groups: sham operation (sham group); I/R group; dexmedetomidine group (Dex group); electroacupuncture group (EA group); and EA + Dex group. The myocardial I/R model was established. The EA group received EA at the Neiguan acupoint [pericardium 6 (PC6)] every day for 1 week before modeling. Rats in the EA + Dex group received EA at PC6 every day for 1 week before modeling, and intraperitoneal injection of Dex was performed 15 minutes before modeling. Dex was injected intraperitoneally in the Dex group 15 minutes before modeling. The rats were sacrificed 1 hour after reperfusion, and myocardial tissue was obtained to measure the myocardial infarction area. The myocardial tissue pathologic changes were shown by hematoxylin and eosin (HE) staining, and the superoxide dismutase (SOD), malondialdehyde (MDA), adenosine triphosphate (ATP), and reactive oxygen species (ROS) content in serum was determined. RESULTS: Compared with the sham group, the myocardial infarction area was significantly increased (P<0.01), SOD and ATP content was significantly decreased (P<0.01), and MDA and ROS content was significantly increased (P<0.01) in the I/R group; this change was significantly reduced in the Dex, EA, and EA + Dex groups (P<0.01). The indicators in the EA + Dex group were better than those in the EA and Dex groups (P<0.05). There was no significant change in the above indices in the Dex group compared with the EA group (P>0.05). CONCLUSIONS: EA + Dex pretreatment improved the damage of myocardial I/R by increasing SOD and ATP content and reducing the generation of MDA and ROS in an oxygen-free radical system.

Guanxin V attenuates myocardial ischaemia reperfusion injury through regulating iron homeostasis.

CONTEXT: Guanxin V (GX), a traditional Chinese medicine formula, is safe and effective in the treatment of coronary artery disease. However, its protective effect on myocardial ischaemia reperfusion injury (MIRI) is unclear. OBJECTIVE: To investigate the cardioprotective effect of GX on MIRI and explore the potential mechanism. MATERIALS AND METHODS: Sprague-Dawley male rats were divided into Sham, MIRI and MIRI + GX groups. GX (6 g/kg) was administered to rats via intragastric administration for seven days before ischaemia reperfusion (IR) surgery. The infarct size, histopathology, serum enzyme activities, ultrastructure of the cardiac mitochondria were assessed. H9c2 cells were pre-treated with GX (0.5 mg/mL), and then exposed to hypoxia/reoxygenation (HR). The cell viability and LDH levels were measured. Network pharmacology was conducted to predict the potential mechanism. The related targets of GX were predicted using the TCMSP database, DrugBank database, etc. Finally, pharmacological experiments were used to validate the predicted results. RESULTS: In vivo, GX significantly reduced the myocardial infarct size from 56.33% to 17.18%, decreased the levels of AST (239.32 vs. 369.18 U/L), CK-MB (1324.61 vs. 2066.47 U/L) and LDH (1245.26 vs. 1969.62 U/L), and reduced mitochondrial damage. In vitro, GX significantly increased H9c2 cell viability (IC50 = 3.913 mg/mL) and inhibited the release of LDH (207.35 vs. 314.33). In addition, GX could maintain iron homeostasis and reduce oxidative stress level by regulating iron metabolism-associated proteins. CONCLUSIONS: GX can attenuate MIRI via regulating iron homeostasis, indicating that GX may act as a potential candidate for the treatment of MIRI.

Modified Taohong Siwu decoction improves cardiac function after myocardial ischaemia and reperfusion in rats by promoting endogenous stem cell mobilization and regulating metabolites.

CONTEXT: Taohong Siwu decoction (THSWD) has been shown to promote heart repair in myocardial infarction. OBJECTIVE: To determine the effects of modified THSWD (THSWD plus four ingredients) on myocardial ischaemia and reperfusion (I/R) injury. MATERIALS AND METHODS: Sixty Sprague-Dawley rats were randomly divided into the I/R group and three different modified THSWD dose groups (gavage administration, 1.215, 2.43, and 4.86 g, respectively). 2,3,5-Triphenyltetrazolium chloride and Evans blue staining were used to detect the infarct area at 24 h after treatment. The serum biochemical indexes and cell apoptosis were examined to determine myocardial injury. The number of endogenous stem cells, expression of stromal dell derived factor-1 (SDF-1) and stem cell factor (SCF), and cardiac function were measured at 4 weeks. The serum was collected for metabolomic analysis. RESULTS: The high-dose modified THSWD group presented a reduced infarction area (decreased by 21.3%), decreased levels of lactate dehydrogenase and creatinine kinase, attenuated cell apoptosis, and enhanced superoxide dismutase activity in early stage I/R compared with other groups. The serum SCF and SDF-1 levels were higher in the high-dose group than in the I/R group. At 4 weeks, the infarct size and collagen content were the lowest, and the ejection fraction and fractional shortening values were the highest in the high-dose group. Moreover, high-dose modified THSWD affected the metabolism of phosphonate and phosphonate, taurine, and hypotaurine. CONCLUSIONS: Endogenous stem cell mobilization and metabolic regulation were related to the cardioprotection of modified THSWD. We provided a new strategy and direction for the treatment of cardiovascular diseases with traditional Chinese medicine.

Phytochemical profile and protective effects on myocardial ischaemia-reperfusion injury of sweated and non-sweated Salvia miltiorrhiza. Bge alcoholic extracts.

OBJECTIVES: This study aims to compare the fingerprint and the content of the three components of sweated and non-sweated Salvia miltiorrhiza alcoholic extracts (SSAE and NSAE). It also aims to investigate the difference in protective effects of SSAE and NSAE on myocardial ischaemia-reperfusion injury (MIRI). METHODS: The fingerprints of SSAE and NSAE were established by HPLC with a UV detector to identify the common peaks and detect the content of the three major components (cryptotanshinone, tanshinone I and tanshinone IIA). The protective effects of SSAE and NSAE were compared with MIRI rat model after orally administered SSAE and NSAE (2 g/kg of raw drug) for 7 days. The ST segment, PR and QT interval changes and the infarct size were assessed in the rat hearts. Moreover, the activity of aspartate transaminase (AST), lactate dehydrogenase (LDH), superoxide dismutase (SOD) and the level of cardiac troponin I (cTn I) in serum as well as the cardiac H&E staining were evaluated. KEY FINDINGS: The results showed that the fingerprints of SSAE and NSAE were similar, and cluster analysis showed that the sweating methods had effects on the alcoholic extracts. The content determination showed that sweating could increase the total content of cryptotanshinone, tanshinone I and tanshinone IIA of S. miltiorrhiza. The results of electrocardiograms (ECG) showed that SSAE could make the ST segment drop more obviously, PR and QT intervals become shorter, and the size of the infarct much smaller. Compared with NSAE, SSAE had more significant effects on the enzymatic activity of AST, LDH and the level of cTn I in serum. The H&E staining showed that both SSAE and NSAE could reduce the degree of heart damage. CONCLUSIONS: The present investigation results demonstrated that sweating increased the content of tanshinone components in S. miltiorrhiza alcoholic extracts, and SSAE had a better protective effect on MIRI.

Recent advances in potential of Fisetin in the management of myocardial ischemia-reperfusion injury-A systematic review.

BACKGROUND: The primary therapeutic strategy in managing ischemic heart diseases is to restore the perfusion of the myocardial ischemic area by surgical methods that often result in an unavoidable injury called ischemia-reperfusion injury (IR). Fisetin is an effective flavonoid with antioxidant and anti-inflammatory properties, proven to be cardioprotective against IR injury in both in-vitro and invivo models, apart from its promising health benefits against cancer, diabetes, and neurodegenerative ailments. PURPOSE: The potential of fisetin in attenuating myocardial IR is inconclusive as the effectiveness of fisetin needs more understanding in terms of its possible target sites and underlying different mechanisms. Considering the surge in recent scientific interests in fisetin as a pharmacological agent, this review not only updates the existing preclinical and clinical studies with fisetin and its underlying mechanisms but also summarizes its possible targets during IR protection. METHODS: We performed a literature survey using search engines Pubmed, PMC, Science direct, Google, and research gate published across the years 2006-2021. The relevant studies were extracted from the databases with the combinations of the following keywords and summarized: myocardial ischemia-reperfusion injury, natural products, flavonoid, fisetin, PI3K, JAK-STAT, Nrf2, PKC, JNK, autophagy. RESULTS: Fisetin is reported to be effective in attenuating IR injury by delaying the clotting time, preserving the mitochondrial function, reducing oxidative stress, and inhibiting GSK 3ß. But it failed to protect diseased cardiomyocytes challenged to IR. As discussed in the current review, fisetin not only acts as a conventional antioxidant and anti-inflammatory agent to exert its biological effect but may also exert modulatory action on the cellular metabolism and adaptation via direct action on various signalling pathways that comprise PI3K, JAK-STAT, Nrf2, PKC, JNK, and autophagy. Moreover, the dosage of fisetin and co-morbidities like diabetes and obesity are found to be detrimental factors for cardioprotection. CONCLUSION: For further evaluation and smooth clinical translation of the fisetin molecule in IR treatment, researchers should pay close attention to the potential of fisetin to possibly alter the key cardioprotective pathways and dosage, as the efficacy of fisetin is tissue and cell type-specific and varies with different doses.

Improved Cardiac Function Following Ischemia Reperfusion Injury Using Exercise Preconditioning and L-Arginine Supplementation via Oxidative Stress Mitigation and Angiogenesis Amelioration.

The formation of new blood vessels in the ischemic area is a fundamental strategy that can reduce myocardial infarction-induced damage by mitigating hypoxia. This paper set out to investigate the cardioprotective effect of high-intensity interval training preconditioning and L-arginine supplementation on myocardial ischemia-reperfusion-induced angiogenesis and oxidative stress. 50 male rats were randomly distributed into following groups: (1) Sham, (2) Sedentary control (Con, n = 10), 3) L-arginine treatment (La, n = 10), (4) High-Intensity Interval Training (HIIT, n = 10), and High-Intensity Interval Training plus L-arginine supplementation (HIIT + La, n = 10). Rats in the training groups performed high-intensity interval training for 8 weeks (5 day per week). Subjects in La and HIIT + La groups received L-arginine in drinking water (4 g/L). 72 h after treatments, all subjects underwent myocardial ischemia-reperfusion operation. Cardiac function, angiogenesis, stress oxidative, and infarction size were measured after reperfusion. Results showed exercise training and L-arginine supplementation promoted Cat and GSH activities and decreased MDA activity following myocardial ischemia-reperfusion injury in non-infarcted area. Compared with the con group, VEGF and Ang-1 as well as Ang-1 to Ang-2 ratio following myocardial ischemia-reperfusion in the non-infarct area were higher in La + HIIT group. Meanwhile, capillary density and capillary-to-muscle fiber ratio were higher in response to training and L-arginine supplementation. HIIT and L-arginine alone and synergistically decreased ischemia-reperfusion-induced infarction size. Cardiac output and stroke volume ameliorate in response to exercise training and L-arginine supplementation. Taken together, exercise preconditioning and l-arginine supplementation improved left ventricular function following ischemia-reperfusion by stress oxidative mitigation and angiogenesis amelioration.

Advances in research on the protective mechanisms of traditional Chinese medicine (TCM) in myocardial ischaemia-reperfusion injury.

CONTEXT: Developing effective drugs to treat myocardial ischaemia-reperfusion (MI/R) injury is imperative. Traditional Chinese medicines (TCMs) have had considerable success in the treatment of cardiovascular diseases. Elucidating the mechanisms by which TCMs improve MI/R injury can supplement the literature on MI/R prevention and treatment. OBJECTIVE: To summarise TCMs and their main protective mechanisms against MI/R injury reported over the past 40 years. METHODS: Relevant literature published between 1980 and 2020 in Chinese and English was retrieved from the Web of Science, PubMed, SpringerLink, PubMed Central, Scopus, and Chinese National Knowledge Infrastructure (CNKI) databases. Search terms included 'medicinal plants', 'myocardial ischaemia reperfusion injury', 'Chinese medicine prescriptions', 'mechanisms', 'prevention', 'treatment' and 'protection'. For inclusion in the analysis, medicinal plants had to be searchable in the China Medical Information Platform and Plant Database. RESULTS: We found 71 medicinal species (from 40 families) that have been used to prevent MI/R injury, of which Compositae species (8 species) and Leguminosae species (7 species) made up the majority. Most of the effects associated with these plants are described as antioxidant and anti-inflammatory. Furthermore, we summarised 18 kinds of Chinese compound prescriptions, including the compound Danshen tablet and Baoxin pill, which mainly reduce oxidative stress and regulate mitochondrial energy metabolism. DISCUSSION AND CONCLUSIONS: We summarised TCMs that protect against MI/R injury and their pharmacological mechanisms. This in-depth explanation of the roles of TCMs in MI/R injury protection provides a theoretical basis for the research and development of TCM-based treatment drugs.

Electroacupuncture at PC6 (Neiguan) Attenuates Angina Pectoris in Rats with Myocardial Ischemia-Reperfusion Injury Through Regulating the Alternative Splicing of the Major Inhibitory Neurotransmitter Receptor GABRG2.

Angina pectoris is the most common manifestation of coronary heart disease, causing suffering in patients. Electroacupuncture at PC6 can effectively alleviate angina by regulating the expression of genes, whether the alternative splicing (AS) of genes is affected by acupuncture is still unknown. We established a rat model of myocardial ischemia-reperfusion by coronary artery ligation and confirmed electroacupuncture alleviated the abnormal discharge caused by angina pectoris measured in EMG electromyograms. Analysis of the GSE61840 dataset established that AS events were altered after I/R and regulated by electroacupuncture. I/R decreased the expression of splicing factor Nova1 while electroacupuncture rescued it. Further experiments in dorsal root ganglion cells showed Nova1 regulated the AS of the GABRG2, specifically on its exon 9 where an important phosphorylation site is present. In vivo, results also showed that electroacupuncture can restore AS of GABRG2. Our results proved that electroacupuncture alleviates angina results by regulating alternative splicing.

Anshen-Buxin-Liuwei pill, a Mongolian medicinal formula could alleviate cardiomyocyte hypoxia/reoxygenation injury via mitochondrion pathway.

BACKGROUND: Anshen Buxin Liuwei pill (ABLP) is a Mongolian medicinal formula that is composed of six medicinal materials: the Mongolian medicine Bos taurus domesticus Gmelin, Choerospondias axillaris (Roxb.) Burtt et Hill, Myristica fragrans Houtt., Eugenia caryophµllata Thunb., Aucklandia lappa Decne., and Liqui dambar formosana Hance. ABLP is considered to have a therapeutic effect on symptoms such as coronary heart disease, angina pectoris, arrhythmia, depression and irritability, palpitation, and shortness of breath. METHODS: H9c2 cardiomyocytes were used to construct a hypoxia/reoxygenation (HR) injury model. CCK-8 assay and Annexin V-FITC cell apoptosis assays were used for cell viability and cell apoptosis determination. The LDH, SOD, MDA, CAT, CK, GSH-Px, Na+-K+-ATPase, and Ca2+-ATPase activities in cells were determined to assess the protective effects of ABLP. The mRNA levels of Sirtuin3 (Sirt3) and Cytochrome C (Cytc) in H9c2 cells were determined by quantitative real-time PCR. RESULTS: The results indicate that HR-treated cells began to shrink from the spindle in an irregular shape with some floated in the medium. By increasing the therapeutic dose of ABLP (5, 25, and 50 µg/mL), the cells gradually reconverted in a concentration-dependent manner. The release of CK in HR-treated cells was significantly increased, indicating that ABLP exerts a protective effect in H9c2 cells against HR injury and can improve mitochondrial energy metabolism and mitochondrial function integrity. The present study scrutinized the cardioprotective effects of ABLP against HR-induced H9c2 cell injury through antioxidant and mitochondrial pathways. CONCLUSIONS: ABLP could be a promising therapeutic drug for the treatment of myocardial ischemic cardiovascular disease. The results will provide reasonable information for the clinical use of ABLP.

Tubeimoside I Ameliorates Myocardial Ischemia-Reperfusion Injury through SIRT3-Dependent Regulation of Oxidative Stress and Apoptosis.

Myocardial ischemia-reperfusion injury (MIRI) is a phenomenon that reperfusion leads to irreversible damage to the myocardium and increases mortality in acute myocardial infarction (AMI) patients. There is no effective drug to treat MIRI. Tubeimoside I (TBM) is a triterpenoid saponin purified from Chinese traditional medicine tubeimu. In this study, 4 mg/kg TBM was given to mice intraperitoneally at 15 min after ischemia. And TBM treatment improved postischemic cardiac function, decreased infarct size, diminished lactate dehydrogenase release, ameliorated oxidative stress, and reduced apoptotic index. Notably, ischemia-reperfusion induced a significant decrease in cardiac SIRT3 expression and activity, while TBM treatment upregulated SIRT3's expression and activity. However, the cardioprotective effects of TBM were largely abolished by a SIRT3 inhibitor 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP). This suggests that SIRT3 plays an essential role in TBM's cardioprotective effects. In vitro, TBM also protected H9c2 cells against simulated ischemia/reperfusion (SIR) injury by attenuating oxidative stress and apoptosis, and siSIRT3 diminished its protective effects. Taken together, our results demonstrate for the first time that TBM protects against MIRI through SIRT3-dependent regulation of oxidative stress and apoptosis. TBM might be a potential drug candidate for MIRI treatment.

Majonoside-R2 Postconditioning Protects Cardiomyocytes Against Hypoxia/Reoxygenation Injury by Attenuating the Expression of HIF1α and Activating RISK Pathway.

Reoxygenation of hypoxic cardiac myocytes can paradoxically induce myocardial injury and affect the recovery processes. Pharmacological postconditioning is an efficient strategy used in clinical practice that protects cardiomyocytes from hypoxia/reoxygenation (HR) injury. Natural products or foods have been known to possess effective cardioprotective properties. Majonoside-R2 (MR2) is a dominant saponin component of Vietnamese ginseng that has several biological effects. In this study, we evaluated the protective effect of MR2 on HR-stimulated cardiomyocytes and investigated the related molecular mechanisms. H9C2 cardiomyocytes were exposed to HR conditions with or without MR2 supplementation. Samples from experimental groups were used to analyze the expression of apoptosis- and activating reperfusion injury salvage kinase (RISK)-related factors in response to HR injury by using enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blotting. Post-treatment, MR2 enhanced cell viability under HR conditions. We found that MR2 suppressed the expression of hypoxia-inducible factor 1-alpha (HIF1α) and transforming growth factor beta 1 (TGFß1), modulated Akt/GSK3ß/cAMP response element-binding signaling, and regulated gene expression related to apoptosis (B cell lymphoma-extra-large [Bcl-xl], Bcl-2 homologous killer [Bak], Bcl-2 associated X [Bax], and connexin 43 [Cnx43]). Thus, the present findings demonstrate that MR2 protects cardiomyocytes against HR injury by suppressing the expression of HIF1α and activating the RISK pathway.

Lycium barbarum polysaccharide protects rats and cardiomyocytes against ischemia/reperfusion injury via Nrf2 activation through autophagy inhibition.

The irreversible loss of cardiomyocytes is mainly the result of ischemic/reperfusion (I/R) myocardial injury, leading to persistent heart dysfunction and heart failure. It has been reported that Lycium barbarum polysaccharide (LBP) has protective effects on cardiomyocytes, but the specific mechanism is still not completely understood. The present study examined the protective role of LBP in myocardial I/R injury. Rats were subjected to myocardial I/R injury and LBP treatment. Moreover, rat myocardial H9C2 cells exposed to hypoxia/reoxygenation (H/R) were used to simulate cardiac injury during myocardial I/R process and were exposed to LBP, rapamycin (an autophagy activator) or nuclear factor­erythroid factor 2­related factor 2 (Nrf2) transfection. Morphological examination, histopathological examination and echocardiography were used to determine the cardiac injury after I/R injury. Cell viability and apoptosis were determined via MTT and flow cytometry assays, respectively. The levels of lactate dehydrogenase (LDH), creatine kinase (CK), cardiac troponin T (cTnT), IL­1ß, IL­6, TNF­α, malondialdehyde (MDA) and superoxidase dismutase (SOD) in rat serum, hearts and/or cells were assessed using ELISAs. The expression levels of Beclin 1, LC3II/LC3I, P62 and Nrf2 were analyzed via reverse transcription­quantitative PCR and western blotting. The results demonstrated that LBP improved heart function and repaired cardiomyocyte damage in I/R model rats, as well as reduced the production of cTnT, CK, LDH, IL­1ß, IL­6 and TNF­α. The in vitro study results indicated that LBP increased cell viability, the apoptosis rate, and the levels of SOD and P62, as well as reduced the levels of LDH, CK, IL­1ß, IL­6, TNF­α, MDA, Beclin 1 and LC3­II/LC3­I in H/R­injured H9C2 cells. Moreover, LBP promoted Nrf2 nuclear translocation, but decreased Nrf2 expression in the cytoplasm. Rapamycin exacerbated the aforementioned effects in H/R injured H9C2 cells, and partially reversed LBP­induced effects. Overexpressing Nrf2 counteracted I/R­induced effects and partially resisted rapamycin­induced effects. These findings demonstrated that LBP exhibited a cardiac protective effect on the ischemic myocardium of rats after reperfusion and attenuated myocardial I/R injury via autophagy inhibition­induced Nrf2 activation.

Electroacupuncture interventions alleviates myocardial ischemia reperfusion injury through regulating gut microbiota in rats.

Electroacupuncture (EA) intervention has a remarkable cardioprotection against myocardial ischemia reperfusion injury (MIRI). Recently, it has been suggested that the gut microbiota plays an important role in regulating the progression and prognosis of MIRI. The purpose of this study was to illustrate the relationship between gut microbiota and cardioprotection of EA on MIRI. We conducted a MIRI model by ligating the left anterior descending coronary artery for 30 min followed by reperfusion in male Sprague Dawley rats, which then received 7 days of EA intervention. Echocardiography was employed to evaluate left ventricular function. Fecal samples were collected for microbial analysis by 16S rDNA high-throughput sequencing. Blood samples and myocardium were collected for inflammatory cytokine detection by enzyme linked immunosorbent assay (ELISA) and Western blot. Hematoxylin & eosin (HE) staining and immunofluorescence of ileum tissue were performed for intestinal damage evaluation. After 7 days of EA intervention, the left ventricular function was improved with significantly increased ejection fraction and fractional shortening. Furthermore, we found that EA intervention reversed the changed gut microbiota induced by MIRI, including Clostridiales, RF39, S24-7, Desulfovibrio, and Allobaculum, improved the impaired gut barrier, reduced the production and circulation of lipopolysaccharide (LPS), inhibited the level of interleukin 6 (IL-6) and interleukin 12 (IL-12) in periphery and decreased the expression of Toll like receptor 4 (TLR4) and IL-6 in myocardium. EA intervention could improve the impaired gut mucosal barrier and reduce the production and circulation of LPS after MIRI through regulating gut microbiota, thus inhibiting the circulation and myocardium inflammation and finally exerted the cardioprotective effect.