lignans and Myocardial-Infarction

Epidemiologic and biological evidence supports an inverse association between polyphenol consumption and the risk of cardiovascular disease (CVD). However, no previous studies have prospectively evaluated the relationship between polyphenol intake and the incidence of CVD in such a comprehensive way. The aim was to evaluate the association between intakes of total polyphenol and polyphenol subgroups, and the risk of major cardiovascular events (myocardial infarction, stroke or death from cardiovascular causes) in the PREDIMED study.. The present work is an observational study within the PREDIMED trial. Over an average of 4.3 years of follow-up, there were 273 confirmed cases of CVD among the 7172 participants (96.3%) who completed a validated 137-item food frequency questionnaire (FFQ) at baseline. Polyphenol consumption was calculated by matching food consumption data from the FFQ with the Phenol-Explorer database on polyphenol content of each reported food. After multivariate adjustment, a 46% reduction in risk of CVD risk was observed comparing Q5 vs. Q1 of total polyphenol intake (HR = 0.54; 95% confidence interval [CI] = 0.33-0.91; P-trend = 0.04). The polyphenols with the strongest inverse associations were flavanols (HR = 0.40; CI 0.23-0.72; P-trend = 0.003), lignans (HR = 0.51; CI 0.30-0.86; P-trend = 0.007), and hydroxybenzoic acids (HR = 0.47; CI 0.26-0.86; P-trend 0.02).. Greater intake of polyphenols, especially from lignans, flavanols, and hydroxybenzoic acids, was associated with decreased CVD risk. Clinical trials are needed to confirm this effect and establish accurate dietary recommendations.

Topics: Age Factors; Aged; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Cardiovascular Diseases; Cohort Studies; Diet, Mediterranean; Female; Flavonols; Follow-Up Studies; Humans; Hydroxybenzoates; Incidence; Lignans; Male; Middle Aged; Myocardial Infarction; Nuts; Olive Oil; Plant Oils; Risk Factors; Spain; Stroke

In this study, we screened potential natural compounds for the treatment of myocardial infarction (MI) and explored the underlying mechanisms. We built three machine learning models to screen the potential compounds. qPCR, flow cytometry, immunohistochemistry, and immunofluorescence analyses were applied to analyze the pharmacological effects of the compounds on macrophages/monocytes in vivo and in vitro. Arctigenin (AG) was selected as a candidate, and echocardiography, Masson's trichrome staining, and TUNEL staining were utilized to detect the effect of AG on MI in vivo. Transcriptome analysis and subsequent bioinformatics analyses were performed to predict the target of the selected compound. Western blot and luciferase reporter assays were used to confirm the target and mechanism of AG. The reversibility of the effects of AG were verified through overexpression of NFAT5. The results showed that AG can improve cardiac injury after MI by reducing infarct size, improving heart function, and inhibiting cardiac death. In addition, AG suppresses inflammatory macrophages/monocytes and proinflammatory cytokines in vivo and in vitro. Transcriptomic and biological experiments revealed that AG modulates macrophage polarization via the NFAT5-induced signaling pathway. Therefore, our data suggest that AG can improve MI by inhibiting the inflammatory phenotype of macrophages/monocytes through targeting of NFAT5.

Topics: Animals; Furans; Heart; Inflammation; Lignans; Macrophages; Male; Mice; Mice, Inbred C57BL; Monocytes; Myocardial Infarction; Myocardium; RAW 264.7 Cells; Signal Transduction; Transcription Factors

Physiologically, following myocardial infarction (MI), retinoid levels elevate locally in the infarcted area. Whereas therapeutic systemic application of retinoids was shown to reduce the progression of ventricular dilatation and the onset of heart failure, the role of acute physiologically increased retinoids in the infarction zone is unknown to date. To reveal the role of local retinoids in the MI zone is the central aim of this study. Using human cell culture and co-culture models for hypoxia as well as various assays systems, lentivirus-based transgene expression, in silico molecular docking studies, and an MI model in rats, we analysed the impact of the retinoid all-trans retinoic acid (ATRA) on cell signalling, cell viability, tissue survival, heart function, and MI-induced death in rats. Based on our results, ATRA-mediated signalling does aggravate the MI phenotype (e.g. 2.5-fold increased mortality compared to control), whereas 5'-methoxyleoligin (5ML), a new agent which interferes with ATRA-signalling rescues the ATRA-dependent phenotype. On the molecular level, ATRA signalling causes induction of TXNIP, a potent inhibitor of the physiological antioxidant thioredoxin (TRX1) and sensitizes cells to necrotic cell death upon hypoxia. 5ML-mediated prevention of ATRA effects were shown to be based on the inhibition of cellular ATRA uptake by interference with the cholesterol (and retinol) binding motif of the transmembrane protein STRA6. 5ML-mediated inhibition of ATRA uptake led to a strong reduction of ATRA-dependent gene expression, reduced ROS formation, and protection from necrotic cell death. As 5ML exerted a cardioprotective effect, also independent of its inhibition of cellular ATRA uptake, the agent likely has another cardioprotective property, which may rely on the induction of TRX1 activity. In summary, this is the first study to show i) that local retinoids in the early MI zone may worsen disease outcome, ii) that inhibition of endothelial retinoid uptake using 5ML may constitute a novel treatment strategy, and iii) that targeting endothelial and myocardial retinoid uptake (e.g. via STRA6 inhibition) may constitute a novel treatment target in acute MI.

Topics: Animals; Cell Cycle Proteins; Cell Death; Cell Hypoxia; Human Umbilical Vein Endothelial Cells; Humans; Lignans; Male; Myocardial Infarction; Myocardium; Oxidative Stress; Rats; Retinoids; Signal Transduction

The natural medicinal monomer, schisandrin B (Sch B), has been shown to exert cardioprotective effects; however, the underlying mechanisms of these effects remain to be fully elucidated. Therefore, the aim of the present study was to investigate whether Sch B attenuated myocardial ischemia/reperfusion (I/R) injury via the phosphoinositide 3‑kinases (PI3K)/Akt signaling pathway. To confirm this, I/R models were established in rats by ligation of the left anterior descending coronary artery. A group of animals were administered with Sch B (60 mg/kg, lavage) and/or the PI3K inhibitor, LY294002 (0.3 mg/kg, intraperitoneal). Myocardial infarct size, myocardial infarct serum markers, myocardial apoptotic index and the expression of Akt were measured in each group. The results demonstrated that the administration of Sch B reduced the size of the myocardial infarct, and this effect was eliminated following LY294002 treatment. In addition, the administration of Sch B decreased the apoptotic index and the serum markers of myocardial infarction. Sch B administration also increased the expression of phosphorylated Akt, and Sch B treatment decreased the B‑cell lymphoma 2 (Bcl‑2)‑like protein 4/Bcl‑2 ratio and the expression of cleaved caspase‑3. Therefore, Sch B may protect myocardial tissue from I/R injury via the PI3K/Akt signaling pathway in rats.

Topics: Animals; Apoptosis; Biomarkers; Creatine Kinase, MB Form; Cyclooctanes; Disease Models, Animal; Lignans; Male; Myocardial Infarction; Myocardial Reperfusion Injury; Phosphatidylinositol 3-Kinases; Polycyclic Compounds; Protective Agents; Proto-Oncogene Proteins c-akt; Rats; Signal Transduction; Troponin T

The present study aimed to determine the protective effects of arctigenin against myocardial infarction (MI), and its effects on oxidative stress and inflammation in rats. Left anterior coronary arteries of Sprague‑Dawley rats were ligated, in order to generate an acute MI (AMI) model. Arctigenin was administered to AMI rats at 0, 50, 100 or 200 µmol/kg. Western blotting and ELISAs were performed to analyze protein expression and enzyme activity. Arctigenin was demonstrated to effectively inhibit the levels of alanine transaminase, creatine kinase‑MB and lactate dehydrogenase, and to reduce infarct size in AMI rats. In addition, the activity levels of malondialdehyde, interleukin (IL)‑1β and IL‑6 were significantly suppressed, and the levels of glutathione peroxidase, catalase and superoxide dismutase were significantly increased by arctigenin treatment. Arctigenin treatment also suppressed the protein expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX‑2) and heme oxygenase 1 (HO‑1), and increased the protein expression levels of phosphorylated‑extracellular signal‑regulated kinase 1/2 (p‑ERK1/2) in AMI rats. Overall, the results of the present study suggest that arctigenin may inhibit MI, and exhibits antioxidative and anti‑inflammatory effects through regulation of the iNOS, COX‑2, ERK1/2 and HO‑1 pathways in a rat model of AMI.

Topics: Animals; Cyclooxygenase 2; Enzymes; Furans; Gene Expression Regulation; Heme Oxygenase-1; Lignans; Male; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Myocardial Infarction; Nitric Oxide Synthase Type II; Oxidative Stress; Protective Agents; Rats; Rats, Sprague-Dawley

Traditional Chinese medicine (TCM) has been used in clinical practice for thousands of years and has accumulated considerable knowledge concerning the in vivo efficacy of targeting complicated diseases. TCM formulae are a mixture of hundreds of chemical components with multiple potential targets, essentially acting as a combination therapy of multi-component drugs. However, the obscure substances and the unclear molecular mechanisms are obstacles to their further development and internationalization. Therefore, it is necessary to develop new modern drugs based on the combination of effective components in TCM with exact clinical efficacy. In present study, we aimed to detect optimal ratio of the combination of effective components based on Sheng-Mai-San for myocardial ischemia.. On the basis of preliminary studies and references of relevant literature about Sheng-Mai-San for myocardial ischemia, we chose three representative components (ginsenoside Rb1 (G), ruscogenin (R) and schisandrin (S)) for the optimization design studies. First, the proper proportion of the combination was explored in different myocardial ischemia mice induced by isoproterenol and pituitrin based on orthogonal design. Then, the different proportion combinations were further optimized through uniform design in a multi-model and multi-index mode. Finally, the protective effect of combination was verified in three models of myocardial ischemia injured by ischemia/reperfusion, chronic intermittent hypoxia and acute infarction.. The optimized combination GRS (G: 6 mg/kg, R: 0.75 mg/kg, S: 6 mg/kg) obtained by experimental screening exhibited a significant protective effect on myocardial ischemia injury, as evidenced by decreased myocardium infarct size, ameliorated histological features, decreased myocardial myeloperoxidase (MPO) and malondiadehyde (MDA), calcium overload, and decreased serum lactate dehydrogenase (LDH), creatine kinase MB isoenzyme (CK-MB), cardiac troponin I (cTn-I) activity. In addition, the interactions of three components in combination GRS were also investigated. The combination, compared to G, R and S, could significantly reduce the concentration of serum CK-MB and cTn-I, and decrease myocardial infarct size, which demonstrated the advantages of this combination for myocardial ischemia.. Our results demonstrated that the optimized combination GRS could exert significant cardioprotection against myocardial ischemia injury with similar effect compared to Sheng Mai preparations, which might provide some pharmacological evidences for further development of new modern Chinese drug for cardiovascular diseases basing on traditional Chinese formula with affirmative therapeutic effect.

Topics: Animals; Creatine Kinase, MB Form; Cyclooctanes; Disease Models, Animal; Drug Combinations; Drugs, Chinese Herbal; Ginsenosides; Heart; Isoproterenol; L-Lactate Dehydrogenase; Lignans; Medicine, Chinese Traditional; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Myocardial Infarction; Myocardial Ischemia; Myocardial Reperfusion Injury; Myocardium; Pituitary Hormones, Posterior; Polycyclic Compounds; Spirostans; Troponin I

Arctigenin (ATG) has been shown to possess anti-inflammatory, immunemodulatory, anti-viral, anti-microbial, anti-carcinogenic, vasodilatory and anti-platelet aggregation properties. However, the protective role of ATG in prevention of arrhythmias induced by myocardial ischemia/reperfusion is unknown. The aim of this study was to investigate the anti-arrhythmia effect of ATG in an ischemia/reperfusion injured rat heart model and explore the related mechanisms.. Rats were randomly exposed to sham operation, myocardial ischemia/ reperfusion (MI/R) alone, ATG+ MI/R, pretreated with ATG in low (12.5 mg/kg/day), medium (50 mg/kg/day) and high dose (200 mg/kg/day), respectively. Ventricular arrhythmias were assessed. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the level of malondialdehyde (MDA) in myocardial tissue were determined by chemical analysis.. Compared to MI/R, rats pretreated with ATG in doses of 50 mg/kg/day and 200 mg/kg/day showed significantly reduced incidence and duration of ventricular fibrillation, ventricular tachycardia and ventricular ectopic beat (VEB), and decreased the arrhythmia score during the 30-min ischemia. Incidence and duration of ventricular tachycardia, infarction size and arrhythmia scores in these groups were significantly decreased during the 120-min reperfusion. No ventricular fibrillation occurred during the period of reperfusion. Rats pretreated with ATG in doses of 50 mg/kg/day and 200 mg/kg/ day markedly enhanced the activities of antioxidant enzymes SOD and GSH-Px, reduced the level of MDA. No differences were observed between the group pretreated with a low dose of ATG and the sham group. Administration of ATG significantly increased the expression of antioxidant stress protein Nrf2, Trx1 and Nox1.. Our data suggested that ATG plays anti-arrhythmia role in ischemia/reperfusion injury, which is probably associated with attenuating oxidative stress by Nrf2 signaling pathway.

Topics: Animals; Arrhythmias, Cardiac; Disease Models, Animal; Furans; Glutathione Peroxidase; Lignans; Male; Malondialdehyde; Myocardial Infarction; Myocardium; NADPH Oxidase 1; NF-E2-Related Factor 2; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Superoxide Dismutase; Thioredoxins

Myocardial infarction is a devastating event, especially when reperfusion is not performed. The inflammatory response has been associated with the pathogenesis of left ventricular remodeling after myocardial infarction. This study focused on the anti-apoptotic and anti-inflammatory effects of sesamin on ligation of the left anterior descending artery in an experimental mouse model and the potential mechanism underlying the activation of JNK and NF-κB pathways. Mice with MI induced by surgical left anterior descending coronary artery ligation were treated with sesamin by gavage for 1 week. Results showed that after treatment with sesamin, MI-induced cardiac damage was alleviated significantly, indicated by the histopathological examination. The myocardial apoptosis in the border zone was dramatically reduced by sesamin, resulting from the altered expression of apoptosis factors. Moreover, treatment with sesamin also mitigated the inflammatory response, decreased expression of cytokines and the inactivation of NF-κB (nuclear factor κB) signaling. Sesamin decreased the levels of p-JNK protein, which in turn inactivated pro-apoptotic signaling events by restoring the balance between mitochondrial pro-apoptotic Bcl-2 and Bax proteins. Thus, our study suggests that sesamin could alleviate MI-induced cardiac dysfunction through decrease of myocardial apoptosis and inflammatory response.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Dioxoles; Disease Models, Animal; Humans; Lignans; Male; MAP Kinase Kinase 4; Mice; Myocardial Infarction; NF-kappa B; Plant Extracts; Sesamum; Signal Transduction

Schisandrin B (Sch B) is clinically applied for the treatment of hepatitis and ischemic disease. However, its clinical efficacy is limited due to the poor solubility and low bioavailability. This study aimed to develop matrix metalloproteinase (MMP)-sensitive peptide-modified, polyethylene glycol (PEG)-modified (PEGylated) solid lipid nanoparticles (SLNs) for loading Sch B (MMP-Sch B SLNs), and to evaluate the therapeutic effect in the myocardial infarction model.. PEG lipid and MMP-targeting peptide conjugate were synthesized. MMP-Sch B SLNs were prepared by solvent displacement technique. The physicochemical properties and pharmacokinetics of SLNs were investigated. In vivo effects on infarct size was evaluated in rats.. The successful synthesis of lipid-peptide conjugate was confirmed. MMP-Sch B SLNs had a particle size of 130 nm, a zeta potential of 18.3 mV, and a sustained-release behavior. Higher heart drug concentration and longer blood circulation times were achieved by Sch B loaded SLNs than the drug solution according to the pharmacokinetic and biodistribution results. The best therapeutic efficacy was exhibited by MMP-Sch B SLNs by reducing the infarction size to the greatest extent.. The modified SLNs may be a good choice for delivery of Sch B for the treatment of myocardial infarction.

Topics: Animals; Biological Availability; Cardiotonic Agents; Cell Death; Cyclooctanes; Disease Models, Animal; Drug Delivery Systems; Drug Liberation; Humans; Lignans; Lipids; Matrix Metalloproteinases; Myocardial Infarction; Nanoparticles; Particle Size; Peptides; Polycyclic Compounds; Polyethylene Glycols; Proton Magnetic Resonance Spectroscopy; Rats, Sprague-Dawley; Tissue Distribution

Metabonomics is a useful tool for studying mechanisms of drug treatment using systematic metabolite profiles. Ginsenosides Rg1 and Rb1, ophiopogonin D, and schizandrin are the main bioactive components of a traditional Chinese formula (Sheng-Mai San) widely used for the treatment of coronary heart disease. It remains unknown the effect of individual bioactive component and how the multi-components in combination affect the treating acute myocardial infarction (AMI).. Rats were divided into 7 groups and dosed consecutively for 7 days with mono and combined-therapy administrations. Serum samples were analyzed by proton nuclear magnetic resonance (1H NMR) spectroscopy. Partial least squares discriminate analysis (PLS-DA) was employed to distinguish the metabolic profile of rats in different groups and identify potential biomarkers.. Score plots of PLS-DA exhibited that combined-therapy groups were significantly different from AMI group, whereas no differences were observed for mono-therapy groups. We found that AMI caused comprehensive metabolic changes involving stimulation of glycolysis, suppression of fatty acid oxidation, together with disturbed metabolism of arachidonic acid, linoleate, leukotriene, glycerophospholipid, phosphatidylinositol phosphate, and some amino acids. β-hydroxybutyrate, cholines and glucose were regulated by mono-therapy of schizandrin and ginsenosides respectively. Besides these metabolites, combined-therapy ameliorated more of the AMI-induced metabolic changes including glycerol, and O-acetyl glycoprotein. A remarkable reduction of lactate suggested the therapeutic effect of combined-therapy through improving myocardial energy metabolism.. This study provided novel metabonomic insights on the mechanism of synergistic cardioprotection of combined-therapy with ginsenosides, schizandrin, and ophiopogonin D, and demonstrated the potential of discovering new drugs by combining bioactive components from traditional Chinese formula.

Topics: Animals; Cyclooctanes; Drug Combinations; Drugs, Chinese Herbal; Ginsenosides; Lignans; Magnetic Resonance Spectroscopy; Male; Metabolome; Metabolomics; Myocardial Infarction; Polycyclic Compounds; Rats; Rats, Sprague-Dawley; Saponins; Spirostans

Insufficient angiogenesis and arteriogenesis in cardiac tissue after myocardial infarction (MI) is a significant factor hampering the functional recovery of the heart. To overcome this problem we screened for compounds capable of stimulating angiogenesis, and herein investigate the most active molecule, 5-Methoxyleoligin (5ML), in detail.. 5ML potently stimulated endothelial tube formation, angiogenic sprouting, and angiogenesis in a chicken chorioallantoic membrane assay. Further, microarray- and knock down- based analyses revealed that 5ML induces angiogenesis by upregulation of CYP26B1. In an in vivo rat MI model 5ML potently increased the number of arterioles in the peri-infarction and infarction area, reduced myocardial muscle loss, and led to a significant increase in LV function (plus 21% 28 days after MI).. The present study shows that 5ML induces CYP26B1-dependent angiogenesis in vitro, and arteriogenesis in vivo. Whether or not CYP26B1 is relevant for in vivo arteriogenesis is not clear at the moment. Importantly, 5ML-induced arteriogenesis in vivo makes the compound even more interesting for a post MI therapy. 5ML may constitute the first low molecular weight compound leading to an improvement of myocardial function after MI.

Topics: Animals; Arterioles; Asteraceae; Chick Embryo; Coronary Circulation; Coronary Vessels; Cytochrome P-450 Enzyme System; Disease Models, Animal; Human Umbilical Vein Endothelial Cells; Humans; Lignans; Male; Myocardial Infarction; Myocardium; Neovascularization, Physiologic; Rats; Rats, Wistar; Retinoic Acid 4-Hydroxylase; Ventricular Function, Left

Our 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.. Anesthetized 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.. These 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.

Topics: Animals; Apoptosis; Arrhythmias, Cardiac; Cardiotonic Agents; Caspase 3; Cyclooctanes; Cytoprotection; Dioxoles; Disease Models, Animal; Gene Expression Regulation; Hemodynamics; Hydrogen Peroxide; Lignans; Male; Malondialdehyde; Membrane Glycoproteins; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Myocytes, Cardiac; NADPH Oxidase 2; NADPH Oxidases; Polycyclic Compounds; Rats; Rats, Wistar; RNA, Messenger; Superoxide Dismutase

The fruit of Schisandra chinensis has been used in the traditional Chinese medicine for thousands of years. Accumulating evidence suggests that Schisandrin B (Sch B) has cardioprotection effect on myocardial ischemia in vitro. However, it is unclear whether Sch B has beneficial effects on continuous myocardial ischemia in vivo. The aim of the present study was to investigate whether Sch B could improve cardiac function and attenuate myocardial remodeling after myocardial infarction (MI) in mice. Mice model of MI was established by permanent ligation of the left anterior descending (LAD) coronary artery. Then the MI mice were randomly treated with Sch B or vehicle alone. After treatment for 3 weeks, Sch B could increase survival rate, improve heart function and decrease infarct size compared with vehicle. Moreover, Sch B could down-regulate some inflammatory cytokines, activate eNOS pathway, inhibit cell apoptosis, and enhance cell proliferation. Further in vitro study on H9c2 cells showed similar effects of Sch B on prevention of hypoxia-induced inflammation and cell apoptosis. Taken together, our results demonstrate that Sch B can reduce inflammation, inhibit apoptosis, and improve cardiac function after ischemic injury. It represents a potential novel therapeutic approach for treatment of ischemic heart disease.

Topics: Animals; Apoptosis; Cell Line; Cyclooctanes; Fruit; Humans; Lignans; Male; Mice; Mice, Inbred C57BL; Myocardial Infarction; Polycyclic Compounds; Rats; Schisandra

Plant lignans present in foods such as whole grains, seeds and nuts, fruits and vegetables, and beverages. Plant lignans are converted by intestinal bacteria into the enterolignans enterodiol and enterolactone. Up to now, epidemiological evidence for a protective role of enterolignans on cardiovascular diseases is limited and inconsistent. We investigated the association between plasma enterodiol and enterolactone and nonfatal myocardial infarction risk in a prospective study. During follow-up (1987-1998) of 15,107 subjects, aged 20-59 years, 236 incident nonfatal myocardial infarction cases were diagnosed. Controls (n=283) were frequency matched to the cases on age, sex, and study center. No statistically significant associations between plasma enterodiol and enterolactone and risk of nonfatal myocardial infarction were detected. The odds ratio for the highest versus the lowest quartile of enterodiol was 1.21 (95% confidence interval (CI): 0.70, 2.12; p for trend=0.74), and that of enterolactone 1.51 (95% CI: 0.87, 2.61; p for trend=0.12) after adjustment for known dietary risk factors for coronary heart disease. No effect modification was observed for sex, menopausal status, or smoking status. Our results do not support the hypothesis that high plasma enterodiol or enterolactone concentrations are associated with a reduced risk of nonfatal myocardial infarction.

Topics: 4-Butyrolactone; Adult; Antioxidants; Cardiovascular Diseases; Case-Control Studies; Female; Humans; Lignans; Male; Middle Aged; Myocardial Infarction; Prospective Studies; Risk; Treatment Outcome

Magnolol, an active component extracted from Magnolia officinalis, has been reported to have protective effect on ischemia and reperfusion (I/R)-induced injury in experimental animals. The aim of the present investigation was to further evaluate the mechanism(s) by which magnolol reduces I/R-induced myocardial injury in rats in vivo. Under anesthesia, left anterior descending (LAD) coronary artery was occluded for 30 min followed by reperfusion for 24 h (for infarct size and cardiac function analysis). In some experiments, reperfusion was limited to 1 h or 6 h for analysis of biochemical and molecular events. Magnolol and DMSO solution (vehicle) were injected intra-peritoneally 1 h prior to I/R insult. The infarct size was measured by TTC technique and heart function was monitored by Millar Catheter. Apoptosis related events such as p-ERK, p-Bad, Bcl-xl and cytochrome c expression were evaluated by Western blot analysis and myocardial caspase-3 activity was also measured. Magnolol (10 mg/kg) reduced infarct size by 50% (P < 0.01 versus vehicle), and also improved I/R-induced myocardial dysfunction. Left ventricular systolic pressure and positive and negative maximal values of the first derivative of left ventricular pressure (dP/dt) were significantly improved in magnolol-treated rats. Magnolol increased the expression of phosphor ERK and Bad which resulted in inhibition of myocardial apoptosis as evidenced by TUNEL analysis and DNA laddering experiments. Application of PD 98059, a selective MEK1/2 inhibitor, strongly antagonized the effect of magnolol. Taken together, we concluded that magnolol inhibits apoptosis through enhancing the activation of ERK1/2 and modulation of the Bcl-xl proteins which brings about reduction of infarct size and improvement of cardiac function in I/R-induced injury.

Topics: Animals; Apoptosis; Biphenyl Compounds; Caspase 3; Disease Models, Animal; Flavonoids; Heart; Lignans; Male; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Myocardial Infarction; Myocardial Reperfusion Injury; Plant Extracts; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Signal Transduction

The accumulation of oxygen-free radicals and activation of neutrophils are strongly implicated as important pathophysiological mechanisms mediating myocardial ischemia/reperfusion injury. It has been proven that various antioxidants have cardioprotective effects. Magnolol, an active component extracted from the Chinese medicinal herb Magnolia officinalis, possesses potent antioxidant and free radical scavenging activities. In this study, the cardioprotective activity of magnolol was evaluated in an open-chest anesthetized rat model of myocardial ischemia/reperfusion injury. The results demonstrated that pretreatment with magnolol (0.2 and 0.5 microg/kg, i.v. bolus) at 10 min before 45 min of left coronary artery occlusion, significantly suppressed the incidence of ventricular fibrillation and mortality when compared with the control group. Magnolol (0.2 and 0.5 microg/kg) also significantly reduced the total duration of ventricular tachycardia and ventricular fibrillation. After 1 h of reperfusion, pretreatment with magnolol (0.2 and 0.5 microg/kg) caused a significant reduction in infarct size. In addition, magnolol (0.2 microg/kg) significantly reduced superoxide anion production and myeloperoxidase activity, an index of neutrophil infiltration in the ischemic myocardium. In addition, pretreatment with magnolol (0.2 and 0.5 microg/kg) suppressed ventricular arrhythmias elicited by reperfusion following 5 min of ischemia. In vitro studies of magnolol (5, 20 and 50 microM) significantly suppressed N-formylmethionyl-leucyl-phenylalanine (fMLP; 25 nM)-activated human neutrophil migration in a concentration-dependent manner. It is concluded that magnolol suppresses ischemia- and reperfusion-induced ventricular arrhythmias and reduces the size of the infarct resulting from ischemia/reperfusion injury. This pronounced cardioprotective activity of magnolol may be mediated by its antioxidant activity and by its capacity for neutrophil inhibition in myocardial ischemia/reperfusion.

Topics: Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Biphenyl Compounds; Chemotaxis, Leukocyte; Dose-Response Relationship, Drug; Female; Hemodynamics; Lignans; Male; Myocardial Infarction; Myocardial Ischemia; Myocardial Reperfusion Injury; Myocardium; Neutrophils; Peroxidase; Rats; Rats, Sprague-Dawley; Superoxides

Honokiol is an active component of Magnolia officinalis. It was reported to be 1000 times more potent than alpha-tocopherol in inhibiting lipid peroxidation in rat heart mitochondria. In this study, we investigated the in vivo antiarrhythmic and antiischemic effects of honokiol in coronary ligated rats. Male Sprague-Dawley rats were anesthetized with urethane. Honokiol, at dosages of 10(-7) g/kg, 10(-8) g/kg, and 10(-9) g/kg, was administered intravenously 15 min before ligation of the coronary artery. Incidence and duration of ventricular tachycardia and ventricular fibrillation during 30 min coronary ligation were significantly reduced by 10(-7) g/kg honokiol. Ventricular arrhythmia during 10 min reperfusion after the relief of coronary ligation was also reduced. In rats subjected to 4 hours coronary ligation, 10(-7) g/kg, 10(-8) g/kg, and 10(-9) g/kg honokiol significantly reduced the infarct zone. We concluded that honokiol may protect the myocardium against ischemic injury and suppress ventricular arrhythmia during ischemia and reperfusion.

Topics: Animals; Anti-Arrhythmia Agents; Biphenyl Compounds; Drugs, Chinese Herbal; Heart; Lignans; Male; Myocardial Infarction; Rats; Rats, Sprague-Dawley