Protective Effect of Hydroxytyrosol Against Cardiac Remodeling After Isoproterenol-Induced Myocardial Infarction in Rat

Antioxidant activity and inhibitory effects on angiotensin I-converting enzyme and α-glucosidase of trans-p-coumaroyl-secologanoside (comselogoside) and its inclusion complex with β-cyclodextrin. Bioaccessibility during simulated in vitro gastrointestinal digestion

This study explored the impact of complexing comselogoside (COM) with β-cyclodextrin (β-CD) on antioxidant capacity and investigated its in vitro inhibitory effects against α-glucosidase and angiotensin I-converting enzyme (ACE). The COM: β-CD complex in three molar ratios (1:2, 1:1, and 2:1) showed significantly higher antioxidant activity compared to free COM, assessed by DPPH and ferric reducing power assays. COM exhibited weak to moderate α-glucosidase inhibition (IC50 1221 μM) and notable ACE inhibition (IC50 119.4 μM). Encapsulation improved ACE inhibition notably for the 1:2 and 2:1 M ratios. The cleavage of secoiridoid moiety of COM by β-glucosidase further enhanced ACE inhibition from IC50 of 63.91 to 41.75 μg/mL in the hydrolysed mixture. In vitro gastrointestinal digestion revealed 34-40% bioaccessibility of COM and its β-CD complex. This study demonstrates the potential of encapsulated COM as a functional food or supplement for preventing and treating diabetes, hypertension, and oxidative stress-related diseases.

Anti-inflammatory, cardioprotective effect of gypenoside against isoproterenol-induced cardiac remodeling in rats via alteration of inflammation and gut microbiota

BACKGROUND

Myocardial infarction (MI), commonly referred to as a heart attack, occurs when the blood flow to a portion of the heart is blocked, causing damage to the heart muscle. In this study, we scrutinized the cardioprotective effect of gypenoside against the isoproterenol (ISO)-induced myocardial injury (MI) in the rats.

METHODS

Wistar rats were divided into four groups as follow: normal, gypenoside (10 mg/kg), ISO control, and ISO control treated with the gypenoside (2.5, 5, and 10 mg/kg). Various parameters were estimated such as infract size, hemodynamic, inflammatory, antioxidant, cardiac, cytokines, and apoptotic markers. We also estimated the gut microbiota in the faces of the experimental rats. Finally, heart tissue histopathology performed.

RESULT

Dose-dependent treatment of gypenoside significantly (P < 0.001) reduced the infracted size along with suppression of the heart weight and heart ratio along with enhance the body weight. Gypenoside treatment considerably altered the level of cardiac parameters, cardiac membrane stabilizing enzyme, hemodynamic parameters, antioxidant, lipid parameters, hepatic parameters, renal parameters, inflammatory cytokines, and mediators. Gypenoside significantly (P < 0.001) suppressed the level of apoptotic markers such as caspase-3, caspase-6, and caspase-9. Gypenoside significantly (P < 0.001) altered the relative abundance of unclassified bacteria, Tenericutes, Candidatus_Saccharibacteria, Verrucomicrobia, Actinobacteria, Bacteroidetes, Firmicutes and suppressed the ratio of F/B.

CONCLUSION

Gypenoside acts as a protective phytoconstituents against the ISO-induced myocardial infraction in the rats via alteration of gut microbiota, inflammatory, and oxidative stress.

DNAzyme loaded nano-niosomes attenuate myocardial ischemia/reperfusion injury by targeting apoptosis, inflammation in a NF-κB dependent mechanism

Although DNAzymes have been found to reduce injury after myocardial ischemia/reperfusion (MI/R), their efficiency have been limited due to rapid degradation in vivo. Thus, this study was conducted to extend their half-life by encapsulation into nano‑niosomes and examine their cardioprotective effects in a rat model of myocardial infarction (MI). In order to synthesize nano‑niosomes, surface active agent film hydration method was used. Characterization of nano‑niosomes was performed using the atomic force microscopy (AFM). In order to establish MI/R model in rats, left anterior descending coronary artery (LAD) was ligated for 30 min. A single dose (150µL) of drug formulations was injected into the infarcted region. The cardiac function was evaluated using echocardiography. The expression of pro-inflammatory cytokines, apoptotic factors, and nuclear factor-κB (NF-κB) were evaluated using Western blot and immunohistochemistry, respectively. Particle size of only nano-niosomes was in the range of 60-90 nm, while a shift to 70-110 nm was seen after DNAzyme encapsulation. MI rats treated with DNAzyme‑loaded nano‑niosomes could markedly reduce Bax, caspase3, TNF-α, IL-1β, and NF-κB as well as increase Bcl-2 compared to only MI/R group. Collectively, our finding show that nano‑niosomes can be considered excellent drug delivery platforms to extend half-life and stability of DNAzyme, when it is used to reduce myocardial I/R injury.

Protocatechuic acid reverses myocardial infarction mediated by β-adrenergic agonist via regulation of Nrf2/HO-1 pathway, inflammatory, apoptotic, and fibrotic events

Myocardial infarction (MI) is an instant ischemic death of cardiomyocytes that remains a major global cause of mortalities. MI is accompanied by oxidative, inflammatory, apoptotic, and fibrotic insults. Protocatechuic acid (PCA) is a polyphenolic compound with various potent biological activities. In this study, we explored the possible cardioprotective role of PCA against isoproterenol (ISO)-mediated MI. Rats were either injected with ISO (85 mg/kg, subcutaneously) or pretreated with PCA (100 or 200 mg/kg, orally). PCA supplementation markedly normalized ISO-induced disturbed cardiac function markers (creatine kinase-MB, lactate dehydrogenase, and troponin T). Notably, PCA administration exerted remarkable increases in glutathione and its derived enzymes, superoxide dismutase, and catalase, as well as decreases in malondialdehyde and nitric oxide levels in the injured cardiac tissue. The molecular findings validated the augmented cellular antioxidative capacity by PCA via increasing the gene expressions of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1. The cardioprotective efficacy of PCA extended to suppress cardiac inflammation as demonstrated by the decreased levels of tumor necrosis factor-alpha, interleukin-1 beta, and nuclear factor kappa B. Additionally, PCA prevented cardiomyocyte loss and fibrosis by decreasing Bax, caspase-3, transforming growth factor-β1 and matrix metalloproteinase-9, and enhancing B-cell lymphoma 2 and tissue inhibitors of metalloproteinase-3. The cardiac histological screening further confirmed the PCA's protective action. The obtained data recommend PCA as an alternative therapeutic agent to attenuate the molecular, biochemical, and histological alterations associated with MI development.

Intensification of Biophenols Extraction Yield from Olive Pomace Using Innovative Green Technologies

Olive pomace is the main by-product generated by the olive oil production process. Although toxic to the environment, olive pomace is an important source of natural antioxidants due to its high content of phenolic compounds. The aim of the current study is to maximize the extraction yields of the main phenolic compounds present in olive pomace using innovative green technologies. For this purpose, the present work is divided into two parts. The first part is based on a solubility study of targeted phenolic compounds in various ethanol/water ratios at two different temperatures (20 °C and 50 °C). A computational prediction using COSMO-RS software was applied for the calculation of eventual solubility, which was subsequently confirmed by practical experiments. The determination of the optimal extraction conditions of solvent ratio (EtOH/H2O) (60:40 v/v) and temperature (50 °C) led to the second part of the work, which concerns the intensification of extraction yields. Furthermore, various green extractions using innovative technologies, including accelerated solvent extraction (ASE), ultrasound with its both system (probe (UAE-P) and bath (UAE-B)), bead milling (BM) and microwave (MAE), were carried out and then compared to conventional maceration (CM). Results showed that ASE was the most effective method for extracting phenolic compounds from dried olive pomace powder (5.3 milligrams of tyrosol equivalent (TE) per gram of dried olive pomace powder (DOP)) compared to CM (3.8 mg TE/g DOP).

Hydroxytyrosol improves strenuous exercise-associated cardiac pathological changes via modulation of mitochondrial homeostasis

Strenuous exercise is reported to provoke deleterious consequences including cardiac impairments, while the detailed mechanisms and effective interventions remain limited. The current study aims to explore the profitable effects of hydroxytyrosol (HT), one of the most abundant polyphenols derived from olive oil, on strenuous exercise-induced pathological changes in the heart and its underlying mechanisms. Sprague-Dawley male rats at the age of 8-week-old were supplemented with 25 mg kg^-1 day^-1 of HT 45 min before the beginning of strenuous exercise for a total of 8 weeks. HT treatment obviously improved the heart weight and morphology with lowered serum cardiac hypertrophy markers as well as cardiac oxidative stress. Moreover, the down-regulated mitochondrial biogenesis pathway, impaired mitochondrial complex activity, dysregulated expression of mitochondrial dynamics-related proteins and activated apoptotic pathway induced by Exe were all improved by HT. In vitro, 10 μM HT effectively reduced the reactive oxygen species level, promoted mitochondrial biogenesis, and inhibited apoptosis and cardiomyocyte hypertrophy in an angiotensin II-induced cardiomyocyte hypertrophy model. In addition, knockdown of the peroxisome proliferator-activated receptor gamma coactivator-1 alpha, the key regulator of mitochondrial biogenesis, partially abolished the benefits of HT. Our results demonstrate that the disturbance of mitochondrial homeostasis plays a substantial role in strenuous exercise-induced pathological cardiac hypertrophy, and HT presents as an effective intervention strategy targeting mitochondrial homeostasis for cardiac health.

Platelet-rich plasma exhibits anti-inflammatory effect and attenuates cardiomyocyte damage by reducing NF-κB and enhancing VEGF expression in isoproterenol induced cardiotoxicity model

The present study investigated the cardioprotective effects of activated platelet-rich plasma (PRP) on high dose isoproterenol (ISO) induced cardiotoxicity. ISO was injected at a dose of 85 mg/kg/day, s.c. for 2 days. Cardiac function parameters including dp/dt max/min, left ventricular end diastolic pressure (LVEDP), relaxation constant (tau) and electrocardiogram (ECG) changes, anti-oxidant and membrane bound enzymes assays, pro-inflammatory cytokine levels, collagen content, immunohistochemical staining/gene expression of vascular endothelial growth factor (VEGF), cTnI (cardiac troponin I), NF-κB (nuclear factor kappa B), Smad-2/3, TGF-β (transforming growth factor), collagen-1/3 proteins were evaluated. PRP and platelet-poor plasma (PPP) were injected intramyocardially (200 μl in each ventricle region) 3 h after first dose of ISO under anesthesia. ISO injection induced cardiac dysfunction, hypertrophy, fibrosis, necrosis due to decline in anti-oxidant capacity, enhanced NF-κB and reduced cTnI immunostaining. However, the PRP injection attenuated these cardiac pathological changes by exerting anti-inflammatory properties and promoting cardiomyocyte repair.

Effects of swimming training on myocardial protection in rats

Swimming is important for promoting and maintaining health, as it can increase the efficiency of the cardiovascular system and decrease the occurrence of cardiovascular diseases. The objective of the present study was to examine whether swimming training could decrease myocardial injury in rats caused by myocardial ischemia/reperfusion (I/R). Sprague-Dawley rats were randomized into four groups, namely the Sham, coronary artery occlusion, swimming training and ischemic preconditioning (IPC) groups. Myocardial I/R was induced in anesthetized male Sprague-Dawley rats by a 40-min occlusion followed by a 3-h reperfusion of the left anterior descending coronary artery. The rats were sacrificed after surgery and their hearts were examined. The results demonstrated that the number of TUNEL-positive nuclei and degree of caspase-3 activation were both significantly increased in the myocardium following myocardial I/R in rats, indicating increased cardiomyocyte apoptosis. On the other hand, swimming training decreased the serum levels of creatine phosphokinase, lactate dehydrogenase and cardiac troponin I, and was associated with reduced histological damage and myocardial infarct size. Furthermore, swimming training also reduced TNF-α levels, caspase-3 activation and enhanced Bcl-2 activation, which decreased the number of apoptotic cells in the myocardium. The findings of the present study showed that swimming training and IPC could similarly decrease myocardial injury following myocardial I/R, and may therefore be used as exercise training to effectively prevent myocardial injury.

3,4-Dihydroxyphenylethanol ameliorates lipopolysaccharide-induced septic cardiac injury in a murine model

3,4-Dihydroxyphenylethanol (DOPET) is a polyphenol found in olive oil. The present study evaluated the protective role of DOPET on LPS provoked septic cardiac injury in a murine model. Four groups were used in the study (n = 3): control, LPS, DOPET alone, and DOPET + LPS. LPS (15 mg/kg; i.p.); they were used to induce cardiac sepsis. The cardiac markers like LDH, CK-MB, and troponin-T, as well as inflammatory cytokines like TNF-α and IL-6 were measured in the serum. The antioxidants and oxidative stress parameters were measured in cardiac tissues. RT-PCR and western blot methods were done to evaluate the expression of inflammatory mediators and apoptotic markers. DOPET significantly decreased the cardiac markers (LDH, CK-MB, and troponin-T) and TNF-α and IL-6 level in the serum. DOPET effectively reduced the levels of MDA and NO in LPS intoxicated rats. DOPET also increased the levels of antioxidants like SOD, CAT, GPx, and GSH in LPS intoxicated rats. The mRNA levels of TNF-α, IL-6, and NF-κB were significantly downregulated by DOPET in cardiac tissues of LPS rats. The protein expression of Bcl-2 was upregulated, and Bax and caspase-3 were downregulated by DOPET. DOPET effectively attenuates LPS-induced cardiac dysfunction through its antioxidant, anti-inflammatory, and anti-apoptotic mechanisms.

Oleuropein Protects Against Cerebral Ischemia Injury in Rats: Molecular Docking, Biochemical and Histological Findings

This study was designed to evaluate the underlying protective mechanisms of oleuropein involved in alleviating brain damage in a rat model of ischemic stroke. Male Wistar rats were divided into four groups; Control, stroke (MCAO), MCAO + clopidogrel (Clop) and MCAO + oleuropein (Ole). Results showed that the MCAO group evidenced significant brain edema (+ 9%) as well as increases of plasma cardiac markers such as lactate deshydrogenase (LDH), creatine kinase (CK-MB), fibrinogen and Trop-T by 11 %, 43%, 168 and 590%, respectively, as compared to the control group. Moreover, infarcted rats exhibited remarkable elevated levels of angiotensin converting enzyme (ACE), both in plasma and brain tissue, with astrocyte swelling and necrotic neurons in the infarct zone, hyponatremia, and increased rate of thiobarbituric acid-reactive substances (TBARS) by 89% associated with decreases in the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (Cat) by 51%, 44 and 42%, respectively, compared to normal control rats. However, MCAO rats treated with oleuropein underwent mitigation of cerebral edema, correction of hyponatremia, remarkable decrease of plasma fibrinogen and cardiac dysfunctional enzymes, inhibition of ACE activity and improvement of oxidative stress status in brain tissue. Furthermore, in silico analysis showed considerable inhibitions of ACE, protein disulfide isomerase (PDI) and TGF-β1, an indicative of potent anti-embolic properties. Overall, oleuropein offers a neuroprotective effect against ischemic stroke through its antioxidative and antithrombotic activities.

Boeravinone B alleviates gut dysbiosis during myocardial infarction-induced cardiotoxicity in rats

Myocardial infarction (MI) is the most common heart disease, and also, it is one of the leading causes of death from cardiovascular disease. It is well known that MI causes additional injury during blood flow restoration in ischaemic myocardium. Boeravinone B (BB) is a well-known antioxidant and anti-inflammatory drug. We investigated the cardioprotective effect of BB drug against isoproterenol (ISO)-induced MI in rats in this experimental study, along with we analysed its underlying mechanism. Adult Sprague Dawley (SD) rats were treated subcutaneously with ISO (45 mg/kg), then divided into groups and then given BB drug was administered orally. The cardioprotective effect of BB on ISO-induced MI rats was analysed by estimating the heart injury markers, antioxidant pro-inflammatory cytokines and inflammatory parameters. We also detected quantified expression of inflammation and apoptosis-related marker protein family. We estimated the effect of BB drug on GUT microbiota in ISO-induced MI rats and scrutinized the histopathological variations in heart tissues. BB treatment significantly (P < .001) diminished the level of heart markers such as lactate dehydrogenase (LDH), troponin (TnT), creatine kinase (CK) and creatine kinase isoenzymes MB (CK-MB). BB treatment also altered the antioxidant parameters and reduced the pro-inflammatory cytokines in the serum and tissues. Additionally, the histopathological aspects demonstrated that the pathological changes observed in the heart tissue of the ISO group rats were suppressed by the BB treatment to varying degrees. Furthermore, the expressions of caspase-3, p53, caspase-9, Bax, interleukin-6 (IL-6), cytochrome C, neutrophil gelatinase-associated lipocalin (NGAL), tumour necrosis factor-α (TNF-α), nuclear factor kappa B (NF-κB) and interleukin-1β (IL-1β) in the heart tissue were down-regulated whereas the Bcl-2 expression seemed to be enhanced. BB treatment not only alleviated ISO-induced gut dysbiosis by its enhanced specified Firmicutesto-Bacteroidetes (F/B) ratio but also maintained the relative abundance of major bacteria such as Clostridium IV, Butyricicoccus, Clostridium XIVs, Akkermansia and Roseburia. Collectively, our findings showed that the BB drug acted against myocardial infraction and prevented the damage by reducing the oxidative stress and controlling the inflammatory pathways, and gut microbiota.

Efficacy of Alkaloids in Alleviating Myocardial Ischemia-Reperfusion Injury in Rats: A Meta-Analysis of Animal Studies

Background

Animal models are well established for studying the effects of alkaloids in preventing myocardial ischemia-reperfusion injury. However, few studies have investigated the therapeutic effects of alkaloids in humans. This meta-analysis and systematic review assessed the efficacy of alkaloids in attenuating infarct size in rats with myocardial ischemia-reperfusion injury.

Methods

An integrated literature search including the PubMed, Embase, and Cochrane Library databases was performed to identify studies that evaluated the therapeutic effects of alkaloids on myocardial ischemia-reperfusion injury in rats. The main outcome was infarct size, and SYRCLE's risk of bias tool was used to assess the quality of the studies.

Results

22 studies were brought into the meta-analysis. Compared with the effects of vehicle, alkaloids significantly reduced infarct size (standardized mean difference (SMD) = -0.45; 95% confidence interval (CI) = -0.64 to - 0.26). In subgroup analyses, isoquinoline alkaloids (SMD = -0.43; 95%CI = -0.70 to - 0.16) significantly reduced infarct size versus the control.

Conclusion

Isoquinoline alkaloids can potentially alleviate myocardial ischemia-reperfusion injury. This meta-analysis and systematic review supply a reference for research programs aiming to develop alkaloid-based clinical drugs. This trial is registered with CRD42019135489.

Functional dynamics of myocardial injury biomarkers production during acute isoprenaline treatment in rats

Introduction: Isoprenaline or isoproterenol (1-(3,4-dihydroxyphenyl)-2-isopropylaminoethanolhydrochloride; ISO), a synthetic b-adrenergic agonist, can be used to establish myocardial ischemia, cardiotoxicity, necrosis and/or an experimental model of infarction in rats. Aim: Determination of the dynamics of myocardial injury biomarkers production of aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and high-sensitive troponin T (hsTnT), with changes on electrocardiogram (ECG) parameters during the subcutaneous aplication of ISO in male Wistar rats. Material and methods: All animals (n = 23) were divided into two groups: control group (n = 11) treated with a saline solution, during two consecutive days (0,2 ml/kg b.m. daily, sc); and the ISO group (n = 12) treated with isoprenaline, during two consecutive days (85 mg/kg b.m. daily, sc). Blood was drawn from the rat tail vein in both groups, in order to determine serum activity levels of myocardial injury biomarkers, and an ECG (n = 6) was registered prior to the application, as well as 48h following the first dose of of saline solution or isoprenaline. Results: In comparison to the control group, in which no significant enzyme activities elevation (p > 0.05) nor ECG changes were registered, ISO group presented a significant rise of two clinically significant biomarkers of acute myocardial injury/myocardial infarction (AMI), CK (p = 0.05) and hsTnT (p < 0.01), as well as an ST segment elevation, with a patognomonic ECG change. Conclusion: Obtained results support previous studies, proving that isoprenaline represents an adequate experimental model for myocardial injury/AMI induction, and a "golden standard" for evaluating potential cardioprotective effects of pharmacological and non-pharmacological therapeutic modalities, with the ultimate goal of lowering the degree of lesions and improving post-infarction myocardium function.

Oleic Acid Prevents Isoprenaline-Induced Cardiac Injury: Effects on Cellular Oxidative Stress, Inflammation and Histopathological Alterations

The present study was designed to assess the cardio-protective role of oleic acid in myocardial injury (MI) induced by intra-peritoneal injection of isoprenaline (ISO) in rats for 2 consecutive days. Oleic acid (OA) was administered orally (@ 5 mg/kg b.wt and 10 mg/kg b.wt) for 21 days before inducing MI. Pre-exposure to OA at higher dose significantly improved the HW/BW ratio, myocardial infarct size, lipid profiles (total cholesterol, HDL-C) and cardiac injury biomarkers (LDH, CK-MB, cardiac troponin-I, MMP-9), thus suggesting its cardio-protective role. The ameliorative potential of the higher dose of OA was further substantiated by its ability to reduce the cardiac oxidative stress as evidenced by significant decrease in lipid peroxidation coupled with increase in superoxide dismutase activity and reduced glutathione level. Significant decrease in heart rate as well as increase in RR and QT intervals in oleic acid pre-exposed rats were also observed. OA pre-treatment also reduced the histopathological alterations seen in myocardial injury group rats. The mRNA expression of cardiac UCP-2 gene, a regulator of reactive oxygen species (ROS) generation, was significantly increased in oleic acid pre-exposure group compared to the ISO-induced myocardial injury group. Thus increase in expression of UCP-2 gene in cardiac tissue seems to be one of the protective measures against myocardial injury. Based on the above findings, it may be inferred that oleic acid possesses promising cardio-protective potential against myocardial injury due to its anti-oxidative property and ability to modulate cardiac metabolic processes.

(E)-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide protecting rat heart tissues from isoproterenol toxicity: Evidence from in vitro and in vivo tests

The current study was aimed to assess the protective effect of a new molecule (E)-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide, denoted 1c, against cardiac remodeling process in isoproterenol (Isop) induced myocardial infarction (MI) in rats. Male Wistar rats were randomly divided into four groups, control, Isop (85 mg/kg body weight was injected subcutaneously into rats at an interval of 24 h for 2 days (6^th and 7^th day) to induce MI and pretreated animals with acenocoumarol (Ace) (150 μg/kg bw) and 1c (150 μg/kg bw) by oral administration during 7 days and injected with isoproterenol (Isop + Ace) and (Isop + 1c) groups. Results in vitro showed that 1c is endowed with potent inhibition of angiotensin-converting enzyme (ACE) with an IC₅₀ 39.12 μg/ml. The in vivo exploration evidenced alteration in the ECG pattern, notable cardiac hypertrophy and increase in plasma level of fibrinogen, troponin-T, CK-MB and LDH, AST and ALT by 171%, 300%, 50%, 64% and 75% respectively with histological myocardium necrosis and cells inflammatory infiltration. However, pre-treatment with 1c improved the ECG pattern reduced significantly the cardiac dysfunction markers and ameliorated the thrombolytic process by decreasing fibrinogen level as compared to untreated infracted rats. Overall, (E)-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide 1c could be used as anticoagulant agent to prevent thrombosis in acute myocardial infarction.

(E)-N'-(1-(7-Hydroxy-2-Oxo-2H-Chromen-3-Yl) Ethylidene) Benzohydrazide, a Novel Synthesized Coumarin, Ameliorates Isoproterenol-Induced Myocardial Infarction in Rats through Attenuating Oxidative Stress, Inflammation, and Apoptosis

The present study was directed to investigate the effect of precotreatment with (E)-N'-(1-(7-hydroxy-2-oxo-2H-chromen-3-yl) ethylidene) benzohydrazide (7-hyd.HC), a novel potent synthesized coumarin, on isoproterenol- (ISO-) induced myocardial infarction (MI) in rats. The hydrazone compound was characterized by IR, 1D, and 2D NMR analyses. Experimental induction of MI in rats was established by ISO (85 mg/kg/day, s.c) for two consecutive days (6th and 7th days). 7-hyd.HC or sintrom was given for 7 days prior and simultaneous to ISO injection. 7-hyd.HC offered a cardiopreventive effect by preventing heart injury marker leakage (LDH, ALT, AST, CK-MB, and cTn-I) from cardiomyocytes and normalizing cardiac function and ECG pattern, as well as improving lipid profile (TC, TG, LDL-C, and HDL-C), which were altered by ISO administration. Moreover, 7-hyd.HC precotreatment significantly mitigated the oxidative stress biomarkers, as evidenced by the decrease of lipid peroxidation and the increased level of the myocardial GSH level together with the SOD, GSH-Px, and catalase activities. 7-hyd.HC inhibited the cardiac apoptosis by upregulating the expression of Bcl-2 and downregulating the expression of Bax and caspase-3 genes. In addition, 7-hyd.HC reduced the elevated fibrinogen rate and better prevented the myocardial necrosis and improved the interstitial edema and neutrophil infiltration than sintrom. Overall, 7-hyd.HC ameliorated the severity of ISO-induced myocardial infarction through improving the oxidative status, attenuating apoptosis, and reducing fibrinogen production. The 7-hyd.HC actions could be mediated by its antioxidant, antiapoptotic, and anti-inflammatory capacities.

Cardioprotective effects of (E)-4-hydroxy-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide: a newly synthesized coumarin hydrazone against isoproterenol-induced myocardial infarction in a rat model

The current study was carried out to evaluate the effect of pretreatment and co-treatment with a newly synthesized coumarin hydrazone, (E)-4-hydroxy-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide (hereinafter EK6), against isoproterenol-induced myocardial infarction in rats. Changes in biochemistry, cardiac biomarkers, electrocardiography, and histopathology after treatment with EK6 or acenocoumarol (Sintrom) were studied. Animals were randomly divided into 4 groups: vehicle control (C), isoproterenol + Sintrom (ISO + Sin), isoproterenol + EK6 (ISO + EK6), and isoproterenol (ISO). Myocardial infarction was induced by subcutaneous ISO administration at a dose of 85 mg·kg^-1·day^-1 with a drug-free interval of 24 h on days 6 and 7. Treatment with ISO led to significant elevation (p < 0.05) in serum levels of cardiac injury biomarkers, namely cardiac troponin-T, lactate dehydrogenase, creatine kinase-MB, alanine aminotransferase, and aspartate aminotransferase compared with levels in the vehicle control. A change in the lipid profile was also observed as a significant increase in total cholesterol and triglycerides. Furthermore, ISO caused significant alterations in the electrocardiogram pattern, including significant ST-segment elevation, significant decreased R wave amplitude, and significant increase in heart rate (16%) as well as marked changes in the histopathology of the heart tissue. Pretreatment and co-treatment with newly synthesized coumarin hydrazone restored all ISO-induced biochemical, lipid, cardiac, and histopathological changes in rats with myocardial infarction.

Anti-fibrotic Actions of Roselle Extract in Rat Model of Myocardial Infarction

Heart failure-associated morbidity and mortality is largely attributable to extensive and unregulated cardiac remodelling. Roselle (Hibiscus sabdariffa) calyces are enriched with natural polyphenols known for antioxidant and anti-hypertensive effects, yet its effects on early cardiac remodelling in post myocardial infarction (MI) setting are still unclear. Thus, the aim of this study was to investigate the actions of roselle extract on cardiac remodelling in rat model of MI. Male Wistar rats (200-300 g) were randomly allotted into three groups: Control, MI, and MI + Roselle. MI was induced with isoprenaline (ISO) (85 mg/kg, s.c) for two consecutive days followed by roselle treatment (100 mg/kg, orally) for 7 days. Isoprenaline administration showed changes in heart weight to body weight (HW/BW) ratio. MI was especially evident by the elevated cardiac injury marker, troponin-T, and histological observation. Upregulation of plasma levels and cardiac gene expression levels of inflammatory cytokines such as interleukin (IL)-6 and IL-10 was seen in MI rats. A relatively high percentage of fibrosis was observed in rat heart tissues with over-expression of collagen (Col)-1 and Col-3 genes following isoprenaline-induced MI. On top of that, cardiomyocyte areas were larger in heart tissues of MI rats with upregulation of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) gene expression, indicating cardiac hypertrophy. Interestingly, roselle supplementation attenuated elevation of plasma troponin-T, IL-6, IL10, and gene expression level of IL-10. Furthermore, reduction of cardiac fibrosis and hypertrophy were observed. In conclusion, roselle treatment was able to limit early cardiac remodelling in MI rat model by alleviating inflammation, fibrosis, and hypertrophy; hence, the potential application of roselle in early adjunctive treatment to prevent heart failure.

Expression of Notch-1 and nuclear factor-κB signal pathway in myocardial cells of coronary heart disease rats

Expression changes of Notch-1 and nuclear factor-κB (NF-κB) in cardiomyocytes from coronary heart disease (CHD) rats were investigated. The CHD model established by high-fat diet in 48 clean SD rats was set as the observation group, and another 48 healthy rats routinely fed were the control group. Rats were sacrificed on the 1st, 3rd, 7th, and 14th days after successful modeling. The rat myocardial cells were harvested to examine the changes of Notch-1 and NF-κB using immunoblot (western blot analysis) and TUNEL assay. Cardiomyocyte apoptotic rate, by Pearson's correlation test was used to analyze the correlation between Notch-1 and NF-κB. With the prolongation of the course of CHD in rats, the expression levels of Notch-1 and NF-κB proteins gradually increased, and the expression in the observation group was significantly higher than that in the control group (P<0.01). On the seventh day, the expression levels of Notch-1 and NF-κB protein in the rats in the observation group showed significant difference from those on day 1 and day 3 (P<0.05), and they were significantly different on the 7th and 14th days (P<0.05). There was no correlation between the expression level of the two proteins with the age and sex of the rats. Pearson's correlation analysis showed that Notch-1 was positively correlated with NF-κB protein (r=0.745, P=0.005). The results of myocardial apoptosis test showed that with the prolongation of the CHD course in the rats of the observation group, the cardiomyocyte apoptosis rate did not differ from the control group. The expression of Notch-1 and NF-κB protein is increased in cardiomyocytes of CHD rats. Notch-1 and NF-κB participate in the occurrence and development of CHD.

Eugenol protects the transplanted heart against ischemia/reperfusion injury in rats by inhibiting the inflammatory response and apoptosis

The aim of the present study was to investigate the protective effect of eugenol on the transplanted heart and explore its mechanisms of action. Male Sprague-Dawley rats were randomly divided into a sham group (n=10), a eugenol group (n=10 pairs, donors and recipients) and a control group (n=10 pairs, donors and recipients). The recipients in the eugenol group received an intraperitoneal injection of eugenol (20 mg/kg/day). The sham group and the control group received equal volumes of physiological saline by intraperitoneal injection. After 15 days the recipients in the control and eugenol groups underwent abdominal heterotopic heart transplantation, while the sham group received only a coeliotomy. The orthotopic hearts in the sham group and the heterotopic hearts in the eugenol and control groups, as well as the peripheral blood samples from all three groups were taken 3 h post operation for biochemical, histopathological, molecular and apoptosis analyses. Compared with the control group, the eugenol treatment significantly reduced the myocardial malondialdehyde content, serum cardiac troponin I, creatine kinase-MB, tumor necresis factor-α and interleukin-6 levels (P<0.05) and significantly alleviated myocardial injury. Western blot analysis demonstrated that the protein expression of cleaved Poly (ADP-ribose) polymerase 1, BAX and active caspase-3 in the eugenol group were significantly decreased, while B-cell lymphoma 2 expression was significantly increased compared with the control group (P<0.05). The myocardial apoptosis rate of the eugenol group was significantly decreased compared with the control group (P<0.05). In conclusion eugenol treatment significantly reduced myocardial injury and demonstrated protective effects for the transplanted heart.

Investigation of the Protective Effect of Kefir against Isoproterenol Induced Myocardial Infarction in Rats

This study aims to investigate the protective effects of kefir against myocardial infarction induced by isoproterenol (ISO). The rats were randomly divided into 4 groups, each group consisting of 8 rats. The control group, the kefir group (5 mL/kg/d kefir administered to rats as intra-gastric gavage for 60 d), the ISO group (100 mg/kg ISO was administered to rats, s.c. on 61. and 62. d), and kefir+ISO group (5 mL/kg/d kefir was administered to rats intra gastric gavage for 60 days prior to ISO, 100 mg/kg in two doses on day 61 and 62). 12 h after the last ISO dose, all rats were decapitated and their blood samples were collected. Cardiac tissue was reserved for histopathological examination. creatine kinase (CK), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triglycerides, total cholesterol,very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL) and glucose were measured by autoanalyzer, whole blood malondialdehyde (MDA), glutathione (GSH) and plasma advanced oxidation protein products (AOPP) levels were measured spectrophotometrically. It was determined that in the group of kefir+ISO, the levels of AST (p<0.001), CK (p<0.001), LDH (p<0.001), MDA (p<0.001) and AOPP (p<0.001) were decreased, while the GSH (p<0.05) increased, compared to ISO group. There were no significant changes in lipid profile and glucose levels between these two groups. In conclusion, by examining cardiac enzymes and histopathological changes in cardiac tissue, it can be concluded that the administration of kefir in myocardial infarction induced by ISO can protect the heart with its antioxidant characteristic and minimize the toxic damage created by ISO.

Protective Effects of Olive Leaf Extract on Acrolein-Exacerbated Myocardial Infarction via an Endoplasmic Reticulum Stress Pathway

Many studies reported that air pollution particulate matter (PM) exposure was associated with myocardial infarction (MI). Acrolein representing the unsaturated aldehydes, the main component of PM, derives from the incomplete combustion of wood, plastic, fossil fuels and the main constitute of cigarette smoking. However, the effect of acrolein on MI remains not that clear. In the current study, the effect of acrolein-exacerbated MI was investigated. In vivo, male Sprague–Dawley rats received olive leaf extract (OLE) followed by acrolein, then isoprenaline (ISO) was received by subcutaneous injection to induce MI. Results showed that the expression levels of GRP78 and CHOP, two major components of endoplasmic reticulum (ER) stress were higher in the combination of acrolein and ISO than those in ISO treatment. The apoptosis marker, Bax, was also higher while the anti-apoptosis indicator, Bcl2 expression was lower both at protein and mRNA levels in the combination group. Also, the acrolein-protein adducts and myocardial pathological damage increased in the combination of acrolein and ISO relative to the ISO treatment. Besides, cardiac parameters, ejection fraction (EF) and fractional shortening (FS) were reduced more significantly when acrolein was added than in ISO treatment. Interestingly, all the changes were able to be ameliorated by OLE. Since hydroxytyrosol (HT) and oleuropein (OP) were the main components in OLE, we next investigated the effect of HT and OP on cardiomyocyte H9c2 cell apoptosis induced by acrolein through ER stress and Bax pathway. Results showed that GRP78, CHOP and Bax expression were upregulated, while Bcl2 expression was downregulated both at the protein and mRNA levels, when the H9c2 cells were treated with acrolein. In addition, pretreatment with HT can reverse the expression of GRP78, CHOP, Bax and Bcl2 on the protein and mRNA levels, while there was no effect of OP on the expression of GRP78 and CHOP on the mRNA levels. Overall, all these results demonstrated that OLE and the main components (HT and OP) could prevent the negative effects of acrolein on myocardium and cardiomyocytes.

Hydroxytyrosol in the Prevention of the Metabolic Syndrome and Related Disorders

Virgin olive oil (VOO) constitutes the main source of fat in the Mediterranean diet. VOO is rich in oleic acid, displaying health-promoting properties, but also contains minor bioactive components, especially phenolic compounds. Hydroxytyrosol (HT), the main polyphenol of olive oil, has been reported to be the most bioactive component. This review aims to compile the results of clinical, animal and cell culture studies evaluating the effects of HT on the features of Metabolic Syndrome (MetS) (body weight/adiposity, dyslipidemia, hypertension, and hyperglycemia/insulin resistance) and associated complications (oxidative stress and inflammation). HT was able to improve the lipid profile, glycaemia, and insulin sensitivity, and counteract oxidative and inflammatory processes. Experimental studies identified multiple molecular targets for HT conferring its beneficial effect on health in spite of its low bioavailability. However, rodent experiments and clinical trials with pure HT at biologically relevant concentrations are still lacking. Moreover, the roles of intestine and its gut microbiota have not been elucidated.

Anti-inflammatory, Antithrombotic and Cardiac Remodeling Preventive Effects of Eugenol in Isoproterenol-Induced Myocardial Infarction in Wistar Rat

This study aimed to evaluate the antithrombotic, anti-inflammatory and anti-cardiac remodeling properties of eugenol in isoproterenol-induced myocardial infarction in rats. Male Wistar rats were randomly divided into four groups, control, iso [100 mg/kg body weight was injected subcutaneously into rats at an interval of 24 h for 2 days (6th and 7th day) to induce MI] and pretreated animals with clopidogrel (0.2 mg/kg) and eugenol (50 mg/kg) orally for 7 days and intoxicated with isoproterenol (Iso + Clop) and (Iso + EG) groups. Isoproterenol-induced myocardial infarcted rats showed notable changes in the ECG pattern, increase in heart weight index, deterioration in the hemodynamic function and rise in plasma level of troponin-T, CK-MB and LDH and ALT by 316, 74, 172 and 45 %, respectively, with histological myocardium necrosis and cells inflammatory infiltration. In addition, significant increases in plasma levels of inflammatory biomarkers such as fibrinogen, α1, α2, β1, β2 and γ globulins with decrease level of albumin were observed in infarcted rats as compared to normal ones. Else, the angiotensin-converting enzyme (ACE) activity in plasma, kidney and heart of the isoproterenol-induced rats was significantly increased by 34, 47 and 93 %, respectively, as compared to normal group. However, the administration of eugenol induced a clear improvement in cardiac biomarkers injury, reduced inflammatory mediators proteins, increased heart activities of superoxide dismutase and glutathione peroxidase with reduce in thiobarbituric acid-reactive substances content and inhibition of ventricular remodeling process through inhibition of ACE activity. Overall, eugenol evidences high preventive effects from cardiac remodeling process.

Protective Effects of Cardamom in Isoproterenol-Induced Myocardial Infarction in Rats

Cardamom is a popular spice that has been commonly used in cuisines for flavor since ancient times. It has copious health benefits such as improving digestion, stimulating metabolism, and exhibits antioxidant and anti-inflammatory effects. The current study investigated the effect of cardamom on hemodynamic, biochemical, histopathological and ultrastructural changes in isoproterenol (ISO)-induced myocardial infarction. Wistar male albino rats were randomly divided and treated with extract of cardamom (100 and 200 mg/kg per oral) or normal saline for 30 days with concomitant administration of ISO (85 mg/kg, subcutaneous) on 29th and 30th days, at 24 h interval. ISO injections to rats caused cardiac dysfunction evidenced by declined arterial pressure indices, heart rate, contractility and relaxation along with increased preload. ISO also caused a significant decrease in endogenous antioxidants, superoxide dismutase, catalase, glutathione peroxidase, depletion of cardiomyocytes enzymes, creatine kinase-MB, lactate dehydrogenase and increase in lipid peroxidation. All these changes in cardiac and left ventricular function as well as endogenous antioxidants, lipid peroxidation and myocyte enzymes were ameliorated when the rats were pretreated with cardamom. Additionally, the protective effects were strengthened by improved histopathology and ultrastructural changes, which specifies the salvage of cardiomyocytes from the deleterious effects of ISO. The present study findings demonstrate that cardamom significantly protects the myocardium and exerts cardioprotective effects by free radical scavenging and antioxidant activities.