Cardioprotective activity of Amaranthus viridis Linn: effect on serum marker enzymes, cardiac troponin and antioxidant system in experimental myocardial infarcted rats

Research progress on the natural products in the intervention of myocardial infarction

Coronary heart disease is a prevalent cardiovascular ailment globally, with myocardial infarction (MI) being one of its most severe manifestations. The morbidity and mortality of MI are escalating, showing an increasing trend among younger, highly educated individuals, thereby posing a serious threat to public health. Currently, thrombolysis, percutaneous coronary intervention, and coronary artery bypass grafting are the primary clinical treatments for MI. Although these methods significantly reduce patient mortality, complications often result in poor prognoses. Due to limitations in chemical synthetic drug research, the focus has shifted towards developing herbs based on natural substances. Natural medicines represent a novel approach for safer and more effective MI management and treatment. They can control multiple pathogenic variables by targeting various pathways and systems. This paper investigates the molecular mechanisms of MI and evaluates the application of natural products and medicinal plants in MI treatment over the past 5 years, demonstrating their specific good therapeutic potential and superior tolerance. These natural therapies have been shown to mitigate myocardial cell damage caused by MI through mechanisms such as oxidative stress, inflammation, apoptosis, angiogenesis, myocardial fibrosis, autophagy, endoplasmic reticulum stress, mitophagy, and pyroptosis. This review offers the latest insights into the application of natural products and medicinal plants in MI treatment, elucidating their mechanisms of action and serving as an important reference for MI prevention.

Association of Blood Metals and Metal Mixtures with the Myocardial Enzyme Profile: An Occupational Population-Based Study in China

To investigate a cross-sectional association between blood metal mixture and myocardial enzyme profile, we quantified creatine kinase (CK), creatine kinase-MB (CK-MB), lactate dehydrogenase (LD), α-hydroxybutyrate dehydrogenase (α-HBD), and aspartate transaminase (AST) levels among participants from the manganese-exposed workers healthy cohort (MEWHC) (n = 544). The levels of 22 metals in blood cells were determined using inductively coupled plasma mass spectrometry. The least absolute shrinkage and selection operator (LASSO) penalized regression model was utilized for screening metals. The exposure-response relationship between specific metal and myocardial enzyme profile was identified by general linear regression and restricted cubic spline analyses. The overall effect and interactions were evaluated using Bayesian kernel machine regression (BKMR). Manganese was linearly and positively associated with CK (Poverall = 0.019, Pnon-linearity = 0.307), dominating the positive overall effect of mixture exposure (manganese, arsenic, and rubidium) on CK level. Calcium and zinc were linearly and negatively associated with LD levels (Poverall < 0.05, Pnon-linearity > 0.05), and asserted dominance in the negative overall effect of metal mixtures (rubidium, molybdenum, zinc, nickel, cobalt, calcium, and magnesium) on LD level. Interestingly, we observed a U-shaped dose-response relationship of molybdenum with LD level (Poverall < 0.001, Pnon-linearity = 0.015), an interaction between age and calcium on LD level (Pinteration = 0.041), and an interaction between smoking and molybdenum on LD level (Pinteration = 0.035). Our study provides evidence that metal mixture exposure affects the myocardial enzyme profile. Additional investigation is required to confirm these associations, and to reveal the fundamental mechanisms involved.

Medicinal Plants in the Treatment of Myocardial Infarction Disease: A Systematic Review

BACKGROUND

Myocardial infarction (MI), also referred to as a "heart attack," is brought on by a partial or total interruption of blood supply to the myocardium. Myocardial infarction can be "silent," go undiagnosed, or it can be a catastrophic occurrence that results in hemodynamic decline and untimely death. In recent years, herbal remedies for MI have become effective, secure, and readily accessible.

OBJECTIVE

The purpose of this review was to examine the medicinal plants and phytochemicals that have been used to treat MI in order to assess the potential contribution of natural substances to the development of herbal MI treatments.

METHODOLOGY

A literature search was employed to find information utilizing electronic databases, such as Web of Science, Google Scholar, PubMed, Sci Finder, Reaxys, and Cochrane.

RESULTS

The identification of 140 plants from 12 families led to the abstraction of data on the plant families, parts of the plant employed, chemical contents, extracts, model used, and dose.

CONCLUSION

The majority of the MI plants, according to the data, belonged to the Fabaceae (11%) and Asteraceae (9%) families, and the most prevalent natural components in plants with MI were flavonoids (43%), glucosides (25%), alkaloids (23%), phenolic acid (19%), saponins (15%), and tannins (12%).

Linalool attenuates lipid accumulation and oxidative stress in metabolic dysfunction-associated steatotic liver disease via Sirt1/Akt/PPRA-α/AMPK and Nrf-2/HO-1 signaling pathways

INTRODUCTION

Linalool is a monoterpene that occurs naturally in various aromatic plants and is identified in our previous study as a potential candidate for protection against high-fat diet (HFD)-induced metabolic dysfunction-associated steatotic liver disease (MASLD). However, little is known about its direct effects on hepatic lipid metabolism and oxidative stress. Therefore, this study aims to investigate the therapeutic effect of linalool against MASLD and the underlying mechanism.

METHODS

To establish a rat model of MASLD, male Wistar rats were fed HFD for 16 weeks and orally administered linalool (100 mg/kg body weight) for 45 days starting from week 14.

RESULTS

Linalool significantly reduced HFD-induced liver lipid accumulation and restored altered adipokine levels. Mechanistically, linalool downregulated the mRNA expression of sterol regulatory element binding protein 1 and its lipogenesis target genes fatty acid synthase and acetyl-CoA carboxylase, and upregulated the mRNA expression of genes involved in fatty acid oxidation (peroxisome proliferator-activated receptor (PPAR)-alpha [PPAR-α], lipoprotein lipase and protein kinase B [Akt]) as well as the upstream mediators sirtuin 1 (Sirt1) and AMP-activated protein kinase (AMPK) in the liver of MASLD rats. In addition, linalool also curbed oxidative stress by increasing antioxidant enzymes and activating nuclear erythroid-2-related factor 2 (Nrf-2) and its downstream target genes involved in antioxidant properties.

CONCLUSION

Therefore, this study concludes that linalool attenuates lipid accumulation in the liver by inhibiting de novo lipogenesis, promoting fatty acid oxidation, and attenuating oxidative stress by regulating Sirt1/Akt/PPRA-α/AMPK and Nrf-2/ HO-1 signaling pathways.

Cardioprotective action of Amaranthus viridis methanolic extract and its isolated compound Kaempferol through mitigating lipotoxicity, oxidative stress and inflammation in the heart

The current study was designed to evaluate the cardio-protective efficacy of Amaranthus viridis L. methanolic extract (AVME) and kaempferol, which was isolated from AVME in isoproterenol (ISO)-induced cardiotoxicity in rats. The rats were pre-treated with AVME (250 mg/kg body weight) and kaempferol (50 mg/kg BW) for 30 days, respectively, and then administered with ISO (20 mg/100 g body weight) on the 31st and 32nd days. We assessed the protective effects of AVME and kaempferol against ISO-induced cardiotoxicity, oxidative stress, and inflammation. The study revealed that supplementation with AVME and kaempferol significantly attenuated cardiac lipotoxicity by reducing cholesterol and triglyceride levels and simultaneously increasing the levels of high-density lipoproteins. In addition, AVME and kaempferol suppressed oxidative stress by enhancing the activities of superoxide dismutase, catalase, and glutathione peroxidase in the heart. Further, they ameliorated cardiac inflammation by mitigating the production of pro-inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6, and interleukin-1β). Hence, the study results and histopathological analysis emphasized that AVME and kaempferol could be prospective prophylactic agents against ISO-induced cardiotoxicity and may be considered nutraceuticals in the prevention of cardiovascular disorders.

Cardioprotective Effect of Flibanserin against Isoproterenol-Induced Myocardial Infarction in Female Rats: Role of Cardiac 5-HT2A Receptor Gene/5-HT/Ca2+ Pathway

Myocardial infarction (MI) is a life-threatening ischemic disease and is one of the leading causes of morbidity and mortality worldwide. Serotonin (5-HT) release during myocardial ischemia plays an important role in the progression of myocardial cellular injury. This study was conducted to investigate the possible cardioprotective effect of flibanserin (FLP) against isoproterenol (ISO)-induced MI in rats. Rats were randomly divided into five groups and were treated orally (p.o.) with FLP (15, 30, and 45 mg/kg) for 28 days. ISO was administered subcutaneously (S.C.) (85 mg/kg) on the 27th and 28th days to induce MI. ISO-induced myocardial infarcted rats exhibited a significant increase in cardiac markers, oxidative stress markers, cardiac and serum 5-HT levels, and total cardiac calcium (Ca2+) concentration. ISO-induced myocardial infarcted rats also revealed a remarkable alteration of electrocardiogram (ECG) pattern and significantly upregulated expression of the 5-Hydroxytryptamine 2A (5-HT2A) receptors gene. Moreover, ISO-induced myocardial infarcted rats showed significant histopathological findings of MI and hypertrophic signs. However, pretreatment with FLP significantly attenuated the ISO-induced MI in a dose-dependent manner, as the effect of FLP (45 mg/kg) was more pronounced than that of the other two doses, FLP (15 and 30 mg/kg). The present study provides evidence for the cardioprotective efficacy of FLP against ISO-induced MI in rats.

Current Perspective and Mechanistic Insights on Bioactive Plant Secondary Metabolites for the Prevention and Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are one of the most prevalent medical conditions of modern era and are one of the primary causes of adult mortality in both developing and developed countries. Conventional medications such as use of aspirin, beta-blockers, statins and angiotensin- converting enzyme inhibitors involve use of drugs with many antagonistic effects. Hence, alternative therapies which are safe, effective, and relatively cheap are increasingly being investigated for the treatment and prevention of CVDs. The secondary metabolites of medicinal plants contain several bioactive compounds which have emerged as alternatives to toxic modern medicines. The detrimental effects of CVDs can be mitigated via the use of various bioactive phytochemicals such as catechin, isoflavones, quercetin etc. present in medicinal plants. Current review intends to accumulate previously published data over the years using online databases concerning herbal plant based secondary metabolites that can help in inhibition and treatment of CVDs. An in-depth review of various phytochemical constituents with therapeutic actions such as antioxidant, anti-inflammatory, vasorelaxant, anti-hypertensive and cardioprotective properties has been delineated. An attempt has been made to provide a probable mechanistic overview for the pertinent phytoconstituent which will help in achieving a better prognosis and effective treatment for CVDs.

Prevention and Treatment of Cardiovascular Diseases with Plant Phytochemicals: A Review

Cardiovascular diseases (CVDs) are the world's leading killers, accounting for 30% deaths. According to the WHO report, CVDs kill 17.9 million people per year, and there will be 22.2 million deaths from CVD in 2030. The death rates rise as people get older. Regarding gender, the death rate of women by CVD (51%) is higher than that of men (42%). To decrease and prevent CVD, most people rely on traditional medicine originating from the plant (phytochemicals) in addition to or in preference to commercially available drugs to recover from their illness. The CVD therapy efficacy of 92 plants, including 15 terrestrial plants, is examined. Some medicinal plants well known to treat CVD are, Daucus carota, Nerium oleander, Amaranthus Viridis, Ginkgo biloba, Terminalia arjuna, Picrorhiza kurroa, Salvia miltiorrhiza, Tinospora cordifolia, Mucuna pruriens, Hydrocotyle asiatica, Bombax ceiba, and Andrographis paniculate. The active phytochemicals found in these plants are flavonoids, polyphenols, plant sterol, plant sulphur compounds, and terpenoids. A general flavonoid mechanism of action is to prevent low-density lipoprotein oxidation, which promotes vasodilatation. Plant sterols prevent CVD by decreasing cholesterol absorption in the blood. Plant sulphur compound also prevent CVD by activation of nuclear factor-erythroid factor 2-related factor 2 (Nrf2) and inhibition of cholesterol synthesis. Quinone decreases the risk of CVD by increasing ATP production in mitochondria while terpenoids by decreasing atherosclerotic lesion in the aortic valve. Although several physiologically active compounds with recognized biological effects have been found in various plants because of the increased prevalence of CVD, appropriate CVD prevention and treatment measures are required. More research is needed to understand the mechanism and specific plants' phytochemicals responsible for treating CVD.

A Novel Synthetized sulfonylhydrazone coumarin (E)-4-methyl-N'-(1-(3-oxo-3H-benzo[f]chromen-2- yl)ethylidene)benzenesulfonohydrazide Protect against Isoproterenol Induced Myocardial Infarction in Rats by attenuating Oxidative damage, Biological Changes, and Electrocardiogram

Coumarins and their derivatives are becoming a potential source for new drug discovery due to their vast array of biological activities. The present study was designed to investigate the cardioprotective effects of a newly synthesized coumarin, symbolized as 5,6-PhSHC, against cardiac remodeling process in isoproterenol (ISO) induced myocardial infarction (MI) in male Wistar rats by evaluating hematological, biochemical, and cardiac biomarkers. Rats were pre/co-treated with 5,6-PhSHC or clopidogrel (150 μg/kg body weight) daily for a period of 7 days and then MI was induced by injecting ISO (85 mg/kg body weight), at an interval of 24 hours for 2 consecutive days, on 6^th and 7^th days. The in vivo exploration indicated that the injection of 5,6-PhSHC improved the electrocardiographic (ECG) pattern and prevented severe heart damages by reducing leakage of the cardiac injury markers, such as troponin-T (cTn-T), lactate dehydrogenase (LDH), and creatine kinase-MB. The cellular architecture of cardiac sections, altered in the myocardium of infracted rats, was reversed by 5,6-PhSHC treatment. Results showed that injection of 5,6-PhSHC elicited significant cardioprotective effects by prevention of myocardium cell necrosis and inflammatory cells infiltration, along with marked decrease in plasma levels of fibrinogen. In addition, the total cholesterol, triglyceride, LDL-c, and HDL profiles underwent remarkable beneficial changes. It was also interesting to note that 5,6-PhSHC enhanced the antioxidative defense mechanisms by increasing myocardial glutathione (GSH) level, superoxide dismutase (SOD), and catalase (CAT) activities, together with reducing the levels of thiobarbituric-acid-reactive substances (TBARS), when compared with ISO-induced rats. Taken together, these findings suggested a beneficial role for 5,6-PhSHC against ISO-induced MI in rats. Furthermore, in silico analysis showed that 5,6-PhSHC pocess high computational affinities (E-value > - 9.0 kcal/mol) against cyclooxygenase-2 (PDB-ID: 1CX2), vitamin K epoxide reductase (PDB-ID: 3KP9), glycoprotein IIb/IIIa (PDB-ID: 2VDM) and catalase (PDB-ID: 1DGF). Therefore, the present study provided promising data that the newly synthesized coumarin can be useful in the design and synthesis of novel drug against Myocardial infarction. This article is protected by copyright. All rights reserved.

Genotoxicity, nitric oxide level modulation and cardio-protective potential of Kalanchoe Integra Var. Crenata (Andr.) Cuf Leaves in murine models

ETHNOPHARMACOLOGICAL RELEVANCE

Advancement in cancer therapy has improved survival among patients. However, use of anticancer drugs like anthracyclines (e.g., doxorubicin) is not without adverse effects. Notable among adverse effects of doxorubicin (DOX) is cardiotoxicity, which ranges from mild transient blood pressure changes to potentially serious heart failure. Anecdotal reports suggest that Kalanchoe integra (KI) may have cardio-protective potential.

AIMS OF THE STUDY

This study sought to determine the cardio-protective potential of KI against doxorubicin-induced cardiotoxicity and also examined any possible genotoxic potential of KI in selected organs. Additionally, the nitric oxide modulatory potential of KI was assessed.

MATERIALS AND METHODS

The leaves of KI were collected, air-dried, pulverised and extracted using 70% ethanol. High-performance liquid chromatography (HPLC) fingerprinting was done for KI. Also, the single-cell gel electrophoresis assay (Comet assay) was employed to ascertain the genotoxic potential of KI. In assessment of cardio-protective potential of KI against doxorubicin-induced cardiotoxicity, a total of 42 female Sprague-Dawley rats were put into 7 groups (n = 6). Group I: vehicle control, received normal saline (1 mL/kg p.o) for 30 days. Group II: toxic control, received DOX (20 mg/kg i.p.) once on the 29th day. Group III: KI control, received KI (300 mg/kg p.o) for 30 days. Group IV: vitamin E control, received vitamin E (100 mg/kg p.o) for 30 days. Group V: KI treated-1, received KI (300 mg/kg p.o) for 30 days and DOX (20 mg/kg i.p) on the 29th day. Group VI: KI treated-2, received KI (600 mg/kg p.o) for 30 days and DOX (20 mg/kg i.p) on the 29th day. Group VII: vitamin E treated, received vitamin E (100 mg/kg p.o) for 30 days and DOX (20 mg/kg i.p) on the 29th day. Thirty-six (36) hours after last administration, rats were sacrificed. Blood samples were taken via cardiac puncture to determine levels of aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), creatine kinase (CK), lactate dehydrogenase (LDH), enzymatic antioxidants such as glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). Nitric oxide level was also determined. Hearts of rats in each group were excised and taken through histopathological examination.

RESULTS

In the HPLC fingerprint analysis, 13 peaks were identified, and peak with retention time of 24.0 min had the highest peak area (3.223 x104 mAU). Comet assay showed that the KI extract was non-genotoxic. Pretreatment with KI protected rats against doxorubicin-induced cardiotoxicity as evidenced by the low levels of AST, ALT, ALP, CK and LDH compared with the controls (p < 0.05). SOD, CAT and GPX levels were also high for rats administered KI extracts, further showing that KI protected rats against doxorubicin-induced cardiotoxicity. KI also inhibited nitric oxide levels at 300 mg/kg and 600 mg/kg effective doses. Histological examination revealed that rats pretreated with KI showed no signs of abnormal myocardial fibres (shape, size and configuration).

CONCLUSION

Ethanolic (70%) leaf extract of KI showed no genotoxic potential and possessed cardioprotective effects against doxorubicin-induced cardiotoxicity in Sprague-Dawley rats. KI also inhibited nitric oxide production, thus, a potential nitric oxide scavenger.

Polyherbal Formulation Ameliorates Diabetic Cardiomyopathy Through Attenuation of Cardiac Inflammation and Oxidative Stress Via NF-κB/Nrf-2/HO-1 Pathway in Diabetic Rats

ABSTRACT

The present study was intended to evaluate the effect of polyherbal formulation (PHF) made with 3 nutraceuticals, such as Piper nigrum, Terminalia paniculata, and Bauhinia purpurea on inflammation and oxidative stress in diabetic cardiomyopathy (DCM), which is induced by streptozotocin and nicotinamide administration in rats. We supplemented DCM rats with PHF (250 and 500 mg/kg/BW) for 45 days and evaluated their effects on oxidative stress markers, proinflammatory cytokines, and messenger RNA expressions of the nuclear factor erythroid 2-related factor-2 (Nrf-2) and its linked genes [heme oxygenase-1 (HO-1), superoxide dismutase, catalase] along with inflammatory genes [tumour necrosis factor α and nuclear factor kappa B (NF-κB)]. Our study demonstrated that PHF successfully attenuated inflammation and oxidative stress via messenger RNA upregulation of Nrf-2, HO-1, superoxide dismutase, and catalase and concomitantly with downregulation of tumour necrosis factor α and NF-κB. Conversely, PHF also protected hyperglycemia-mediated cardiac damage, which was confirmed with histopathological and scanning electron microscopy analysis. In conclusion, our results suggested that PHF successfully ameliorated hyperglycemia-mediated inflammation and oxidative stress via regulation of NF-κB/Nrf-2/HO-1 pathway. Therefore, these results recommend that PHF may be a prospective therapeutic agent for DCM.

Alleviation of isoprenaline hydrochloride induced myocardial ischemia injury by brucine through the inhibition of Na+/K+-ATPase

Myocardial infarction (MI) is the most extensive manifestations of cardiovascular disease (CVD), associated with prolonged supply and demand blood oxygen imbalance to the heart muscle. The treatment of MI includes several conventional medicines which are beta-blockers and calcium antagonists. Though, these were reported to be either not efficient or associated with life threatening adverse effects. Brucine, the main alkaloid bioactive compound from Strychnos nux-vomica seeds, offers unique compatibility advantages in inflammatory diseases associated clinical practices. Thus, the present investigation was projected to explore the activity of brucine towards MI provoked by isoprenaline hydrochloride (ISO) in rats. The cardioprotective properties of brucine were evaluated via detecting the infarct size, serum cardiac marker enzymes (CK, CK-MB, cTnT, and cTnI), endogenous antioxidants (CAT, SOD, GPx), and lipid peroxidation (TBARS and LOOH), inflammatory mediators (NF-κB, TNF-α and IL-6) and histopathological analysis. The results demonstrated, brucine effectively restored the infarct size by increasing the endogenous antioxidants and decreasing the status of TBARS and LOOH, marker enzymes and ameliorated the histopathological injuries. Brucine's cardioprotective effect might be associated with TNF-α, IL-6 signaling molecules activation, revealing its pharmacological actions.

Attenuation of lipid metabolic abnormalities, proinflammatory cytokines, and matrix metalloproteinase expression by biochanin-A in isoproterenol-induced myocardial infarction in rats

In the present study, we assessed the therapeutic potential of Biochanin-A (BCA) (10 mg/kg BW/day) pretreatment for 30 days on lipid metabolic abnormalities, proinflammatory cytokines and matrix metalloproteinase expression in isoproterenol (ISO)-induced myocardial infarction (MI) in rats. We measured the potential role of BCA on tissue and circulatory lipid profiles as well as on lipid metabolic enzymes: serum inflammatory cytokines (TNF-α, IL-1α, IL-1β, IL-6 and MCP1) and serum Matrix Metalloproteinases (particularly, MMP-2 and MMP-9) together with mRNA expressions of TNF-α, IL-6, MMP-2 and MMP-9 by RT-PCR analysis. Administration of ISO to rats significantly distorted their lipid metabolism and augmented inflammatory process, MMP expression and proteolytic activity. In addition, pretreatment with BCA of ISO-induced MI rats significantly reestablished the altered lipid metabolism and concealed the inflammation of cytokines. BCA suppressed the expressions of proinflammatory cytokines and MMPs in ISO-induced MI in rats when compared to normal untreated MI rats. Hence, these results established that BCA could improve the pathological processes of myocardial remodeling which was confirmed by histopathology of heart in MI rats and might be an effective beneficial ingredient for the management of heart failure disorders.

Translocator Protein Modulation by 4'-Chlorodiazepam and NO Synthase Inhibition Affect Cardiac Oxidative Stress, Cardiometabolic and Inflammatory Markers in Isoprenaline-Induced Rat Myocardial Infarction

The possible cardioprotective effects of translocator protein (TSPO) modulation with its ligand 4'-Chlorodiazepam (4'-ClDzp) in isoprenaline (ISO)-induced rat myocardial infarction (MI) were evaluated, alone or in the presence of L-NAME. Wistar albino male rats (b.w. 200-250 g, age 6-8 weeks) were divided into 4 groups (10 per group, total number N = 40), and certain substances were applied: 1. ISO 85 mg/kg b.w. (twice), 2. ISO 85 mg/kg b.w. (twice) + L-NAME 50 mg/kg b.w., 3. ISO 85 mg/kg b.w. (twice) + 4'-ClDzp 0.5 mg/kg b.w., 4. ISO 85 mg/kg b.w. (twice) + 4'-ClDzp 0.5 mg/kg b.w. + L-NAME 50 mg/kg b.w. Blood and cardiac tissue were sampled for myocardial injury and other biochemical markers, cardiac oxidative stress, and for histopathological evaluation. The reduction of serum levels of high-sensitive cardiac troponin T hs cTnT and tumor necrosis factor alpha (TNF-α), then significantly decreased levels of serum homocysteine Hcy, urea, and creatinine, and decreased levels of myocardial injury enzymes activities superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as lower grades of cardiac ischemic changes were demonstrated in ISO-induced MI treated with 4'-ClDzp. It has been detected that co-treatment with 4'-ClDzp + L-NAME changed the number of registered parameters in comparison to 4'-ClDzp group, indicating that NO (nitric oxide) should be important in the effects of 4'-ClDzp.

Biochanin A attenuates obesity cardiomyopathy in rats by inhibiting oxidative stress and inflammation through the Nrf-2 pathway

OBJECTIVE

In the present study, we evaluated the effect of biochanin A (BCA) on high-fat diet (HFD)-induced obesity cardiomyopathy.

METHODS

BCA (10 mg/kg body weight) was administered to HFD-induced obese rats for 30 days, and its effect on anthropometrical, morphological, plasma cardiac, and inflammatory biomarkers, along with cardiac lipid profiles was assessed.

RESULTS

Supplementation of HFD to rats significantly increased body mass index, obesity index parameters, and cardiac lipid profile along with notable oxidative stress and inflammation. Additionally, BCA treatment in obese rats demonstrated a superior therapeutic action by restoring the altered parameters to almost normal levels. Simultaneously, BCA increased the activities and mRNA expressions of enzymatic antioxidants by upregulating the Nrf-2 pathway and inhibiting the NF-κB cascade.

CONCLUSION

BCA may attenuate obesity and its associated cardiomyopathy by suppressing oxidative stress and inflammation through activation of the Nrf-2 pathway and inhibition of NF-κB activation.

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.

Phenolic fraction extracted from Kedrostis foetidissima leaves ameliorated isoproterenol-induced cardiotoxicity in rats through restoration of cardiac antioxidant status

In this study, the cardioprotective effects of partially purified phenolic fraction of Kedrostis foetidissima leaves (PFK) were evaluated in isoproterenol (ISO)-induced myocardial infarction rat model. ISO induction to experimental rats for two consecutive days significantly increased the levels of triglycerides, cholesterol, phospholipids, free fatty acids, low-density lipoproteins, and cardiac biomarker enzymes, and decreased the levels of high-density lipoproteins and antioxidant enzyme activity. Pretreatment of experimental rats with PFK for 45 days led to a significant elevation in antioxidant enzyme activity. PFK-pretreated rats exhibited significantly reduced levels of circulating lipids and cardiac-specific biomarker enzymes compared to ISO-treated rats. Thus, the present study demonstrated that PFK ameliorated ISO-induced cardiotoxicity through the augmentation of the endogenous cardiac antioxidant system, thereby modulating the lipid peroxidation caused by ISO-induced free radicals, and prevented the myocardial damage, which was confirmed through histopathological analysis. PRACTICAL APPLICATIONS: Kedrostis foetidissima is edible medicinal plant and phenolic fraction extracted from the leaves of this plant may help the common man in the protection of heart. The phenolic fraction shows significant antioxidant activity, so this might be referred to as dietary supplement and also helps to develop new pharmaceutical formulations.

Diabetic cardiomyopathy: molecular mechanisms, detrimental effects of conventional treatment, and beneficial effects of natural therapy

ABSTARCT

Diabetic complications are among the largely exigent health problems currently. Cardiovascular complications, including diabetic cardiomyopathy (DCM), account for more than 80% of diabetic deaths. Investigators are exploring new therapeutic targets to slow or abate diabetes because of the growing occurrence and augmented risk of deaths due to its complications. Research on rodent models of type 1 and type 2 diabetes mellitus, and the use of genetic engineering techniques in mice and rats have significantly sophisticated for our understanding of the molecular mechanisms in human DCM. DCM is featured by pathophysiological mechanisms that are hyperglycemia, insulin resistance, oxidative stress, left ventricular hypertrophy, damaged left ventricular systolic and diastolic functions, myocardial fibrosis, endothelial dysfunction, myocyte cell death, autophagy, and endoplasmic reticulum stress. A number of molecular and cellular pathways, such as cardiac ubiquitin proteasome system, FoxO transcription factors, hexosamine biosynthetic pathway, polyol pathway, protein kinase C signaling, NF-κB signaling, peroxisome proliferator-activated receptor signaling, Nrf2 pathway, mitogen-activated protein kinase pathway, and micro RNAs, play a major role in DCM. Currently, there are a few drugs for the management of DCM and some of them have considerable adverse effects. So, researchers are focusing on the natural products to ameliorate it. Hence, in this review, we discuss the pathogical, molecular, and cellular mechanisms of DCM; the current diagnostic methods and treatments; adverse effects of conventional treatment; and beneficial effects of natural product-based therapeutics, which may pave the way to new treatment strategies. Graphical Abstract.

(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.

Occupational exposure to manganese and risk of creatine kinase and creatine kinase-MB elevation among ferromanganese refinery workers

BACKGROUND

Elevated exposure to manganese (Mn) could induce cardiovascular dysfunction. However, limited research is available on the effects of occupational Mn exposure on myocardial enzymes. We aimed to evaluate the relationships between Mn exposure and myocardial enzyme elevation among Mn-exposed workers.

METHODS

Data were from a follow-up investigation of a Mn-exposed workers healthy cohort in 2017. A total of 744 workers were divided into low-exposure and high-exposure groups according to Mn time-weighted average (Mn-TWA) of less than or equal to 0.15 mg/m³ or greater than 0.15 mg/m³ , respectively. Serum levels of myocardial enzymes, including creatine kinase (CK) and creatine kinase-MB (CK-MB), lactic dehydrogenase, α-hydroxybutyrate dehydrogenase, and aspartate transaminase, were assessed, as well as airborne Mn exposure levels.

RESULTS

After adjustment for sex, body mass index, seniority, education, current smoking status, current drinking status, and hypertension, Mn-TWA levels were positively associated with the risk of CK elevation (odds ratio [OR] = 1.47 (95% confidence interval [CI]: 1.18-1.83) per interquartile range [IQR] increase), and risk of CK-MB elevation [OR = 1.57 (95% CI: 1.03-2.38) per IQR increase]. In a stratified analysis, Mn-TWA levels were positively correlated with CK elevation in workers of seniority greater than 19 years, male workers, current smokers, and drinkers.

CONCLUSION

Our results suggest that occupational exposure to Mn is associated with increased risk of CK and CK-MB elevation. The potential mechanisms of the associations between airborne exposure to Mn and increased risk of these myocardial enzyme elevations warrant further investigation.

Therapeutic Potential of Biochanin-A Against Isoproterenol-Induced Myocardial Infarction in Rats

BACKGROUND

This study determined the effect of Biochanin A (BCA) on isoproterenol (ISO) induced Myocardial Infarction (MI) in male Wistar rats.

METHODS

Animals (weighing 150-180 g) were divided into four groups, with six animals in each group and pretreated with BCA (10mg/kg Body Weight [BW]) and ɑ-tocopherol (60mg/kg BW) for 30 days; and ISO (20mg/kg BW) was administrated subcutaneously on the 31st and 32nd day.

RESULTS

ISO-induced MI rats demonstrated the significant elevation of serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, lactate dehydrogenase, creatine kinase-MB and cardiac troponin; however, concomitant pretreatment with BCA protected the rats from cardiotoxicity caused by ISO. Activities of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase significantly reduced in the heart with ISO-induced MI. Pretreatment with BCA produced a marked reversal of these antioxidant enzymes related to MI-induced by ISO.

CONCLUSION

In conclusion, this study suggested that BCA exerts cardioprotective effects through modulating lipid peroxidation, enhancing antioxidants, and detoxifying enzyme systems.

Moringa oleifera leaf extract ameliorated high-fat diet-induced obesity, oxidative stress and disrupted metabolic hormones

Background

Obesity is a health problem in many countries, and maintaining a perfect weight is challenging. Moringa oleifera leaf extract (ME) is rich in polyphenols with antioxidant and pharmaceutical potential. The present study investigated the potential protective effect of Moringa oleifera leaf extract against obesity induced from a high-fat diet (HFD), oxidative stress and disruption of metabolic hormones compared to simvastatin (SIM) or their combination.

Results

Rats fed a HFD for 6 weeks exhibited a significant increase in body weight and levels of serum glucose and lipid fractions, verifying an obesity state. There were also higher levels of insulin and leptin and lower gherlin in sera of HFD rats compared to the levels in control rats. Homeostasis model assessment for insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI) and the atherogenic index were elevated, indicating the development of insulin resistance and dyslipidaemia in these rats. These changes were accompanied with a significant increase in oxidative stress, as indicated by elevated lipid peroxidation and protein oxidation with low levels of antioxidants in liver. The activities of liver function enzymes, including aspartate amino transferase, alanine amino transferase, alkaline phosphatase and gamma glutamyltransferase, were also significantly increased in serum. Concurrent treatment with 300 mg/kg ME for 6 weeks ameliorated the increase in body weight and improved the levels of glucose, lipid fractions and metabolic hormones, indicating the anti-obesity effect and amelioration of tissue insulin resistance potential of ME. ME treatment also normalized oxidative stress and antioxidants in liver and improved liver function enzymes, indicating the antioxidant potential of ME. The effects of ME were similar to SIM, and the combination of these agents was better than each agent alone.

Conclusion

We propose that ME extract has anti-obesity and antioxidant potential and may be used as a lipid-lowering drug to control weight, obesity and its pathophysiological consequences.

Evaluation of the cardioprotective effect of Casuarina suberosa extract in rats

The aim of the current study was to examine and compare the cardioprotective activities of the chloroform and petroleum extracts the leaves of Casuarina suberosa in isoproterenol (ISO)-induced cardiac tissue oxidative stress. Rats were categorized into 6 groups as follows: control group, vehicle or Tween 80-treated group, ISO-treated group, chloroform extract + ISO treated group, petroleum ether extract + ISO treated group and Reference drug (Captopril) + ISO treated group. ISO injection significantly (p < 0.05) increased the activities of cardiac marker enzymes (CK-MB, LDH, ALT, and AST), cardiac troponin-I, levels of lipid peroxides (MDA), nitric oxide (NO), and vascular endothelial growth factor (VEGF), serum angiotensin-converting enzyme (ACE) activity and neutrophil infiltration marker; myeloperoxidase (MPO) in the cardiac tissues. Pretreatment with chloroform or petroleum ether extracts significantly (p < 0.05) prevented the ISO-induced alteration; they upregulated VEGF expression. Histopathological findings corroborated biochemical results. These extracts exerted a cardioprotective effect by alleviating oxidative stress.

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.

Correlation between the blood level of irisin and the severity of acute myocardial infarction in exercise-trained rats

Background Acute myocardial infarction is a major cause of death all over the world. Irisin is a novel myokine released after exercise. This work aimed to study the correlation between the serum irisin level and the severity of the acute myocardial infarction in the exercise-trained rats. Methods Forty-eight male rats were classified into four groups (12 for each): group I, control sedentary (C); group II, exercise-trained (EX) (swimming for 8 weeks); group III, isoprenaline-induced infarct (MI); and group IV, exercise-trained infarct (EX-MI) (swimming for 8 weeks followed by isoprenaline-induced infarction). ECG was recorded at start and end of the study, before and after induction of infarction. The serum level of irisin, lipid peroxidation [malondialdehyde (MDA)], total antioxidant status (TAS), creatine phosphokinase-MB (CK-MB), and troponin I was determined. The hearts were excised for histopathology and immunohistochemistry for caspase-3. Results The infarct rats showed significant prolongation in QTc interval and elevation in the ST segment as well as significant elevation of serum CK-MB, troponin I, and MDA, whereas TAS and serum irisin level were significantly decreased. With exercise, we observed a high positive correlation between the serum irisin and QRS duration (+0.643), amplitude (+0.860), and TAS (+0.887). In addition, there was a high negative correlation between the serum irisin and ST elevation (-0.865), QTc (-0.886), CK-MB (-0.891), troponin (-0.882), and MDA (-0.868). This was confirmed by the negative correlation between serum irisin and both collagen deposition and caspase-3 expression (-0.823 and -0.822, respectively). Conclusions We recommend regular exercise or taking recombinant irisin as a supplement to protect at-risk individuals against acute myocardial infarction.

Role of ashwagandha methanolic extract in the regulation of thyroid profile in hypothyroidism modeled rats

This study aimed to evaluate the anti-hypothyroidism potential of ashwagandha methanolic extract (AME). This target was performed through induction of animal model of hypothyroidism by propylthiouracil. After 1 month from treatments, blood samples were collected for biochemical determinations, and liver and kidney were removed for the determination of oxidative stress markers and thyroid gland was removed for histopathological examination. The total phenolic compounds in the extract and the in vitro radical scavenging activity of extract were also determined. The results revealed that the induction of hypothyroidism by propylthiouracil induced a significant increase in serum TSH level but it induced significant decreases in the levels of total T3, free T3, free T4, and total T4 hormones compared with the control values. Also, serum glucose, Il-6, and body weight gain increased significantly while Il-10 and blood hemoglobin levels showed significant decrease. Induction of hypothyroidism increased also the levels of hepatic and renal MDA and NO and decreased significantly the values of GSH, GPx and Na⁺/ K⁺-ATPase. Both AME and the anti-hypothyroidism drug significantly ameliorated the changes occurred in the levels of the above parameters and improved histological picture of thyroid gland but with different degrees; where ashwagandha methanolic extract showed the strongest effect. We can conclude that ashwagandha methanolic extract treatment improves thyroid function by ameliorating thyroid hormones and by preventing oxidative stress.

Cardioprotective Potential of Plant-Derived Molecules: A Scientific and Medicinal Approach

Since the beginning of human civilization, plants have been used in alleviating the human distress and it was recorded for about thousands of years ago that the plants are being used for medicinal purposes. Natural bioactive compounds called phytochemicals are obtained from medicinal plants, vegetables, and fruits, which functions to combat against various ailments. There is dire need to explore the plant biodiversity for its medicinal and pharmacological potentials. Different databases such as Google scholar, Medline, PubMed, and the Directory of Open Access Journals were searched to find the articles describing the cardioprotective function of medicinal plants. Various substances from a variety of plant species are used for the treatment of cardiovascular abnormalities. The cardioprotective plants contain a variety of bioactive compounds, including diosgenin, isoflavones, sulforaphane, carotinized, catechin, and quercetin, have been proved to enhance cardioprotection, hence reducing the risk of cardiac abnormalities. The present review article provides the data on the use of medicinal plants particularly against cardiac diseases and to explore the molecules/phytoconstituents as plant secondary metabolites for their cardioprotective potential.

Evaluation of Paeonia emodi for its cardioprotective potentials: An investigative study towards possible mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Paeonia emodi Wall. ex Royle (peony) is an important member of family Paeoniaceae. Different parts of the plant have been folklorically used for treatment of different diseases. Infusion of dried flowers is used to treat diarrhea, the seeds are emetic and cathartic while the rhizome has been indicated for the treatment of hysteria, abdominal spasm, nervine tonic and headache. Besides these, peony has also been used in different respiratory and cardiovascular diseases (CVDs) like hypertension, palpitations, congestive heart failure and atherosclerosis. Being a folkloric remedy for the treatment of CVDs, Paeonia emodi (P. emodi) requires to be explored scientifically for MI management.

AIM

The current research work was designed to explore the possible cardioprotective mechanism of P. emodi in Isoproterenol hydrochloride (ISO) induced MI in mice.

MATERIALS AND METHODS

Experimental animals randomly divided in different groups, received methanolic extract of P. emodi (Pe.ME) and its subsequent fractions for 15 days followed by ISO (100 mg/kg s.c) at 24 h interval for two days. The cardioprotective potential of the test samples were investigated by determining the serum levels of Alanine Amino Transferase (ALT), Aspartate Amino Transferase (AST), Lactate Dehydrogenase (LDH) and Creatine Phosphokinase (CPK). The ethyl acetate fraction (Pe.EA) was found potent among all the tested samples of P. emodi. Based on its high potency, Pe.EA was subjected to GC-MS analysis and further relevant experiments including anti-hyperlipidemic, antioxidant, lipid peroxidation, membrane stabilization, thrombolytic, DNA ladder assay and histopathological study.

RESULTS

Pe.EA exhibited significant cardioprotective activity through reduction in levels of serum biomarkers responsible for MI. It significantly reduced serum levels of ALT (p < 0.001), AST (p < 0.001), CPK (p < 0.05) and LDH (p < 0.001) at a dose of 300 mg/kg as compared to ISO treated group. The GC-MS analysis confirmed the presence of potential compounds (esculetin, methyl eugenol, isovanillic acid) which might play a role in cardioprotection. Further screening confirmed that the effect of Pe.EA is mediated through multiple targets/mechanisms, which include anti-hyperlipidemia, antioxidant, lipid peroxidation inhibition, membrane stabilization, thrombolytic and DNA protective effects. Histopathological studies revealed the palliative effect for the damage caused in myocardial tissues.

CONCLUSION

Findings of current study provide evidence that P. emodi is a potential candidate for the treatment and management of MI.

Syringic acid protects from isoproterenol induced cardiotoxicity in rats

Identification of pharmacologically potent antioxidant compounds for their use in preventive medicine is thrust area of current research. This study was undertaken with the aim of determining the protective role of syringic acid (SA) on isoproterenol (ISO) induced myocardial infarction (MI) in rats. SA was orally given to rats for 21 days at three different concentrations (12.5, 25 and 50 mg/kg). At 20th and 21st day, rats were subcutaneously injected with ISO and at the end of experimental period, rats were killed. ISO induced myocardial damage was averted by pre-co-treatment of SA, as decrease was found in serum level of marker enzymes (CKMB, LDH, AST, ALT), lipid peroxidation, protein carbonyl (PC) and proinflammatory cytokines (TNFα, IL 6). Furthermore, content of glutathione (GSH) and activities of antioxidant enzymes in heart tissue were significantly raised. Improvement in infarct size and erythrocyte (RBCs) morphology was also observed. The biochemical findings were supported by histopathological outcome and protective effect of SA was found to be dose dependent. The results of our study demonstrated that the cardioprotective potential of SA in rat model of ISO induced MI might be due to anti-lipid peroxidative and endogenous antioxidant system enhancement effects.

Novel Mesenchymal Stem Cell Strategy in Alleviating Toll-Like Receptor-4, p53 and Nrf2 Signaling in Isoproterenol-Induced Myocardial Infarction in Rat Model

Mesenchymal stem cells (MSCs) are multipotent stromal cells that merit the differentiation into various cell types. The present study was designed to test the hypothesis that the cardioprotective effect of MSCs transplantation and digoxin treatment is mediated via the regulation of messenger RNA gene expression of pro-inflammatory cytokines and apoptotic markers. Myocardial infarction was induced in Wistar rats via isoproterenol injection in a dose of (85 mg/kg, subcutaneously, twice at an interval of 24 h). Four weeks post-MSCs transplantation and digoxin treatment a significant reduction in serum cardiac markers, aspartate aminotransferase, creatine kinase-MB and troponine II was observed. Meanwhile, isoproterenol significantly reduced the gene and protein expression of the oxidative stress marker nuclear-related factor-2 (Nrf2) with a concomitant elevation in (MDA) level and inflammatory markers toll-like receptor-4 (TLR-4), intercellular adhesion molecules (ICAMs) and (VCAM-1). Moreover, apoptotic marker (P53) was significantly down-regulated. This was confirmed by histopathological investigations. It was hypothesized that MSCs transplantation was superior over digoxin treatment regimen in improving heart function.

Protective effect of syringaldehyde on biomolecular oxidation, inflammation and histopathological alterations in isoproterenol induced cardiotoxicity in rats

BACKGROUND

Ischemic injury during myocardial infarction (MI) is responsible for increased deaths among patients with cardiovascular disorders. Recently, research has been directed for finding treatment using natural compounds. This study was performed to investigate the effects of syrigaldehyde (SYD), a phytochemical against isoproterenol (ISO) induced cardiotoxicity model.

METHODS

For induction of MI, rats were intoxicated with two doses of ISO and were treated with SYD at three different concentrations (12.5, 25 & 50 mg/kg) both prior and simultaneous to ISO administration.

RESULTS

ISO group revealed amplified activity of marker enzymes (CKMB, LDH, AST, ALT), increased oxidation of proteins and lipid molecules. Moreover, augmentation in pro-inflammatory markers was also found. The same group also displayed marked changes in histopathology and erythrocyte (RBCs) morphology. SYD treated groups showed diminished levels of serum markers enzymes, lipid peroxidation and protein carbonyl (PC) with increment in antioxidant defense in cardiac tissues of ISO administered rats. Our findings also revealed the modulatory effect of SYD on membrane bound ATPases, showing that SYD significantly improved the ISO induced changes in membrane fluidity. Furthermore, decline in infarct size, alleviation of structural RBC damage and improved myocardial histopathological outcome were observed in treated groups. In addition, mitigation of biochemical and histopathological changes by SYD was found to be dependent on its concentration.

CONCLUSION

SYD had cardioprotective efficacy owing to its antioxidative and anti-inflammatory properties. Our results support incorporation of SYD in regular diet for prevention of MI.

Hsp70 expression induced by Co-Enzyme Q10 protected chicken myocardial cells from damage and apoptosis under in vitro heat stress

The aim of this study was to investigate whether induction of Hsp70 expression by co-enzyme Q10 (Q10) treatment protects chicken primary myocardial cells (CPMCs) from damage and apoptosis in response to heat stress for 5 hours. Analysis of the expression and distribution of Hsp70 and the levels of the damage-related enzymes creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH), as well as pathological analysis showed that co-enzyme Q10 alleviated the damage caused to CPMCs during heat stress. Further, analysis of cell apoptosis and the expression of cleaved caspase-3 indicated that co-enzyme Q10 did have an anti-apoptotic role during heat stress. Western blot analysis showed that pretreatment with co-enzyme Q10 led to a significant increase in the expression of Hsp70 during heat stress. Immunostaining assays confirmed the results of western blot analysis and also showed that co-enzyme Q10 could accelerate the translocation of Hsp70 into the nucleus during heat stress, but this was not observed in the group that was treated with only co-enzyme Q10. These findings seem to indicate that co-enzyme Q10 protected CPMCs from heat stress via the induction of Hsp70. To investigate this, 200 μM quercetin, an Hsp70 inhibitor, was used to inhibit the expression of Hsp70 2 h before heat stress. Quercetin pre-treatment was observed to suppress the expression of Hsp70 as well the protective function of co-enzyme Q10 at 5 h of heat stress. This finding confirms that Q10 brought about its effects via Hsp70 expression, but the mechanism underlying this needs further investigation.

Silymarin ameliorates expression of urotensin II (U-II) and its receptor (UTR) and attenuates toxic oxidative stress in the heart of rats with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular disease (CVD). Urotensin II ((U-II)) and its receptor (UTR) are involved in the progression of CVD through enhancement in the production of reactive oxygen species (ROS). Since silymarin (SMN) is a natural agent with anti-diabetic effects, this study aimed to investigate the antioxidant potency of SMN on the expression of (U-II)/UTR system and oxidative stress status in the heart of type 2 diabetic rats. Thirty-six male Wistar rats were randomly divided into six groups (n = 6). Control and diabetic groups treated with or without SMN (60 and 120 mg/kg/day) for 2 months. Fasting blood sugar (FBS), insulin, lipid profile, creatine kinase-MB ((CK-MB)), lactate dehydrogenase (LDH) and markers of oxidative stress were measured by spectrophotometric methods while (U-II) and UTR gene expression was determined by qPCR method. SMN significantly reduced the FBS level, increased the concentration of insulin and improved HOMA-IR. SMN prevented diabetes-induced weight loss, and attenuated the increased levels of total oxidative status (TOS), malondialdehyde (MDA), and nitric oxide (NO). Diabetes-induced reduction of total thiol molecules content (TTM) was normalized to the normal level in SMN treated rats. SMN significantly modulated serum lipid profile, reduced the expression of (U-II) and UTR in the heart, and improved histopathological changes in the heart tissues. Therefore, the current study indicated that SMN ameliorated unpleasant diabetic characteristics via down-regulation of (U-II) and UTR gene expression and modulation of oxidative stress in the heart tissue of type 2 diabetic rats.

Biotransformation of Dioscorea nipponica by Rat Intestinal Microflora and Cardioprotective Effects of Diosgenin

Studying the biotransformation of natural products by intestinal microflora is an important approach to understanding how and why some medicines-particularly natural medicines-work. In many cases, the active components are generated by metabolic activation. This is critical for drug research and development. As a means to explore the therapeutic mechanism of Dioscorea nipponica (DN), a medicinal plant used to treat myocardial ischemia (MI), metabolites generated by intestinal microflora from DN were identified, and the cardioprotective efficacy of these metabolites was evaluated. Our results demonstrate that diosgenin is the main metabolite produced by rat intestinal microflora from DN. Further, our results show that diosgenin protects the myocardium against ischemic insult through increasing enzymatic and nonenzymatic antioxidant levels in vivo and by decreasing oxidative stress damage. These mechanisms explain the clinical efficacy of DN as an anti-MI drug.

Molecular understanding of the protective role of natural products on isoproterenol-induced myocardial infarction: A review

Modern medicine has been used to treat myocardial infarction, a subset of cardiovascular diseases, and have been relatively effective but not without adverse effects. Consequently, this issue has stimulated interest in the use of natural products, which may be equally effective and better tolerated. Many studies have investigated the cardioprotective effect of natural products, such as plant-derived phytochemicals, against isoproterenol (ISO)-induced myocardial damage; these have produced promising results on the basis of their antioxidant, anti-atherosclerotic, anti-apoptotic and anti-inflammatory activities. This review briefly introduces the pathophysiology of myocardial infarction (MI) and then addresses the progress of natural product research towards its treatment. We highlight the promising applications and mechanisms of action of plant extracts, phytochemicals and polyherbal formulations towards the treatment of ISO-induced myocardial damage. Most of the products displayed elevated antioxidant levels with decreased oxidative stress and lipid peroxidation, along with restoration of ionic balance and lowered expression of myocardial injury markers, pro-inflammatory cytokines, and apoptotic parameters. Likewise, lipid profiles were positively altered and histopathological improvements could be seen from, for example, the better membrane integrity, decreased necrosis, edema, infarct size, and leukocyte infiltration. This review highlights promising results towards the amelioration of ISO-induced myocardial damage, which suggest the direction for future research on natural products that could be used to treat MI.

Bone marrow-derived mesenchymal stem cells mitigate caspase-3 and 8-hydroxy proline induced via β-adrenergic agonist in pulmonary injured rats

Estimating the ability of bone marrow-derived mesenchymal stem cells (BM-MSCs) to alleviate pulmonary injury induced via isoproterenol (ISP). ISP was injected in a dose of (100 mg/kg, subcutaneously twice at an interval of 24 h). One month post BM-MSCs transplantation by intravenous injection, pulmonary oxidative stress was assessed, and Western blot analyses and histopathological investigations were conducted. Compared with the normal control group, BM-MSCs transplantation significantly decreased the expression of pulmonary anti-oxidative stress marker. Western blot analysis revealed that ISP significantly reduced the protein expression of the anti-oxidative stress marker nuclear related factor-2 (Nrf2). However, the apoptotic marker (caspase-3) and collagen content marker (8-hydroxyproline) were markedly elevated. These biochemical markers were confirmed by histopathological investigations. Finally, it was demonstrated that BM-MSCs transplantation showed a superior effect in improving pulmonary function through alleviating oxidative stress, apoptosis, and collagen content.

Antioxidant Properties and Cardioprotective Mechanism of Malaysian Propolis in Rats

Propolis contains high concentrations of polyphenols, flavonoids, tannins, ascorbic acid, and reducing sugars and proteins. Malaysian Propolis (MP) has been reported to exhibit high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. Herein, we report the antioxidant properties and cardioprotective properties of MP in isoproterenol- (ISO-) induced myocardial infarction in rats. Male Wistar rats (n = 32) were pretreated orally with an ethanol extract of MP (100 mg/kg/day) for 30 consecutive days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes and cardiac troponin I levels and altered serum lipid profiles. In addition significantly increased lipid peroxides and decreased activities of cellular antioxidant defense enzymes were observed in the myocardium. However, pretreatment of ischemic rats with MP ameliorated the biochemical parameters, indicating the protective effect of MP against ISO-induced ischemia in rats. Histopathological findings obtained for the myocardium further confirmed the biochemical findings. It is concluded that MP exhibits cardioprotective activity against ISO-induced oxidative stress through its direct cytotoxic radical-scavenging activities. It is also plausible that MP contributed to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.

Aspirin-induced heat stress resistance in chicken myocardial cells can be suppressed by BAPTA-AM in vitro

Our recent studies have displayed the protective functions of aspirin against heat stress (HS) in chicken myocardial cells, and it may be associated with heat shock proteins (HSPs). In this study, we further investigated the potential role of HSPs in the aspirin-induced heat stress resistance. Four of the most important HSPs including HspB1 (Hsp27), Hsp60, Hsp70, and Hsp90 were induced by aspirin pretreatment and were suppressed by BAPTA-AM. When HSPs were induced by aspirin, much slighter HS injury was detected. But more serious damages were observed when HSPs were suppressed by BAPTA-AM than those cells exposed to HS without BAPTA-AM, even the myocardial cells have been treated with aspirin in prior. Comparing to other HSPs, HspB1 presented the largest increase after aspirin treatments, 86-fold higher than the baseline (the level before HS). These findings suggested that multiple HSPs participated in aspirin's anti-heat stress function but HspB1 may contribute the most. Interestingly, during the experiments, we also found that apoptosis rate as well as the oxidative stress indicators (T-SOD and MDA) was not consistently responding to heat stress injury as expected. By selecting from a series of candidates, myocardial cell damage-related enzymes (CK-MB and LDH), cytopathological tests, and necrosis rate (measured by flow cytometry assays) are believed to be reliable indicators to evaluate heat stress injury in chicken's myocardial cells and they will be used in our further investigations.

Sundarban Honey Confers Protection against Isoproterenol-Induced Myocardial Infarction in Wistar Rats

The present study was designed to investigate the cardioprotective effects of Sundarban honey (SH) in rats with isoproterenol- (ISO-) induced myocardial infarction. Adult male Wistar Albino rats were pretreated with Sundarban honey (5 g/kg) daily for a period of 6 weeks. After the treatment period, ISO (85 mg/kg) was subcutaneously injected into the rats at 24 h intervals for 2 days. ISO-induced myocardial damage was indicated by increased serum cardiac specific troponin I levels and cardiac marker enzyme activities including creatine kinase-MB, lactate dehydrogenase, aspartate transaminase, and alanine transaminase. Significant increases in serum total cholesterol, triglycerides, and low-density lipoprotein-cholesterol levels were also observed, along with a reduction in the serum high-density lipoprotein-cholesterol level. In addition to these diagnostic markers, the levels of lipid peroxide products were significantly increased. The activities of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and glutathione reductase were significantly decreased in the hearts after ISO-induced myocardial infarction. However, pretreatment of ischemic rats with Sundarban honey brought the biochemical parameters to near normalcy, indicating the protective effect of Sundarban honey against ISO-induced ischemia in rats. Histopathological findings of the heart tissues further confirmed the biochemical findings, indicating that Sundarban honey confers protection against ISO-induced oxidative stress in the myocardium.

In vitro evaluation of aspirin-induced HspB1 against heat stress damage in chicken myocardial cells

To understand the potential association of heat stress resistance with HspB1 induction by aspirin (ASA) in chicken myocardial cells, variations of HspB1 expression and heat stressed-induced damage of myocardial cells after ASA administration were studied in primary cultured myocardial cells. Cytopathological lesions as well as damage-related enzymes, such as creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH), indicated the considerable protective ability of ASA pre-treatment against acute heat stress. Immunostaining assays showed that heat stress caused HspB1 to relocate into the nucleus, while ASA did not. ELISA analysis, revealed that HspB1 expression induced by ASA averaged 45.62-fold higher than that of the control. These results indicated that the acute heat-stressed injuries were accompanied by comparatively lower HspB1 expression caused by heat stress in vitro. ASA pre-treatment induced a level of HspB1 presumed to be sufficient to protect myocardial cells from acute heat stress in the extracorporal model, although more detailed mechanisms will require further investigation.

Animal models of myocardial infarction: Mainstay in clinical translation

Preclinical models with high prognostic power are a prerequisite for translational research. The closer the similarity of a model to myocardial infarction (MI), the higher is the prognostic value for clinical trials. An ideal MI model should present cardinal signs and pathology that resemble the human disease. The increasing understanding of MI stratification and etiology, however, complicates the choice of animal model for preclinical studies. An ultimate animal model, relevant to address all MI related pathophysiology is yet to be developed. However, many of the existing MI models comprising small and large animals are useful in answering specific questions. An appropriate MI model should be selected after considering both the context of the research question and the model properties. This review addresses the strengths, and limitations of current MI models for translational research.