Cardioprotective effect of paeonol and danshensu combination on isoproterenol-induced myocardial injury in rats

Immunohistochemical and histological evaluations of cyclophosphamide-induced acute cardiotoxicity in wistar rats: The role of turmeric extract (curcuma)

Chemotherapy-induced cardiac derangement is a major concern in health sector. Cyclophosphamide as a chemotherapeutic agent induces acute cardiotoxicity through its toxic metabolite, acrolein. This study evaluated the effect of ethanol extract of turmeric on cyclophosphamide-induced acute cardiotoxicity in Wistar rats. Thirty-five healthy Wistar rats, weighing 200-250g were randomly assigned into 7 groups (Groups A, B, C, D, E, F and G) N=5. Group A was the control, group B was negative control, and group C was administered 200mg/kg of turmeric extract (orally) only. While groups B, D, E, F and G were all administered 100mg/kg cyclophosphamide (i.p) for 10 days. Groups D and E were administered 100mg/kg and 200mg/kg of turmeric extract (orally) respectively for 72 hours before cyclophosphamide administration. Groups F and G were concomitantly administered 100mg/kg cyclophosphamide (i.p) with doses of 100mg/kg and 200mg/kg of turmeric extract (orally) respectively. The rats were sacrificed under ketamine anesthesia (30mg/kg i.m). The left ventricle of the heart was excised. One-way ANOVA was used to analyze data. Results revealed that there was statistically significant (P<0.05) difference in body weight change, CK-MB, and LDH across all experimental groups; which were significantly lower in cyclophosphamide group. Histology and Immunohistochemistry revealed that there were morphological alterations in the myocardium of the left ventricle in group B while turmeric extract ameliorated cyclophosphamide-induced damage in the myocardium in other experimental groups. In conclusion, cyclophosphamide-induced myocardial alterations were significantly ameliorated through administration of ethanol extract of turmeric.

Effect of syringic acid and syringaldehyde on oxidative stress and inflammatory status in peripheral blood mononuclear cells from patients of myocardial infarction

Oxidative stress and inflammation are considered as therapeutic targets in myocardial injury. The aim of the present study was to investigate the protective effect of syringic acid (SA) and syringaldehyde (SYD) on peripheral blood mononuclear cells (PBMCs) of myocardial infarction (MI) patients. PBMCs from MI patients were cultured in the presence and absence of SA and SYD. The level of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and nitric oxide (NO) was estimated. Reactive oxygen species (ROS) formation, oxidation of lipids, proteins, and activity of antioxidant enzymes were also quantified. To further determine biomolecular changes in treated PBMCs, Fourier transform infrared (FTIR) spectroscopic analysis was done. Molecular docking study was also conducted to evaluate the binding interaction of SA and SYD with various target proteins. SA and SYD treated PBMCs of MI patients showed decreased secretion of TNF-α, IL-6, and NO. Moreover, the content of ROS, level of lipid, and protein oxidation showed diminution by treatment with both the compounds. Enhanced antioxidant defense was also observed in treated PBMCs. The FTIR spectra of treated cells revealed safeguarding effect of SA and SYD on biomolecular structure. The molecular docking analysis displayed significant binding affinity of the two compounds towards TNF-α, IL-6, and antioxidant enzymes. Our findings demonstrated potent antioxidant and anti-inflammatory effects of SA and SYD on PBMCs of MI patients. Thus, SA and SYD supplementation might be beneficial in attenuating oxidative stress and inflammation in MI.

Icariin attenuates isoproterenol-induced cardiac toxicity in Wistar rats via modulating cGMP level and NF-κB signaling cascade

Icariin, a major component of Epimedium species, was evaluated using isoproterenol (ISO)-induced cardiotoxicity in Wistar rats. Rats were treated with icariin at the doses of 1, 5, and 10 mg kg^-1 orally for 15 days. Afterward, rats were administered with ISO (85 mg kg^-1, subcutaneous) on 14th and 15th day to produce cardiac injury. Sildenafil (0.7 mg kg^-1, intraperitoneal) was used as a positive reference to compare the effects of icariin. ISO-treated rats showed significant changes in hemodynamic parameters. Elevated levels of cardiac troponin T, nitric oxide, and tumor necrosis factor-alpha in serum, positive expression of nuclear factor-kappa B (NF-κB) and inducible nitric oxide synthase in cardiac tissue, and a decrease in serum level of interleukin-10, manifested inflammation and associated cardiac injury. However, pretreatment with icariin and sildenafil significantly prevented the hemodynamic fall and showed improved contractile and lusitropic states. Furthermore, pretreatment groups also showed a reversal of other toxicity markers to normal. Additionally, pretreatment with icariin and sildenafil significantly increased the myocardial cyclic guanosine monophosphate (cGMP) levels. Our results thus indicated the potential role of icariin in the restoration of the ISO-induced cardiac toxicity and restored membrane integrity through modulation of cGMP and NF-κB signaling.

CD47 Deficiency Attenuates Isoproterenol-Induced Cardiac Remodeling in Mice

In this study, we investigated whether CD47 deficiency attenuates isoproterenol- (ISO-) induced cardiac remodeling in mice. Cardiac remodeling was induced by intraperitoneal (i.p.) injection of ISO (60 mg·kg⁻¹·d⁻¹ in 100 μl of sterile normal saline) daily for 14 days and was confirmed by increased levels of lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB), increased heart weight to body weight (HW/BW) ratios, and visible cardiac fibrosis. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Levels of malondialdehyde (MDA) and reactive oxygen species (ROS) were found to be significantly higher in the ISO group than in the control group, while superoxide dismutase (SOD) levels were suppressed in the ISO group. However, CD47 knockout significantly limited ISO-induced increases in LDH, CK-MB, and HW/BW ratios, cardiac fibrosis, oxidative stress, and apoptosis in the heart. In addition, CD47 deficiency also increased p-AMPK and LAMP2 expression and decreased HDAC3, cleaved Caspase-3, cleaved Caspase-9, LC3II, and p62 expression in cardiac tissues. In conclusion, CD47 deficiency reduced i.p. ISO-induced cardiac remodeling probably by inhibiting the HDAC3 pathway, improving AMPK signaling and autophagy flux, and rescuing autophagic clearance.

Solid-Phase Preparation of Al-TiO2 for Efficient Separation of Bioderived Product Danshensu

Four kinds of Al-TiO2 solid samples with different Ti/Al ratios of 1 : 0.1, 1 : 0.09, 1 : 0.07, and 1 : 0.05 were synthesized via a solid-phase synthesis method and characterized by XRD, SEM, EDS, BET, and other techniques. The prepared solids were used for separation of the bioderived product danshensu, the content of which was determined by UV spectrophotometry. Moreover, the effects of extract concentration, PH value, adsorption time, and ethanol elution volume were investigated. The results showed that these Al-TiO2 samples had good adsorption and desorption ability. Especially, the solid Al-TiO2 with a Ti/Al ratio of 1 : 0.05 is more suitable for the separation of danshensu, exhibiting a higher adsorption (77.70%) under 2 h adsorption time and pH = 3; meanwhile, the high desorption rate (70.29%）was received under 80% ethanol and the sample concentration of 3.0 mg/mL.

Paeonol protects against hypertension in spontaneously hypertensive rats by restoring vascular endothelium

The present study focused on the effect of paeonol, one of the main components of Guizhi Fuling Pill, on blood pressure, cerebral blood flow, and vascular endothelium injury in spontaneously hypertensive rats to provide theoretical basis for the treatment of hypertension. After treatment with paeonol, the mean arterial pressure (MAP) of LSHRT and HSHRT rats decreased gradually with the prolongation of treatment time. The systolic blood flow velocity (Vs), diastolic blood flow velocity (Vd) and mean blood flow velocity (Vm) were significantly increased after paeonol treatment (p &lt; 0.05). Paeonol effectively improved the blood pressure and increased the cerebral blood flow velocity in spontaneously hypertensive rats. This may be related to the fact that paeonol reduced the blood viscosity and the oxidative stress and improved the antioxidant capacity. Moreover, paeonol protected vascular endothelial cells and reduced vascular endothelial injury in spontaneously hypertensive rats.

Cardioprotective Mechanisms of Exenatide in Isoprenaline-induced Myocardial Infarction: Novel Effects on Myocardial α-Estrogen Receptor Expression and IGF-1/IGF-2 System

Myocardial infarction (MI) is one of the main causes of morbidity and mortality in diabetic patients. The antidiabetic glucagon-like polypeptide-1 receptor (GLP-1R) agonists, such as exenatide, proved to confer cardioprotection; however, their exact mechanisms are not fully elucidated. Although the cardioprotective effect of α-estrogen receptor (ERα) activation is well established, its involvement in exenatide-induced cardioprotection has never been investigated. Moreover, modulation of insulin-like growth factor-1/2 (IGF-1/IGF-2) system by exenatide, and the consequent effect on cardiomyocyte apoptosis, is yet to be established. Current study aimed to investigate the cardioprotective potential of exenatide versus the standard cardioprotective agent, 17β-estradiol, against isoprenaline (ISO)-induced MI in rats. MI-insulted group showed electrocardiographic abnormalities, elevated serum cardiac markers, higher serum IGF-2 level along with histopathological abnormalities. Treatment with exenatide and/or 17β-estradiol, commenced 8 weeks before ISO insult, ameliorated these anomalies with maximum cardioprotection achieved with combined treatment. This was associated with upregulation of both ERα and IGF-1R, and downregulation of IGF-2R in left ventricles. Inhibition of ERs in Langendorff preparations confirmed their involvement in mediating exenatide-induced cardioprotective effect. Current study showed that the GLP-1R agonist exenatide exerted cardioprotection associated with upregulation of ERα and modulation of IGF-1/IGF-2 signaling in favor of antiapoptosis.

Effect of Kaempferol Pretreatment on Myocardial Injury in Rats

The present study was undertaken to evaluate the effect of kaempferol in isoprenaline (ISP)-induced myocardial injury in rats. ISP was administered subcutaneously for two subsequent days to induce myocardial injury. Assessment of myocardial injury was done by estimation of hemodynamic functions, myocardial infarcted area, cardiac injury markers, lipid profile, oxidative stress, pro-inflammatory cytokines and histopathology of heart and liver. Rats pretreated with kaempferol showed reduction in the myocardial infarcted area and heart rate. However, no improvement was observed in change in body weight, mean arterial, systolic and diastolic blood pressure. Kaempferol showed significant decrease in serum LDH, CK-MB, troponin-I and lipid profile. However, highest dose of kaempferol did not reduce the serum triglyceride level. Further, antioxidant enzymes, SOD and catalase, were also higher. However, reduced glutathione, serum SGOT and creatinine did not show any improvement. Kaempferol showed reduction in MDA level. Kaempferol at highest dose showed reduction in pro-MMP-2 expression and MMP-9 level. mRNA expression level of TNF-α was not different in kaempferol-pretreated myocardial injured rats with ISP-alone group. Pretreatment with kaempferol at highest dose showed mild mononuclear infiltration and degenerative changes in heart tissue section of myocardial injured rats. Rats pretreated with kaempferol at higher concentration showed normal cordlike arrangement of hepatocytes with moderate swelling of hepatocytes (vacuolar degeneration) around the central vein. Study suggests that kaempferol attenuated lipid profile, infarcted area and oxidative stress in ISP-induced myocardial injury in rats.

Danshensu for Myocardial Ischemic Injury: Preclinical Evidence and Novel Methodology of Quality Assessment Tool

Background: Danshensu (DSS) possesses unique bioactivity on the cardiovascular system. However, there is a lack of systematical summary of DSS for acute myocardial ischemia injury and no quality assessment tool for the systematical review of cell experiments. Here, we aimed to assess the preclinical evidences and possible mechanisms of DSS for myocardial ischemia injury, and to develop a quality assessment tool for the systematical review of cell experiments.

Methods: Thirty-two studies with 473 animals and 134 cells were identified by searching seven databases. All data analysis was performed using RevMan 5.3. CAMARADES 10-item checklist was used to assess the methodological quality of animal experiments. A new 10-item checklist was first developed to assess the methodological quality of cell studies.

Results: The score of study quality ranged from 3 to 7 points in animal studies, while the cell studies scored 3–6 points. Meta-analysis showed that DSS had significant effects on reducing myocardial infarct (MI) size in vivo, and increasing cell viability and reducing apoptosis rate in vitro compared with controls (P < 0.01). The possible mechanisms of DSS for MI are improving circulation, antioxidant, anti-apoptosis, anti-inflammatory, promoting angiogenesis, anti-excessive autophagy, anti-calcium overload, and improving energy metabolism.

Conclusions: DSS could exert cardioprotective effect on myocardial ischemia injury, and thus is a probable candidate for further clinical trials andtreatment of AMI. In addition, the newly devloped 10-item checklist for assessing methodological quality of cell study that recommened to use the sysmatic review of cell studies.

Berbamine ameliorates isoproterenol-induced myocardial infarction by inhibiting mitochondrial dysfunction and apoptosis in rats

Berbamine (BBM), a bisbenzylisoquinoline alkaloid from roots, bark, and stem of Berberis plant such as Berberis aristata has a wide range of pharmacological activities. However, the evidence for the cardioprotective effect of BBM is inadequate and the molecular mechanism of BBM remains unclear. This study investigated the underlying molecular mechanism of BBM-mediated cardioprotection on isoproterenol (ISO)-induced mitochondrial dysfunction and apoptosis in rats. The assays of mitochondria antioxidant status, mitochondrial marker enzymes, and electron microscopic analysis of mitochondria revealed BBM significantly prevented the mitochondrial dysfunction induced by ISO. The ISO-induced elevation of mitochondrial oxidative stress was also curbed by BBM. Furthermore, pretreatment with BBM protected the heart tissue from ISO-induced apoptosis as evident from decreased terminal dUTP nickend-labeling positive cells and decreased expression of Bax, cytochrome c, cleaved caspase-9, and caspase-3, and poly (ADP-ribose) polymerase and increased expression of Bcl-2 in ISO-induced rats. These current findings suggest that BBM exerts a significant cardioprotective effect on ISO-induced myocardial infarction in rats.

YaTCM: Yet another Traditional Chinese Medicine Database for Drug Discovery

Traditional Chinese Medicine (TCM) has a long history of widespread clinical applications, especially in East Asia, and is becoming frequently used in Western countries. However, owing to extreme complicacy in both chemical ingredients and mechanism of action, a deep understanding of TCM is still difficult. To accelerate the modernization and popularization of TCM, a single comprehensive database is required, containing a wealth of TCM-related information and equipped with complete analytical tools. Here we present YaTCM (Yet another Traditional Chinese Medicine database), a free web-based toolkit, which provides comprehensive TCM information and is furnished with analysis tools. YaTCM allows a user to (1) identify the potential ingredients that are crucial to TCM herbs through similarity search and substructure search, (2) investigate the mechanism of action for TCM or prescription through pathway analysis and network pharmacology analysis, (3) predict potential targets for TCM molecules by multi-voting chemical similarity ensemble approach, and (4) explore functionally similar herb pairs. All these functions can lead to one systematic network for visualization of TCM recipes, herbs, ingredients, definite or putative protein targets, pathways, and diseases. This web service would help in uncovering the mechanism of action of TCM, revealing the essence of TCM theory and then promoting the drug discovery process. YaTCM is freely available at http://cadd.pharmacy.nankai.edu.cn/yatcm/home.

Paeonol-mediated apoptosis of hepatocellular carcinoma cells by NF-κB pathway

The aim of the study was to investigate the effect of paeonol on the apoptosis of hepatocellular carcinoma cells and to explore the possible mechanism of its effect. During the experiment, the human hepatoma (Huh7) cell line was cultured and treated with different concentrations of paeonol. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect the effects of paeonol at different concentrations on the proliferation of Huh7 cells after 24 h, and the optimal concentration of paeonol was selected for follow-up experiments. Huh7 cells were divided into the blank control group (C group), parthenolide [(an inhibitor of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB)] group (CE group), paeonol group (PO group), and paeonol + tumor necrosis factor-α (TNF-α) (an activator of NF-κB) group (PN group). The effect of paeonol on the apoptosis of Huh7 cells was detected via flow cytometry and Hoechst staining, respectively. The expression levels of NF-κB and protein apoptosis inhibitor-5 (p-API-5) were detected by semi-quantitative polymerase chain reaction (PCR) and western blot analysis, respectively, and the activity of NF-κB in cells was measured by NF-κB p65/50. After determination of the effects of paeonol at different concentrations on Huh7 cells by MTT assay, it was found that paeonol at the concentration of 200–800 µM could inhibit the proliferation of Huh7 cells (P<0.01), with 500 µM phenol being selected as the treatment concentration for follow-up experiments. Results of flow cytometry and Hoechst staining showed that the apoptotic levels of Huh7 cells in the PO and CE groups were significantly increased compared with that in the C group, and that in the PO group was higher than that in the PN group. The differences were statistically significant (P<0.01). Results of semi-quantitative PCR and western blot analysis revealed that the expression levels of NF-κB and p-API-5 in the PO and CE groups were significantly lower than those in the C group, and those in the PO group were lower than those in the PN group. The differences were statistically significant (P<0.01). The expression level of NF-κB p65/50 in the PO group was significantly lower than that in the C group (P<0.01). The results suggest that paeonol can significantly increase the apoptosis rate of Huh7 cells, and the possible mechanism of inducing apoptosis is related to the downregulation of NF-κB and p-API-5 and inhibition of the NF-κB signaling pathway.

Beneficial Effects Exerted by Paeonol in the Management of Atherosclerosis

Atherosclerosis, a chronic luminal stenosis disorder occurred in large and medium arteries, is the principle pathological basis of cardiovascular diseases with the highest morbidity and mortality worldwide. In oriental countries, traditional Chinese medicine Cortex Moutan has been widely used for the treatment of atherosclerosis-related illnesses for thousands of years. Paeonol, a bioactive monomer extracted from Cortex Moutan, is an important pharmacological component responsible for the antiatherosclerotic effects. Numerous lines of findings have established that paeonol offers beneficial roles against the initiation and progression of atherosclerotic lesions through inhibiting proatherogenic processes, such as endothelium damage, chronic inflammation, disturbance of lipid metabolism, uncontrolled oxidative stress, excessive growth, and mobilization of vascular smooth muscle cells as well as abnormality of platelet activation. Investigations identifying the atheroprotective effects of paeonol present substantial evidence for potential clinical application of paeonol as a therapeutic agent in atherosclerosis management. In this review, we summarize the antiatherosclerotic actions by which paeonol suppresses atherogenesis and provide newly insights into its atheroprotective mechanisms and the future clinical practice.

Suppression of isoproterenol-induced cardiotoxicity in rats by raspberry ketone via activation of peroxisome proliferator activated receptor-α

The peroxisome proliferator-activated receptor-α (PPAR-α) controls the lipid and glucose metabolism and also affects inflammation, cell proliferation and apoptosis during cardiovascular disease. Raspberry ketone (RK) is a red raspberry (Rubusidaeus, Family-Rosaceae) plant constituent, which activates PPAR-α. This study was conducted to assess the cardioprotective action of RK against isoproterenol (ISO)-induced cardiotoxicity. Wistar rats were randomly divided into six groups (six rats/group). Rats were orally administered with RK (50, 100 and 200 mg/kg, respectively) and fenofibrate (standard, 80 mg/kg) for 28 days and ISO was administered (85 mg/kg, subcutaneously) on 27th and 28th day. Administration of ISO in rats significantly altered hemodynamic and electrocardiogram patterns, total antioxidant capacity, PPAR-α, and apolipoprotein C-III levels. These myocardial aberrations were further confirmed during infarct size, heart weight to body weight ratio and immunohistochemical assessments (caspase-3 and nuclear factor-κB). RK pretreatment (100 and 200 mg/kg) significantly protected rats against oxidative stress, inflammation, and dyslipidemia caused by ISO as demonstrated by change in hemodynamic, biochemical and histological parameters. The results so obtained were quite comparable with fenofibrate. Moreover, RK was found to have binding affinity with PPAR-α, as confirmed by docking analysis. PPAR-α expression and concentration was also found increased in presence of RK which gave impression that RK probably showed cardioprotection via PPAR-α activation, however direct binding study of RK with PPAR-α is needed to confirm this assumption.

Isoproterenol-induced cardiac ischemia and fibrosis: Plant-based approaches for intervention

Heart is the most active and incumbent organ of the body, which maintains blood flow, but due to various pathological reasons, several acute and chronic cardiac complications arise out of which myocardial infarction is one of the teething problems. Isoproterenol (ISP)-induced myocardial ischemia is a classical model to screen the cardioprotective effects of various pharmacological interventions. Phytochemicals present a novel option for treating various human maladies including those of the heart. A large number of plant products and their active ingredients have been screened for efficacy in ameliorating ISP-induced myocardial ischemia including coriander, curcumin, Momordica, quercetin, and Withania somnifera. These phytochemicals constituents may play key role in preventing disease and help in cardiac remodeling. Reactive oxygen species scavenging, antiinflammatory, and modulation of various molecular pathways such as Nrf2, NFкB, p-21 activated kinase 1 (PAK1), and p-smad2/3 signaling modulation have been implicated behind the claimed protection. In this review, we have provided a focused overview on the utility of ISP-induced cardiotoxicity, myocardial ischemia, and cardiac fibrosis for preclinical research. In addition, we have also surveyed molecular mechanism of various plant-based interventions screened for cardioprotective effect in ISP-induced cardiotoxicity, and their probable mechanistic profile is summarized.

Cardioprotective effect of Amaranthus tricolor extract in isoprenaline induced myocardial damage in ovariectomized rats

Red spinach (Amaranthus tricolor) has been reported to possess many benefits and medicinal properties and used as a part of traditional medicine in Ayurveda and Siddha. The aim of the study was to investigate the effects of Amaranthus tricolor on isoproterenol-induced oxidative stress, fibrosis, and myocardial damage in ovariectomized rats. Ovariectomy surgery was conducted to remove both ovaries from the rats. After recovery, rats were administered with ISO subcutaneously (50 mg/kg) twice a week and were treated with ethanolic extracts of A. tricolor. This investigation showed that the level of oxidative stress markers was significantly increased while the superoxide dismutase (SOD) activity decreased in ISO administered ovariectomized rats. A. tricolor extract and atenolol treatment prevented the rise of malondialdehyde, nitric oxide and advanced protein oxidation product. Moreover, elevated activities of AST, ALT, and CK-MB enzymes were also lowered by both atenolol and A. tricolor treatment. Increased uric acid and creatinine levels were also normalized by atenolol, and A. Tricolor treatment in ISO administered ovariectomized rats. ISO-induced ovariectomized rats also showed massive inflammatory cell infiltration, fibrosis and iron deposition in heart compared to sham rats. Atenolol and A. tricolor treatment prevented the inflammatory cells infiltration, fibrosis, and iron deposition. These results suggest that A. tricolor treatment may protect against ISO administered myocardial infarction in ovariectomized rats probably by preventing inflammation, oxidative stress, and fibrosis. Further research is warranted to examine molecular mechanism of cardioprotective effect of A. tricolor.

Salvia miltiorrhizaBurge (Danshen): a golden herbal medicine in cardiovascular therapeutics

Salvia miltiorrhiza Burge (Danshen) is an eminent medicinal herb that possesses broad cardiovascular and cerebrovascular protective actions and has been used in Asian countries for many centuries. Accumulating evidence suggests that Danshen and its components prevent vascular diseases, in particular, atherosclerosis and cardiac diseases, including myocardial infarction, myocardial ischemia/reperfusion injury, arrhythmia, cardiac hypertrophy and cardiac fibrosis. The published literature indicates that lipophilic constituents (tanshinone I, tanshinone IIa, tanshinone IIb, cryptotanshinone, dihydrotanshinone, etc) as well as hydrophilic constituents (danshensu, salvianolic acid A and B, protocatechuic aldehyde, etc) contribute to the cardiovascular protective actions of Danshen, suggesting a potential synergism among these constituents. Herein, we provide a systematic up-to-date review on the cardiovascular actions and therapeutic potential of major pharmacologically active constituents of Danshen. These bioactive compounds will serve as excellent drug candidates in small-molecule cardiovascular drug discovery. This article also provides a scientific rationale for understanding the traditional use of Danshen in cardiovascular therapeutics.

Comparative Pharmacokinetics of Gallic Acid After Oral Administration of Gallic Acid Monohydrate in Normal and Isoproterenol-Induced Myocardial Infarcted Rats

Gallic acid (GA) is a polyphenolic natural product widely distributed in food, beverage, and traditional Chinese herbs with beneficial effects on the cardiovascular system. In this research, a comparative study was conducted to investigate the possible difference of pharmacokinetic process in normal and isoproterenol-induced myocardial infarcted rats after oral administration of GA monohydrate with the dose of 50 and 100 mg/kg, respectively. Quantification of GA in rat plasma was achieved by using a simple and rapid high-performance liquid chromatographic method. The results revealed that pharmacokinetics of GA were greatly different between normal and pathological state. GA exhibited slower absorption into the bloodstream, and yielded 1.7-fold (50 mg/kg GA) and 1.3-fold (100 mg/kg GA) less values of area under concentration-time curve as well as 2.5-fold lower of maximum blood concentration (C_max) in MI rats than those in normal rats. In addition, significant prolonged T_1/2 and MRT as well as decreased CL were also registered in MI rats. Our findings suggest that myocardial infarction could alter the pharmacokinetic process of GA, and thus the potential pharmacokinetic differences of herbal preparations (or dietary nutrition) containing GA between normal and pathological conditions should be brought to the forefront seriously in clinical practice.

Sacubitril and valsartan protect from experimental myocardial infarction by ameliorating oxidative damage in Wistar rats

BACKGROUND

Sacubitril (SAC), a neprilysin inhibitor prevent degradation of neprilysin and activate cGMP signaling pathways leading to rise in blood volume concurrent to blood pressure by means of vasoactive peptides, adrenomedullin, and bradykinin.

OBJECTIVE

The aim of this study was to evaluate the anti-ischemic effects of SAC through inhibiting neprilysin in isoproterenol (ISO) induced myocardial infarction (MI) in Wistar albino rats. ISO (85 mg/kg) was injected subcutaneously at the end of 14 days pre-treatment with SAC and valsartan (VAL).

RESULT

Biochemical investigation revealed that SAC along with VAL significantly prevented the antioxidant enzymes (SOD, Catalase, GR, GPx, GST, and GSH) degradation and malondialdehyde (MDA) induced by ISO intoxication in Wistar rats. Along with this, cardiac biomarkers (LDH, CK-MB, ALT, AST, and ALP) were also significantly ameliorated by SACand VAL in ISO-treated rats. Concurrently, decreased infarction area (IA)and marked reduction in myofibril damage by SACand VAL further supported its protective benefits in MI.

CONCLUSION

Taken together, the results suggest that inhibition of enzyme neprilysin alleviated the ISO induces myocardial damage mediated by its strong antioxidant potential.

Cardioprotective effect of rosuvastatin against isoproterenol-induced myocardial infarction injury in rats

Rosuvastatin, a member of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, exerts various pharmacological activities. This study evaluated the cardioprotective effect of rosuvastatin on isoproterenol-induced myocardial infarction injury in rats. A rat model of myocardial infarction injury was induced by isoproterenol (ISO) for 2 consecutive days, rosuvastatin was administered for 8 weeks. The levels of myocardial infarct size, aspartate transaminase (AST), alanine transaminase (ALT), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH) activities, as well as malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) activities and reduced glutathione (GSH) concentrations were determined. Hematoxylin and eosin staining was used to observe cardiac histological changes. Interleukin-1β (IL-1β) and IL-18 levels in heart tissues were detected with ELISA kits. The mRNA and protein levels of NOD-like receptor superfamily, pyrin domain containing 3 (NLRP3) inflammasome were measured by qRT-PCR and western blot analysis, respectively. Our results showed that treatment with rosuvastatin reduced myocardial infract area, ameliorated histopathological alterations in myocardium, and decreased activities of myocardial injury marker enzymes in ISO-induced rats. In addition, rosuvastatin remarkably restored ISO-induced elevation of lipid peroxidation and decrease of antioxidants, significantly reduced myocardial pro-inflammatory cytokines concentrations in this animal model. Furthermore, rosuvastatin significantly inhibited the activation of NLRP3 inflammasome in this animal model. This study demonstrates that rosuvastatin significantly alleviates ISO-induced myocardial infarction injury. The mechanism is associated with attenuation of oxidative stress and inflammation, via the inhibition of NLRP3 inflammasome.

Protection by Ethanolic Extract from Ulva lactuca L. against Acute Myocardial Infarction: Antioxidant and Antiapoptotic Activities

Background

Reactive oxygen species (ROS) play a major role in myocardial damage during acute myocardial infarction (AMI). This study aimed to determine the antioxidant and antiapoptotic activities of an ethanolic extract from Ulva lactuca L. (EEUL) against AMI.

Methods

Thirty-six male Wistar rats were divided into six groups: one control group and five treatment groups. Treatment group II was given 85 mg/kg body weight (BW) of isoproterenol (ISO). Group III, IV and V were given ISO and EEUL at 250, 500 and 750 mg/kg BW, respectively. Group VI were given 10 mg/kg BW of ISO and melatonin. EEUL and melatonin were orally administered for 28 days. ISO was injected subcutaneously on day 29 and 30 to chemically induce AMI. On day 31, blood was collected for antioxidant assay and heart tissues were collected for histological examination.

Results

The activity of catalase (CAT), an endogenous antioxidant, in the EEUL-treatment groups was significantly increased compared to the ISO-treatment group (P < 0.001). The EEUL-treatment groups showed significantly decreased expression of caspase-3 (P < 0.001) and better myocardial tissue morphology.

Conclusion

EEUL possibly protects against AMI because of its antioxidant and antiapoptotic properties.

Elevated DNA Damage, Oxidative Stress, and Impaired Response Defense System Inflicted in Patients With Myocardial Infarction

BACKGROUND

Ischemic tissue damage in myocardial infarction (MI) is allied with the exaggerated production of reactive oxygen species (ROS) beyond the countering capability of chain-breaking radical scavengers, fallouts in the form of oxidatively burdened myocardial tissue.

METHODS

One hundred and twenty five patients with MI were included in the study to evaluate the dynamics of redox status of patients by monitoring the antioxidant potential, biomarkers of oxidative stress, lipid indices, RBC membrane damage when compared to healthy individuals in patients with MI congregated on the basis of Global Registry of Acute Coronary Events (GRACE) score, risk factors, and age.

RESULTS

Higher levels of malondialdehyde, 8-hydroxy-2-deoxyguanosine, lipid indices, ROS content, and membrane deterioration in erythrocytes were seen in patients with MI. Furthermore, reduced activities of erythrocyte antioxidant enzymes and lower concentrations of antioxidant molecules, plus reduced total antioxidant capacity, were observed in plasma of all patients with MI with respect to control. However, elevation in oxidative stress was found to be significantly marked in patients having GRACE score >100, risk factors, and MI >45 years when compared to patients with GRACE score ≤100, without risk factors, and MI ≤45 years, respectively.

CONCLUSION

These findings indicate the existence of increased oxidative damage and reduced antioxidant potential in patients with MI have a potent relationship with their GRACE risk score, risk factors, and age.

Cardiovascular Protective Effects of Salvianic Acid A on db/db Mice with Elevated Homocysteine Level

The onsets of left ventricular hypertrophy (LVH) and endothelial dysfunction (ED) in diabetics, especially in those with elevated homocysteine (Hcy), precede the development of cardiovascular (CV) events. Salvianic acid A (SAA) is a renowned Traditional Chinese Medicine (TCM) that has been applied in the treatment of cardiovascular disease for many decades. In this study, we aimed (1) to investigate the CV protective effects of SAA on ameliorating LVH and ED in db/db mice with elevated blood Hcy level and (2) to decipher whether the observed CV protective effects of SAA are associated with Hcy metabolism by modulating the methylation potential and redox status in the liver of the db/db mice with elevated blood Hcy level. Our results found that the administration of SAA could significantly slow down the build-up of left ventricular mass and ameliorate ED. Immunological assay analysis on the mouse liver tissue also indicated that SAA treatment on db/db mice with elevated Hcy was associated with reduced methylation potential but improved redox status. In conclusion, we revealed that SAA has the potential to protect against the hyperglycemia- and hyperhomocysteinemia-induced oxidative stress on diabetic mice via modulation in Hcy metabolism.

Cardioprotective effect of Malva sylvestris L. in myocardial ischemic/reprefused rats

PURPOSE

The present investigation evaluated the cardioprotective effect of Malva sylvestris L. (MS) on myocardial ischemic/reperfusion (MI/R) in rats.

METHODS

All animals were divided into four groups: the sham operated group, ischemia/reperfusion group (MI/R), and the MS (250 and 500mg/kg) treated groups, who received MS 250 and 500mg/kg intragastrically for 15 consecutive days, respectively. At the end of the protocol, concentrations of aspartate transaminase (AST), creatine kinase-MB fraction (CK-MB) and lactate dehydrogenase (LDH) were estimated in serum and the concentrations of other parameters, such as C-reactive protein, macrophage inflammatory protein 1 alpha (MIP-1α), and nitric oxide (NO) were also estimated in the blood. Tissue homogenate concentrations of inflammatory cytokines, such as tumour necrosis factor-α (TNF-α), interlukin-1β (IL-1β), IL-10 and IL-6 as well as oxidative stress parameters, such as lipid peroxidation, catalase, and superoxide dismutase were estimated in MI/R rats.

RESULT

Significant decreases (p<0.01) in AST, LDH, and CK-MB levels were observed in the MS-treated group compared with those in the MI/R group. C-reactive protein and MIP-1α levels decreased in the MS-treated group compared with those in the MI/R group. Plasma NO level was significantly enhanced in the MS-treated group than in the MI/R group. Moreover, treatment with MS significantly reduced TNF-α, IL-1β, and IL-6 levels and increased IL-10 levels in the MS group compared with the MI/R group. Treatment with MS also attenuated the altered oxidative stress parameters in MI/R rats.

CONCLUSION

The present results indicate the cardioprotective effects of MS of reducing oxidative stress and the inflammatory response in MI/R rats.

Danshensu attenuates aldosterone-induced cardiomyocytes injury through interfering p53 pathway

Heart failure, characterized by impaired systolic and/or diastolic function, is a common cardiovascular disease. The loss of cardiomyocytes due to various factors, including through necrosis or apoptosis can result in heart failure. Previous studies have indicated that excessive aldosterone (ALD) serves an essential role in the process of heart failure, and the heart is also one of the direct targets of ALD, which can provoke hypertrophy and the apoptosis of cardiomyocytes. The aim of the present study was to investigate the protective effect of danshensu (DSS) on ALD‑induced cardiomyocytes injury. The present results demonstrated that DSS increased cell viability and decreased the leakage of lactate dehydrogenase in cardiomyocytes exposed to ALD. In addition, DSS decreased the apoptotic rate of ALD‑stimulated cells. Further research indicated that DSS‑ and cellular tumor antigen p53 (p53)‑alone or combination treatment was able to decrease the expression levels of apoptosis regulator BAX and caspase‑3, and increase the expression of apoptosis regulator B‑cell lymphoma (Bcl)‑2 in ALD‑stimulated cardiomyocytes. Taken together, the results of the present study suggest that DSS inhibits the harmful effects of ALD on cardiomyocytes via interfering with the p53 signaling pathway. These results provide novel evidence for the potential protective effects of DSS.

Sugemule-3 Protects against Isoprenaline-induced Cardiotoxicity In vitro

Background:

Sugemule-3 (SD) is a traditional Chinese medicine with protective effect of myocardium. However, the underlying mechanisms of the effect had not been elucidated.

Materials and Methods:

In the present study, the serum of SD was prepared. A model of β-adrenergic agonist isoprenaline (ISO)-induced H9c2 cardiomyocytes injury was established in vitro. The changes in cell viability were examined to determine the available concentration of ISO and serum of SD. ELISA, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay, and flow cytometry were used to detect the effect of serum of SD on oxidative stress and apoptosis. The expression levels of the mitochondria-dependent apoptotic pathway and mitogen-activated protein kinase signalling-related proteins were analyzed.

Results:

Incubation with different dose of ISO (0.015, 0.01, 0.005, and 0.0025 mol/L) for 24 h caused dose-dependent loss of cell viability and 0.01 mol/L of ISO approximately reduced the cell viability to 50%. Pretreatment with 50 μ mol/L serum of SD effectively decreased the levels of ISO-induced cell toxicity. Serum of SD relived ISO-induced oxidative stress and apoptosis in H9c2 cardiomyocytes. A further mechanism study indicated that serum of SD inhibited the mitochondria-dependent apoptotic pathways and regulated the expression levels of Bcl-2 family. ISO activated ERK and P38, whereas serum of SD inhibited their activation.

Conclusion:

Serum of SD inhibits the ISO-induced activation of the mitochondria-dependent apoptotic pathway, oxidative stress, and ERK, P38 inactivation. Serum of SD is used for the treatment of ISO-induced cardiomyopathy.

SUMMARY

The serum of SD pretreatment significantly ameliorated ISO-induced H9c2 cardiomyocytes injuries.

The protective effect related with apoptosis and oxidative stress

Inhibition of MAPK pathway was involed in serum of SD induced cardioprotection.

The serum of SD is used for the treatment of ISO-induced cardiomyopathy.

Abbreviations used: ELISA: Enzyme-linked Immunosorbent Assay; TUNEL: TdT-mediated dUTP nick end labeling; MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, DMSO: dimethyl sulfoxide; MDA: Malondialdehyde; SOD: Superoxide Dismutase; GSH-Px: Glutathione peroxidase.

Serum metabolomics analysis reveals that obvious cardioprotective effects of low dose Sini decoction against isoproterenol-induced myocardial injury in rats

BACKGROUND

Sini decoction (SND) is used for cardiovascular disease over thousands of years in China. However, it is still lacking of dose-response relationship of SND in cardiovascular disease at the metabolic level.

PURPOSE

The present study is designed to explore the cardioprotective effects of different dosages of SND pretreatment on the isoproterenol (ISO)-induced myocardial injury and elucidate the mechanism underlying this protective effect.

METHODS

The cardioprotective effects of different dosages of SND pretreatment on the isoproterenol-induced myocardial injury were compared through a serum metabolomics approach based on ultraperformance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). In addition, the cardioprotective effects were evaluated by serum biochemical analysis and histopathological examination of myocardial tissue. Finally, in view of the fact that these perturbed bile acid and phospholipid metabolisms are connected with NF-κB signaling pathway, nuclear expression of NF-κB p65 and the activation of NF-κB were analyzed by immunohistochemistry, immunoblotting and electrophoretic mobility shift assay (EMSA), respectively.

RESULTS

The cardioprotective effect was observed in SND pretreatment groups, especially in low dosage SND group. The results of serum enzyme activities and histopathology were consistent with the above effect. Meanwhile, fifteen latent biomarker candidates were identified involving glucose, phospholipid, bile acid and amino acid metabolisms. Among them, five bile acids including ursodeoxycholic acid, murideoxycholic acid, muricholic acid, hyodeoxycholic acid and cholic acid, were for the first time identified as latent pathological biomarkers related to ISO-induced myocardial injury. Further, different dose SND groups exerted different of inhibition degrees to the activation of NF-κB, which was obvious in the SND-L group.

CONCLUSION

The results revealed that Sini decoction protreatment protects myocardium better at a low dose level and one of possible cardioprotective mechanisms is modulating NF-κB signaling pathway against isoproterenol-induced myocardial injury through regulating phospholipid and bile acid metabolisms.

Crude terpene glycoside component from Radix paeoniae rubra protects against isoproterenol-induced myocardial ischemic injury via activation of the PI3K/AKT/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Radix paeoniae rubra, also known as chishao (CS), is a frequently used traditional Chinese medicine that can promote blood circulation to remove blood stasis. It has been widely used for the prevention and treatment of cardiovascular diseases in China. Although terpene glycoside (TG), the major component in CS, has been shown to possess cardioprotective properties, the mechanism underlying CS-TG's preventive effect against myocardial ischemia injury is unknown. This study was conducted to explore the protective and curative effects of CS-TG against isoproterenol (ISO)-induced myocardial ischemic injury in rats and investigate the underlying myocardial protective mechanisms.

MATERIALS AND METHODS

A rat model of ISO-induced myocardial ischemia was established to evaluate the protective effect of CS-TG in ameliorating heart injury. Myocardial ischemia was induced by administering ISO (40mg/kg/d) subcutaneously for 2 days. Serum was collected and analyzed for the levels of different cardiac biomarkers, and heart tissues were isolated and prepared for ATP analysis, glycogen content determination, histopathology assay, and ultrastructure observation. The regulatory effects of CS-TG on myocardial apoptosis in rats were studied by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and the levels of cleaved caspase-3, Bax, and Bcl-2 were detected by western blotting. Furthermore, in vitro experiments were conducted to examine whether the CS-TG's cardioprotective effects were linked to the inhibition of apoptosis via activation of the phosphoinositide-3-kinase/serine-threonine kinase AKT/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway.

RESULTS

CS-TG (300mg/kg/d) significantly decreased serum levels of creatine kinase and lactate dehydrogenase in ISO-induced myocardial ischemic rats. Analysis of ATP and glycogen contents, myocardial ultrastructure, and pathological examination showed that CS-TG (300mg/kg/d) significantly improved energy metabolism and alleviated myocardial injury in vivo. In addition, the expression of p-AKT and p-mTOR in rats subjected to CS-TG significantly elevated, while the levels of caspase-3 and Bax/Bcl-2 dramatically reduced. Moreover, treatment with LY294002, a PI3K inhibitor, abrogated CS-TG (200μg/mL) induced down-regulation of cleaved caspase-3, Bax/Bcl-2 in the serum.

CONCLUSIONS

CS-TG protects the heart from ISO-induced myocardial ischemia, potentially by improving cardiac energy metabolism and inhibiting cardiomyocyte apoptosis via activation of the PI3K/AKT/mTOR signaling pathway. Thus, CS -TG might be a potential therapeutic candidate for the prevention and treatment of myocardial ischemia.

Origins, Phytochemistry, Pharmacology, Analytical Methods and Safety of Cortex Moutan (Paeonia suffruticosa Andrew): A Systematic Review

Cortex Moutan (CM), a well-known traditional Chinese medicine, is commonly used for treating various diseases in China and other eastern Asian countries. Recorded in Pharmacopeias of several countries, CM is now drawing increasing attention and under extensive studies in various fields. Phytochemical studies indicate that CM contains many valuable secondary metabolites, such as monoterpene glycosides and phenols. Ample evidence from pharmacological researches suggest that CM has a wide spectrum of activities, such as anti-inflammatory, anti-oxidant, anti-tumor, anti-diabetic, cardiovascular protective, neuroprotective, hepatoprotective effects. Moreover, various analytical methods were established for the quality evaluation and safety control of CM. This review synopsizes updated information concerning the origins, phytochemistry, pharmacology, analytical method and safety of CM, aiming to provide favorable references for modern CM research and application. In conclusion, continuing pharmacological investigations concerning CM should be conducted to unravel its pharmacological mechanisms. Further researches are necessary to obtain comprehensive and applicable analytical approach for quality evaluation and establish harmonized criteria of CM.

Chronic treatment with paeonol improves endothelial function in mice through inhibition of endoplasmic reticulum stress-mediated oxidative stress

Endoplasmic reticulum (ER) stress leads to endothelial dysfunction which is commonly associated in the pathogenesis of several cardiovascular diseases. We explored the vascular protective effects of chronic treatment with paeonol (2'-hydroxy-4'-methoxyacetophenone), the major compound from the root bark of Paeonia suffruticosa on ER stress-induced endothelial dysfunction in mice. Male C57BL/6J mice were injected intraperitoneally with ER stress inducer, tunicamycin (1 mg/kg/week) for 2 weeks to induce ER stress. The animals were co-administered with or without paeonol (20 mg/kg/oral gavage), reactive oxygen species (ROS) scavenger, tempol (20 mg/kg/day) or ER stress inhibitor, tauroursodeoxycholic acid (TUDCA, 150 mg/kg/day) respectively. Blood pressure and body weight were monitored weekly and at the end of treatment, the aorta was isolated for isometric force measurement. Protein associated with ER stress (GRP78, ATF6 and p-eIF2α) and oxidative stress (NOX2 and nitrotyrosine) were evaluated using Western blotting. Nitric oxide (NO) bioavailability were determined using total nitrate/nitrite assay and western blotting (phosphorylation of eNOS protein). ROS production was assessed by en face dihydroethidium staining and lucigenin-enhanced chemiluminescence assay, respectively. Our results revealed that mice treated with tunicamycin showed an increased blood pressure, reduction in body weight and impairment of endothelium-dependent relaxations (EDRs) of aorta, which were ameliorated by co-treatment with either paeonol, TUDCA and tempol. Furthermore, paeonol reduced the ROS level in the mouse aorta and improved NO bioavailability in tunicamycin treated mice. These beneficial effects of paeonol observed were comparable to those produced by TUDCA and tempol, suggesting that the actions of paeonol may involve inhibition of ER stress-mediated oxidative stress pathway. Taken together, the present results suggest that chronic treatment with paeonol preserved endothelial function and normalized blood pressure in mice induced by tunicamycin in vivo through the inhibition of ER stress-associated ROS.

Effects of salvianolic acid B on L-type calcium channels and myocardial contractility in isolated rat ventricular myocytes and hERG K+ channels expressed in HEK293 cells

Salvianolic acid B (Sal B), one of the chief water-soluble constituents in Radix Salviae Milthiorrhizae, has often been reported to possess considerable cardiovascular regulatory effects. However, the underlying biochemical and cellular mechanisms of its cardioprotection remain unclear. This study was designed to evaluate the role of Sal B regulation in L-type Ca²⁺ channel currents (I_Ca,L) and cell contractility in rat cardiomyocytes and hERG K⁺ channels expressed in HEK293 cells with the patch-clamp and Ca²⁺ imaging techniques to clarify its underlying cardioprotective mechanisms. Exposure to Sal B blocked I_Ca,L with IC₅₀ of 2.07 × 10^-5 M, shifted the curves of current and voltage upwards, shifted the curves of activation and inactivation to the left, and significantly inhibited the amplitude of the cell shortening, but the regulatory effects of Sal B on the expressed rapidly activating delayed rectifier potassium current (I_Kr) did not reach a significant level. These results indicate that the cardioprotective mechanisms of Sal B may be related to the attenuation of calcium overload by directly inhibiting I_Ca,L and consequently decreasing myocardial contractility without causing drug-induced long QT syndrome (LQTS).

High-Throughput Determination of Sodium Danshensu in Beagle Dogs by the LCMS/MS Method, Employing Liquid-Liquid Extraction Based on 96-Well Format Plates

Sodium Danshensu (sodium d-(+)-β-(3,4-dihydroxyphenyl) lactate), one of the water-soluble ingredients in Salvia miltiorrhiza, exhibits potent relaxation of the coronary artery and anticoagulation effection. A high-throughput, rapid, and sensitive method combining liquid chromatography with electrospray ionization tandem mass spectrometry to determine the sodium danshensu in beagle dog plasma was developed and validated, using gallic acid as an internal standard (IS). Acidified plasma samples were extracted using 96-well liquid-liquid extraction, and were eluted on a CNW Athena C18 column (3 μm, 2.1 × 100 mm) by using a gradient mobile phase system of methanol and water (containing 0.2% formic acid). The mass spectrometric detection was achieved using negative ion electrospray ionization mode and monitoring the precursor→production combinations of m/z 197→135 for sodium danshensu and 169→125 for IS, in multiple reaction monitoring modes. Good linearity was achieved, and the linear range was 10-1000 ng/mL (R² > 0.996) with a quantification limit of 10 ng/mL for sodium danshensu in beagle dog plasma. The intra- and inter-day precision (RSD) ranged from 2.1% to 9.0%. The accuracy (RE) was between -8.6% and 5.7% at all quality control levels. The validated method was successfully applied to the pharmacokinetics study of sodium danshensu in beagle dog plasma after intravenous injection and oral administration of sodium danshensu.

Efficacy of gold nanoparticles against isoproterenol induced acute myocardial infarction in adult male albino rats

This study was undertaken to investigate the role of gold nanoparticles (GNPs) of 50 nm diameter on isoproterenol (ISO) induced acute myocardial infarction in adult male albino rats. Forty five adult Wistar male albino rats were equally divided into three groups. Control (group I) was further subdivided into three subgroups. In group II, the rats received ISO subcutaneously at a dose of 100 mg/kg for three days. In group III, rats received ISO as group II and then GNPs (400 μg/kg/day) intravenously for 14 consecutive days. Echocardiography was performed. Left ventricular specimens were prepared for H&E, van Gieson staining, immunohistochemical analysis for (eNOs and Bcl-2), and Electron microscope examination. Energy dispersive X-ray microanalysis was also performed. Cardiac markers such as creatine Kinase-MB (CK-MB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and cardiac troponin T (cTnT) were measured. Group II revealed cardiomyocytes with deeply stained acidophilic cytoplasm, small dark nuclei, intracellular vacuolations, wide intercellular spaces, and extravasated red blood cells. Increased collagen fibers were observed. Electron microscope examination showed cardiomyocyte with small and irregular outlined nuclei, mitochondria with irregular cristae and others with ruptured mitochondrial membrane, abnormal alignment of myofibrils, dilated cisternae of smooth endoplasmic reticulum, and disorganized intercalated discs. Group III showed that most cardiomyocytes preserved the normal architecture. Increased expression of eNOs immunoreaction and decreased Bcl-2 immunoreaction were detected in group II as compared to the control and GNP-treated groups. These findings suggested that GNPs of 50 nm diameter improved myocardial injury after ISO-induced myocardial infarction in rats.

ABBREVIATIONS

Myocardial infarction (MI), Isoproterenol (ISO), Nitric oxide (NO), Neuronal NOS (nNOs), Endothelial NOs (eNOs), Gold nanoparticle (GNPs), Diamiobenzidine (DAB), Serum Creatine Kinase-MB (CK-MB), Alanine aminotransferase (ALT), Cardiac troponin T (cTnT), Electrochemiluminiscence (ECLIA), Cardiomyocytes (CMC), Peroxisomal proliferator activated receptor (PPARs), Reactive oxygen species (ROS).

The New Synthetic H2S-Releasing SDSS Protects MC3T3-E1 Osteoblasts against H2O2-Induced Apoptosis by Suppressing Oxidative Stress, Inhibiting MAPKs, and Activating the PI3K/Akt Pathway

Reactive oxygen species (ROS) are important in osteoporosis development. Oxidative stress induces apoptosis of osteoblasts and arrest of their differentiation. Both Danshensu (DSS) and hydrogen sulfide (H₂S) produce significant antioxidant effect in various systems. In this study, we synthesized SDSS, a novel H₂S-releasing compound derived from DSS, and studied its antioxidant effect in an H₂O₂-induced MC3T3-E1 osteoblastic cell injury model. We first characterized the H₂S releasing property of SDSS in both in vivo and in vitro models. HPLC chromatogram showed that intravenous injection of SDSS in adult rats released ADT-OH, a well proved H₂S sustained-release moiety, within several minutes in the rat plasma. Using an H₂S selective fluorescent probe, we further confirmed that SDSS released H₂S in MC3T3-E1 osteoblastic cells. Biological studies revealed that SDSS had no significant toxic effect but produced protective effects against H₂O₂-induced MC3T3-E1 cell apoptosis. SDSS also reversed the arrest of cell differentiation caused by H₂O₂ treatment. This was caused by the stimulatory effect of SDSS on bone sialoprotein, runt-related transcription factor 2, collagen expression, alkaline phosphatase activity, and bone nodule formation. Further studies revealed that SDSS reversed the reduced superoxide dismutase activity and glutathione content, and the increased ROS production in H₂O₂ treated cells. In addition, SDSS significantly attenuated H₂O₂-induced activation of p38-, ERK1/2-, and JNK-MAPKs. SDSS also stimulated phosphatidylinositol 3-kinase/Akt signaling pathway. Blockade of this pathway attenuated the cytoprotective effect of SDSS. In conclusion, SDSS protects MC3T3-E1 cells against H₂O₂-induced apoptosis by suppressing oxidative stress, inhibiting MAPKs, and activating the phosphatidylinositol 3-kinase/Akt pathway.

Momordica charantia polysaccharides ameliorate oxidative stress, hyperlipidemia, inflammation, and apoptosis during myocardial infarction by inhibiting the NF-κB signaling pathway

The polysaccharide extract of Momordica charantia has various biological activities; however, its effect on endothelial dysfunction in myocardial infarction remains unclear. To elucidate this, myocardial infarction was induced in rats using isoproterenol (ISP). Pretreatment with M. charantia polysaccharides (MCP; 150 or 300mg/kg) for 25days significantly inhibited increases in heart weight, the heart-weight-to-body-weight ratio, and infarction size, and ameliorated the increased serum levels of aspartate transaminase, creatine kinase, lactate dehydrogenase, total cholesterol, triglycerides, very-low-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. In addition, MCP enhanced the activity of superoxide dismutase, catalase, and non-protein sulfhydryls, and decreased the level of lipid peroxidation. Moreover, MCP pretreatment downregulated the expression of proinflammatory cytokines (tumor necrosis factor alpha, interleukin (IL)-6, and IL-10), inflammatory markers (nitric oxide, myeloperoxidase, and inducible nitric oxide synthase), and apoptotic markers (caspase-3 and BAX), and upregulated Bcl-2 expression. Pretreatment with MCP reduced myonecrosis, edema, and inflammatory cell infiltration, and restored cardiomyocytes architecture. This myocardial protective effect could be related to the enhancement of the antioxidant defense system through the nuclear factor kappa B (NF-kB) pathways, and to anti-apoptosis through regulation of Bax, caspase-3, and Bcl-2.

Vagal nerve stimulation improves mitochondrial dynamics via an M3 receptor/CaMKKβ/AMPK pathway in isoproterenol-induced myocardial ischaemia

Mitochondrial dynamics-fission and fusion-are associated with ischaemic heart disease (IHD). This study explored the protective effect of vagal nerve stimulation (VNS) against isoproterenol (ISO)-induced myocardial ischaemia in a rat model and tested whether VNS plays a role in preventing disorders of mitochondrial dynamics and function. Isoproterenol not only caused cardiac injury but also increased the expression of mitochondrial fission proteins [dynamin-related peptide1 (Drp1) and mitochondrial fission protein1 (Fis-1)) and decreased the expression of fusion proteins (optic atrophy-1 (OPA1) and mitofusins1/2 (Mfn1/2)], thereby disrupting mitochondrial dynamics and leading to increase in mitochondrial fragments. Interestingly, VNS restored mitochondrial dynamics through regulation of Drp1, Fis-1, OPA1 and Mfn1/2; enhanced ATP content and mitochondrial membrane potential; reduced mitochondrial permeability transition pore (MPTP) opening; and improved mitochondrial ultrastructure and size. Furthermore, VNS reduced the size of the myocardial infarction and ameliorated cardiomyocyte apoptosis and cardiac dysfunction induced by ISO. Moreover, VNS activated AMP-activated protein kinase (AMPK), which was accompanied by phosphorylation of Ca2+ /calmodulin-dependent protein kinase kinase β (CaMKKβ) during myocardial ischaemia. Treatment with subtype-3 of muscarinic acetylcholine receptor (M3 R) antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide or AMPK inhibitor Compound C abolished the protective effects of VNS on mitochondrial dynamics and function, suggesting that M3 R/CaMKKβ/AMPK signalling are involved in mediating beneficial effects of VNS. This study demonstrates that VNS modulates mitochondrial dynamics and improves mitochondrial function, possibly through the M3 R/CaMKKβ/AMPK pathway, to attenuate ISO-induced cardiac damage in rats. Targeting mitochondrial dynamics may provide a novel therapeutic strategy in IHD.

Delonix regia Leaf Extract (DRLE): A Potential Therapeutic Agent for Cardioprotection

Delonix regia (Boj. Ex. Hook) is a flowering plant in the pea family found in tropical areas and its leaves are used informally to treat diseases in folk medicine. However, the cardioprotective effects in this plant are still unclear. In this study, we found that the Delonix regia leaf extract (DRLE) (400 mg/kg/d) can reduce the mortality rate in an isoproterenol (ISO)-induced heart injury and hypertrophy mouse model. Decreased serum levels of creatine phosphokinase, LDH, GOT, TNF-alpha and increased nitric oxide levels were found in DRLE-treated ISO-injured mice. In the in vitro study, the porcine coronary artery exhibited vasodilation effect induced by DRLE in a dose-dependent manner. In the DRLE toxic test, overdose of DRLE showed the high safety in normal mice and may have the ability to remove the metabolic wastes in blood. In conclusion, we demonstrated for the first time that DRLE has the cardioprotective effects by activating the vasodilation through NO pathway and preventing the myocyte injury via inhibition of TNF-alpha pathway. We suggest that DRLE may act as a promising novel herbal medicine for cardioprotection.

Chlorogenic acid ameliorates isoproterenol-induced myocardial injury in rats by stabilizing mitochondrial and lysosomal enzymes

This study was deliberated to aspire the effects of chlorogenic acid (CGA) against myocardial infarction (MI) induced by Isoproterenol (ISO), in a rat model. In the pathology of MI, enzymes released due to the mitochondrial and lysosomal lipid peroxidation play an integral role. Induction of rats with ISO (85mg/kg BW) for 2 consecutive days resulted in a significant decrease in the activities of heart mitochondrial enzymes isocitrate dehydrogenase (ICDH), α-ketoglutarate dehydrogenase (α-KGDH), succinate dehydrogenase (SDH) and malate dehydrogenase (MDH). The activities of lysosomal enzymes (β- glucosidase, β-glucuronidase, α-galactosidase, β-galactosidase, cathepsin-B and cathepsin-D) were increased significantly in the heart tissue. A prominent expression of LDH 1 and LDH 2 isoenzymes in the serum were observed and changes in the Electrocardiographic (ECG) patterns were also recorded in the ISO-induced rats. The prior administrations of CGA (40mg/kg BW) for 19days markedly ameliorated ISO induced alterations in ECG and significantly restored the activities of all the above enzymes in the heart of ISO-induced rats, which substantiates the stress stabilizing action of CGA. Oral administration of CGA (40mg/kg BW) to normal rats did not show any significant changes. These biochemical functional alterations were supported by the histology of heart (Massion's trichrome and Picrosirius red staining for collagen formation). Thereupon, this study shows that 40mg/kg BW of CGA gives protection against ISO-induced MI and demonstrates that CGA has a significant effect in the protection of heart.

Mechanisms underlying the cardioprotective effect of Salvianic acid A against isoproterenol-induced myocardial ischemia injury in rats: Possible involvement of L-type calcium channels and myocardial contractility

ETHNOPHARMACOLOGICAL RELEVANCE

Salvianic acid A (SAA), which is the main water-soluble fraction in Radix Salviae Milthiorrhizae, has been widely applied for treating cardiovascular diseases in China.

AIM OF THE STUDY

To explore the effects of SAA against myocardial ischemia injury induced by isoproterenol (ISO) in rats and to clarify its underlying myocardial protective mechanisms based on l-type calcium channels and myocardial contractility.

MATERIALS AND METHODS

The myocardial ischemia injured rat model was induced by administering ISO (85mg/kg) subcutaneously at evenly spaced intervals throughout the day and night for 2 consecutive days. Serum cardiac biomarkers were analyzed, and heart tissues were isolated and prepared for histopathology assay. The regulatory effects of SAA on the L-type calcium current (ICa-L) in rat ventricular myocytes were observed by the patch clamp technique. The IonOptix Myocam detection system was used to observe the contractility of isolated rat ventricular myocytes.

RESULTS

SAA significantly ameliorated changes in heart morphology and electrocardiographic patterns and reduced serum levels of creatine kinase and lactate dehydrogenase in the ISO-induced myocardial ischemia injured rat model. Meanwhile, SAA reduced ICa-L in a concentration-time dependent way with an IC50 of 1.47×10(-5)M, upshifted the current-voltage, activation, and inactivation curves of ICa-L, and significantly inhibited the amplitude of the cell shortening.

CONCLUSIONS

These results indicate that SAA exhibits significant cardioprotective effects against the ISO-induced myocardial ischemia injury, potentially through inhibiting ICa-L and decreasing myocardial contractility.