Acute Myocardial Ischemia In Rats Research Articles

Metabolomics analysis reveals the effects of Salvia Miltiorrhiza Bunge extract on ameliorating acute myocardial ischemia in rats induced by isoproterenol

Salvia miltiorrhiza Bunge (SM) is a widespread herbal therapy for myocardial ischemia (MI). Nevertheless, the therapeutic signaling networks of SM extract on MI is yet unknown. Emerging evidences suggested that alterations in cardiac metabolite influences host metabolism and accelerates MI progression. Herein, we employed an isoproterenol (ISO)-induced acute myocardial ischemia (AMI) rat model to confirm the pharmacological effects of SM extract (0.8, 0.9, 1.8 g/kg/day) via assessment of the histopathological alterations that occur within the heart tissue and associated cytokines; we also examined the underlying SM extract-mediated signaling networks using untargeted metabolomics. The results indicated that 25 compounds with a relative content higher than 1 % in SM aqueous extract were identified using LC-MS/MS analysis, which included salvianolic acid B, lithospermic acid, salvianolic acid A, and caffeic acid as main components. An in vivo experiment showed that pretreatment with SM extract attenuated ISO-induced myocardial injury, shown as decreased myocardial ischemic size, transformed electrocardiographic, histopathological, and serum biochemical aberrations, reduced levels of proinflammatory cytokines, inhibited oxidative stress (OS), and reversed the trepidations of the cardiac tissue metabolic profiles. Metabolomics analysis shows that the levels of 24 differential metabolites (DMs) approached the same value as controls after SM extract therapy, which were primarily involved in histidine; alanine, aspartate, and glutamate; glycerophospholipid; and glycine, serine, and threonine metabolisms through metabolic pathway analysis. Correlation analysis demonstrated that the levels of modulatory effects of SM extract on the inflammation and OS were related to alterations in endogenous metabolites. Overall, SM extract demonstrated significant cardioprotective effects in an ISO-induced AMI rat model, alleviating myocardial injury, inflammation and oxidative stress, with metabolomics analysis indicating potential therapeutic pathways for myocardial ischemia.

Metagenomic sequencing revealed the regulative effect of Danshen and Honghua herb pair on the gut microbiota in rats with myocardial ischemia injury.

In recent years, more and more evidence has shown that the disorder of gut microbiota (GM) is closely correlated with myocardial ischemia (MI). Even though the Danshen and Honghua herb pair (DHHP) is widely used in treating cardiovascular disease in China and exhibits obvious clinical efficacy on MI, the anti-MI mechanism of DHHP remains and needs to be explored in depth. Thus, in this study, we investigated whether the amelioration effect and molecular mechanism of DHHP on MI were related to regulating GM through pharmacodynamics evaluation and metagenomic sequencing. Histopathological testing results showed that DHHP treatment could alleviate the pathological changes of myocardial tissue in the acute MI (AMI) rats induced by isoproterenol (ISO), especially structural disorder, irregular distribution, and enlargement of the myocardial space. These pathological changes were all alleviated to some extent by DHHP treatment. Biochemical analysis results suggested that compared with the control group, the serum levels of AST, CTn-I, CK-MB, and TNF-α in model group rats were notably decreased, and the CAT and SOD levels in serum were markedly increased. These abnormal trends were significantly reversed by DHHP treatment. Furthermore, metagenomic sequencing analysis results indicated that DHHP could improve disorders in the composition and function of GM in AMI rats, mainly reflected in increasing diversity and richness, and obviously enhancing the abundance of Bacteroides fluxus, B. uniformis, B. stercoris, Roseburia hominis, Schaedlerella arabinosiphila, and R. intestinalis, and reducing the abundance of Enterococcus avium and E. canintestini, which were associated with purine metabolism, tyrosine metabolism, cyanoamino acid metabolism, and glutathione metabolism. In conclusion, DHHP may attenuate ISO-induced MI by regulating the structure, composition, and function of GM, thus contributing to further our understanding of the anti-MI mechanisms of DHHP and providing new therapeutic ideas and diagnostic targets for the clinical studies of MI.

Analysis of compatibility mechanism of shenxiong glucose injection after multiple dosing based on differences of PK-PD correlation and cytochrome P450 enzyme

Shenxiong glucose injection (SGI) containing a water extract from the roots of Danshen and Ligustrazine hydrochloride, is the main drug used for the prevention and treatment of acute myocardial ischemia (AMI) in China. Based on the characteristics of drug clinical applications, this study aims to uncover the compatibility mechanism of SGI by investigating pharmacokinetic (PK) and pharmacodynamic (PD) differences between Danshen glucose injection (DGI), Ligustrazine glucose injection (LGI) and SGI groups after multiple dosing during the pathological state from the perspective of metabolic enzymes. Compared to the LGI group, the absorption (Cmax) and exposure (AUC) of ligustrazine increased significantly, and the protein expression of CYP1A2, CYP2C11 and CYP3A2 in the SGI group decreased significantly. Furthermore, the PK and PD experimental data for Danshen and ligustrazine in AMI rats were fitted to obtain a PK-PD binding model with three components. PK-PD parameter analysis showed that in the SGI group the IC50 values of ligustrazine and danshensu on AST, CK-MB, cTn-I and the IC50 values of rosmarinic acid on AST and CK-MB were lower than the DGI or LGI group. It is speculated that Danshen inhibited CYP1A2, CYP2C11 and CYP3A2 mediating the metabolism of ligustrazine and decreased the expression of these three isozymes, which further affected the in vivo process of ligustrazine. Moreover, the combination of Danshen and ligustrazine could have better regulating effect on AST, CK-MB and cTn-I. This preliminary study has provided a scientific basis for understanding the compatibility mechanism of SGI from the viewpoint of the regulation of CYP enzymes in the PK-PD model.

Integration of metabolomics and network pharmacology to reveal the protective mechanism underlying Wogonoside in acute myocardial ischemia rats

Ethnopharmacological relevanceIn traditional medicine, both Scutellaria baicalensis Georgi (SBG) and the traditional formulas composed of it have been used to treat a wide range of diseases, including cancer and cardiovascular. Wogonoside (Wog) is the biologically active flavonoid compound extracted from the root of SBG, with potential cardiovascular protective effects. However, the mechanisms underlying the protective effect of Wog on acute myocardial ischemia (AMI) have not yet been clearly elucidated. Aim of the studyTo explore the protective mechanism of Wog on AMI rats by comprehensively integrating traditional pharmacodynamics, metabolomics, and network pharmacology. MethodsThe rat was pretreatment with Wog at a dose of 20 mg/kg/d and 40 mg/kg/d once daily for 10 days and then ligated the left anterior descending coronary artery of rats to establish the AMI rat model. Electrocardiogram (ECG), cardiac enzyme levels, heart weight index (HWI), Triphenyltetrazolium chloride (TTC) staining, and histopathological analyses were adopted to evaluate the protective effect of Wog on AMI rats. Moreover, a serum metabolomic-based UHPLC-Q-Orbitrap MS approach was performed to find metabolic biomarkers and metabolic pathways, and network pharmacology analysis was applied to predict targets and pathways of Wog in treating AMI. Then, the network pharmacology and metabolomic results were integrated to elucidate the mechanism of Wog in treating AMI. Finally, RT- PCR was used to detect the mRNA expression levels of PTGS1, PTGS2, ALOX5, and ALOX15 to validate the result of integrated metabolomics and network analysis. ResultsPharmacodynamic studies suggest that Wog could effectively prevent the ST-segment of electrocardiogram elevation, reduce the myocardial infarct size, heart weight index, and cardiac enzyme levels, and alleviate cardiac histological damage in AMI rats. Metabolomics analysis showed that the disturbances of metabolic profile in AMI rats were partly corrected by Wog and the cardio-protection effects on AMI rats involved 32 differential metabolic biomarkers and 4 metabolic pathways. In addition, the integrated analysis of network pharmacology and metabolomics showed that 7 metabolic biomarkers, 6 targets, and 6 crucial pathways were the main mechanism for the therapeutic application of Wog for AMI. Moreover, the results of RT-PCR showed that PTGS1, PTGS2, ALOX5, and ALOX15 mRNA expression levels were reduced after treatment with Wog. ConclusionWog exerts cardio-protection effects on AMI rats via the regulation of multiple metabolic biomarkers, multiple targets, and multiple pathways, our current study will provide strong scientific evidence supporting the therapeutic application of Wog for AMI.

Protective effect of the seeds of Allium fistulosum extract against acute myocardial ischemia in rats and dogs

Protective effect of the seeds of Allium fistulosum extract against acute myocardial ischemia in rats and dogs

Effects and correlation of ligustrazine hydrochloride-Salviae Miltiorrhizae Radix et Rhizoma compatibility on pharmacokinetics and CYP450 enzyme

The present study investigated the effects of ligustrazine hydrochloride(LH)-Salviae Miltiorrhizae Radix et Rhizoma(SM) before and after compatibility on the pharmacokinetics of acute myocardial ischemia(AMI) rats and revealed the mechanism of pharmacokinetic changes from the perspective of metabolic enzymes. AMI rats underwent single injection of SM Glucose Injection, LH Glucose Injection, and LH-SM Glucose Injection in the caudal vein, respectively(3.78 mg·kg~(-1) salvianic acid, 0.049 mg·kg~(-1) rosmarinic acid, and 13.68 mg·kg~(-1) ligustrazine). Blood samples were collected from the orbital venous plexus at different time points, and the liver of the rats was removed after the last blood sampling. The plasma concentrations of salvianic acid, rosmarinic acid, and ligustrazine were detected by UPLC-MS/MS. Western blot was used to detect the protein expression of CYP1 A2, CYP2 C11, CYP2 C19, CYP2 D4, CYP2 E1, and CYP3 A2 in the liver of rats in each group. As revealed by the pharmacokinetic results, compared with the LH Glucose Injection group, the LH-SM Glucose Injection group showed a downward trend of T_(1/2) of ligustrazine in AMI rats and decreased AUC(P<0.05). Compared with the SM Glucose Injection, there were no significant differences in the pharmacokinetic parameters of salvianic acid and rosmarinic acid in the LH-SM Glucose Injection group. Protein expression results showed that the expression levels of CYP1 A2, CYP2 C11, CYP2 D4, CYP2 E1, and CYP3 A2 in the LH-SM Glucose Injection group increased(P<0.05) and the expression level of CYP2 C19 decreased(P<0.05) compared with those in the LH Glucose Injection group. CYP1 A2, CYP2 C11, and CYP3 A2 are isoenzymes involved in ligustrazine Ⅰ metabolism. When LH and SM were used in combination, the expression of these three enzymes increased, which changed the pharmacokinetic process in rats and accelerated the metabolism of ligustrazine.

Hyperlipidemia attenuates the mobilization of endothelial progenitor cells induced by acute myocardial ischemia via VEGF/eNOS/NO/MMP-9 pathway.

This study aims to explore the role of hyperlipidemia in the mobilization of bone marrow (BM) endothelial progenitor cells (EPCs) induced by acute myocardial ischemia (AMI). To establish the hyperlipidemia complicated with AMI (HL-AMI) model, SD rats were intragastrically administered the high-fat emulsion for 4 weeks. Then their left anterior descending arteries were ligated. Rats in each group were randomly subdivided into seven subgroups. During 1st ~ 7th day following AMI modeling, rats in 1st ~ 7th subgroups were selected to be phlebotomized from their celiac artery after being anesthetized by pentobarbitone in turn. The quantity of circulating EPCs (CEPCs) was detected by flow cytometry, the expression of VEGF, eNOS, NO, MMP-9 in myocardial tissue was analyzed by western blot, and their plasma level was assayed by ELISA. Dynamic curves were plotted using these data. Within 7 days following AMI, compared with the AMI rats, in the HL-AMI rats, the myocardial infarct size, the plasma activity of CK, CK-MB, and the collagen deposition all remained at the higher levels; meanwhile, these rats showed more significant decreases in the count of CEPCs, the plasma level of VEGF etc., and their expression in myocardial tissue (P < 0.05 or P < 0.01). Our study showed that hyperlipidemia may attenuate the mobilization of BM EPCs induced by AMI via VEGF/eNOS/NO/MMP-9 signal pathway, which might partly account for hyperlipidemia hampering the repairs of AMI-induced cardiac injury.

Oxidative-Damaged Mitochondria Activate GABARAPL1-Induced NLRP3 Inflammasomes in an Autophagic-Exosome Manner after Acute Myocardial Ischemia.

Objective This study is aimed at identifying the potential diagnostic markers for circulating endothelial cells (CECs) for acute myocardial ischemia (AMI) and exploring the regulatory mechanisms of the selected biomarker in mitochondrial oxidative damage and vascular inflammation in AMI pathology. Methods Utilizing the Gene Expression Omnibus dataset GSE66360, we scanned for differentially expressed genes (DEGs) in 49 AMI patients and 50 healthy subjects. To discover possible biomarkers, LASSO regression and support vector machine recursive feature elimination examinations were conducted. Using the GSE60993 and GSE123342 datasets and AMI rat models, the expression levels and diagnostic accuracy of the biomarkers in AMI were thoroughly verified. CIBERSORT was employed to evaluate the compositional patterns of 22 distinct immunological cell percentages in AMI according to combined cohorts. The oxidative-damaged mitochondria were detected by confocal microscopy observation of MitoTracker, ROS-DCFH-DA, and mCherry-GFP-LC3B. Results In total, 122 genes were identified. The identified DEGs primarily contributed in arteriosclerosis, arteriosclerotic cardiovascular disorders, bacterial infectious disorder, coronary artery disease, and myocardial infarction. Nine features (NR4A2, GABARAPL1 (GEC1), CLEC4D, ITLN1, SNORD89, ZFP36, CH25H, CCR2, and EFEMP1) of the DEGs were shared by two algorithms, and GABARAPL1 (GEC1) was identified and verified as a diagnostic mitochondrial biomarker for AMI. Confocal results showed that there existed mitochondrial damage and oxidative stress in cardiac CMECs after AMI, and the blocked autophagy flux could be released by exosome burst in cardiac CMECs and blood CECs. Immune cell infiltration testing declared that elevated GEC1 expression in blood CECs was linked to the rise of monocytes and neutrophils. Functional tests revealed that high GEC1 expression in CMECs and CECs could activate the vascular inflammatory response by stimulating NLRP3 inflammasome production after AMI. Conclusion Oxidative-damaged mitochondria in cardiac CMECs activate GEC1-mediated autophagosomes but block autophagy flux after AMI. The exfoliated cardiac CMECs evolve into abnormal blood CECs, and the undegraded GEC1 autophagosomes produce a large number of NLRP3 inflammasomes by exosome burst, stimulating the increase in monocytes and neutrophils and ultimately triggering vascular inflammation after AMI. Therefore, GEC1 in blood CECs is a highly specific diagnostic mitochondrial biomarker for AMI.

Muscone suppresses myocardial ischemia damage by regulating PI3K/Akt signaling pathway

Muscone is the main active compound of Moschus. In this paper, the cardioprotective effect of Muscone on acute myocardial ischemia (AMI) rats and its potential mechanisms were investigated. AMI rat models were established to evaluate the protective effect and antioxidative function of Muscone on the hearts. Moreover, Western blot analysis was conducted to quantify the phosphorylated PI3K and AKT levels in PI3K/Akt pathway for further investigating the mechanism of Muscone. Results showed that Muscone could markedly lessen the infarct size and myocardial injury, improve cardiac function, inhibit cardiomyocyte apoptosis and down-regulate serum reactive oxygen species level as indicated by the decreased MDA, BNP and c-TnI activities and the increased SOD, GSH-px, CAT activities and the expression of Bax protein. In addition, it was revealed that Muscone notably promoted the phosphorylation of PI3K and AKT. These findings denote that Muscone exerts a protective effect in heart via inhibition of oxidative stress and apoptosis, offering new insights into the treatment of CHD and the clinical application of Muscone.

Modulation effects of danshen-honghua herb pair on gut microbiota of acute myocardial ischemia model rat.

In the recent years, a growing number of studies have shown that the occurrence of myocardial ischemia (MI) is closely related to the gut microbiota (GM). The Danshen-Honghua herb pair (DHHP), a classic combination in traditional Chinese herbal formulas, has been widely applied throughout history to cure cardiovascular disease, exhibiting remarkable clinical efficacy to treat ischemic heart disease (IHD). However, the intrinsic regulation mechanism of DHHP in treating MI remains unclear. This study aims to investigate the possible protective mechanism of DHHP in rats with acute myocardial ischemia (AMI) induced by isoproterenol (ISO) through 16S rRNA gene sequencing technique. Pharmacodynamic results showed that DHHP significantly ameliorated the pathological changes and improved the abnormal cardiac enzymes levels in the AMI rats. In addition, GM analysis demonstrated that DHHP effectively ameliorated the ISO-induced dysbiosis of the GM community, mainly by enhancing the GM diversity and increasing the relative abundance of Bacteroides, Roseburia, unclassified_f__Lachnospiraceae, and Lachnospiraceae_NK4A136_group, the abundance ratio of Bacteroidetes to Firmicutes, and decreasing the relative abundance of Escherichia-Shigella and Enterococcus. In summary, this study revealed that DHHP could improve ischemic myocardial injury in rats, and that its regulation mechanism is associated with significantly ameliorating the composition of GM, thus contributing to further our understanding of the anti-MI mechanisms of DHHP.

Combined metabolomics and machine learning algorithms to explore metabolic biomarkers for diagnosis of acute myocardial ischemia.

Acute myocardial ischemia (AMI) remains the leading cause of death worldwide, and the post-mortem diagnosis of AMI represents a current challenge for both clinical and forensic pathologists. In the present study, the untargeted metabolomics based on ultra-performance liquid chromatography combined with high-resolution mass spectrometry was applied to analyze serum metabolic signatures from AMI in a rat model (n = 10 per group). A total of 28 endogenous metabolites in serum were significantly altered in AMI group relative to control and sham groups. A set of machine learning algorithms, namely gradient tree boosting (GTB), support vector machine (SVM), random forest (RF), logistic regression (LR), and multilayer perceptron (MLP) models, was used to screen the more valuable metabolites from 28 metabolites to optimize the biomarker panel. The results showed that classification accuracy and performance of MLP model were better than other algorithms when the metabolites consisting of L-threonic acid, N-acetyl-L-cysteine, CMPF, glycocholic acid, L-tyrosine, cholic acid, and glycoursodeoxycholic acid. Finally, 17 blood samples from autopsy cases were applied to validate the classification model's value in human samples. The MLP model constructed based on rat dataset achieved accuracy of 88.23%, and ROC of 0.89 for predicting AMI type II in autopsy cases of sudden cardiac death. The results demonstrated that MLP model based on 7 molecular biomarkers had a good diagnostic performance for both AMI rats and autopsy-based blood samples. Thus, the combination of metabolomics and machine learning algorithms provides a novel strategy for AMI diagnosis.

Electroacupuncture of acupoints of heart meridian ameliorates acute myocardial ischemia via Akt/mTOR pathway

To observe the effect of electroacupuncture (EA) on the expression of myocardial protein kinase B (Akt) and mammalian target of rapamycin (mTOR) in acute myocardial ischemia (AMI) rats. Thirty male SD rats were randomly divided into control, model and EA groups (n=10 in each group). The AMI model was established by occlusion of the descending anterior branch (DAB) of the left coronary artery. EA (2 Hz, 1-2 mA) was applied to bilateral "Shenmen" (HT7) and "Tongli" (HT5) for 20 min, once daily for consecutive 7 days. The electrocardiogram (ECG) of nape-xiphoid lead was recorded for assessing changes of myocardial ischemia. Histopathologic changes of the ischemic myocardial tissue were observed after H.E. staining and ultra-microstructural changes of cardiomyocytes observed by transmission electron microscopy (TEM). The expression levels of Akt, phosphorylated-Akt (p-Akt), mTOR and phosphorylated-mTOR (p-mTOR) in the myocardium were detected by Western blot, followed by calculating the ratios of p-Akt/Akt and p-mTOR/mTOR. Following ligature of DAB, the ECG-ST level was significantly increased in the model group in comparison with the control group (P<0.01). At 30 min after treatment, the ECG-ST level decreased significantly compared with the model group (P<0.01). At the end of the 7-day treatment period, the ECG-ST level increased compared with the model group (P<0.05). The levels of myocardial p-Akt and p-mTOR protein expression, and the ratios of p-Akt/Akt and p-mTOR/mTOR were significantly lower in the model group than those in the control group (P<0.01), and considerably increased in the EA group than in the model group (P<0.01). No significant differences were found among the three groups in the expression levels of Akt and mTOR proteins (P>0.05). Outcomes of H.E. staining and TEM showed damage of mitochondria and occurrence of a large number of autophagosomes in myocardiocytes in the model group, which was milder in the EA group. EA at HT5 and HT7 can improve AMI in AMI rats, which may be related to its effect in facilitating Akt/mTOR signaling.

Influence of Acupuncture on Microcirculation Perfusion of Pericardium Meridian and Heart in Acute Myocardial Ischemia Model Rats.

To observe the influence of acupuncture on microcirculation perfusion of the pericardium meridian and heart in acute myocardial ischemia (AMI) rats and evaluate whether acupuncture can simultaneously affect the meridians and corresponding viscera. Additionally, acupoints at different meridians were compared and whether they exert the same effects was discussed. Totally 32 Sprague-Dawley rats were subjected to left anterior descending (LAD) ligation to develop an AMI model. Rats were divided into 4 groups, including AMI, acupuncture Neiguan (PC 6), Lieque (LU 7) and Qiansanli (LI 10) groups (n=8). Eight rats received only thoracotomy (sham-operated group). The rats in the acupuncture groups received manual acupuncture at PC 6, LU 7 and LI 10 acupoints for 15 min, respectively. The microcirculation perfusion of pericardium meridian and heart was monitored by laser speckle perfusion imager (LSPI) before, during and after acupuncture manipulation for 15 min. Subsequently, the perfusion unit (PU) was calculated and analyzed by PSI System. After LAD, compared to pre-acupuncture stage, the heart microcirculation perfusion (HMP) in the AMI group decreased continuously at during-acupuncture (P>0.05) and post-acupuncture stages (P<0.05), and the pericardium meridian microcirculation perfusion (PMP) showed no significant differences at 3 stages (P>0.05). Compared to pre-acupuncture stage, the PMP and HMP in PC 6 group significantly increased during acupuncture manipulation (both P<0.05), and PMP decreased obviously after acupuncture (P<0.05). The PMP in the LU 7 and LI 10 groups were slightly elevated (both P>0.05); however, they were significantly reduced after acupuncture manipulation (both P<0.05). Additionally, HMP of LI 10 group was decreased significantly during acupuncture, especially compared to pre-acupuncture stage (P<0.05). Acupuncture at PC 6 obviously increased the PMP and HMP in AMI rats, and the effects were superior to at LU 7 and LI 10 acupoints. It was further confirmed that acupuncture promoted qi and blood circulation, indicating that acupoint specificity exists and features a meridian-propagated effect.

Uncoupling protein 1 knockout aggravates isoproterenol-induced acute myocardial ischemia via AMPK/mTOR/PPAR\u03b1 pathways in rats

Uncoupling protein 1 (UCP1) was found exclusively in the inner membranes of the mitochondria of brown adipose tissue (BAT). We found that UCP1 was also expressed in heart tissue and significantly upregulated in isoproterenol (ISO)-induced acute myocardial ischemia (AMI) rat model. The present study is to determine the underlying mechanism involved in the UCP1 upregulation in ISO-induced AMI rat model. The Ucp1−/− rats were generated by CRISPR-Cas9 system and presented decreased BAT volume. 2-months old Sprague Dawley (SD) wild-type (WT) and Ucp1−/− rats were treated with ISO intraperitoneally 30 mg/kg once a day for 3 consecutive days to establish AMI model. In saline group, the echocardiographic parameters, serum markers of myocardial injury cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), oxidant malondialdehyde (MDA), antioxidant superoxide dismutase (SOD) or fibrosis were comparable between WT and Ucp1−/− rats. ISO treatment induced worse left ventricle (LV) hypertrophy, myocardial fibrosis, increased higher cTnI, CK-MB and MDA and decreased lower SOD level in Ucp1−/− rats compared with that of WT rats. Ucp1−/− rats also presented lower myocardial phosphocreatine (PCr)/ATP-ratio, which demonstrated worse cardiac energy regulation defect. ISO treatment induced the phosphorylation of AMP-activated protein kinase (AMPK) activation, subsequently the phosphorylation of mammalian target of rapamycin (mTOR) inhibition and peroxisome proliferators-activated receptor α (PPARα) activation in WT rats, whereas activation of AMPK/mTOR/PPARα pathways significantly inhibited in Ucp1−/− rats. To sum up, UCP1 knockout aggravated ISO-induced AMI by inhibiting AMPK/mTOR/PPARα pathways in rats. Increasing UCP1 expression in heart tissue may be a cytoprotective therapeutic strategy for AMI.

Therapeutic evaluation and metabolic reprograming of isosteviol sodium in a rat model of ischemic cardiomyopathy

Ischemia heart disease, one of the lethal cardiovascular diseases, irreversibly impairs cardiac function and is recognized as the primary risk factor for mortality in industrialized countries. The myocardial ischemia treatment still faces a considerable degree of increasing unmet needs. Isosteviol sodium (STVNa) and its derivatives have been proven to effectively alleviate metabolic diseases, hypertension, and heart hypertrophy. Little is known about how STVNa confers the cardioprotective effect during acute myocardial ischemia (AMI). In the present study, a rat model of acute ST-segment–elevation myocardial ischemia by left anterior descending (LAD) ligation was established. Compared to the AMI model group, STVNa administration (4 mg/kg, twice a day) well preserved left ventricle function by ejection fraction (45.10 ± 10.39 vs. 73.64 ± 13.15, p = 0.0013) and fractional shortening (22.94 ± 6.28 vs. 44.00 ± 11.05, p = 0.0017). Further analysis shows that high-dose STVNa (4 mg/kg) significantly improved the hemodynamics in AMI rats, with LVSP (88.25 ± 12.78 vs 99.75 ± 5.10, p = 0.018), max dP/dt (2978.45 ± 832.46 vs 4048.56 ± 827.23, p = 0.096), LVEDP (19.88 ± 2.00 vs 22.26 ± 3.21, p = 0.04) and left ventricular relaxation time constant (Tau) (0.030 ± 0.006 vs 0.021 ± 0.004, p = 0.021). Mechanically, STVNa administration retained the myocardial levels of phosphorylated AMPK, and CPT1b. Moreover, STVNa significantly increased the total energy expenditure, and reduced fatty acid accumulation through mitochondrial oxidative phosphorylation, which was supported by the indirect calorimetry and cellular energy analysis. Taken together, these findings suggest that STVNa is a potential cardioprotection agent for ischemic cardiomyopathy, likely through improving energy homeostasis, left ventricular hemodynamics, and heart function.

Salvia miltiorrhiza and Pueraria lobata, two eminent herbs in Xin-Ke-Shu, ameliorate myocardial ischemia partially by modulating the accumulation of free fatty acids in rats

BackgroundXin-Ke-Shu (XKS), a commonly used traditional Chinese medicine, has been clinically proven to be effective for treatment of acute myocardial ischemia (AMI). Numerous studies underscore the important role of fatty acid metabolism in the pathogenesis of AMI. PurposeThis study examined the relationship between free fatty acids (FFAs) and AMI and the contributions of individual herbs found in XKS to provide a basis for the study of the compatible principle of XKS. MethodsUFLC-MS/MS-based targeted metabolomics was performed to analyze the levels of 15 FFAs in the plasma and myocardium of isoproterenol (ISO)-induced AMI rats treated with XKS and the subtracted prescriptions of XKS. Electrocardiogram data, H&E staining, biochemical analysis and western blotting were assayed to illustrate the cardioprotection of XKS and its subtracted prescription in AMI. Correlation analysis was used to reveal the relationship between the levels of FFAs and overexpressed proteins/biochemical enzymes. ResultsWe found aberrant fatty acid metabolism in AMI rats. In both plasma and myocardium, the concentrations of most of quantified FFAs were significantly altered, whereas the concentrations of stearic acid and behenic acid were similar between the control and AMI groups. Correlation analysis revealed that palmitic acid, oleic acid, linoleic acid and arachidonic acid were potentially the most relevant FFAs to inflammatory and apoptotic proteins and CK-MB. Moreover, XKS effectively alleviated pathological alterations, FFA metabolism abnormity, inflammation and apoptosis found in the myocardium of AMI rats. Notably, the removal of Salvia miltiorrhiza and Pueraria lobata from XKS resulted in markedly regulation loss of cardioprotection during AMI, especially mediation loss of FFA metabolism. The other three herbs of XKS also played a role in improving AMI. ConclusionFatty acid metabolism aberrance occurred during AMI. S. miltiorrhiza and P. lobata play vital roles in the anti-inflammatory and anti-apoptotic action partially by regulating FFA levels. Our findings revealed potential novel clinical FFAs for predicting AMI and extended the insights into the compatible principle of XKS in which S. miltiorrhiza and P. lobata can potently modulate FFA metabolism.

Comparative Protective Effect of Nigella sativa Oil and Vitis vinifera Seed Oil in an Experimental Model of Isoproterenol-Induced Acute Myocardial Ischemia in Rats

The study’s aim was to characterize the composition of Nigella sativa seed (NSO) and grape seed (GSO) oils, and to evaluate their cardioprotective and anti-inflammatory effect on isoproterenol (ISO)-induced ischemia in rats. Materials and Methods: NSO and GSO supplements were physicochemically characterized. Liquid chromatography–mass spectrometry (HPLC-MS), Fourier-transform infrared spectroscopy (FTIR), and gas chromatography–mass spectrometry (GC-MS) analyses were used to determine the phytochemical composition in the oils. Total polyphenol content (TPC) and in vitro antioxidant activity were also determined. Pretreatment with 4 mL/kg/day NSO or GSO was administered to rats for 14 days. The experimental ischemia was induced by a single administration of ISO 45 mg/kg after 14 days. An electrocardiogram (ECG) was performed initially and 24 h after ISO. Biological evaluation was done at the end of experiment. Results: The HPLC-MS, GC-MS, and FTIR analyses showed that both NSO and GSO are important sources of bioactive compounds, especially catechin and phenolic acids in GSO, while NSO was enriched in flavonoids and thymol derivatives. Pretreatment with GSO and NSO significantly reduced ventricular conduction, prevented the cardiotoxic effect of ISO in ventricular myocardium, and reduced the level of proinflammatory cytokines and CK-Mb. Conclusion: Both NSO and GSO were shown to have an anti-inflammatory and cardioprotective effect in ISO-induced ischemia.

Paraventricular Nucleus P2X7 Receptors Aggravate Acute Myocardial Infarction Injury via ROS-Induced Vasopressin-V1b Activation in Rats

The present study was designed to investigate the mechanisms by which P2X7 receptors (P2X7Rs) mediate the activation of vasopressinergic neurons thereby increasing sympathetic hyperactivity in the paraventricular nucleus (PVN) of the hypothalamus of rats with acute myocardial ischemia (AMI). The left anterior descending branch of the coronary artery was ligated to induce AMI in rats. The rats were pretreated with BBG (brilliant blue G, a P2X7R antagonist), nelivaptan (a vasopressin V1b receptor antagonist), or diphenyleneiodonium (DPI) [an nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor]. Hemodynamic parameters of the heart were monitored. Myocardial injury and cardiomyocyte apoptosis were assessed. In the PVN of AMI rats, P2X7R mediated microglial activation, while reactive oxygen species (ROS) and NADPH oxidase 2 (NOX2) were higher than in the sham group. Intraperitoneal injection of BBG effectively reduced ROS production and vasopressin expression in the PVN of AMI rats. Moreover, both BBG and DPI pretreatment effectively reduced sympathetic hyperactivity and ameliorated AMI injury, as represented by reduced inflammation and apoptosis of cardiomyocytes. Furthermore, microinjection of nelivaptan into the PVN improved cardiac function and reduced the norepinephrine (AE) levels in AMI rats. Collectively, the results suggest that, within the PVN of AMI rats, P2X7R upregulation mediates microglial activation and the overproduction of ROS, which in turn activates vasopressinergic neuron-V1b receptors and sympathetic hyperactivity, hence aggravating myocardial injury in the AMI setting.

Conditioned medium harvested from Hif1α engineered mesenchymal stem cells ameliorates LAD-occlusion -induced injury in rat acute myocardial ischemia model.

Acute myocardial infarction (AMI) is the most common type of ischemic heart diseases with a high mortality rate. Although recent advances in medical cares and therapies have increased the patient's outcomes, but, still there is no real and effective therapeutic modality for AMI. Hence, development of novel therapeutic strategies is under focus of investigations. MSCs-based therapy has been proposed for AMI, though its efficacy is controversial yet. It is believed that MSCs exert their healing effects via secretion of growth factors/cytokines. However, these cells produce a very minute amount of the factors under normal cultivation. Here, in an attempt to improve the potential therapeutic effect of MSCs-derived conditioned medium (CM) on AMI, we transfected the cells with a recombinant plasmid encoding Hif1α-3A (a mutant form of Hif1α stable under normoxic condition), so Hif1α expression and secretion into CM (MSCs-Hif1α-CM) could be up-regulated under normoxic condition. The therapeutic potential of the MSCs-Hif1α-3A-CM was investigated in a rat model of AMI and compared to the CM harvested from non-manipulated MSCs. Our results showed that the MSCs-Hif1α-3A-CM mitigated MI-induced tissues injury, decreased fibrosis, reduced apoptosis, and limited infarct area size. These findings propose a potential therapeutic strategy for treatment of AMI. However, further preclinical and clinical investigations in this regard are still needed.

Study on effects of different habitat processing methods of Salviae Miltiorrhizae Radix et Rhizoma in rats with acute myocardial ischemia

To investigate the effects of different habitat processing methods of Salviae Miltiorrhizae Radix et Rhizoma on acute myocardial ischemia induced by pituitrin in rats. In this experiment, the tail vein injection of pituitrin was used to induce acute myocardial ischemia in rats. Electrocardiograph(ECG) heart rate and ΔST changes were recorded, and the levels of creatine kinase isoenzyme(CK-MB), lactate dehydrogenase(LDH), superoxide dismutase(SOD) and malondialdehyde(MDA) in serum of rats were detected to comprehensively evaluate the effects of six processing methods of Salviae Miltiorrhizae Radix et Rhizoma on serum biochemical indexes of rats with acute myocardial injury. The ECG results showed that the Salviae Miltiorrhizae Radix et Rhizoma dried in a drying oven had a good effect on the improvement of heart rate and ΔST of electrocardiogram after ischemia, and all the other groups had some protective effects to different degrees. The results of biochemical indexes in serum of each group after ischemia showed that the activity of CK-MB decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in a drying oven after sweating and losing weight in a drying oven, high-dose group with drying in the shade and low-dose group with drying in the shade. The activity of LDH decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in the shade and low-dose group of drying in the shade. The activity of SOD increased most significantly in Salviae Miltiorrhizae Radix et Rhizoma low-dose group with drying in sun, low-dose group with drying in sun after sweating and losing weight in sun, and low-dose group with drying in a drying oven. The activity of MDA decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma low-dose group with drying in sun. The comprehensive scoring results showed that the highest score was obtained in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in the shade while the scores of other treatment groups were higher than that of the model group. It could be seen that the Salviae Miltiorrhizae Radix et Rhizoma dried in a drying oven had a good improvement effect on electrocardiograph indexes after acute myocardial injury, the Salviae Miltiorrhizae Radix et Rhizoma dried in the shade had a good improvement effect on serum myocardial enzymes after acute myocardial injury, and the other processing methods had a certain protective effect on myocardial injury. The six processing methods evaluated by pharmacodynamics showed that the Salviae Miltiorrhizae Radix et Rhizoma dried in the shade and dried in a drying oven had good efficacy.