Search Results (71)

Autonomic imbalance is one of the major pathological disturbances in chronic heart failure (CHF). Additionally, enhanced oxidative stress and inflammation are considered to be the main contributors to the disease progression. A growing body of evidence suggests cholinergic stimulation as a potential therapeutic approach in CHF, since it corrects the autonomic imbalance and alters the inflammatory response via the cholinergic anti-inflammatory pathway. Although previous research has provided some insights into the potential mechanisms behind these effects, there is a gap in knowledge regarding different cholinergic stimulation methods and their specific mechanisms of action. In the present study, an isoprenaline model (5 mg/kg/day s.c. for 7 days, followed by 4 weeks of CHF development) was used. Afterwards, rats received pyridostigmine (22 mg/kg/day in tap water for 14 days) or no treatment. Pyridostigmine treatment prevented the progression of CHF, decreasing chamber wall thinning (↑ PWDd, ↑ PWDs) and left ventricle dilatation (↓ LVIDd, ↓ LVIDs), thus improving cardiac contractile function (↑ EF). Additionally, pyridostigmine improved antioxidative status (↓ TBARS, ↓ NO₂⁻; ↑ CAT, ↑ GSH) and significantly reduced cardiac fibrosis development, confirmed by pathohistological findings and biochemical marker reduction (↓ MMP2, ↓ MMP9). However, further investigations are needed to fully understand the exact cellular mechanisms involved in the CHF attenuation via pyridostigmine. Full article

This study offers a detailed assessment of the polyphenolic composition and antioxidant, anti-inflammatory, and cardioprotective properties of lyophilized extracts derived from the aerial parts of Agastache mexicana and Agastache scrophulariifolia. The polyphenolic content was determined through the quantification of total polyphenols, flavonoids, and caffeic acid derivatives, complemented by LC-MS profiling. The antioxidant activity was evaluated in vitro using DPPH and FRAP assays, while the in vivo antioxidant and anti-inflammatory effects were investigated in a rat model of turpentine-oil-induced acute inflammation. Cardioprotective potential was assessed in a separate rat model of isoprenaline-induced myocardial infarction. Phytochemical analysis revealed a complex polyphenolic profile for both species, with tilianin and rosmarinic acid identified as predominant compounds. In the DPPH assay, both extracts exhibited marked radical scavenging activity (IC₅₀: 65.91 ± 1.21 μg/mL for A. mexicana; 68.64 ± 2.48 μg/mL for A. scrophulariifolia). In the in vivo assays, the administration of the extracts significantly decreased pro-oxidant biomarkers (TOS, OSI, MDA, NO) and enhanced antioxidant markers (TAC, SH groups). Furthermore, the extracts led to a significant reduction in serum levels of GOT, GPT, and CK-MB in rats subjected to myocardial injury, supporting their cardioprotective efficacy. Overall, the results suggest that A. mexicana and A. scrophulariifolia represent promising natural sources of polyphenolic compounds with potential therapeutic value in oxidative-stress-related inflammatory and cardiovascular disorders. Full article

The protective effect of isorhamnetin on myocardial injury induced by isoproterenol (ISO) was investigated to identify the key targets and pathways involved, offering potential therapeutic insights for cardiovascular diseases. A myocardial injury model was established through intraperitoneal ISO injection, and the effects of isorhamnetin on apoptosis and oxidative stress in ISO-induced myocardial injury rats were assessed. Additionally, an ISO-induced H9c2 cell injury model was established to evaluate the impact of isorhamnetin on cellular damage. The transcriptomic sequencing of H9c2 cells was conducted to identify differentially expressed genes, followed by gene enrichment analysis. Intracellular glucose, lactate, and ATP levels were quantified, and the protein expression of key pathway targets ENO1, PPARα, and PGC-1α was analyzed via immunoblotting. Isorhamnetin improved cardiac function and morphological damage, reduced serum markers of cardiac injury, and exerted cardioprotective effects by regulating oxidative stress and inhibiting apoptosis. Compared to the ISO group, the glycolytic process—with ENO1 as a key target and the PPAR signaling pathway as the core regulator—was significantly suppressed in the isorhamnetin-pretreated group. Furthermore, isorhamnetin pretreatment reduced intracellular glucose and lactate levels while increasing ATP content in a concentration-dependent manner. These findings suggest that isorhamnetin protects the heart by inhibiting ENO1, activating the PPARα/PGC-1α signaling axis, reversing isoprenaline-induced metabolic shifts in H9c2 cells, suppressing glycolysis, and enhancing ATP release, thereby mitigating apoptosis and oxidative stress. Full article

Background: Myocardial injury (MI) is characterized by an increased level of at least one cardiac troponin. Experimental MI can be induced by isoprenaline, a β-adrenergic agonist, and it can lead to heart failure (HF). Liraglutide is glucagon-like 1 peptide receptor agonist used in diabetes management, but it has anti-inflammatory and antioxidative effects, which can be beneficial in treatment of HF. The aim of this study was to investigate the effects of liraglutide on isoprenaline-induced MI and prevention of HF. Methods: Male Wistar albino rats were divided into four groups: Con—received saline the first 2 days + saline the next 7 days; Iso—isoprenaline the first 2 days + saline the next 7 days; Lir—saline the first 2 days + liraglutide the next 7 days; Iso + Lir—isoprenaline the first 2 days + liraglutide the next 7 days. On day 10, blood samples were taken for biochemical analysis and oxidative stress marker evaluation, and hearts were isolated for pathohistological analysis. Cardiac function was assessed by electrocardiography (ECG) and echocardiography (ECHO). Results: Liraglutide treatment significantly attenuated oxidative stress, repaired ECG and ECHO parameters, and mitigated myocardial morphological changes induced by isoprenaline. Conclusions: Liraglutide restores cardiac function in isoprenaline-induced HF. Full article

Lagopsis supina (Steph. ex. Willd.) Ikonn.-Gal., an ancient Chinese herbal medicine, is traditionally used to treat blood stasis diseases such as myocardial ischemia (MI). However, its pharmacodynamics substances of the anti-MI effect and their potential mechanisms remain unclear. This study aims to elucidate the pharmacodynamics effects of L. supina against MI and reveal their underlying mechanisms in zebrafish. LSD fraction was screened out for anti-MI active fraction from L. supina by isoprenaline hydrochloride (ISO)-induced zebrafish. It could increase the stroke volume, ejection fraction, and ventricular short-axis systolic rate in the zebrafish model. A total of 30 compounds (Nos. 1–30) were isolated and identified from LSD by various chromatographic techniques and nuclear magnetic resonance spectroscopy. Among them, six compounds, including three lignin compounds (Nos. 15, 16, and 18) and three flavonoid glycosides (Nos. 14, 25, and 26), showed noticeable anti-MI activities, and tiliroside (No. 25) was more active. Molecular docking indicated that tiliroside has a strong binding ability with the proteins KDR, PI3K, Akt, Erk, p38, Bcl-2, Bax, and Caspase3. In the end, the results of RT-qPCR manifested that tiliroside markedly upregulated expression levels of genes kdr, pik3cb, akt2, mapk1, mapk11, mapk14, and bcl-2b and prominently downregulated expression levels of genes bax and caspase3. According to the above results, tiliroside activated the kdr-mediated PI3K-Akt and MAPK signaling pathways to exert the anti-MI activity. These discoveries give a scientific basis for applying L. supina in MI treatment and suggest new avenues for developing tiliroside as a candidate for MI therapy. Full article

Background: Heart failure (HF) is a serious public health concern. Baicalin is one of the major active ingredients of a traditional Chinese herbal medicine, Huang Qin, which is used to treat patients with chest pain or cardiac discomfort. However, the underlying mechanism(s) of the cardioprotective effect of baicalin are still not fully understood. Methods: Isoprenaline injection or transverse aortic constriction-induced animal models and isoprenaline or angiotensin 2 administration-induced cell models of heart failure were established. Baicalin (15 mg/kg/day or 25 mg/kg/day) was administered in vivo, and 10 μM baicalin was administered in vitro. Potential pharmacological targets of baicalin and genes related to heart failure were identified via different databases, which suggested that PI3K–Akt may be involved in the effects of baicalin. Molecular docking was carried out to reveal the effect of baicalin on p85a. Results: We observed significant antihypertrophic and antifibrotic effects of baicalin both in vivo and in vitro. The mean cross-sectional area of cardiomyocytes recovered from 390 μm² in the HF group to 195 μm² in the baicalin-treated group. The area of fibrosis was reduced from 2.8-fold in the HF group to 1.62-fold in the baicalin-treated group. Baicalin displayed a significant cardioprotective effect via the inhibition of the PI3K signaling pathway by binding with five amino acid residues of the p85a regulatory subunit of PI3K. The combination treatment of baicalin and an inhibitor of PI3K p110 demonstrated a stronger cardioprotective effect. The mean ejection fraction increased from 54% in the baicalin-treated group to 67% in the combination treatment group. Conclusions: Our work identified baicalin as a new active herbal ingredient that is able to treat isoprenaline-induced heart dysfunction and suggests that p85a is a pharmacological target. These findings reveal the significant potential of baicalin combined with an inhibitor of PI3K p110 for the treatment of heart failure and support more clinical trials in the future. Full article

Glucagon can increase the force of contraction (FOC) in, for example, canine hearts. Currently, whether glucagon can also increase the FOC via cAMP-increasing receptors in the human atrium is controversial discussed. Glucagon alone did not (up to 1 µM) raise the FOC in human right atrial preparations (HAP). Only in the additional presence of the phosphodiesterase (PDE) 3 inhibitor cilostamide (1 µM) or 1 nM isoprenaline did glucagon raise the FOC, starting at 1 µM. The positive inotropic effects of glucagon in HAP were attenuated by a glucagon receptor antagonist (1 µM SC203972), but not by 100 nM exendin(9-39), a glucagon-like peptide-1 receptor (GLP-1R) antagonist. Glucagon (in the presence of cilostamide) demonstrated a reduced efficacy in elevating the FOC in HAP when compared with isoprenaline. In contrast to glucagon, exenatide alone, a GLP-1R agonist, starting at 1 nM, increased the FOC and was more potent and effective than glucagon in raising the FOC in HAP. The effects of exenatide on the FOC were attenuated by exendin(9-39). Hence, glucagon and GLP-1R agonists act functionally via different receptors in the human right atrium. Clinically, these data suggest that endogenous or exogenous glucagon can stimulate glucagon receptors in the human atrium, but only in the presence of PDE inhibitors. Full article

CACNA1C encodes the α1c subunit of the L-type Ca²⁺ channel, Cav1.2. Ventricular myocytes from haploinsufficient Cacna1c (Cacna1c^+/−) rats exhibited reduced expression of Cav1.2 but an apparently normal sarcolemmal Ca²⁺ influx with an impaired response to sympathetic stress. We tested the hypothesis that the altered phosphorylation of Cav1.2 might underlie the sarcolemmal Ca²⁺ influx phenotype in Cacna1c^+/− myocytes using immunoblotting of the left ventricular (LV) tissue from Cacna1c^+/− versus wildtype (WT) hearts. Activation of cAMP-dependent protein kinase A (PKA) increases L-type Ca²⁺ current and phosphorylates Cav1.2 at serine-1928. Using an antibody directed against this phosphorylation site, we observed elevated phosphorylation of Cav1.2 at serine-1928 in LV myocardium from Cacna1c^+/− rats under basal conditions (+110% versus WT). Sympathetic stress was simulated by isoprenaline (100 nM) in Langendorff-perfused hearts. Isoprenaline increased the phosphorylation of serine-1928 in Cacna1c^+/− LV myocardium by ≈410%, but the increase was significantly smaller than in WT myocardium (≈650%). In conclusion, our study reveals altered PKA-dependent phosphorylation of Cav1.2 with elevated phosphorylation of serine-1928 under basal conditions and a diminished phosphorylation reserve during β-adrenergic stimulation. These alterations in the phosphorylation of Cav1.2 may explain the apparently normal sarcolemmal Ca²⁺ influx in Cacna1c^+/− myocytes under basal conditions as well as the impaired response to sympathetic stimulation. Full article

Mitochondrial damage and associated oxidative stress are considered to be major contributory factors in cardiac pathology. One of the most potent naturally occurring antioxidants is taxifolin, especially in its water-soluble form. Herein, the effect of a 14-day course of the peroral application of the water-soluble taxifolin (aqTAX, 15 mg/kg of body weight) on the progression of ultrastructural and functional disorders in mitochondria and the heart’s electrical activity in a rat model of myocardial injury induced with isoprenaline (ISO, 150 mg/kg/day for two consecutive days, subcut) was studied. The delayed ISO-induced myocardial damage was accompanied by an increase in the duration of RR and QT intervals, and long-term application of aqTAX partially restored the disturbed intraventricular conduction. It was shown that the injections of ISO lead to profound ultrastructural alterations of myofibrils and mitochondria in cardiomyocytes in the left ventricle myocardium, including the impairment of the ordered arrangement of mitochondria between myofibrils as well as a decrease in the size and the number of these organelles per unit area. In addition, a reduction in the protein level of the subunits of the respiratory chain complexes I-V and the activity of the antioxidant enzymes catalase, glutathione peroxidase, and Mn-SOD in mitochondria was observed. The application of aqTAX caused an increase in the efficiency of oxidation phosphorylation and a partial restoration of the morphometric parameters of mitochondria in the heart tissue of animals with the experimental pathology. These beneficial effects of aqTAX are associated with the inhibition of lipid peroxidation and the normalization of the enzymatic activities of glutathione peroxidase and Mn-SOD in rat cardiac mitochondria, which may reduce the oxidative damage to the organelles. Taken together, these data allow one to consider this compound as a promising cardioprotector in the complex therapy of heart failure. Full article

Tegaserod (1-{[(5-methoxy-1H-indol-3-yl)methyliden]amino}-3-pentylguanidine) is a potent agonist at human recombinant 5-HT₄ serotonin receptors. Consequently, tegaserod is utilized in the treatment of bowel diseases. The objective of this study was to test the hypothesis that tegaserod stimulates human cardiac atrial 5-HT₄-receptors via cyclic adenosine monophosphate (cAMP)-dependent pathways. Tegaserod exerted positive inotropic effects (PIEs) and positive chronotropic effects (PCEs) in isolated left and right atrial preparations, respectively, from mice with cardiac-specific overexpression of the human 5-HT₄ serotonin receptor (5-HT₄-TG) in a concentration- and time-dependent manner. However, no effect was observed in the hearts of littermates of wild-type mice (WT). Western blot analysis revealed that the expression of 5-HT₄ receptors was significantly higher in 5-HT₄-TG mice compared to WT mice. The specificity of the signal for the 5-HT₄ receptor was confirmed by the absence of the signal in the hearts of 5-HT₄ receptor knockout mice. Furthermore, tegaserod increased the force of contraction (at concentrations as low as 10 nM), reduced the time of tension relaxation, and increased the rate of tension development in isolated electrically stimulated (at a rate of 60 beats per minute) human right atrial preparations (HAPs, obtained during open-heart surgery) when administered alone. The potency and efficacy of tegaserod to raise the force of contraction were enhanced in the presence of cilostamide, a phosphodiesterase III inhibitor. The positive inotropic effect of tegaserod in HAPs was found to be attenuated by the 5-HT₄ serotonin receptor antagonist GR 125487 (0.1 µM). The efficacy of tegaserod (10 µM) in raising the force of contraction in HAPs was less pronounced than that of serotonin (10 µM) or isoprenaline (1 µM). Tegaserod shifted the concentration–response curve of the force of contraction to serotonin to the right in HAPs, indicating that it is a partial agonist at 5-HT₄ serotonin receptors in this model. We propose that the mechanism of action of tegaserod in HAPs involves cAMP-dependent phosphorylation of cardiac regulatory proteins. Full article

Background: Hypoxia is one of the most significant pathogenic factors in cardiovascular diseases. Preclinical studies suggest that nonpsychoactive cannabidiol (CBD) and β-adrenoceptor stimulation might possess cardioprotective potential against ischemia-reperfusion injury. The current study evaluates the influence of hypoxia-reoxygenation (H/R) on the function of atria and ventricular papillary muscles in the presence of CBD and the nonselective β-adrenoceptor agonist isoprenaline (ISO). Methods: The concentration curves for ISO were constructed in the presence of CBD (1 µM) before or after H/R. In chronic experiments (CBD 10 mg/kg, 14 days), the left atria isolated from spontaneously hypertensive (SHR) and their normotensive control (WKY) rats were subjected to H/R following ISO administration. Results: Hypoxia decreased the rate and force of contractions in all compartments. The right atria were the most resistant to hypoxia regardless of prior β-adrenergic stimulation. Previous β-adrenergic stimulation improved recovery in isolated left atria and right (but not left) papillary muscles. Acute (but not chronic) CBD administration increased the effects of ISO in left atria and right (but not left) papillary muscles. Hypertension accelerates left atrial recovery during reoxygenation. Conclusions: H/R directly modifies the function of particular cardiac compartments in a manner dependent on cardiac region and β-adrenergic prestimulation. The moderate direct cardioprotective potential of CBD and β-adrenergic stimulation against H/R is dependent on the cardiac region, and it is less than in the whole heart with preserved coronary flow. In clinical terms, our research expands the existing knowledge about the impact of cannabidiol on cardiac ischemia, the world′s leading cause of death. Full article

Patients suffering from cholelithiasis have an increased risk of developing cardiovascular complications, particularly ischemic myocardial disease. Ursodeoxycholic acid (UDCA), already used in clinical practice for the treatment of cholelithiasis and related conditions, has proven antioxidative, anti-inflammatory, and cytoprotective effects. Therefore, the aim of this study was to investigate the cardioprotective effect of UDCA pre-treatment on isoprenaline-induced myocardial injury in rats. Male Wistar albino rats were randomized into four groups. Animals were pre-treated for 10 days with propylene glycol + saline on days 9 and 10 (control), 10 days with propylene glycol + isoprenaline on days 9 and 10 (I group), 10 days with UDCA + saline on days 9 and 10 (UDCA group), and 10 days with UDCA + isoprenaline on days 9 and 10 (UDCA + I group). UDCA pre-treatment significantly reduced values of high-sensitivity troponin I (hsTnI) and aspartate aminotransferase (AST) cardiac markers (p < 0.001 and p < 0.01, respectively). The value of thiobarbituric acid reactive substances (TBARS) was also decreased in the UDCA + I group compared to the I group (p < 0.001). UDCA also significantly increased glutathione (GSH) levels, while showing a tendency to increase levels of superoxide dismutase (SOD) and catalase (CAT). The level of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) expression, a key regulatory gene of inflammation, was diminished when UDCA was administered. A reduction of cardiac damage was also observed in the UDCA pre-treated group. In conclusion, UDCA pre-treatment showed a cardioprotective effect on isoprenaline-induced myocardial injury in rats, primarily by reducing oxidative stress and inflammation. Full article

Objective: This study aimed to compare the effects of β-sitosterol nanoparticles (BETNs) and β-sitosterol (BET) on cognitive impairment, oxidative stress, and inflammation in a myocardial infarction (MI) rat model using in silico and in vivo methods. Methods: β-Sitosterol (BET) and myeloperoxidase (MPO) ligand-receptor binding affinities were evaluated using Autodock Vina for docking and Gromacs for dynamics simulations. BET nanoparticles, prepared via solvent evaporation, had their size confirmed by a nanoparticle analyzer. ISO-induced cognitive impairment in rats was assessed through Morris water maze and Cook’s pole climbing tests. Oxidative stress, inflammation, and cardiac injury were evaluated by measuring GSH, SOD, MDA, MPO, CkMB, LDH, lipid profiles, and ECGs. Histopathology of the CA1 hippocampus and myocardial tissue was performed using H&E staining. Results: In silico analyses revealed strong binding affinities between BET and MPO, suggesting BET’s potential anti-inflammatory effect. BETN (119.6 ± 42.6 nm; PDI: 0.809) significantly improved MI-induced cognitive dysfunction in rats (p < 0.001 ***), increased hippocampal GSH (p < 0.01 **) and SOD (p < 0.01 **) levels, and decreased hippocampal MDA (p < 0.05 *) and MPO levels (p < 0.01 **). BETNs also elevated cardiac GSH (p < 0.01 **) and SOD (p < 0.01 **) levels and reduced cardiac MPO (p < 0.01 **), CkMB (p < 0.001 **) and LDH (p < 0.001 **) levels. It restored lipid profiles, normalized ECG patterns, and improved histology in the hippocampal CA1 region and myocardium. Conclusions: Compared with BET treatment, BETNs were more effective in improving cognitive impairment, oxidative damage, and inflammation in MI rats, suggesting its potential in treating cognitive dysfunction and associated pathological changes in MI. Full article

The present study examined three hallucinogenic amphetamine derivatives, namely, 2,5-dimethoxy-4-iodoamphetamine (DOI) as well as 2,5-dimethoxy-4-methylamphetamine (DOM) and 4-methylmethcathinone (mephedrone). The objective of this study was to test the hypothesis that DOI, DOM, and mephedrone would increase the contractile force in isolated human atrial preparations in a manner similar to amphetamine. To this end, we measured contractile force under isometric conditions in electrically stimulated (1 Hz) human atrial preparations obtained during open surgery. DOI and DOM alone or in the presence of isoprenaline reduced the contractile force concentration-dependently in human atrial preparations. These negative inotropic effects of DOM and DOI were not attenuated by 10 µM atropine. However, mephedrone increased the contractile force in human atrial preparations in a concentration- and time-dependent manner. Furthermore, these effects were attenuated by the subsequent addition of 10 µM propranolol or pretreatment with 10 µM cocaine in the organ bath. Therefore, it can be concluded that amphetamine derivatives may exert opposing effects on cardiac contractile force. The precise mechanism by which DOI and DOM exert their negative inotropic effects remains unknown at present. The cardiac effects of mephedrone are probably due to the release of cardiac noradrenaline. Full article

Takotsubo syndrome (TTS) is a stress-induced cardiomyopathy, characterized by an increased concentration of catecholamines, free radicals, and inflammatory cytokines, endothelial dysfunction, and increased apoptotic activity. High doses of isoprenaline are used in animal models to induce Takotsubo (TT)-like myocardial injury. The aim of the study was to investigate the antiapoptotic effects of liraglutide in experimental TTS and its role in the NF-κB pathway. Wistar rats were pretreated with liraglutide for 10 days, and on days 9 and 10, TT-like myocardial injury was induced with isoprenaline. After the sacrifice on day 11, hearts were isolated for histopathological and immunohistochemical analysis. Liraglutide reduced isoprenaline-induced cardiomyocyte apoptosis by decreasing cleaved caspase-3 (CC3), BCL-2-associated X protein (BAX), and NF-κB and increasing B-cell lymphoma/leukemia-2 (BCL-2). An increase in NF-κB in isoprenaline-treated rats was in positive correlation with proapoptotic markers (BAX and CC3) and in negative correlation with antiapoptotic marker BCL-2. Liraglutide increased BCL-2 and decreased NF-κB, BAX, and CC3, preserving the same correlations of NF-κB to apoptotic markers. It is concluded that liraglutide protects cardiomyocytes against isoprenaline-induced apoptosis in experimental TT-like myocardial injury through downregulation of the NF-κB pathway. Full article