Cardioprotective effect of Sanguisorba minor against isoprenaline-induced myocardial infarction in rats

Introduction: Oxidative stress is a major instigator of various cardiovascular diseases, including myocardial infarction (MI). Despite available drugs, there is still an increased need to look for alternative therapies or identify new bioactive compounds. Sanguisorba minor (S. minor) is a native herb characterized by its potent antioxidant activity. This study was designed to evaluate the effect of S. minor against isoprenaline-induced MI. Methods: Rats were treated with the hydro-ethanolic extract of the aerial parts of S. minor at doses of 100 or 300 mg/kg orally for 9 days. Isoprenaline was injected subcutaneously at the dose of 85 mg/kg on days 8 and 9. Then, the activities of various cardiac injury markers including cardiac troponin (cTnT), lactate dehydrogenase (LDH), creatinine kinase muscle brain (CK-MB), creatinine phosphokinase (CPK), and antioxidant enzymes in serum were determined. Malondialdehyde (MDA) and thiol content were measured in cardiac tissue, and histopathological analysis was conducted. Results: Our results show that isoprenaline increased the serum levels of cTnT, LDH, CK-MB, and CPK (p < 0.001) and elevated MDA levels (p < 0.001) in cardiac tissue. Isoprenaline also reduced superoxide dismutase (SOD), catalase, and thiol content (p < 0.001). Importantly, the extract abolished isoprenaline-induced MI by elevating SOD and catalase (p < 0.001), reducing levels of MDA, and diminishing levels of cTnT, LDH, CK-MB, and CPK cardiac markers (p < 0.001). Histopathological studies of the cardiac tissue showed isoprenaline-induced injury that was significantly attenuated by the extract. Conclusion: Our results suggest that S. minor could abrogate isoprenaline-induced cardiac toxicity due to its ability to mitigate oxidative stress.

Catecholamine-induced cardiotoxicity: A critical element in the pathophysiology of stroke-induced heart injury

Cerebrovascular diseases such as ischemic stroke, brain hemorrhage, and subarachnoid hemorrhage provoke cardiac complications such as heart failure, neurogenic stress-related cardiomyopathy and Takotsubo cardiomyopathy. With regards to the pathophysiology of stroke-induced heart injury, several mechanisms have been postulated to contribute to this complex interaction between brain and heart, including damage from gut dysbiosis, immune and systematic inflammatory responses, microvesicle- and microRNA-mediated vascular injury and damage from a surge of catecholamines. All these cerebrovascular diseases may trigger pronounced catecholamine surges through diverse ways, including stimulation of hypothalamic-pituitary adrenal axis, dysregulation of autonomic system, and secretion of adrenocorticotropic hormone. Primary catecholamines involved in this pathophysiological response include norepinephrine (NE) and epinephrine. Both are important neurotransmitters that connect the nervous system with the heart, leading to cardiac damage via myocardial ischemia, calcium (Ca²⁺) overload, oxidative stress, and mitochondrial dysfunction. In this review, we will aim to summarize the molecular mechanisms behind catecholamine-induced cardiotoxicity including Ca²⁺ overload, oxidative stress, apoptosis, cardiac hypertrophy, interstitial fibrosis, and inflammation. In addition, we will focus on how synchronization among these pathways evokes cardiotoxicity.

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.

Comprehensive review of cardiovascular toxicity of drugs and related agents

Cardiovascular diseases are a leading cause of morbidity and mortality in most developed countries of the world. Pharmaceuticals, illicit drugs, and toxins can significantly contribute to the overall cardiovascular burden and thus deserve attention. The present article is a systematic overview of drugs that may induce distinct cardiovascular toxicity. The compounds are classified into agents that have significant effects on the heart, blood vessels, or both. The mechanism(s) of toxic action are discussed and treatment modalities are briefly mentioned in relevant cases. Due to the large number of clinically relevant compounds discussed, this article could be of interest to a broad audience including pharmacologists and toxicologists, pharmacists, physicians, and medicinal chemists. Particular emphasis is given to clinically relevant topics including the cardiovascular toxicity of illicit sympathomimetic drugs (e.g., cocaine, amphetamines, cathinones), drugs that prolong the QT interval, antidysrhythmic drugs, digoxin and other cardioactive steroids, beta-blockers, calcium channel blockers, female hormones, nonsteroidal anti-inflammatory, and anticancer compounds encompassing anthracyclines and novel targeted therapy interfering with the HER2 or the vascular endothelial growth factor pathway.

Intravenous rutin in rat exacerbates isoprenaline-induced cardiotoxicity likely due to intracellular oxidative stress

OBJECTIVES

Rutin, quercetin-3-O-rutinoside, a natural flavonol glycoside, has shown various in vitro benefits with potential use treating human diseases, especially cardiovascular system disorders. Antioxidant properties are assumed to underlie the majority of these benefits. Yet rutin pro-oxidant properties have been reported as well. Our research group has recently shown aggravating effects on isoprenaline (ISO)-induced cardiotoxicity in Wistar:Han rats after 24 hours.

METHODS

This study was designed to examine in more detail the reasons for the negative effects of rutin (11.5 and 46 mg/kg, i.v.) after administration of ISO (100 mg/kg, s.c.) in rats within 2 hours of continuous experiment and in the H9c2 cardiomyoblast-derived cell line.

RESULTS

Like our previous findings, rutin did not (11.5 or 46 mg/kg, i.v.) reduce the ISO-induced mortality within 2 hours although the lower dose significantly reduced cardiac troponin T (cTnT) and partly improved the histological findings. In contrast, the higher dose increased the mortality in comparison with solvent (1.26% w/v sodium bicarbonate). This was not caused by any specific haemodynamic disturbances. It appears to be associated with oxidative stress as rutin enhanced intracellular reactive oxygen species formation in vitro and had the tendency to increase it in vivo.

CONCLUSIONS

Rutin, likely due to its pro-oxidative effects, can exacerbate catecholamine cardiotoxicity depending on the dose used.

Use of pressure-volume conductance catheters in real-time cardiovascular experimentation

BACKGROUND

Most applications of pressure-volume conductance catheter measurements assess cardiovascular function at a single point in time after genetic, pharmacologic, infectious, nutritional, or toxicologic manipulation. Use of these catheters as a continuous monitor, however, is fraught with complexities and limitations.

METHODS

Examples of the limitations and optimal use of conductance catheters as a continuous, real-time monitor of cardiovascular function are demonstrated during inotropic drug infusion in anesthetised rats.

RESULTS

Inotropic drug infusion may alter ventricular dimensions causing relative movement of a well-positioned catheter, generating artifacts, including an abrupt pressure rise at end-systole that leads to over estimation of indices of contractility (max dP/dt) and loss of stroke volume signal. Simple rotation of the catheter, echocardiography-guided placement to the centre of the ventricle, or ventricular expansion through crystalloid infusion may correct for these artifacts. Fluid administration, however, alters left ventricular end-diastolic pressure and volume and therefore stroke volume, thereby obscuring continuous real-time haemodynamic measurements.

CONCLUSIONS

Pressure-volume artifacts during inotropic infusion are caused by physical contact of the catheter with endocardium. Repeated correction of catheter position may be required to use pressure volume catheters as a continuous real-time monitor during manipulations that alter ventricular dimensions, such as inotropic therapy.