Liraglutide Protects Cardiomyocytes against Isoprenaline-Induced Apoptosis in Experimental Takotsubo Syndrome.

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.

Effect of folic acid on isoprenaline-induced myocardial injury in rats.

Background: Isoprenaline (ISO), a synthetic catecholamine and a ß-adrenoceptor agonist, is widely used to develop an experimental model of myocardial injury (MI) in rats. The leading hypothesis for ISO-induced MI in rats is that it results from catecholamine overstimulation, oxidative stress, inflammatory responses, and development of cardiomyopathy during ISO administration. Folic acid (FA) reduces oxidative stress, improves endothelial function and prevents apoptosis, thereby contributing to cardiovascular protection. This study aimed to investigate the potentially protective effect of FA pretreatment on ISO-induced MI in rats. Methods: For 7 days, adult male Wistar albino rats were pretreated with 5 mg/kg/day of FA. On the sixth and seventh days, MI in rats was induced by administering 85 mg/kg/day of ISO. Prooxidant markers in plasma samples, antioxidant capacity in erythrocyte lysates, cardiac damage markers, lipid profile, electrocardiography (ECG) and histopathological analysis were evaluated. Results: FA pretreatment significantly alleviated changes induced by ISO; it decreased the homocysteine and high-sensitivity troponin I level. FA moderately decreased the reactive oxygen species (ROS) levels (superoxide anion radical, hydrogen peroxide and thiobarbituric acid reactive substances) and improved the antioxidant activities of catalase, superoxide dismutase and reduced glutathione. ISO reduced the nitrite level and FA significantly alleviated this change. Conclusion: It can be concluded that FA, as a mild antioxidant, could be an appropriate cardioprotective substance in the rat model of ISO-induced MI.

Methodological challenges in using human umbilical artery as a model for in vitro studies.

NEW FINDINGS: What is the central question of this study? What are the biggest challenges in performing in vitro studies on isolated human umbilical arteries? What is the main finding and its importance? The protocols presented in this study indicate some potential outcomes important for interpretation of the vascular responsivities of human umbilical arteries and could be useful for planning future in vitro studies with human umbilical arteries. ABSTRACT: Human umbilical artery (HUA) preparations are of particular importance for in vitro studies on isolated blood vessels because their sampling is not risky for the patient, and they can provide the closest possible impression of changes related to the uteroplacental circulation during pre-eclampsia. Using organ bath techniques, useful experimental protocols are provided for measuring some pathophysiological phenomena in the vascular responses of HUAs. Several vasoconstrictors (serotonin, prostaglandin F and phenylephrine) and vasodilators (acetylcholine and minoxidil) were seleted for determination of their vasoactivity in HUAs. The role of L-type voltage-operated calcium channels and different types of potassium channels (KATP , BKCa and KV ) were assessed, as was the impact of homocysteine. Serotonin was confirmed to be the most potent vasoconstrictor, while acetylcholine and phenylephrine caused variability in the relaxation and contraction response of HUA, respectively. The observed increase in serotonin-induced contraction and a decrease in minoxidil-induced relaxation in the presence of homocysteine suggested its procontractile effect on HUA preparations. Using selective blockers, it was determined that KATP and KV channels participate in the minoxidil-induced relaxation, while L-type voltage-dependent Ca2+  channels play an important role in the serotonin-induced contraction. The presented protocols reveal some of the methodological challenges related to HUA preparations and indicate potential outcomes in interpreting the vascular effects of the investigated substances, both in physiological conditions and in the homocysteine-induced pre-eclampsia model.

Pomegranate Peel Extract Attenuates Isoprenaline-Induced Takotsubo-like Myocardial Injury in Rats.

Takotsubo syndrome (TTS) is an acute heart failure syndrome characterised by catecholamine-induced oxidative tissue damage. Punica granatum, a fruit-bearing tree, is known to have high polyphenolic content and has been proven to be a potent antioxidant. This study aimed to investigate the effects of pomegranate peel extract (PoPEx) pre-treatment on isoprenaline-induced takotsubo-like myocardial injury in rats. Male Wistar rats were randomised into four groups. Animals in the PoPEx(P) and PoPEx + isoprenaline group (P + I) were pre-treated for 7 days with 100 mg/kg/day of PoPEx. On the sixth and the seventh day, TTS-like syndrome was induced in rats from the isoprenaline(I) and P + I groups by administering 85 mg/kg/day of isoprenaline. PoPEx pre-treatment led to the elevation of superoxide dismutase and catalase (p < 0.05), reduced glutathione (p < 0.001) levels, decreased the thiobarbituric acid reactive substances (p < 0.001), H2O2, O2- (p < 0.05), and NO2- (p < 0.001), in the P + I group, when compared to the I group. In addition, a significant reduction in the levels of cardiac damage markers, as well as a reduction in the extent of cardiac damage, was found. In conclusion, PoPEx pre-treatment significantly attenuated the isoprenaline-induced myocardial damage, primarily via the preservation of endogenous antioxidant capacity in the rat model of takotsubo-like cardiomyopathy.

Folic Acid and Leucovorin Have Potential to Prevent SARS-CoV-2-Virus Internalization by Interacting with S-Glycoprotein/Neuropilin-1 Receptor Complex.

The interaction of the SARS-CoV-2 spike (S) glycoprotein receptor-binding domain with the host-cell ACE2 receptor is a well-known step in virus infection. Neuropilin-1 (NRP-1) is another host factor involved in virus internalization. The interaction between S-glycoprotein and NRP-1 has been identified as a potential COVID-19 treatment target. Herein, the effectiveness of folic acid and leucovorin in preventing contact between S-glycoprotein and NRP-1 receptors was investigated using in silico studies and then confirmed in vitro. The results of a molecular docking study showed that leucovorin and folic acid had lower binding energies than EG01377, a well-known NRP-1 inhibitor, and lopinavir. Two hydrogen bonds with Asp 320 and Asn 300 residues stabilized the leucovorin, while interactions with Gly 318, Thr 349, and Tyr 353 residues stabilized the folic acid. The molecular dynamic simulation revealed that the folic acid and leucovorin created very stable complexes with the NRP-1. The in vitro studies showed that the leucovorin was the most active inhibitor of the S1-glycoprotein/NRP-1 complex formation, with an IC75 value of 185.95 µg/mL. The results of this study suggest that folic acid and leucovorin could be considered as potential inhibitors of the S-glycoprotein/NRP-1 complex and, thus, could prevent the SARS-CoV-2 virus' entry into host cells.

Cardioprotective effects of liraglutide pretreatment on isoprenaline-induced myocardial injury in rats.

Type 2 diabetes mellitus (T2DM) increases the risk of cardiovascular disease, especially myocardial injury. Due to their hypoglycemic effects, glucagon-like peptide-1 receptor agonists (GLP-1RAs) are efficiently used for T2DM management. GLP-1RAs also have anti-inflammatory and antioxidative effects and can improve cardiac function. The aim of this study was to investigate the cardioprotective effects of liraglutide, a GLP-1RA, on isoprenaline-induced myocardial injury in rats. The study included four groups of animals. They were pretreated with saline for 10 days + saline on days 9 and 10 (control), saline for 10 days + isoprenaline on days 9 and 10 (isoprenaline group), liraglutide for 10 days + saline on days 9 and 10 (liraglutide group), and liraglutide for 10 days, and on days 9 and 10 isoprenaline was administered. This study evaluated ECG, myocardial injury markers, oxidative stress markers, and pathohistological changes. The results showed that liraglutide mitigated the isoprenaline-induced cardiac dysfunction recorded by ECG. Liraglutide reduced serum markers of myocardial injury such as high-sensitive troponin I, aspartate aminotransferase, alanine aminotransferase, reduced thiobarbituric acid reactive substances, increased catalase and superoxide dismutase activity, increased reduced glutathione level, and improved lipid profile. Liraglutide induced antioxidative protection and alleviated isoprenaline-induced myocardial injury.

Dynamic changes in coagulation, hematological and biochemical parameters as predictors of mortality in critically ill COVID-19 patients: A prospective observational study.

INTRODUCTION: This study was created to analyze dynamic alterations in coagulation, hematological and biochemical parameters and their association with mortality of COVID-19 patients. To identify the most sensitive biomarkers as predictors of mortality more research is required. METHODS: The present study was a prospective, one-year-long observational study conducted on all critically ill, COVID-19 patients with respiratory failure. The following data were collected: demographic and clinical characteristics of the study population, comorbidities, coagulation, biochemical and hematological parameters. The primary outcome was the proportion of patients who died. RESULTS: 91 patients with median age 60 (50-67), 76.9% male, met the acute respiratory distress syndrome criteria. It was tested whether dynamic change (delta-Δ) of parameters that were found to be predictors of mortality is independently associated with poor outcome. Adjusted (multivariate) analysis was used, where tested parameters were corrected for basic and clinical patients characteristics. The only inflammatory parameter which dynamic change had statistically significant odds ratio was ΔCRP (p < 0.005), while among coagulation parameters statistically significant OR was found for Δ fibrinogen (p < 0.005) in predicting mortality. CONCLUSION: Monitoring of coagulation, hematological and biochemical parameters abnormalities and their dynamical changes can potentially improve management and predict mortality in critically ill COVID -19 patients.

Homocysteine, Vitamins B6 and Folic Acid in Experimental Models of Myocardial Infarction and Heart Failure-How Strong Is That Link?

Cardiovascular diseases are the leading cause of death and the main cause of disability. In the last decade, homocysteine has been found to be a risk factor or a marker for cardiovascular diseases, including myocardial infarction (MI) and heart failure (HF). There are indications that vitamin B6 plays a significant role in the process of transsulfuration in homocysteine metabolism, specifically, in a part of the reaction in which homocysteine transfers a sulfhydryl group to serine to form α-ketobutyrate and cysteine. Therefore, an elevated homocysteine concentration (hyperhomocysteinemia) could be a consequence of vitamin B6 and/or folate deficiency. Hyperhomocysteinemia in turn could damage the endothelium and the blood vessel wall and induce worsening of atherosclerotic process, having a negative impact on the mechanisms underlying MI and HF, such as oxidative stress, inflammation, and altered function of gasotransmitters. Given the importance of the vitamin B6 in homocysteine metabolism, in this paper, we review its role in reducing oxidative stress and inflammation, influencing the functions of gasotransmitters, and improving vasodilatation and coronary flow in animal models of MI and HF.

A prospective, randomized, double-blind, placebo-controlled trial of polyphenols on the outcomes of inflammatory factors and oxidative stress in patients with type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is commonly associated with hyperglycemia, dyslipidemia, oxidative stress and inflammation which are well known cardiovascular risk factors. Pomegranate peel polyphenols have a proven hypolipemic, antioxidant and anti-inflammatory activity. However, there is a lack of clinical studies that would confirm its antioxidant and anti-inflammatory effects in diabetic patients. The potential of pomegranate peel extract (PoPEx) to counteract inflammation and oxidative stress in T2DM patients was investigated. For this purpose, a randomized, double-blind placebo-controlled study involving adult T2DM patients treated with PoPEx or placebo for eight-weeks was conducted. METHODS: Patients were randomly divided into two groups: the first group (n = 30) received capsules containing PoPEx 250 mg twice daily, while the placebo group (n = 30) received placebo capsules twice daily. Plasma concentration of inflammatory factors (interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and high sensitivity C reactive protein (hsCRP)), oxidative stress biomarkers (thiobarbituric acid reactive substances (TBARS), nitrites (NO2-), superoxide anion radical (O2-), hydrogen peroxide (H2O2), total antioxidant capacity (TAC)), homocysteine and lipid profile were analyzed. RESULTS: The PoPEx treatment showed a significant reduction of inflammatory factors (IL-6, TNF-α, hsCRP), oxidative stress biomarkers (TBARS, NO2-, O2-) and homocysteine, while the TAC was increased. Moreover, a significant improvement in lipid profile was observed in the PoPEx group. Additional analysis showed a significant inverse correlation between the decrements of all measured inflammatory markers and TAC in the PoPEx group. CONCLUSIONS: The study demonstrated that eight-week-long PoPEx administration had favorable effects on inflammatory status and oxidative stress biomarkers in diabetic patients.

Computational study of pomegranate peel extract polyphenols as potential inhibitors of SARS-CoV-2 virus internalization.

The search for effective coronavirus disease (COVID-19) therapy has attracted a great deal of scientific interest due to its unprecedented health care system overload worldwide. We have carried out a study to investigate the in silico effects of the most abundant pomegranate peel extract constituents on the multi-step process of serious acute respiratory syndrome coronavirus 2 (SARS-CoV-2) internalization in the host cells. Binding affinities and interactions of ellagic acid, gallic acid, punicalagin and punicalin were studied on four selected protein targets with a significant and confirmed role in the process of the entry of virus into a host cell. The protein targets used in this study were: SARS-CoV-2 spike glycoprotein, angiotensin-converting enzyme 2, furin and transmembrane serine protease 2. The results showed that the constituents of pomegranate peel extracts, namely punicalagin and punicalin had very promising potential for significant interactions with the selected protein targets and were therefore deemed good candidates for further in vitro and in vivo evaluation.

The impact of low mineral content water on cardiac function in diabetic rats: focus on oxidative stress.

The aim of this study was to estimate the effects of natural low mineral water from the source "Sneznik-1/79" in Serbia on glycemia as well as heart function in rats with diabetes mellitus type 2 (T2DM), with the special emphasis on the role of the oxidative stress. Twenty Wistar albino rats (males, 4 weeks old at the beginning of the study, body weight 180 ± 20 g) were included in the study. Rats were divided randomly into 2 groups (10 animals per group): T2DM: rats with diabetes mellitus type 2 with free access to tap water; T2DM + SW: rats with diabetes mellitus type with free access to natural mineral water from "Sneznik-1/79". Glucose level, ex vivo cardiac function as well as systemic and cardiac redox state were assessed. At the end of the study protocol, glucose level was lower in diabetic rats who consumed mineral water. Moreover cardiac function wasn't affected by mineral water intake, however, significant antioxidant effects were observed. Our study suggests that 4-week consumption of low mineral water from the spring "Sneznik-1/79" has important role in regulation of glycemia and altering redox state in favor of elevated antioxidant capacity without affecting heart function. Based on our findings we may assume that low mineral water from the spring "Sneznik-1/79" has the potential to be used either as preventive strategy or as additional therapeutic strategy in management of T2DM.

The perfusion of cisplatin and cisplatin structural analogues through the isolated rat heart: The effects on coronary flow and cardiodynamic parameters.

The therapeutic use of cisplatin for the treatment of solid tumours is associated with organ toxicity. Amongst those, the cardiotoxicity is an occasional but very serious and severe side effect. To prevent or reduce these negative effects, many cisplatin analogues have been synthesized and evaluated in terms of being a less toxic and more effective agent. In present study, we examined the effects of cisplatin and its three analogues in the isolated rat heart to determine whether changes in the structure of the platinum complexes (changing of carrier ligands - ethylenediamine; 1,2-diaminocyclohexane; 2,2':6',2''-terpyridine) can influence their cardiotoxic effects. The results of our research indicate that the introduction of aromatic rings in the structure of the platinum complexes has a negative influence on the heart function. Conversely, the other two examined complexes had less negative effects on heart function compared to cisplatin. Our findings may be of interest for a possible synthetic strategy of introducing a carrier ligand that will exert a less cardiotoxic effect.

Efficiency of atorvastatin and simvastatin in improving cardiac function during the different degrees of hyperhomocysteinemia.

The aim of this study was to assess the impact of atorvastatin and simvastatin on myocardial contractility during the different degrees of hyperhomocysteinemia (HHcy) in rats. Study was conducted on adult male Wistar albino rats (n = 90; 4 weeks old; 100 ± 15 g body mass) in which HHcy was achieved by dietary manipulation. Animals were exposed to pharmacology treatment with atorvastatin in dose of 3 mg/kg per day i.p. or simvastatin in dose of 5 mg/kg per day i.p. at the same time every day, according to equivalent therapeutic doses of these statins (10 mg atorvastatin = 20 mg simvastatin). After the dietary manipulation and pharmacological treatment and confirmation of HHcy, all animals were sacrificed, hearts were isolated, and cardiac function was tested according to the Langendorff technique. Size of recovery of maximum rate of left ventricular development (dp/dtmax), minimum rate of left ventricular development (dp/dtmin), systolic left ventricular development, diastolic left ventricular development, heart rate, and coronary flow at the 40, 60, 80, 100, and 120 cmH2O coronary perfusion pressure were measured in state of physiological condition (homocysteine less than 15 µmol/L), mild HHcy, and moderate HHcy. Atorvastatin treatment significantly attenuated homocysteine-induced impairment of myocyte contractility and dominantly decreased dp/dtmax, dp/dtmin, and heart rate and induced greater changes in systolic left ventricular development compared with simvastatin. Treatment with atorvastatin seems able to revert systolic abnormalities and improve contractility during the different degrees of HHcy.

The Role of Nutraceuticals in Statin Intolerant Patients.

Statins are the most common drugs administered for patients with cardiovascular disease. However, due to statin-associated muscle symptoms, adherence to statin therapy is challenging in clinical practice. Certain nutraceuticals, such as red yeast rice, bergamot, berberine, artichoke, soluble fiber, and plant sterols and stanols alone or in combination with each other, as well as with ezetimibe, might be considered as an alternative or add-on therapy to statins, although there is still insufficient evidence available with respect to long-term safety and effectiveness on cardiovascular disease prevention and treatment. These nutraceuticals could exert significant lipid-lowering activity and might present multiple non-lipid-lowering actions, including improvement of endothelial dysfunction and arterial stiffness, as well as anti-inflammatory and antioxidative properties. The aim of this expert opinion paper is to provide the first attempt at recommendation on the management of statin intolerance through the use of nutraceuticals with particular attention on those with effective low-density lipoprotein cholesterol reduction.

Cisplatin and cisplatin analogues perfusion through isolated rat heart: the effects of acute application on oxidative stress biomarkers.

Drug-induced oxidative stress can occur in numerous tissues and organ systems (liver, kidney, ear, nervous system, and cardiovascular system). Cancer therapy with cisplatin is associated with side effects to which oxidative stress may contribute. We have compared the influences of cisplatin (reference compound) and its' analogues (dichloro(1,2-diaminocyclohexane)platinum(II) and chloro(2,2':6',2″-terpyridine)platinum(II)) in a model of isolated rat heart using the Langendorff technique. The production of oxidative stress biomarkers, antioxidant enzymes, myocardial damage, and expression of Bax, OH-1, and SODs were studied. Cisplatin and the analogues were perfused at concentration of 10-6 and 10-5 M during 30 min. The results of this study showed that examined platinum complexes had different ability to induce oxidative stress of isolated perfused rat heart. Varying the carrier ligands, such as 1,2-diaminocyclohexane and 2,2':6',2″-terpyridine, related to amino ligands (cisplatin) directly influenced the strength to induce production of oxidative stress biomarkers. Introducing 2,2':6',2″-terpyridine ligands provoked the smallest changes in antioxidant enzymes activity, lipid peroxidation, and expression of heme oxygenase-1, that undoubtedly indicated that this complex had the lowest impact on redox status in heart tissue. These findings may be useful in synthesis of novel platinum analogues with lower potential for oxidative stress induction. However, the fact that platinum complexes could induce toxic effects in the heart by other mechanisms should be taken into the consideration.

Sulphur-containing Amino Acids: Protective Role Against Free Radicals and Heavy Metals.

BACKGROUND: Sulphur is an abundant element in biological systems, which plays an important role in processes essential for life as a constituent of proteins, vitamins and other crucial biomolecules. The major source of sulphur for humans is plants being able to use inorganic sulphur in the purpose of sulphur-containing amino acids synthesis. Sulphur-containing amino acids include methionine, cysteine, homocysteine, and taurine. Methionine and cysteine are classified as proteinogenic, canonic amino acids incorporated in protein structure. Sulphur amino acids are involved in the synthesis of intracellular antioxidants such as glutathione and N-acetyl cysteine. Moreover, naturally occurring sulphur-containing ligands are effective and safe detoxifying agents, often used in order to prevent toxic metal ions effects and their accumulation in human body. METHODS: Literature search for peer-reviewed articles was performed using PubMed and Scopus databases, and utilizing appropriate keywords. RESULTS: This review is focused on sulphur-containing amino acids - methionine, cysteine, taurine, and their derivatives - glutathione and N-acetylcysteine, and their defense effects as antioxidant agents against free radicals. Additionally, the protective effects of sulphur-containing ligands against the toxic effects of heavy and transition metal ions, and their reactivation role towards the enzyme inhibition are described. CONCLUSION: Sulphur-containing amino acids represent a powerful part of cell antioxidant system. Thus, they are essential in the maintenance of normal cellular functions and health. In addition to their worthy antioxidant action, sulphur-containing amino acids may offer a chelating site for heavy metals. Accordingly, they may be supplemented during chelating therapy, providing beneficial effects in eliminating toxic metals.

Lipid-lowering nutraceuticals in clinical practice: position paper from an International Lipid Expert Panel.

In recent years, there has been growing interest in the possible use of nutraceuticals to improve and optimize dyslipidemia control and therapy. Based on the data from available studies, nutraceuticals might help patients obtain theraputic lipid goals and reduce cardiovascular residual risk. Some nutraceuticals have essential lipid-lowering properties confirmed in studies; some might also have possible positive effects on nonlipid cardiovascular risk factors and have been shown to improve early markers of vascular health such as endothelial function and pulse wave velocity. However, the clinical evidence supporting the use of a single lipid-lowering nutraceutical or a combination of them is largely variable and, for many of the nutraceuticals, the evidence is very limited and, therefore, often debatable. The purpose of this position paper is to provide consensus-based recommendations for the optimal use of lipid-lowering nutraceuticals to manage dyslipidemia in patients who are still not on statin therapy, patients who are on statin or combination therapy but have not achieved lipid goals, and patients with statin intolerance. This statement is intended for physicians and other healthcare professionals engaged in the diagnosis and management of patients with lipid disorders, especially in the primary care setting.