Bloqueadores beta: perspectiva histórica y mecanismos de acción

The place of beta-adrenergic receptor blockers in the treatment of arterial hypertension: from bench-to-bedside

Arterial hypertension is a multifaceted condition influenced by numerous pathophysiological factors. The key contributors to its pathogenesis encompass an unhealthy lifestyle, dysregulation of the sympathetic nervous system, alterations in the activity of adrenergic receptors, disruptions in sodium metabolism, structural and functional abnormalities in the vascular bed, as well as endothelial dysfunction, low-grade inflammation, oxidative stress etc. Despite extensive research into the mechanisms of arterial hypertension development over the centuries, its pathogenesis remains incompletely understood, and the selection of an effective treatment strategy continues to pose a significant challenge. Arterial hypertension is characterized by a diminished sensitivity of the β-adrenergic system, leading to the utilization of β-adrenergic blockers and other antihypertensive drugs in its treatment. This review delves into the mechanisms of action of beta-adrenergic receptor blockers in the treatment of hypertension and their respective effects.

MRGPRB2/X2 and the analogous effects of its agonist and antagonist in DSS-induced colitis in mice

The mast cell receptor Mrgprb2, a mouse orthologue of human Mrgprx2, is known as an inflammatory receptor and its elevated expression is associated with various diseases such as ulcerative colitis. We aimed to elucidate the role of Mrgprb2/x2 and the effect of its ligands on a chemically induced murine colitis model. We showed that in Mrgprb2-/- mice, there is a differential regulation of cytokine releases in the blood plasma and severe colonic damages after DSS treatment. Unexpectedly, we demonstrated that known Mrgprb2/x2 agonists (peptide P17, P17 analogues and CST-14) and antagonist (GE1111) similarly increased the survival rate of WT mice subjected to 4% DSS-induced colitis, ameliorated the colonic damages of 2.5% DSS-induced colitis, restored major protein mRNA expression involved in colon integrity, reduced CD68+ and F4/80+ immune cell infiltration and restored cytokine levels. Collectively, our findings highlight the eminent role of Mrpgrb2/x2 in conferring a beneficial effect in the colitis model, and this significance is demonstrated by the heightened severity of colitis with altered cytokine releases and inflammatory immune cell infiltration observed in the Mrgprb2 knockout mice. Elevated expression of Mrgprb2 in WT colitis murine models may represent the organism's adaptive protective mechanism since Mrgprb2 knockout results in severe colitis. On the other hand, both agonist and antagonist of Mrgprb2 analogously mitigated the severity of colitis in DSS-induced colitis model by altering Mrgprb2 expression, immune cell infiltration and inflammatory cytokine releases.

Electrocardiogram Features in Non-Cardiac Diseases: From Mechanisms to Practical Aspects

Despite the noteworthy advancements and the introduction of new technologies in diagnostic tools for cardiovascular disorders, the electrocardiogram (ECG) remains a reliable, easily accessible, and affordable tool to use. In addition to its crucial role in cardiac emergencies, ECG can be considered a very useful ancillary tool for the diagnosis of many non-cardiac diseases as well. In this narrative review, we aimed to explore the potential contributions of ECG for the diagnosis of non-cardiac diseases such as stroke, migraine, pancreatitis, Kounis syndrome, hypothermia, esophageal disorders, pulmonary embolism, pulmonary diseases, electrolyte disturbances, anemia, coronavirus disease 2019, different intoxications and pregnancy.

An Overview of the Pharmacokinetics and Pharmacodynamics of Landiolol (an Ultra-Short Acting β1 Selective Antagonist) in Atrial Fibrillation

Landiolol is an ultra-short-acting, selective β1-adrenergic receptor blocker that was originally approved in Japan for the treatment of intraoperative tachyarrhythmias. It has gained attention for its use in the management of tachyarrhythmias and perioperative tachycardia, especially atrial fibrillation for both cardiac and non-cardiac surgeries. It can be the ideal agent for heart rate control due to its high β1-selectivity, potent negative chronotropic effect, a limited negative inotropic potential, and an ultrashort elimination half-life (around 4 min); moreover, it may have a potential therapeutic effects for sepsis and pediatric patients. Landiolol seems to be superior to other short-acting and selective beta-blockers such as esmolol. This review aims to provide a comprehensive overview of landiolol, a new ultra-short-acting β1 selective antagonist, including its pharmacology, clinical applications, efficacy, safety profile, and future directions in research and clinical data.

Efficacy of beta-blockers on blood pressure control and morbidity and mortality endpoints in hypertensives of African ancestry: an individual patient data meta-analysis

Introduction

Compared with first-line antihypertensives, beta-blockers (BB) have been reported to lower the central aortic blood pressure suboptimally and are associated with increased stroke risk. This observation has not been investigated in hypertensives of African ancestry. We hypothesised that an individual patient data meta-analysis (IPD-MA) on the efficacy of second- or third-generation beta-blockers (STGBBs) in hypertensives of African descent may provide new insights.

Methods

A single-stage IPD-MA analysed the efficacy of STGBB in lowering the mean arterial blood pressure and reducing the composite outcomes: cardiovascular death, stroke, and myocardial infarction.

Results

A total of 11,860 participants from four randomised control trials were included in the analysis. Second- or third-generation beta-blockers reduced the mean arterial pressure by 1.75 mmHg [95% confidence interval (CI):1.16-2.33; P < 0.001] in all participants included in the analysis, and by 1.93 mmHg (95% CI: 0.86-3.00; P < 0.001) in hypertensive Africans. In patients with established cardiovascular disease, where the benefits of BB therapy are well established, STGBBs were associated with an adjusted odds ratio of 1.33 (95% CI: 1.06-1.65; P = 0.015) of the composite outcome, most likely due to confounding. Similarly, the risk of total myocardial infarction was 1.76 times higher (95% CI: 1.15-2.68; P = 0.008) in hypertensives of African ancestry on STGBBs.

Conclusion

The STGBBs reduced the mean arterial pressure comparably to other antihypertensives, and they were not associated with an increased risk of stroke.

β1-blockers in the reduction of bleeding risk in patients prescribed with potent dual antiplatelet therapy after acute coronary syndrome or percutaneous coronary intervention

BACKGROUND

β1-blockers could improve clinical outcomes in patients with coronary artery disease by lowering the heart rate, blood pressure, and myocardial contractility. Moreover, recent studies have suggested that β1-blockers may also have the potential to reduce bleeding risk.

OBJECTIVES

This study aimed to evaluate the association between β1-blockers and bleeding risk in the patients prescribed with potent dual antiplatelet therapy (DAPT) after acute coronary syndrome (ACS) or percutaneous coronary intervention (PCI).

METHODS

Patients with ACS or undergoing PCI treated by DAPT of ticagrelor and aspirin were consecutively recruited. Follow-up for all eligible patients was conducted for 1 year. Major bleeding outcomes were defined as events that were type ≥2 based on the Bleeding Academic Research Consortium (BARC) criteria.

RESULTS

A total of 1,113 eligible ticagrelor-treated patients were recruited. During the 1-year follow-up interval, 142 (12.6%) patients experienced BARC ≥2 bleedings including 23 patients (2.1%) suffering BARC ≥3 bleedings, with the most common site of bleeding located in the gastrointestinal tract. β1-blockers treatment was associated with a lower risk of BARC ≥2 bleedings (11.2% vs. 23.3%, adjusted HR: 0.42, 95% CI: 0.28-0.62, P < 0.01). Moreover, metoprolol (11.1% vs. 23.3%, adjusted HR: 0.56, 95% CI: 0.37-0.83, P < 0.01) and bisoprolol (11.3% vs. 23.3%, adjusted HR: 0.56, 95% CI: 0.33-0.96, P = 0.04) had similar effects on the reduction of bleeding risk.

CONCLUSION

β1-blockers might be beneficial for the reduction of bleeding risk in potent dual antiplatelet therapy patients with ACS or undergoing PCI.

The Sympathetic Nervous System in Dental Implantology

The sympathetic nervous system plays a vital role in various regulatory mechanisms. These include the well-known fight-or-flight response but also, for example, the processing of external stressors. In addition to many other tissues, the sympathetic nervous system influences bone metabolism. This effect could be highly relevant concerning osseointegration, which is responsible for the long-term success of dental implants. Accordingly, this review aims to summarize the current literature on this topic and to reveal future research perspectives. One in vitro study showed differences in mRNA expression of adrenoceptors cultured on implant surfaces. In vivo, sympathectomy impaired osseointegration in mice, while electrical stimulation of the sympathetic nerves promoted it. As expected, the beta-blocker propranolol improves histological implant parameters and micro-CT measurements. Overall, the present data are considered heterogeneous. However, the available publications reveal the potential for future research and development in dental implantology, which helps to introduce new therapeutic strategies and identify risk factors for dental implant failure.

Blockade of ß-Adrenergic Receptors by Nebivolol Enables Tumor Control Potential for Uveal Melanoma in 3D Tumor Spheroids and 2D Cultures

Uveal melanoma (UM) is the most common primary cancer of the eye in adults. A new systemic therapy is needed to reduce the high metastasis and mortality rate. As β-blockers are known to have anti-tumor effects on various cancer entities, this study focuses on investigating the effect of β1-selective blockers atenolol, celiprolol, bisoprolol, metoprolol, esmolol, betaxolol, and in particular, nebivolol on UM. The study was performed on 3D tumor spheroids as well as 2D cell cultures, testing tumor viability, morphological changes, long-term survival, and apoptosis. Flow cytometry revealed the presence of all three β-adrenoceptors with a dominance of β2-receptors on cell surfaces. Among the blockers tested, solely nebivolol concentration-dependently decreased viability and altered 3D tumor spheroid structure. Nebivolol blocked the repopulation of cells spreading from 3D tumor spheroids, indicating a tumor control potential at a concentration of ≥20 µM. Mechanistically, nebivolol induced ATP depletion and caspase-3/7 activity, indicating that mitochondria-dependent signaling is involved. D-nebivolol or nebivolol combined with the β2-antagonist ICI 118.551 displayed the highest anti-tumor effects, suggesting a contribution of both β1- and β2-receptors. Thus, the present study reveals the tumor control potential of nebivolol in UM, which may offer a perspective for co-adjuvant therapy to reduce recurrence or metastasis.

Correlation between Adrenoceptor Expression and Clinical Parameters in Degenerated Lumbar Intervertebral Discs

Despite advanced knowledge of the cellular and biomechanical processes of intervertebral disc degeneration (IVDD), the trigger and underlying mechanisms remain unclear. Since the sympathetic nervous system (SNS) has been shown to exhibit catabolic effects in osteoarthritis pathogenesis, it is attractive to speculate that it also influences IVDD. Therefore, we explored the adrenoceptor (AR) expression profile in human IVDs and correlated it with clinical parameters of patients. IVD samples were collected from n = 43 patients undergoing lumbar spinal fusion surgery. AR gene expression was analyzed by semi-quantitative polymerase chain reaction. Clinical parameters as well as radiological Pfirrmann and Modic classification were collected and correlated with AR expression levels. In total human IVD homogenates α1A-, α1B-, α2A-, α2B-, α2C-, β1- and β2-AR genes were expressed. Expression of α1A- (r = 0.439), α2A- (r = 0.346) and β2-AR (r = 0.409) showed a positive and significant correlation with Pfirrmann grade. α1A-AR expression was significantly decreased in IVD tissue of patients with adjacent segment disease (p = 0.041). The results of this study indicate that a relationship between IVDD and AR expression exists. Thus, the SNS and its neurotransmitters might play a role in IVDD pathogenesis. The knowledge of differential AR expression in different etiologies could contribute to the development of new therapeutic approaches for IVDD.

Oral agents for acute severe hypertension in children with minimal or no symptoms

Acute hypertension is common among children admitted to hospital, and large or rapid increases in blood pressure place children at risk of complications such as posterior reversible encephalopathy syndrome. Guidelines in the United States and Europe now include definitions guiding the identification of acute severe hypertension (otherwise known as hypertensive crisis) and its management. This review discusses these recommendations and the appropriate use of oral antihypertensive agents for children with minimal or no symptoms. We focus on the role of oral calcium channel blockers, including isradipine (a second-generation dihydropyridine), given recent changes to regulatory approvals in Australia. The differing pharmacokinetic and pharmacodynamic properties of agents are compared, with the aim of facilitating directed drug selection and dosing.

Beta-adrenergic receptor blockade in angiosarcoma: Which beta-blocker to choose?

Beta-blockers are currently studied to improve therapeutic options for patients with angiosarcoma. However, most of these patients have no cardiovascular co-morbidity and it is therefore crucial to discuss the most optimal pharmacological properties of beta-blockers for this population. To maximize the possible effectiveness in angiosarcoma, the use of a non-selective beta-blocker is preferred based on in vitro data. To minimize the risk of cardiovascular adverse events a beta-blocker should ideally have intrinsic sympathomimetic activity or vasodilator effects, e.g. labetalol, pindolol or carvedilol. However, except for one case of carvedilol, only efficacy data of propranolol is available. In potential follow-up studies labetalol, pindolol or carvedilol can be considered to reduce the risk of cardiovascular adverse events.

Metoprolol Inhibits Developmental Brain Sterol Biosynthesis in Mice

De novo sterol synthesis is a critical homeostatic mechanism in the brain that begins during early embryonic development and continues throughout life. Multiple medications have sterol-biosynthesis-inhibiting side effects, with potentially detrimental effects on brain health. Using LC-MS/MS, we investigated the effects of six commonly used beta-blockers on brain sterol biosynthesis in vitro using cell lines. Two beta-blockers, metoprolol (MTP) and nebivolol, showed extreme elevations of the highly oxidizable cholesterol precursor 7-dehydrocholesterol (7-DHC) in vitro across multiple cell lines. We followed up on the MTP findings using a maternal exposure model in mice. We found that 7-DHC was significantly elevated in all maternal brain regions analyzed as well as in the heart, liver and brain of the maternally exposed offspring. Since DHCR7-inhibiting/7-DHC elevating compounds can be considered teratogens, these findings suggest that MTP utilization during pregnancy might be detrimental for the development of offspring, and alternative beta-blockers should be considered.

Dissecting the role of cell signaling versus CD8+ T cell modulation in propranolol antitumor activity

Preclinical and early clinical mechanistic studies of antitumor activity from the beta-adrenergic receptor (β-AR) blocker propranolol have revealed both cell signaling and immune function pathway effects. Intertumoral studies were performed using propranolol, a β₁-AR selective agent (atenolol), and a β₂-AR selective agent (ICI 118,551) in a preclinical in vivo model, as a step to dissect the contribution of cell signaling and CD8⁺ immunological effects on anticancer activity. We found that repression of β₂-AR but not β₁-AR signaling selectively suppressed cell viability and inhibited xenograft growth in vivo. Moreover, western blot analysis indicated that the phosphorylation levels of AKT/MEK/ERK were significantly decreased following the inhibition of β₂-AR. Furthermore, propranolol was found to activate the tumor microenvironment by inducing an increased intratumoral frequency of CD8⁺ T cells, whereas neither selective β₁ nor β₂-AR blockers had a significant effect on the tumor immune microenvironment. Thus, the results of this mechanistic dissection support a predominant role of tumor cell signaling, rather than the accumulation of CD8⁺ T cells, as the basis for propranolol antitumor activity. KEY MESSAGES : Molecular signaling of AKT/MAPK pathway contributes to propranolol caused cancer control. CD8+ T cells in tumor microenvironment were activated upon propranolol exposure. The basis for propranolol antitumor activity was predominantly dependent on cell signaling, rather than the activation of CD8+ T cells.

A Photoswitchable Ligand Targeting the β 1 ‐Adrenoceptor Enables Light‐Control of the Cardiac Rhythm**

Catecholamine‐triggered β‐adrenoceptor (β‐AR) signaling is essential for the correct functioning of the heart. Although both β₁‐ and β₂‐AR subtypes are expressed in cardiomyocytes, drugs selectively targeting β₁‐AR have proven this receptor as the main target for the therapeutic effects of beta blockers in the heart. Here, we report a new strategy for the light‐control of β₁‐AR activation by means of photoswitchable drugs with a high level of β₁‐/β₂‐AR selectivity. All reported molecules allow for an efficient real‐time optical control of receptor function in vitro. Moreover, using confocal microscopy we demonstrate that the binding of our best hit, pAzo‐2, can be reversibly photocontrolled. Strikingly, pAzo‐2 also enables a dynamic cardiac rhythm management on living zebrafish larvae using light, thus highlighting the therapeutic and research potential of the developed photoswitches. Overall, this work provides the first proof of precise control of the therapeutic target β₁‐AR in native environments using light.

Sex/Gender- and Age-Related Differences in β-Adrenergic Receptor Signaling in Cardiovascular Diseases

Sex differences in cardiovascular disease (CVD) are often recognized from experimental and clinical studies examining the prevalence, manifestations, and response to therapies. Compared to age-matched men, women tend to have reduced CV risk and a better prognosis in the premenopausal period. However, with menopause, this risk increases exponentially, surpassing that of men. Although several mechanisms have been provided, including sex hormones, an emerging role in these sex differences has been suggested for β-adrenergic receptor (β-AR) signaling. Importantly, β-ARs are the most important G protein-coupled receptors (GPCRs), expressed in almost all the cell types of the CV system, and involved in physiological and pathophysiological processes. Consistent with their role, for decades, βARs have been considered the first targets for rational drug design to fight CVDs. Of note, β-ARs are seemingly associated with different CV outcomes in females compared with males. In addition, even if there is a critical inverse correlation between β-AR responsiveness and aging, it has been reported that gender is crucially involved in this age-related effect. This review will discuss how β-ARs impact the CV risk and response to anti-CVD therapies, also concerning sex and age. Further, we will explore how estrogens impact β-AR signaling in women.

Congenital Heart Disease: The State-of-the-Art on Its Pharmacological Therapeutics

Congenital heart disease is one of the most common causes of death derived from malformations. Historically, its treatment has depended on timely diagnosis and early pharmacological and surgical interventions. Survival rates for patients with this disease have increased, primarily due to advancements in therapeutic choices, but mortality remains high. Since this disease is a time-sensitive pathology, pharmacological interventions are needed to improve clinical outcomes. Therefore, we analyzed the applications, dosage, and side effects of drugs currently used for treating congenital heart disease. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and potassium-sparing diuretics have shown a mortality benefit in most patients. Other therapies, such as endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostaglandins, and soluble guanylyl cyclase stimulators, have benefited patients with pulmonary artery hypertension. Likewise, the adjunctive symptomatic treatment of these patients has further improved the outcomes, since antiarrhythmics, digoxin, and non-steroidal anti-inflammatory drugs have shown their benefits in these cases. Conclusively, these drugs also carry the risk of troublesome adverse effects, such as electrolyte imbalances and hemodynamic compromise. However, their benefits for survival, symptom improvement, and stabilization outweigh the possible complications from their use. Thus, cases must be assessed individually to accurately identify interventions that would be most beneficial for patients.

An Up-to-Date Article Regarding Particularities of Drug Treatment in Patients with Chronic Heart Failure

Since the prevalence of heart failure (HF) increases with age, HF is now one of the most common reasons for the hospitalization of elderly people. Although the treatment strategies and overall outcomes of HF patients have improved over time, hospitalization and mortality rates remain elevated, especially in developed countries where populations are aging. Therefore, this paper is intended to be a valuable multidisciplinary source of information for both doctors (cardiologists and general physicians) and pharmacists in order to decrease the morbidity and mortality of heart failure patients. We address several aspects regarding pharmacological treatment (including new approaches in HF treatment strategies [sacubitril/valsartan combination and sodium glucose co-transporter-2 inhibitors]), as well as the particularities of patients (age-induced changes and sex differences) and treatment (pharmacokinetic and pharmacodynamic changes in drugs; cardiorenal syndrome). The article also highlights several drugs and food supplements that may worsen the prognosis of HF patients and discusses some potential drug-drug interactions, their consequences and recommendations for health care providers, as well as the risks of adverse drug reactions and treatment discontinuation, as an interdisciplinary approach to treatment is essential for HF patients.

Single-Pill Combination to Improve Hypertension Treatment: Pharmaceutical Industry Development

Multiple illness is an increasingly common phenomenon. Its consequence is the need for polytherapy, which is particularly common among people suffering from arterial hypertension. The development of combined preparations (containing at least two API-active pharmaceutical ingredients) dedicated to the treatment of hypertension is a response to increased compliance, especially in elderly patients. In our work, we describe in particular the possibilities of using β-adrenergic receptors blockers and angiotensin-converting enzyme inhibitors in combinations. The combinations of APIs are used as single pills in patients with arterial hypertension with concomitant diseases such as hyperlipidemia; blood coagulation problems and diabetes mellitus were also discussed successively. Pharmacoeconomic analysis for the API combinations shown is also presented. As a final conclusion, numerous benefits of using the combined preparations should be indicated, especially by the elderly and/or in patients with coexistence of other diseases.

Psoriasis risk after betablocker exposure: description of a pharmacovigilance signal

AIM

We aimed to investigate French pharmacovigilance data. The objective was to characterize psoriatic conditions occurred after BB exposure and bright to light a possible pharmacovigilance signal.

METHODS

Spontaneous reports of psoriatic conditions recorded in the French national Pharmacovigilance database (FPVD) between 1985 and 2019 were extracted. We performed a retrospective, descriptive analysis of reports linked to BB exposure. Association between psoriasis risk and BB exposure was assessed using a case/non-case study.

RESULTS

Two hundred and twenty-five reports of psoriatic conditions after BB exposure were recorded in the FPVD during the study period. Both, cardioselective and non-cardioselective, topical and systemic, BBs are involved. Therapeutic indication of BB was mainly hypertension Mean time to onset was 5 months and outcome was favorable in 68% after BB discontinuation. These features were concordant with those of literature reports. The reporting odds ratio (ROR) was 8.95 (95%CI 7.75 - 10.33).

CONCLUSION

We highlighted a statistically significant disproportionality which constitutes a pharmacovigilance signal. Psoriasis risk with BBs is a class effect. Increasing surveillance during the 1^st year of BB exposure is needed.

'Ab Ovo' Chiral Phases and Chiral Reagents for Liquid Chromatographic Separation and Isolation of Enantiomers

The de-novo approach of mixing chirally pure reagents or Cu(II)-L-amino acid complexes in the slurry of silica gel for preparing TLC plates was reported from author's laboratory and was successful for separation and isolation of enantiomers. Using high molar absorptivity molecules, e. g., 1,5-difluoro-2,4-dinitrobenzene and cyanuric chloride, more than 38 new chiral derivatizing reagents were synthesized in our laboratory by straightforward nucleophilic substitution with simple chiral auxiliaries. Besides, (S)-naproxen, (S)-ketoprofen, and (S)-levofloxacin were used as chiral platforms. A conceptual approach using both achiral phases in chromatography for enantioseparation was also adopted. ¹ H NMR and DFT based software were used to explain structures of non-covalent and covalent diastereomeric pairs and determination of configuration and separation mechanism. The methods can be easily used to determine and control enantiomeric purity with advantages over a variety of commercial chiral phases.

Lipid emulsion attenuates propranolol-induced early apoptosis in rat cardiomyoblasts

OBJECTIVE

Propranolol is used to treat several cardiovascular diseases; however, toxic doses of propranolol cause severe myocardial depression and cardiac arrest. The aim of this study was to examine the effects of lipid emulsion (LE) on cardiotoxicity induced by toxic doses of propranolol in H9C2 rat cardiomyoblast cell line and to elucidate the underlying mechanism.

METHODS

The experimental groups comprised control, propranolol alone, esmolol alone, or LE followed by propranolol or esmolol treatment, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine (NAC) followed by propranolol treatment. The effects of propranolol, esmolol, NAC, and LE, alone or in combination, on cell viability, apoptosis, and ROS production were examined. Additionally, we investigated the effect of LE on propranolol concentration.

RESULTS

LE and NAC reversed the inhibition of cell viability induced by propranolol (p < .001). However, LE had no effect on the inhibition of cell viability caused by esmolol. The LE inhibited propranolol-induced expressions of cleaved caspase-3 (p < .001), caspase-9 (p < .001), and Bax (p < .01), but not caspase-8. NAC inhibited the propranolol-induced expression of cleaved caspase-3. LE inhibited propranolol-induced early apoptosis, but had no effect on late apoptosis. Additionally, LE inhibited the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells generated by propranolol. It attenuated propranolol-induced ROS production. However, it had no effect on propranolol concentration.

CONCLUSION

LE inhibits early apoptosis caused by a toxic dose of propranolol by suppressing the intrinsic apoptotic pathway, via direct inhibition of ROS production.

Acute autonomic effects of rose oxide on cardiovascular parameters of Wistar and spontaneously hypertensive rats

AIMS

Anti-inflammatory molecules, such as rose oxide (RO), are likely to exert therapeutic effects in systemic arterial hypertension (SAH), a disease associated with abnormal immune responses. We aimed to investigate acute autonomic effects of RO on hemodynamic parameters of Wistar and spontaneously hypertensive rats (SHR).

METHODS

Rats were anesthetized and femoral artery and veins were cannulated. Next day, blood pressure (BP) and heart rate (HR) were recorded. Acute effects of RO (1.25, 2.5, or 5.0 mg/kg; iv) on BP, HR, and variability of systolic arterial pressure (SAP) and pulse interval (PI) were assessed. The effects of RO were also investigated in SHR, which received atropine (2 mg/kg), propranolol (4 mg/kg), or hexamethonium (20 mg/kg) 15 min before receiving RO. Vasorelaxant effects of RO (10-10 to 10-4 M) on aortic rings of rats were also assessed.

KEY FINDINGS

In Wistar rats, none of the RO doses evoked significant changes in BP, HR, and variability of SAP and PI. On the other hand, in SHR, RO elicited reduction in mean arterial pressure (MAP), and prevented the increase in the low frequency power (LF) of the SAP spectra. Pretreatment with atropine or propranolol did not alter hypotension, but attenuated RO-induced bradycardia. Hexamethonium prevented RO-induced hypotension and bradycardia. RO exerted vasorelaxant effects on aortic rings with (Wistar and SHR) or without functional endothelium (SHR only).

SIGNIFICANCE

Rose oxide, a monoterpene with anti-inflammatory properties, acts as an antihypertensive molecule due to its ability to acutely promote hypotension and bradycardia in spontaneously hypertensive rats.

A Review on Medicinal Plants Used in the Management of Headache in Africa

The use of medicinal plants in the management of diverse ailments is entrenched in the culture of indigenous people in African communities. This review provides a critical appraisal of the ethnobotanical uses of medicinal plants for the management of headache in Africa. Research articles published from 2010 (Jan) to 2021 (July) with keywords such as Africa, ethnobotany, headache, medicinal plant and traditional medicine were assessed for eligibility based on sets of pre-defined criteria. A total of 117 plants, representing 56 families, were documented from the 87 eligible studies. Asteraceae (10%), Fabaceae (10%), Lamiaceae (9%) and Mimosaceae (5%) were the most represented plant families. The most popular plant species used in the management of headache were Ocimum gratissimum L. (n = 7), Allium sativum L. (n = 3), Ricinus communis L. (n = 3) and Artemisia afra Jack. ex. Wild (n = 2). The leaves (49%), roots (20%) and bark (12%) were the most common plant parts used. Decoction (40%) and infusion (16%) were the preferred methods of preparation, whereas the oral route (52%) was the most preferred route of administration. The data revealed that medicinal plants continue to play vital roles in the management of headache in African communities. In an attempt to fully explore the benefits from the therapeutic potential of indigenous flora for common ailments, further studies are essential to generate empirical evidence on their efficacies, using appropriate test systems/models. This approach may assist with the ongoing drive towards the integration of African traditional medicine within mainstream healthcare systems.

Metoprolol in Critically Ill Patients With COVID-19

BACKGROUND

Severe coronavirus disease-2019 (COVID-19) can progress to an acute respiratory distress syndrome (ARDS), which involves alveolar infiltration by activated neutrophils. The beta-blocker metoprolol has been shown to ameliorate exacerbated inflammation in the myocardial infarction setting.

OBJECTIVES

The purpose of this study was to evaluate the effects of metoprolol on alveolar inflammation and on respiratory function in patients with COVID-19-associated ARDS.

METHODS

A total of 20 COVID-19 patients with ARDS on invasive mechanical ventilation were randomized to metoprolol (15 mg daily for 3 days) or control (no treatment). All patients underwent bronchoalveolar lavage (BAL) before and after metoprolol/control. The safety of metoprolol administration was evaluated by invasive hemodynamic and electrocardiogram monitoring and echocardiography.

RESULTS

Metoprolol administration was without side effects. At baseline, neutrophil content in BAL did not differ between groups. Conversely, patients randomized to metoprolol had significantly fewer neutrophils in BAL on day 4 (median: 14.3 neutrophils/µl [Q1, Q3: 4.63, 265 neutrophils/µl] vs median: 397 neutrophils/µl [Q1, Q3: 222, 1,346 neutrophils/µl] in the metoprolol and control groups, respectively; P = 0.016). Metoprolol also reduced neutrophil extracellular traps content and other markers of lung inflammation. Oxygenation (PaO2:FiO2) significantly improved after 3 days of metoprolol treatment (median: 130 [Q1, Q3: 110, 162] vs median: 267 [Q1, Q3: 199, 298] at baseline and day 4, respectively; P = 0.003), whereas it remained unchanged in control subjects. Metoprolol-treated patients spent fewer days on invasive mechanical ventilation than those in the control group (15.5 ± 7.6 vs 21.9 ± 12.6 days; P = 0.17).

CONCLUSIONS

In this pilot trial, intravenous metoprolol administration to patients with COVID-19-associated ARDS was safe, reduced exacerbated lung inflammation, and improved oxygenation. Repurposing metoprolol for COVID-19-associated ARDS appears to be a safe and inexpensive strategy that can alleviate the burden of the COVID-19 pandemic.

Chitosan as Valuable Excipient for Oral and Topical Carvedilol Delivery Systems

Chitosan is a valued excipient due to its biocompatibility properties and increasing solubility of poorly water-soluble drugs. The research presented in this paper concerns the preparation of binary combinations of chitosan (deacetylated chitin) with carvedilol (beta-blocker) to develop a formulation with a modified carvedilol release profile. As part of the research, six physical mixtures of chitosan with carvedilol were obtained and identified by spectral (PXRD, FT-IR, and Raman), thermal (DSC), and microscopic (SEM) methods. The next stage of the research estimated the profile changes and the dissolution rate for carvedilol in the obtained drug delivery systems; the reference sample was pure carvedilol. The studies were conducted at pH = 1.2 and 6.8, simulating the gastrointestinal tract conditions. Quantitative changes of carvedilol were determined using the developed isocratic UHPLC-DAD method. Established apparent permeability coefficients proved the changes in carvedilol's permeability after introducing a drug delivery system through membranes simulating the gastrointestinal tract and skin walls. A bioadhesive potential of carvedilol-chitosan systems was confirmed using the in vitro model. The conducted research and the obtained results indicate a significant potential of using chitosan as an excipient in modern oral or epidermal drug delivery systems of carvedilol.

Therapeutic Properties of Highly Selective β-blockers With or Without Additional Vasodilator Properties: Focus on Bisoprolol and Nebivolol in Patients With Cardiovascular Disease

Bisoprolol and nebivolol are highly selective β₁-adrenoceptor antagonists, with clinical indications in many countries within the management of heart failure with reduced left ventricular ejection fraction (HFrEF), ischaemic heart disease (IHD), and hypertension. Nebivolol has additional vasodilator actions, related to enhanced release of NO in the vascular wall. In principle, this additional mechanism compared with bisoprolol might lead to more potent vasodilatation, which in turn might influence the effectiveness of nebivolol in the management of HFrEF, IHD and hypertension. In this article, we review the therapeutic properties of bisoprolol and nebivolol, as representatives of “second generation” and “third generation” β-blockers, respectively. Although head-to-head trials are largely lacking, there is no clear indication from published studies of an additional effect of nebivolol on clinical outcomes in patients with HFrEF or the magnitude of reductions of BP in patients with hypertension.

Metoprolol exerts a non-class effect against ischaemia-reperfusion injury by abrogating exacerbated inflammation

Aims

Clinical guidelines recommend early intravenous β-blockers during ongoing myocardial infarction; however, it is unknown whether all β-blockers exert a similar cardioprotective effect. We experimentally compared three clinically approved intravenous β-blockers.

Methods and results

Mice undergoing 45 min/24 h ischaemia–reperfusion (I/R) received vehicle, metoprolol, atenolol, or propranolol at min 35. The effect on neutrophil infiltration was tested in three models of exacerbated inflammation. Neutrophil migration was evaluated in vitro and in vivo by intravital microscopy. The effect of β-blockers on the conformation of the β1 adrenergic receptor was studied in silico. Of the tested β-blockers, only metoprolol ameliorated I/R injury [infarct size (IS) = 18.0% ± 0.03% for metoprolol vs. 35.9% ± 0.03% for vehicle; P < 0.01]. Atenolol and propranolol had no effect on IS. In the three exacerbated inflammation models, neutrophil infiltration was significantly attenuated only in the presence of metoprolol (60%, 50%, and 70% reductions vs. vehicle in myocardial I/R injury, thioglycolate-induced peritonitis, and lipopolysaccharide-induced acute lung injury, respectively). Migration studies confirmed the particular ability of metoprolol to disrupt neutrophil dynamics. In silico analysis indicated different intracellular β1 adrenergic receptor conformational changes when bound to metoprolol than to the other two β-blockers.

Conclusions

Metoprolol exerts a disruptive action on neutrophil dynamics during exacerbated inflammation, resulting in an infarct-limiting effect not observed with atenolol or propranolol. The differential effect of β-blockers may be related to distinct conformational changes in the β1 adrenergic receptor upon metoprolol binding. If these data are confirmed in a clinical trial, metoprolol should become the intravenous β-blocker of choice for patients with ongoing infarction.

Nebivolol is more effective than atenolol for blood pressure variability attenuation and target organ damage prevention in L-NAME hypertensive rats

β-Adrenergic blockers are no longer recommended as first-line therapy due to the reduced cardioprotection of traditional β-blockers compared with other antihypertensive drugs. It is unknown whether third-generation β-blockers share the limitations of traditional β-blockers. The aim of the present study was to compare the effects of nebivolol or atenolol on central and peripheral systolic blood pressure (SBP) and its variability and target organ damage (TOD) in N-nitro-L-arginine methyl ester (L-NAME) hypertensive rats. Male Wistar rats were treated with L-NAME for 8 weeks together with oral administration of nebivolol 30 mg/kg (n = 8), atenolol 90 mg/kg (n = 8), or vehicle (n = 8). The control group was composed of vehicle-treated Wistar rats. SBP and its variability, as well as echocardiographic parameters, were assessed during the last 2 weeks of treatment. Tissue levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and transforming growth factor β (TGF-β), and histopathological parameters were evaluated in the left ventricle and aorta. Nebivolol had a greater ability than atenolol to decrease central SBP and mid-term and short-term blood pressure variability (BPV) in L-NAME rats. Echocardiographic analysis showed that nebivolol was more effective than atenolol on E/A wave ratio normalization. Compared with atenolol treatment, nebivolol had a greater protective effect on different TOD markers, inducing a decrease in collagen deposition and a reduction in the proinflammatory cytokines IL-6 and TNF-α in the left ventricle and aorta. Our findings suggest that the adverse hemodynamic profile and the reduced cardiovascular protection reported with traditional β-blockers must not be carried forward to third-generation β-blockers.

Progress in the Enantioseparation of β-Blockers by Chromatographic Methods

β-adrenergic antagonists (β-blockers) with at least one chiral center are an exceedingly important class of drugs used mostly to treat cardiovascular diseases. At least 70 β-blockers have been investigated in history. However, only a few β-blockers, e.g., timolol, are clinically marketed as an optically pure enantiomer. Therefore, the separation of racemates of β-blockers is essential both in the laboratory and industry. Many approaches have been explored to obtain the single enantiomeric β-blocker, including high performance liquid chromatography, supercritical fluid chromatography and simulated moving bed chromatography. In this article, a review is presented on different chromatographic methods applied for the enantioseparation of β-blockers, covering high performance liquid chromatography (HPLC), supercritical fluid chromatography (SFC) and simulated moving bed chromatography (SMB).

Pharmacology of Pulmonary Arterial Hypertension: An Overview of Current and Emerging Therapies

Pulmonary arterial hypertension is a rare and devastating disease characterized by an abnormal chronic increase in pulmonary arterial pressure above 20 mmHg at rest, with a poor prognosis if not treated. Currently, there is not a single fully effective therapy, even though a dozen of drugs have been developed in the last decades. Pulmonary arterial hypertension is a multifactorial disease, meaning that several molecular mechanisms are implicated in its pathology. The main molecular pathways regulating the pulmonary vasomotor tone-endothelin, nitric oxide, and prostacyclin-are the most biologically and therapeutically explored to date. However, drugs targeting these pathways have already found their limitations. In the last years, translational research and clinical trials have made a strong effort in suggesting and testing novel therapeutic strategies for this disease. These approaches involve targeting the main molecular pathways with novel drugs, drug repurposing for novel targets, and also using combinatorial therapies. In this review, we summarize current strategies and drugs targeting the endothelin, nitric oxide, and prostacyclin pathways, as well as, the emerging new drugs proposed to cope with vascular remodelling, metabolic switch, perivascular inflammation, epigenetic modifications, estrogen deregulation, serotonin, and other neurohumoral mechanisms characteristic of this disease. Nowadays, pulmonary arterial hypertension remains an incurable disease; however, the incoming new knowledge makes us believe that new promising therapies are coming to the clinical arena soon.

Beta-Blockers and Cancer: Where Are We?

Cancer is one of the leading causes of death worldwide. After diagnosis, cancer treatment may involve radiotherapy, chemotherapy, and surgery. Several of the approaches used to treat cancer also attack normal cells and, thus, there is the need for more effective treatments that decrease the toxicity to normal cells and increase the success rates of treatment. The use of beta-blockers in cancer has been studied for their antagonist action on the adrenergic system through inhibition of beta-adrenergic receptors. Besides regulating processes such as blood pressure, heart rate, and airway strength or reactivity, beta-blockers block mechanisms that trigger tumorigenesis, angiogenesis, and tumor metastasis. This study presents a literature review of the available studies addressing cancer treatments and beta-blockers. Overall, data suggest that propranolol may be used as a complement for the treatment of several types of cancer due to its ability to improve cancer outcomes by decreasing cancer cell proliferation rates. Nonetheless, additional in vitro studies should be performed to fully understand the protective role of BBs in cancer patients.