Nebivolol: a third-generation beta-blocker that augments vascular nitric oxide release: endothelial beta(2)-adrenergic receptor-mediated nitric oxide production

Multitargeting in cardioprotection: An example of biaromatic compounds

A multitarget drug design approach is actively developing in modern medicinal chemistry and pharmacology, especially with regard to multifactorial diseases such as cardiovascular diseases, cancer, and neurodegenerative diseases. A detailed study of many well-known drugs developed within the single-target approach also often reveals additional mechanisms of their real pharmacological action. One of the multitarget drug design approaches can be the identification of the basic pharmacophore models corresponding to a wide range of the required target ligands. Among such models in the group of cardioprotectors is the linked biaromatic system. This review develops the concept of a "basic pharmacophore" using the biaromatic pharmacophore of cardioprotectors as an example. It presents an analysis of possible biological targets for compounds corresponding to the biaromatic pharmacophore and an analysis of the spectrum of biological targets for the five most known and most studied cardioprotective drugs corresponding to this model, and their involvement in the biological effects of these drugs.

Endothelial dysfunction, platelet hyperactivity, hypertension, and the metabolic syndrome: molecular insights and combating strategies

Metabolic syndrome (MetS) is a multifaceted condition that increases the possibility of developing atherosclerotic cardiovascular disease. MetS includes obesity, hypertension, dyslipidemia, hyperglycemia, endothelial dysfunction, and platelet hyperactivity. There is a concerning rise in the occurrence and frequency of MetS globally. The rising incidence and severity of MetS need a proactive, multipronged strategy for identifying and treating those affected. For many MetS patients, achieving recommended goals for healthy fat intake, blood pressure control, and blood glucose management may require a combination of medicine therapy, lifestyles, nutraceuticals, and others. However, it is essential to note that lifestyle modification should be the first-line therapy for MetS. In addition, MetS requires pharmacological, nutraceutical, or other interventions. This review aimed to bring together the etiology, molecular mechanisms, and dietary strategies to combat hypertension, endothelial dysfunction, and platelet dysfunction in individuals with MetS.

Inhibition of eNOS Partially Blunts the Beneficial Effects of Nebivolol on Angiotensin II-Induced Signaling in H9c2 Cardiomyoblasts

We have recently illustrated that nebivolol can inhibit angiotensin II (Ang II)-mediated signaling in cardiomyoblasts; however, to date, the detailed mechanism for the beneficial effects of nebivolol has not been studied. Here, we investigated whether the inhibition of NO bioavailability by blocking eNOS (endothelial nitric oxide synthase) using L-NG-nitroarginine methyl ester (L-NAME) would attenuate nebivolol-mediated favorable effects on Ang II-evoked signaling in H9c2 cardiomyoblasts. Our data reveal that the nebivolol-mediated antagonistic effects on Ang II-induced oxidative stress were retreated by concurrent pretreatment with L-NAME and nebivolol. Similarly, the expressions of pro-inflammatory markers TNF-α and iNOS stimulated by Ang II were not decreased with the combination of nebivolol plus L-NAME. In contrast, the nebivolol-induced reduction in the Ang II-triggered mTORC1 pathway and the mRNA levels of hypertrophic markers ANP, BNP, and β-MHC were not reversed with the addition of L-NAME to nebivolol. In compliance with these data, the inhibition of eNOS by L-N⁵-(1-Iminoethyl) ornithine (LNIO) and its upstream regulator AMP-activated kinase (AMPK) with compound C in the presence of nebivolol showed effects similar to those of the L-NAME plus nebivolol combination on Ang II-mediated signaling. Pretreatment with either compound C plus nebivolol or LNIO plus nebivolol showed similar effects to those of the L-NAME plus nebivolol combination on Ang II-mediated signaling. In conclusion, our data indicate that the rise in NO bioavailability caused by nebivolol via the stimulation of AMPK/eNOS signaling is key for its anti-inflammatory and antioxidant properties but not for its antihypertrophic response upon Ang II stimulation.

Tissue distribution and transcriptional regulation of CCN5 in the heart after myocardial infarction

CCN5 is a divergent member of the cellular communication network factor (CCN) family in that it lacks the carboxyl terminal cystine knot domain common to the other CCN family members. CCN5 has been reported to antagonize the profibrotic actions of CCN2 and to inhibit myocardial collagen deposition and fibrosis in chronic pressure overload of the heart. However, what mechanisms that regulate CCN5 activity in the heart remain unknown. Recombinant, replication defective adenovirus encoding firefly luciferase under control of the human CCN5 promoter was prepared and used to investigate what mechanisms regulate CCN5 transcription in relevant cells. Tissue distribution of CCN5 in hearts from healthy mice and from mice subjected to myocardial infarction was investigated. Contrary to the profibrotic immediate early gene CCN2, we find that CCN5 is induced in the late proliferation and maturation phases of scar healing. CCN5 was identified principally in endothelial cells, fibroblasts, smooth muscle cells, and macrophages. Our data show that CCN5 gene transcription and protein levels are induced by catecholamines via β₂-adrenergic receptors. Myocardial induction of CCN5 was further confirmed in isoproterenol-infused mice. We also find that CCN5 transcription is repressed by TNF-α, an inflammatory mediator highly elevated in early phases of wound healing following myocardial infarction. In conclusion, CCN5 predominates in endothelial cells, fibroblasts, and macrophages of the differentiating scar tissue and its transcription is conversely regulated by β₂-adrenergic agonists and TNF-α.

Comparative beneficial effects of nebivolol and nebivolol/valsartan combination against mitochondrial dysfunction in angiotensin II-induced pathology in H9c2 cardiomyoblasts

OBJECTIVES

Considering the complementary nature of signalling mechanisms and the therapeutic effects of nebivolol, a β1-adrenoreceptor antagonist, and valsartan, an angiotensin receptor blocker (ARB), here we aimed to investigate whether nebivolol/valsartan combination would complement the cardioprotective effects of nebivolol on angiotensin II (ANG II)-induced pathology in H9c2 cardiomyoblasts.

METHODS

H9c2 cardiomyoblasts were used to investigate the protective effects of nebivolol and nebivolol and valsartan combination against ANG II-induced pathology. Reactive oxygen species (ROS) generation was determined by 2',7'-dichlorofluorescein diacetate (DCFDA) and MitoSOX Red staining. Real-time PCR and immunoblotting were employed to quantify the changes in mRNA and protein expression levels, respectively.

KEY FINDINGS

Our data revealed that pretreatment with nebivolol and nebivolol/valsartan combination significantly reduced ANG II-induced oxidative stress and mTORC1 signalling. Concurrently, ANG II-induced activation of inflammatory cytokines and fetal gene expressions were significantly suppressed by nebivolol and nebivolol/valsartan combination. Pretreatment with nebivolol and nebivolol/valsartan combination alleviated ANG II-induced impairment of mitochondrial biogenesis by restoring the gene expression levels of PGC-1α, TFAM, NRF-1 and SIRT3. Our data further show that nebivolol and nebivolol/valsartan combination mediated up-regulation in mitochondrial biogenesis is accompanied by decrease in ANG II-stimulated mitochondrial ROS generation as well as increase in expression of mitochondrial fusion genes MFN2 and OPA1, indicative of improved mitochondrial dynamics.

SUMMARY

These findings suggest that both nebivolol and nebivolol/valsartan combination exert protective effects on ANG II-induced mitochondrial dysfunction by alleviating its biogenesis and dynamics. Moreover, addition of valsartan to nebivolol do not produce any additive effects compared with nebivolol alone on ANG II-induced cardiac pathology.

Multifactorial Basis and Therapeutic Strategies in Metabolism-Related Diseases

Throughout the 20th and 21st centuries, the incidence of non-communicable diseases (NCDs), also known as chronic diseases, has been increasing worldwide. Changes in dietary and physical activity patterns, along with genetic conditions, are the main factors that modulate the metabolism of individuals, leading to the development of NCDs. Obesity, diabetes, metabolic associated fatty liver disease (MAFLD), and cardiovascular diseases (CVDs) are classified in this group of chronic diseases. Therefore, understanding the underlying molecular mechanisms of these diseases leads us to develop more accurate and effective treatments to reduce or mitigate their prevalence in the population. Given the global relevance of NCDs and ongoing research progress, this article reviews the current understanding about NCDs and their related risk factors, with a focus on obesity, diabetes, MAFLD, and CVDs, summarizing the knowledge about their pathophysiology and highlighting the currently available and emerging therapeutic strategies, especially pharmacological interventions. All of these diseases play an important role in the contamination by the SARS-CoV-2 virus, as well as in the progression and severity of the symptoms of the coronavirus disease 2019 (COVID-19). Therefore, we briefly explore the relationship between NCDs and COVID-19.

Efficacy and safety of nebivolol in hypertensive patients: a meta-analysis of randomized controlled trials

Purpose

Our meta-analysis was undertaken to evaluate the efficacy and safety of nebivolol compared with other second-generation β blockers for hypertensive patients.

Methods

We searched PubMed, the Cochrane Library, EMBASE, and Clinical Trials.gov databases for randomized controlled trials (RCTs). The efficacy endpoints included systolic blood pressure (SBP), diastolic blood pressure (DBP), reduction of SBP and DBP, heart rate (HR), and adverse events (AEs).

Findings

Eight RCTs with 1514 patients met the inclusion criteria. HR was significantly lower in patients receiving other second-generation β blockers compared with patients receiving nebivolol. There was no difference the reduction of blood pressure (SBP and DBP) or the reduction of SBP or DBP between the groups. The incidence of AEs was lower in patients taking nebivolol compared with patients taking other second-generation β blockers.

Conclusions

No significant difference was demonstrated between nebivolol and other second-generation β blockers in the reduction of blood pressure, SBP, and DBP. The tolerability of nebivolol was significantly better compared with other second-generation β blockers, and nebivolol was also associated with a stable HR and a lower risk of AEs compared with other second-generation β blockers.

Nebivolol/valsartan combination for the treatment of hypertension: a review

Nebivolol (N) is a β₁-adrenoreceptor antagonist that is approved for treatment of hypertension in the USA. Effective treatment of hypertension is becoming an increasingly difficult process that often requires multiple drug combinations to meet target guidelines. This has resulted in the increasing introduction of multidrug single-pill combinations (SPCs) to facilitate cost and compliance issues. Some of the SPCs have added valsartan (V), an angiotensin receptor blocker, which is an increasingly advocated antihypertensive class. Pharmacological profiles of N and V, alone and combined, are well characterized. In 2007, the SPC of N and V, 5 and 80 mg, respectively, was approved by the US FDA for treatment of hypertension. This paper will summarize and update key issues in pharmacology, clinical use and benefit.

Preparative separation of nebivolol isomers by improved throughput reverse phase tandem two column chromatography

Development of preparative methods for the isolation of chiral molecules has been considered challenging by conventional unit operations due to their identical physical and chemical properties. This has evolved chiral stationary phases for the separation of chiral components using chromatography technique. However, separation method using chiral adsorbents requires high pressure, are expensive, and have low productivity. Generation of bulk quantities purified nebivolols using the available high pressure chiral separation methods is impractical and operating cost-intensive. Thus, there is a need to develop economical methods using nonchiral adsorbents for the purification of nebivolols or similar active ingredients. The present work demonstrates a unique and scalable tandem two-column method for the separation of isomers of nebivolol using inexpensive reverse phase adsorbents. The first column of the scheme causes removal of charged and nonisomeric impurities whereas tandem operation of second column increases resolution of d-nebivolol and l-nebivolol. The maximization of separation due to tandem operation of second column causes enhancement of the throughput of the process. The developed preparative process produces >98% purity of both d-nebivolol and l-nebivolol with overall loading capacity of 56 g (L of adsorbent)^-1 and productivity of 20 g L^-1 day^-1 .

Revisiting pharmacology of oxidative stress and endothelial dysfunction in cardiovascular disease: Evidence for redox-based therapies

According to the latest Global Burden of Disease Study data, non-communicable diseases in general and cardiovascular disease (CVD) in particular are the leading cause of premature death and reduced quality of life. Demographic shifts, unhealthy lifestyles and a higher burden of adverse environmental factors provide an explanation for these findings. The expected growing prevalence of CVD requires enhanced research efforts for identification and characterisation of novel therapeutic targets and strategies. Cardiovascular risk factors including classical (e.g. hypertension, diabetes, hypercholesterolaemia) and non-classical (e.g. environmental stress) factors induce the development of endothelial dysfunction, which is closely associated with oxidant stress and vascular inflammation and results in CVD, particularly in older adults. Most classically successful therapies for CVD display vasoprotective, antioxidant and anti-inflammatory effects, but were originally designed with other therapeutic aims. So far, only a few 'redox drugs' are in clinical use and many antioxidant strategies have not met expectations. With the present review, we summarise the actual knowledge on CVD pathomechanisms, with special emphasis on endothelial dysfunction, adverse redox signalling and oxidative stress, highlighting the preclinical and clinical evidence. In addition, we provide a brief overview of established CVD therapies and their relation to endothelial dysfunction and oxidative stress. Finally, we discuss novel strategies for redox-based CVD therapies trying to explain why, despite a clear link between endothelial dysfunction and adverse redox signalling and oxidative stress, redox- and oxidative stress-based therapies have not yet provided a breakthrough in the treatment of endothelial dysfunction and CVD.

The effects of microgravity and space radiation on cardiovascular health: From low-Earth orbit and beyond

The unique conditions of space harbor considerable challenges for astronauts to overcome. Namely, the ionizing content of space radiation and the effects of microgravity have been implicated in the pathogenesis of cardiovascular disease. Post-flight carotid arterial stiffness was demonstrated in astronaut studies while early arteriosclerosis has been linked with microgravity-induced oxidative stress in cellular studies. Similarly, radiation has been shown to disrupt molecular pathways, enhance reactive oxygen species and increase risk of cardiovascular disease in exposed populations. These results may bear even more significance in space owing to the propensity for microgravity and space radiation to yield synergistic and/or additive interactions. Potential countermeasures such as α-tocopherol and captopril target these oxidative pathways and may help to protect against the effects of microgravity and radiation-induced cardiac damage. However, more research needs to be conducted in this area to facilitate a safe passage for humans to the Moon, Mars and beyond.

G-Protein-Coupled Receptors in Heart Disease

GPCRs (G-protein [guanine nucleotide-binding protein]-coupled receptors) play a central physiological role in the regulation of cardiac function in both health and disease and thus represent one of the largest class of surface receptors targeted by drugs. Several antagonists of GPCRs, such as βARs (β-adrenergic receptors) and Ang II (angiotensin II) receptors, are now considered standard of therapy for a wide range of cardiovascular disease, such as hypertension, coronary artery disease, and heart failure. Although the mechanism of action for GPCRs was thought to be largely worked out in the 80s and 90s, recent discoveries have brought to the fore new and previously unappreciated mechanisms for GPCR activation and subsequent downstream signaling. In this review, we focus on GPCRs most relevant to the cardiovascular system and discuss traditional components of GPCR signaling and highlight evolving concepts in the field, such as ligand bias, β-arrestin-mediated signaling, and conformational heterogeneity.

Vasodilation Elicited by Isoxsuprine, Identified by High-Throughput Virtual Screening of Compound Libraries, Involves Activation of the NO/cGMP and H₂S/KATP Pathways and Blockade of α₁-Adrenoceptors and Calcium Channels

Recently, our research group demonstrated that uvaol and ursolic acid increase NO and H₂S production in aortic tissue. Molecular docking studies showed that both compounds bind with high affinity to endothelial NO synthase (eNOS) and cystathionine gamma-lyase (CSE). The aim of this study was to identify hits with high binding affinity for the triterpene binding-allosteric sites of eNOS and CSE and to evaluate their vasodilator effect. Additionally, the mechanism of action of the most potent compound was explored. A high-throughput virtual screening (HTVS) of 107,373 compounds, obtained from four ZINC database libraries, was performed employing the crystallographic structures of eNOS and CSE. Among the nine top-scoring ligands, isoxsuprine showed the most potent vasodilator effect. Pharmacological evaluation, employing the rat aorta model, indicated that the vasodilation produced by this compound involved activation of the NO/cGMP and H₂S/K_ATP signaling pathways and blockade of α₁-adrenoceptors and L-type voltage-dependent Ca²⁺ channels. Incubation of aorta homogenates in the presence of isoxsuprine caused 2-fold greater levels of H₂S, which supported our preliminary in silico data. This study provides evidence to propose that the vasodilator effect of isoxsuprine involves various mechanisms, which highlights its potential to treat a wide variety of cardiovascular diseases.

New Therapeutic Implications of Endothelial Nitric Oxide Synthase (eNOS) Function/Dysfunction in Cardiovascular Disease

The Global Burden of Disease Study identified cardiovascular risk factors as leading causes of global deaths and life years lost. Endothelial dysfunction represents a pathomechanism that is associated with most of these risk factors and stressors, and represents an early (subclinical) marker/predictor of atherosclerosis. Oxidative stress is a trigger of endothelial dysfunction and it is a hall-mark of cardiovascular diseases and of the risk factors/stressors that are responsible for their initiation. Endothelial function is largely based on endothelial nitric oxide synthase (eNOS) function and activity. Likewise, oxidative stress can lead to the loss of eNOS activity or even “uncoupling” of the enzyme by adverse regulation of well-defined “redox switches” in eNOS itself or up-/down-stream signaling molecules. Of note, not only eNOS function and activity in the endothelium are essential for vascular integrity and homeostasis, but also eNOS in perivascular adipose tissue plays an important role for these processes. Accordingly, eNOS protein represents an attractive therapeutic target that, so far, was not pharmacologically exploited. With our present work, we want to provide an overview on recent advances and future therapeutic strategies that could be used to target eNOS activity and function in cardiovascular (and other) diseases, including life style changes and epigenetic modulations. We highlight the redox-regulatory mechanisms in eNOS function and up- and down-stream signaling pathways (e.g., tetrahydrobiopterin metabolism and soluble guanylyl cyclase/cGMP pathway) and their potential pharmacological exploitation.

Impact of Acute Dietary Nitrate Supplementation during Exercise in Hypertensive Women

INTRODUCTION

the aim of the current investigation was to examine if dietary nitrate supplementation would improve vascular control in hypertensive postmenopausal women (PMW). We tested the hypotheses that acute dietary nitrate supplementation would 1) significantly decrease arterial blood pressure (BP) at rest and during exercise, 2) increase limb blood flow during steady-state (SS) exercise, and 3) improve functional sympatholysis during SS exercise.

METHODS

Ten hypertensive PMW underwent a randomized, double-blind, placebo-controlled trial with a nitrate-rich (NR) or nitrate-poor (NP) supplement. Beat-by-beat BP and heart rate were recorded throughout the trial on the nonexercising limb. Forearm blood flow was measured via ultrasonography on the brachial artery of the exercising limb. All patients performed a resting cold pressor test (CPT) (2 min) and then 7 min of submaximal handgrip exercise with a CPT applied during minutes 5-7.

RESULTS

SS systolic (NR, 170 ± 7; NP, 171 ± 37 mm Hg), diastolic (NR, 89 ± 2; NP, 92 ± 2 mm Hg), and mean arterial (NR, 121 ± 4; NP, 123 ± 2 mm Hg) pressures were not different between NP and NR treatment conditions (P > 0.05). During SS exercise, forearm blood flow (NR, 189 ± 8; NP, 218 ± 8 mL·min; P = 0.03) in the NR treatment was significantly lower compared with NP. When the CPT was applied during minutes 6-7 of exercise, forearm vascular conductance was reduced by 15% in the NR condition, but only 7% in the NR condition.

CONCLUSIONS

In summary, an acute NR supplement improved functional sympatholysis by ~50% versus an NP placebo condition. Improvements in functional sympatholysis may have important implications regarding exercise tolerance in hypertensive PMW.

Carvedilol versus traditional, non-selective beta-blockers for adults with cirrhosis and gastroesophageal varices

BACKGROUND

Non-selective beta-blockers are recommended for the prevention of bleeding in people with cirrhosis, portal hypertension and gastroesophageal varices. Carvedilol is a non-selective beta-blocker with additional intrinsic alpha₁-blocking effects, which may be superior to traditional, non-selective beta-blockers in reducing portal pressure and, therefore, in reducing the risk of upper gastrointestinal bleeding.

OBJECTIVES

To assess the beneficial and harmful effects of carvedilol compared with traditional, non-selective beta-blockers for adults with cirrhosis and gastroesophageal varices.

SEARCH METHODS

We combined searches in the Cochrane Hepato-Biliary's Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, and Science Citation Index with manual searches. The last search update was 08 May 2018.

SELECTION CRITERIA

We included randomised clinical trials comparing carvedilol versus traditional, non-selective beta-blockers, irrespective of publication status, blinding, or language. We included trials evaluating both primary and secondary prevention of upper gastrointestinal bleeding in adults with cirrhosis and verified gastroesophageal varices.

DATA COLLECTION AND ANALYSIS

Three review authors (AZ, RJ and LH), independently extracted data. The primary outcome measures were mortality, upper gastrointestinal bleeding and serious adverse events. We undertook meta-analyses and presented results using risk ratios (RR) or mean differences (MD), both with 95% confidence intervals (CIs), and I² values as a marker of heterogeneity. We assessed bias control using the Cochrane Hepato-Biliary domains and the quality of the evidence with GRADE.

MAIN RESULTS

Eleven trials fulfilled our inclusion criteria. One trial did not report clinical outcomes. We included the remaining 10 randomised clinical trials, involving 810 participants with cirrhosis and oesophageal varices, in our analyses. The intervention comparisons were carvedilol versus propranolol (nine trials), or nadolol (one trial). Six trials were of short duration (mean 6 (range 1 to 12) weeks), while four were of longer duration (13.5 (6 to 30) months). Three trials evaluated primary prevention; three evaluated secondary prevention; while four evaluated both primary and secondary prevention. We classified all trials as at 'high risk of bias'. We gathered mortality data from seven trials involving 507 participants; no events occurred in four of these. Sixteen of 254 participants receiving carvedilol and 19 of 253 participants receiving propranolol or nadolol died (RR 0.86, 95% CI 0.48 to 1.53; I² = 0%, low-quality evidence). There appeared to be no differences between carvedilol versus traditional, non-selective beta-blockers and the risks of upper gastrointestinal bleeding (RR 0.77, 95% CI 0.43 to 1.37; 810 participants; 10 trials; I² = 45%, very low-quality evidence) and serious adverse events (RR 0.97, 95% CI 0.67 to 1.42; 810 participants; 10 trials; I² = 14%, low-quality evidence). Significantly more deaths, episodes of upper gastrointestinal bleeding and serious adverse events occurred in the long-term trials but there was not enough information to determine whether there were differences between carvedilol and traditional, non-selective beta-blockers, by trial duration. There was also insufficient information to detect differences in the effects of these interventions in trials evaluating primary or secondary prevention. There appeared to be no differences in the risk of non-serious adverse events between carvedilol versus its comparators (RR 0.55, 95% CI 0.23 to 1.29; 596 participants; 6 trials; I² = 88%; very low-quality evidence). Use of carvedilol was associated with a greater reduction in hepatic venous pressure gradient than traditional, non-selective beta-blockers both in absolute (MD -1.75 mmHg, 95% CI -2.60 to -0.89; 368 participants; 6 trials; I² = 0%; low-quality evidence) and percentage terms (MD -8.02%, 95% CI -11.49% to -4.55%; 368 participants; 6 trials; I² = 0%; low-quality evidence). However, we did not observe a concomitant reduction in the number of participants who failed to achieve a sufficient haemodynamic response (RR 0.76, 95% CI 0.57 to 1.02; 368 participants; 6 trials; I² = 42%; very low-quality evidence) or in clinical outcomes.

AUTHORS' CONCLUSIONS

We found no clear beneficial or harmful effects of carvedilol versus traditional, non-selective beta-blockers on mortality, upper gastrointestinal bleeding, serious or non-serious adverse events despite the fact that carvedilol was more effective at reducing the hepatic venous pressure gradient. However, the evidence was of low or very low quality, and hence the findings are uncertain. Additional evidence is required from adequately powered, long-term, double-blind, randomised clinical trials, which evaluate both clinical and haemodynamic outcomes.

Rationale for nebivolol/valsartan combination for hypertension: review of preclinical and clinical data

To treat hypertension, combining two or more antihypertensive drugs from different classes is often necessary. β-Blockers and renin–angiotensin–aldosterone system inhibitors, when combined, have been deemed ‘less effective’ based on partially overlapping mechanisms of action and limited evidence. Recently, the single-pill combination (SPC) of nebivolol (Neb) 5 mg – a vasodilatory β1-selective antagonist/β3 agonist – and valsartan 80 mg, an angiotensin II receptor blocker, was US Food and Drug Administration-approved for hypertension. Pharmacological profiles of Neb and valsartan, alone and combined, are well characterized. In addition, a large 8-week randomized trial in stages I–II hypertensive patients (N = 4161) demonstrated greater blood pressure-reducing efficacy for Neb/valsartan SPCs than component monotherapies with comparable tolerability. In a biomarkers substudy (N = 805), Neb/valsartan SPCs prevented valsartan-induced increases in plasma renin, and a greater reduction in plasma aldosterone was observed with the highest SPC dose vs. valsartan 320 mg/day. This review summarizes preclinical and clinical evidence supporting Neb/valsartan as an efficacious and well tolerated combination treatment for hypertension.

The Comparison of the Effects of Nebivolol and Metoprolol on Erectile Dysfunction in the Cases with Coronary Artery Bypass Surgery

PURPOSE

Beta-blocker use is common in the cases with coronary artery bypass surgery. According to the literature, beta-blockers have positive effects but may cause erectile dysfunction (ED). The most commonly used beta-blockers in ischemic cardiac disease are nebivolol and metoprolol. In our clinic, we aimed to compare the effects of nebivolol and metoprolol succinate on ED in the sexually active cases with coronary artery bypass surgery.

METHODS

In our clinic, a total of 119 patients with coronary artery bypass surgery were included in the study. International Index of Erectile Function (IIEF-5) Test was used to evaluate whether the patients had ED and to grade the cases.

RESULTS

No significant difference was found in terms of anti-ischemic efficacy between metoprolol succinate and nebivolol in the postoperative period; however, the incidence of any grade ED was %85.96 in Group 1, %83.87 in Group 2. This difference was considered as statistically significant (p = 0.036).

CONCLUSION

Beta-blocker use increases the risk of ED in cases with ischemic cardiac disease. We suggest that the complaints of ED could be less frequent with nebivolol use in sexually active cases with ischemic cardiac disease.

Nebivolol-Loaded Microsponge Gel for Healing of Diabetic Wound

An attempt was made to formulate nebivolol-loaded microsponge gel to access drug at wound area, incorporated into gel that possess optimum moist wound management environment during later stages of wound closure. Nebivolol, antihypertensive drug, exhibits vasodilating effects via nitric oxide pathway, slows diabetic neuropathy, and restores endothelial function in diabetic wounds. Microsponges were prepared by optimizing independent variables; drug to polymer ratio and internal phase volume and their effects on production yield, entrapment efficiency, and particle size. Formulations of microsponges were evaluated for drug content. Differential scanning calorimetry indicated reduction in crystallinity of NB during the formation of microsponges. In vitro study (drug to polymer 1:4 and 10 ml internal phase volume acetone) showed 80% drug released within 8 h. Spherical and porous microsponges confirmed by scanning electron microscopy were incorporated in the carbopol 934 (2%) gel base. Gel was characterized for pH, viscosity, and drug content. Less spreadability determined by texture analyzer demonstrated viscous nature of gel. In vitro diffusion study revealed entrapped drug in porous microsponges with slow release to heal wound. In vivo study performed using streptozotocin-induced diabetic rats and excision wound model showed wound healing and closure activity within day 10. Histology revealed inflammatory cell infiltrations and neovascularization in granulation tissues, ultimately healing wound. Microsponge gel prolonged drug release due to entrapped form in porous structure of microsponges with significant and fast wound healing and closure in diabetic rats. Microsponges with loaded drug fulfilled accessibility at wound area, while gel provided optimum moist wound management environment during later stages of wound closure.

Beta-blockers for hypertension

BACKGROUND

Beta-blockers refer to a mixed group of drugs with diverse pharmacodynamic and pharmacokinetic properties. They have shown long-term beneficial effects on mortality and cardiovascular disease (CVD) when used in people with heart failure or acute myocardial infarction. Beta-blockers were thought to have similar beneficial effects when used as first-line therapy for hypertension. However, the benefit of beta-blockers as first-line therapy for hypertension without compelling indications is controversial. This review is an update of a Cochrane Review initially published in 2007 and updated in 2012.

OBJECTIVES

To assess the effects of beta-blockers on morbidity and mortality endpoints in adults with hypertension.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to June 2016: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 6), MEDLINE (from 1946), Embase (from 1974), and ClinicalTrials.gov. We checked reference lists of relevant reviews, and reference lists of studies potentially eligible for inclusion in this review, and also searched the the World Health Organization International Clinical Trials Registry Platform on 06 July 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least one year of duration, which assessed the effects of beta-blockers compared to placebo or other drugs, as first-line therapy for hypertension, on mortality and morbidity in adults.

DATA COLLECTION AND ANALYSIS

We selected studies and extracted data in duplicate, resolving discrepancies by consensus. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI) and conducted fixed-effect or random-effects meta-analyses, as appropriate. We also used GRADE to assess the certainty of the evidence. GRADE classifies the certainty of evidence as high (if we are confident that the true effect lies close to that of the estimate of effect), moderate (if the true effect is likely to be close to the estimate of effect), low (if the true effect may be substantially different from the estimate of effect), and very low (if we are very uncertain about the estimate of effect).

MAIN RESULTS

Thirteen RCTs met inclusion criteria. They compared beta-blockers to placebo (4 RCTs, 23,613 participants), diuretics (5 RCTs, 18,241 participants), calcium-channel blockers (CCBs: 4 RCTs, 44,825 participants), and renin-angiotensin system (RAS) inhibitors (3 RCTs, 10,828 participants). These RCTs were conducted between the 1970s and 2000s and most of them had a high risk of bias resulting from limitations in study design, conduct, and data analysis. There were 40,245 participants taking beta-blockers, three-quarters of them taking atenolol. We found no outcome trials involving the newer vasodilating beta-blockers (e.g. nebivolol).There was no difference in all-cause mortality between beta-blockers and placebo (RR 0.99, 95% CI 0.88 to 1.11), diuretics or RAS inhibitors, but it was higher for beta-blockers compared to CCBs (RR 1.07, 95% CI 1.00 to 1.14). The evidence on mortality was of moderate-certainty for all comparisons.Total CVD was lower for beta-blockers compared to placebo (RR 0.88, 95% CI 0.79 to 0.97; low-certainty evidence), a reflection of the decrease in stroke (RR 0.80, 95% CI 0.66 to 0.96; low-certainty evidence) since there was no difference in coronary heart disease (CHD: RR 0.93, 95% CI 0.81 to 1.07; moderate-certainty evidence). The effect of beta-blockers on CVD was worse than that of CCBs (RR 1.18, 95% CI 1.08 to 1.29; moderate-certainty evidence), but was not different from that of diuretics (moderate-certainty) or RAS inhibitors (low-certainty). In addition, there was an increase in stroke in beta-blockers compared to CCBs (RR 1.24, 95% CI 1.11 to 1.40; moderate-certainty evidence) and RAS inhibitors (RR 1.30, 95% CI 1.11 to 1.53; moderate-certainty evidence). However, there was little or no difference in CHD between beta-blockers and diuretics (low-certainty evidence), CCBs (moderate-certainty evidence) or RAS inhibitors (low-certainty evidence). In the single trial involving participants aged 65 years and older, atenolol was associated with an increased CHD incidence compared to diuretics (RR 1.63, 95% CI 1.15 to 2.32). Participants taking beta-blockers were more likely to discontinue treatment due to adverse events than participants taking RAS inhibitors (RR 1.41, 95% CI 1.29 to 1.54; moderate-certainty evidence), but there was little or no difference with placebo, diuretics or CCBs (low-certainty evidence).

AUTHORS' CONCLUSIONS

Most outcome RCTs on beta-blockers as initial therapy for hypertension have high risk of bias. Atenolol was the beta-blocker most used. Current evidence suggests that initiating treatment of hypertension with beta-blockers leads to modest CVD reductions and little or no effects on mortality. These beta-blocker effects are inferior to those of other antihypertensive drugs. Further research should be of high quality and should explore whether there are differences between different subtypes of beta-blockers or whether beta-blockers have differential effects on younger and older people.

Nebivolol Ameliorates Cardiac NLRP3 Inflammasome Activation in a Juvenile-Adolescent Animal Model of Diet-Induced Obesity

NLRP3 is involved in obesity-induced cardiac remodeling and dysfunction. In this study, we evaluated whether the cardiac protective effects of nebivolol relied on attenuating NLRP3 activation in a juvenile-adolescent animal model of diet-induced obesity. Weaning male Sprague-Dawley rats were fed with either a standard chow diet (ND) or a high-fat diet (HFD) for 8 weeks. The obese rats were subsequently subdivided into three groups: 1) HFD control group; 2) HFD with low-dose nebivolol (5 mg/kg/d); 3) HFD with high-dose nebivolol (10 mg/kg/d). Treatment with nebivolol prevented HFD-induced obesity associated excess cardiac lipid accumulation as well as myocardial mitochondrial dysfunction. Nebivolol attenuated pro-inflammatory cytokines secretion and NLRP3 inflammasome activation in myocardium of obese rats. In parallel, nebivolol treatment of obese animals increased cardiac β3-AR expression, reversing the reduction of endothelial nitric oxide synthase (eNOS). In vitro, nebivolol treatment of palmitate-incubated H9C2 cells suppressed autophagy, restored mitochondrial biogenesis, leading to decreased mitochondrial reactive oxygen species (mtROS) generation, and suppressed NLRP3 inflammasome activation. Meanwhile the presence of shRNA against β3-AR or against eNOS deteriorated the protective effects of nebivolol. These data suggest the beneficial effect of nebivolol on myocardial lipotoxicity contributing to inhibiting NLRP3 inflammasome activation possibly via improved mitochondrial dysfunction.

Nebivolol Acts as a S-Nitrosoglutathione Reductase Inhibitor

Background and Purpose:

Published data on nebivolol reveal selective β1 adrenergic selectively along with novel nitric oxide (NO)-dependent vasodilatory properties. However, the exact molecular mechanism is unknown. Protein S-nitrosylation constitutes a large part of the ubiquitous influence of NO on cellular signal transduction and is involved in a number of human diseases. More recently, protein denitrosylation has been shown to play a major role in controlling cellular S-nitrosylation (SNO). Several enzymes have been reported to catalyze the reduction of SNOs and are viewed as candidate denitrosylases. One of the first described is known as S-nitrosoglutathione reductase (GSNOR). Importantly, GSNOR has been shown to play a role in regulating SNO signaling downstream of the β-adrenergic receptor and is therefore operative in cellular signal transduction. Pharmacological inhibition or genetic deletion of GSNOR leads to enhanced vasodilation and characteristic of known effects of nebivolol. Structurally, nebivolol is similar to known inhibitors of GSNOR. Therefore, we hypothesize that some of the known effects of nebivolol may occur through this mechanism.

Experimental Approach:

Using cell culture systems, tissue organ bath, and intact animal models, we report that nebivolol treatment leads to a dose-dependent accumulation of nitrosothiols in cells, and this is associated with an enhanced vasodilation by S-nitrosoglutathione.

Key Results:

These data suggest a new mechanism of action of nebivolol that may explain in part the reported NO activity.

Conclusions and Implications:

Because exogenous mediators of protein SNO or denitrosylation can substantially affect the development or progression of disease, this may call for new utility of nebivolol.

Nebivolol has a beneficial effect in monocrotaline-induced pulmonary hypertension

Pulmonary hypertension is a rare disorder that, without treatment, is progressive and fatal within 3–4 years. Current treatment involves a diverse group of drugs that target the pulmonary vascular bed. In addition, strategies that increase nitric oxide (NO) formation have a beneficial effect in rodents and patients. Nebivolol, a selective β1 adrenergic receptor-blocking agent reported to increase NO production and stimulate β3 receptors, has vasodilator properties suggesting that it may be beneficial in the treatment of pulmonary hypertension. The present study was undertaken to determine whether nebivolol has a beneficial effect in monocrotaline-induced (60 mg/kg) pulmonary hypertension in the rat. These results show that nebivolol treatment (10 mg/kg, once or twice daily) attenuates pulmonary hypertension, reduces right ventricular hypertrophy, and improves pulmonary artery remodeling in monocrotaline-induced pulmonary hypertension. This study demonstrates the presence of β3 adrenergic receptor immunoreactivity in pulmonary arteries and airways and that nebivolol has pulmonary vasodilator activity. Studies with β3 receptor agonists (mirabegron, BRL 37344) and antagonists suggest that β3 receptor-mediated decreases in systemic arterial pressure occur independent of NO release. Our results suggest that nebivolol, a selective vasodilating β1 receptor antagonist that stimulates β3 adrenergic receptors and induces vasodilation by increasing NO production, may be beneficial in treating pulmonary hypertensive disorders.

Endothelial dysfunction and coronary artery disease: assessment, prognosis, and treatment

Progress in the modification of conventional coronary risk factors and lifestyle behavior has reduced the incidence of atherosclerotic coronary artery disease; nonetheless, it continues to be the leading cause of mortality in the world. This might be attributed to the defective risk stratifying and prevention strategy for coronary artery disease. In the current clinical setting, atherosclerotic coronary artery disease risk is estimated on the basis of identifying and quantifying only traditional risk factors; it does not take into consideration nontraditional risk factors. In addition, most of the prevailing therapies for atherosclerosis are targeted toward traditional risk factors rather than atherosclerosis itself. It is desirable to develop a method that can directly assess the activity of atherogenesis at every moment. Endothelial function is an integrated index of all atherogenic and atheroprotective factors present in an individual including nontraditional factors and heretofore unknown factors, and it is reported to have additional predictive value for future cardiovascular events to traditional risk factors. Moreover, endothelial function has a pivotal role in all phases of atherosclerosis, from initiation to atherothrombotic complication, and is reversible at every phase, indicating that endothelial function-guided therapies might be effective and feasible in cardiovascular practice. Thus, the introduction of endothelial function testing into clinical practice might enable us to innovate individualized cardiovascular medicine. In this review, we summarize the current knowledge on the contribution of endothelial dysfunction to atherogenesis and review the methods that assess endothelial function. Finally, we focus on the effects of major antiatherosclerotic disease therapies on endothelial function and argue the possibility of noninvasive assessment of endothelial function aiming at individualized cardiovascular medicine.

Chronic Nebivolol Treatment Suppresses Endothelin-1-Mediated Vasoconstrictor Tone in Adults With Elevated Blood Pressure

Endothelin-1 (ET-1) plays a major role in the pathophysiology of hypertension and its associated cardiovascular risk. We tested the hypothesis that chronic nebivolol treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated blood pressure (BP). Furthermore, reducing ET-1 vasoconstrictor activity contributes to the improvement in endothelial vasodilator function associated with nebivolol treatment. Forty-two middle-aged adults with elevated BP (systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg) completed a 3-month, double-blind, randomized, placebo controlled trial: 14 received nebivolol (8 men/6 women; 5 mg per day); 14 received metoprolol succinate (9 men/5 women; 100 mg per day); and 14 received placebo (9 men/5 women). Forearm blood flow (plethysmography) responses to selective (BQ-123: 100 nmol/min; 60 minutes) and nonselective (BQ-123+BQ-788 [50 nmol/min]; 60 minutes) ET-1 receptor blockade, as well as acetylcholine (4.0, 8.0, and 16.0 μg per 100 mL of tissue per minute) in the absence and presence of nonselective ET-1 receptor blockade were determined before and after each treatment intervention. Forearm blood flow responses to BQ-123 and BQ-123+BQ-788 were similarly and significantly elevated (≈30% and 60%, respectively) from baseline in all 3 groups. Nebivolol, but not metoprolol or placebo, therapy resulted in a marked (≈25% and 45%; P<0.05) reduction in forearm blood flow response to BQ-123 and BQ-123+BQ-788. Moreover, after nebivolol therapy only, vasodilator response to acetylcholine was not significantly increased by ET-1 receptor blockade. These results demonstrate that nebivolol, but not metoprolol, treatment reduces ET-1-mediated vasoconstrictor tone in adult humans with elevated BP. In addition, nebivolol-induced reduction in ET-1-mediated vasoconstrictor tone underlies the favorable effects of this β-blocker on endothelial vasodilation.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01395329.

Nebivolol ameliorates asymmetric dimethylarginine-induced vascular response in rat aorta via β3 adrenoceptor-mediated mechanism

BACKGROUND

Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase (NOS) inhibitor, induces endothelial dysfunction. Nebivolol, a highly selective β1-adrenergic receptor (AR) blocker, is the only beta-blocker known to induce vascular production of nitric oxide.

OBJECTIVE

The present study was designed to evaluate the effect and mechanism of nebivolol on ADMA-induced vascular response in rat aorta in vitro.

METHODS

In vitro, the effects of nebivolol and ADMA on resting tone or contraction induced by phenylephrine (PE, 10(-6 )mol/L) and relaxation induced by acetylcholine (Ach, 10(-10)-10(-5 )mol/L) were evaluated.

RESULTS

ADMA in a concentration-dependent manner increased the resting and PE-induced tone and reduced Ach-induced relaxation. Nebivolol inhibited the ADMA-induced enhancements in tone and reversed the effects of ADMA on Ach-induced relaxation. These effects of nebivolol were blocked by selective β3 receptor blocker cyanopindolol (1 μM), but not by selective β2 receptor blocker butoxamine (50 μM).

CONCLUSIONS

Nebivolol ameliorates the ADMA-induced vascular responses in rat aorta, at least in part, by mechanisms involving β3 adrenoceptor.

Modification of solid lipid nanoparticles loaded with nebivolol hydrochloride for improvement of oral bioavailability in treatment of hypertension: polyethylene glycol versus chitosan oligosaccharide lactate

Nebivolol (NB)-loaded solid lipid nanoparticles (SLNs) were prepared and modified with chitosan oligosaccharide lactate (COL) and polyethylene glycol (PEG) stearate for improvement of its oral bioavailability. Compritol, poloxamer and lecithin were used for the preparation of SLNs by homogenisation method. After in vitro characterisation effect of lipase, pepsin, or pancreatin on degradation and release rate were investigated. Cytotoxicity and permeation were studied on Caco-2 cells. As COL concentration increased in SLNs, size and zeta potential increased. PEG concentration was reversely proportional to particle size with no change in zeta potential. Encapsulation efficiencies (EEs) were determined as 84-98%. DSC confirmed solubilisation of NB in lipid matrix. A sustained release with no burst effect was determined. The presence of enzymes affected the release. SLNs did not reveal cytotoxicity and highest permeability was obtained with PEG modification. PEG-modified SLNs could be offered as a promising strategy for oral delivery of NB.

Exploiting the Pleiotropic Antioxidant Effects of Established Drugs in Cardiovascular Disease

Cardiovascular disease is a leading cause of death and reduced quality of life worldwide. Arterial vessels are a primary target for endothelial dysfunction and atherosclerosis, which is accompanied or even driven by increased oxidative stress. Recent research in this field identified different sources of reactive oxygen and nitrogen species contributing to the pathogenesis of endothelial dysfunction. According to lessons from the past, improvement of endothelial function and prevention of cardiovascular disease by systemic, unspecific, oral antioxidant therapy are obviously too simplistic an approach. Source- and cell organelle-specific antioxidants as well as activators of intrinsic antioxidant defense systems might be more promising. Since basic research demonstrated the contribution of different inflammatory cells to vascular oxidative stress and clinical trials identified chronic inflammatory disorders as risk factors for cardiovascular events, atherosclerosis and cardiovascular disease are closely associated with inflammation. Therefore, modulation of the inflammatory response is a new and promising approach in the therapy of cardiovascular disease. Classical anti-inflammatory therapeutic compounds, but also established drugs with pleiotropic immunomodulatory abilities, demonstrated protective effects in various models of cardiovascular disease. However, results from ongoing clinical trials are needed to further evaluate the value of immunomodulation for the treatment of cardiovascular disease.

Gut and sublingual microvascular effect of esmolol during septic shock in a porcine model

INTRODUCTION

Esmolol may efficiently reduce heart rate (HR) and decrease mortality during septic shock. An improvement of microcirculation dissociated from its macrocirculatory effect may a role. The present study investigated the effect of esmolol on gut and sublingual microcirculation in a resuscitated piglet model of septic shock.

METHODS

Fourteen piglets, anesthetized and mechanically ventilated, received a suspension of live Pseudomonas aeruginosa. They were randomly assigned to two groups: the esmolol (E) group received an infusion of esmolol, started at 7.5 μg⋅kg(-1)⋅min(-1), and progressively increased to achieve a HR below 90 beats⋅min(-1). The control (C) group received an infusion of Ringer's lactate solution. HR, mean arterial pressure (MAP), cardiac index (CI), stroke index (SI), systemic vascular resistance (SVR), arterio-venous blood gas and lactate were recorded. Oxygen consumption (VO2), delivery (DO2) and peripheral extraction (O2ER) were computed. Following an ileostomy, a laser Doppler probe was applied on ileal mucosa to monitor gut microcirculatory laser Doppler flow (GMLDF). Videomicroscopy was also used on ileal mucosa and sublingual areas to evaluate mean flow index (MFI), heterogeneity, ratio of perfused villi and proportion of perfused vessels. Resuscitation maneuvers were performed following a defined algorithm.

RESULTS

Bacterial infusion induced a significant alteration of the gut microcirculation with an increase in HR. Esmolol produced a significant time/group effect with a decrease in HR (P <0.004) and an increase in SVR (P <0.004). Time/group effect was not significant for CI and MAP, but there was a clear trend toward a decrease in CI and MAP in the E group. Time/group effect was not significant for SI, O2ER, DO2, VO2, GMLDF and lactate. A significant time/group effect of ileal microcirculation was found with a lower ileal villi perfusion (P <0.025) in the C group, and a trend toward a better MFI in the E group. No difference between both groups was found regarding microcirculatory parameters in the sublingual area.

CONCLUSIONS

Esmolol provided a maintenance of microcirculation during sepsis despite its negative effects on macrocirculation. Some parameters even showed a trend toward an improvement of the microcirculation in the gut area in the esmolol group.

Anti-thrombotic effects of nebivolol and carvedilol: Involvement of β2 receptors and COX-2/PGI2 pathways

BACKGROUND

Third generation β-adrenolytics, such as selective β1 adrenoceptor antagonist nebivolol and non-selective β1/β2 and α1 adrenoceptor antagonist carvedilol, display beneficial nitric oxide (NO)-dependent vasodilator activities that contribute to their therapeutic efficacy. In the present work, we analyzed whether nebivolol and carvedilol, as well as other β-adrenolytics with similar pharmacological profiles (selective β1 adrenoceptor antagonist - atenolol and non-selective α/β adrenoceptor antagonist - labetalol), possess the ability to induce PGI2-dependent anti-thrombotic activity in vivo in normotensive rats.

METHODS

Anti-thrombotic effects of nebivolol and carvedilol were studied in vivo in anaesthetized rats with extracorporeal circulation superfusing collagen strips. We also assessed vasodilation induced by these drugs in isolated perfused guinea pig hearts according to Langendorff's procedures.

RESULTS

Nebivolol (both d- and l-isomers) (0.1-1mgkg(-1)) and carvedilol (1-3mgkg(-1)), but not atenolol (1mgkg(-1)) or labetalol (3mgkg(-1)), induced a dose-dependent and sustained anti-thrombotic response in rat model of thrombosis with extracorporeal circulation. The cyclooxygenase (COX)-2 inhibitors, rofecoxib (1mgkg(-1)) and indomethacin (5mgkg(-1)) abrogated this response, while l-NAME (5mgkg(-1)) had no significant effect. In the presence of β1/β2 adrenoceptor antagonist nadolol (1mgkg(-1)), but not in the presence of selective β1 adrenoceptor antagonist atenolol (4mgkg(-1)), anti-thrombotic responses to nebivolol, as well as carvedilol, were lost. Neither nebivolol nor carvedilol affected platelet aggregation in vitro, however both nebivolol and carvedilol induced NO-dependent vasodilation in guinea pig coronary circulation that was not dependent on β2 adrenoceptors.

CONCLUSIONS

We demonstrated for the first time that nebivolol and carvedilol, independently of their adrenergic receptor blocking activities, induced anti-thrombotic effects in vivo that involved β2 adrenoceptors and the activation of the COX-2/PGI2 pathway.

Differential effects of nebivolol and metoprolol on arterial stiffness, circulating progenitor cells, and oxidative stress

Unlike traditional beta receptor antagonists, nebivolol activates nitric oxide. We hypothesized that therapy with nebivolol compared with metoprolol would improve arterial stiffness, increase levels of circulating progenitor cells (PC), and decrease oxidative stress (OS). In a randomized, double-blind, cross-over study, 30 hypertensive subjects received either once daily nebivolol or metoprolol succinate for 3 months each. Pulse wave velocity and augmentation index were measured using tonometry. Flow cytometry was used to measure circulating PC. OS was measured as plasma aminothiols. Measurements were performed at baseline, and repeated at 3 and 6 months. No significant differences were present between the levels of OS, arterial stiffness, and PC numbers during treatment with metoprolol compared with nebivolol. In subgroup analyses of beta-blocker naïve subjects (n = 19), nebivolol reduced pulse wave velocity significantly compared with metoprolol (-1.4 ± 1.9 vs. -0.1 ± 2.2; P = .005). Both nebivolol and metoprolol increased circulating levels of CD34+/CD133 + PC similarly (P = .05), suggesting improved regenerative capacity.

Clinical utility of fixed-dose combinations in hypertension: evidence for the potential of nebivolol/valsartan

Despite significant advances in pharmacologic approaches to treat hypertension during the last decades, hypertension- and hypertension-related organ damage are still a high health and economic burden because a large proportion of patients with hypertension do not achieve optimal blood pressure control. There is now general agreement that combination therapy with two or more antihypertensive drugs is required for targeted blood pressure accomplishment and reduction of global cardiovascular risk. The goals of combination therapies are to reduce long-term cardiovascular events by targeting different mechanism underlying hypertension and target organ disease, to block the counterregulatory pathways activated by monotherapies, to improve tolerability and decrease the adverse effects of up-titrated single agents, and to increase persistence and adherence with antihypertensive therapy. Multiple clinical trials provide evidence that fixed-dose combinations in a single pill offer several advantages when compared with loose-dose combinations. This review discusses the advances in hypertension control and associated cardiovascular disease as they relate to the prospect of combination therapy targeting a third-generation beta (β) 1-adrenergic receptor (nebivolol) and an angiotensin II receptor blocker (valsartan) in fixed-dose single-pill formulations.

Cardiovascular function and predictors of exercise capacity in patients with colorectal cancer

BACKGROUND

Patients with colorectal cancer (CRC) often present with dyspnea and fatigue. These are also frequent symptoms in patients with chronic heart failure (CHF).

OBJECTIVES

We hypothesized that similar patterns of cardiovascular perturbations are present in CRC and CHF.

METHODS

We prospectively studied 50 patients with CRC, 51 patients with CHF, and 51 control subjects. The CRC group was divided into 2 subgroups: patients who underwent chemotherapy (n = 26) and chemotherapy-naive patients (n = 24). We assessed exercise capacity (spiroergometry), cardiac function (echocardiography), heart rate variability (Holter electrocardiography), body composition (dual-energy x-ray absorptiometry), and blood parameters.

RESULTS

Compared with the control arm, the left ventricular ejection fraction (CRC group 59.4%; control group 62.5%) and exercise performance as assessed by peak oxygen consumption (peak VO2) (CRC group 21.8 ml/kg/min; control group 28.0 ml/kg/min) were significantly reduced in CRC patients (both p < 0.02). Markers of heart rate variability were markedly impaired in CRC patients compared with control subjects (all p < 0.008). Compared with the control group, the CRC group also showed reduced lean mass in the legs and higher levels of the endothelium-derived C-terminal-pro-endothelin-1 (both p < 0.02). Major determinants of cardiovascular function were impaired in chemotherapy-treated patients and in the chemotherapy-naive patients, particularly with regard to exercise capacity, left ventricular ejection fraction, lean mass, and heart rate variability (all p < 0.05 vs. control subjects).

CONCLUSIONS

Some aspects of cardiovascular function are impaired in patients with CRC. More importantly, our findings were evident independently of whether patients were undergoing chemotherapy.

Nebivolol potentiates the efficacy of PDE5 inhibitors to relax corpus cavernosum and penile arteries from diabetic patients by enhancing the NO/cGMP pathway

INTRODUCTION

The efficacy of oral pharmacotherapy for erectile dysfunction (ED) (i.e., type 5 phosphodiesterase[PDE5] inhibitors) is significantly reduced in diabetic patients. Nebivolol is a selective β1-blocker used for treatinghy pertension that has been shown to increase the efficacy of sildenafil to reverse ED in diabetic rats.

AIM

To evaluate the effects of nebivolol on the efficacy of the PDE5 inhibitors, sildenafil, tadalafil, and vardenafil to relax human corpus cavernosum (HCC) and vasodilate human penile resistance arteries (HPRA) from diabetic patients with ED (DMED). The influence of nebivolol on the capacity of these three PDE5 inhibitors to stimulate cyclic guanosine monophosphate (cGMP) production in HCC was also evaluated.

METHODS

HCC and HPRA were obtained from organ donors without ED (NEND; n = 18) or patients with diabetes undergoing penile prosthesis implantation (DMED; n = 19). Relaxations of HCC strips and HPRA to sildenafil,tadalafil, and vardenafil were evaluated in organ chambers and wire myographs. cGMP content in HCC was determined by ether extraction and quantification by ELISA.

MAIN OUTCOME MEASURES

Effects of nebivolol on PDE5 inhibitor-induced relaxation of HCC, vasodilation ofHPRA and cGMP accumulation in HCC.

RESULTS

Treatment with nebivolol (1 μM) significantly potentiated sildenafil-, tadalafil- and vardenafil-induced relaxations of HCC and vasodilations of HPRA from both NEND and DMED. Enhancement of relaxant capacity by nebivolol resulted in reversion of the impairment of PDE5 inhibition-induced responses in DMED and it was accompanied by enhancing the ability of PDE5 inhibitors to increase cGMP in HCC restoring reduced cGMP levelsin HCC from DMED.

CONCLUSIONS

Nebivolol potentiated the capacity of PDE5 inhibitors to relax vascular structures of erectile tissue from diabetic patients by enhancing the nitric oxide (NO)/cGMP pathway in these tissues. These effects suggest a potential therapeutic utility of nebivolol as an adjunct to PDE5 inhibitors for the treatment of ED associated with diabetes.

Functional sympatholysis in hypertension

Sympathetic vasoconstriction is normally attenuated in exercising muscle by local changes in muscle metabolites and other substances that reduce vascular responsiveness to α-adrenergic receptor activation. Termed functional sympatholysis, this protective mechanism is thought to optimize muscle blood flow distribution to match perfusion with metabolic demand. Emerging evidence from both animal and human studies indicate that functional sympatholysis is impaired in hypertension and may constitute an important underlying cause of skeletal muscle malperfusion during exercise in this common cardiovascular condition. Findings from studies of animal models of hypertension and patients with essential hypertension will be integrated in this review to provide insight into the underlying mechanisms responsible for inappropriate sympathetic vasoconstriction in exercising muscle and the treatment options that may restore functional sympatholysis and improve muscle perfusion during exercise.

Treating coronary disease and the impact of endothelial dysfunction

Ischemic heart disease is the leading cause of morbidity and mortality throughout the world. Many clinical trials have suggested that lifestyle and pharmacologic interventions are effective in attenuating atherosclerotic disease progression and events development. However, an individualized approach with careful consideration to comprehensive vascular health is necessary to perform successful intervention strategies. Endothelial dysfunction plays a pivotal role in the early stage of atherosclerosis and is also associated with plaque progression and occurrence of atherosclerotic complications. The assessment of endothelial function provides us with important information about individual patient risk, progress and vulnerability of disease, and guidance of therapy. Thus, the application of endothelial function assessment might enable clinicians to innovate ideal individualized medicine. In this review, we summarize the current knowledge on the impact of pharmacological therapies for atherosclerotic cardiovascular disease on endothelial dysfunction, and argue for the utility of non-invasive assessment of endothelial function aiming at individualized medicine.

β₁-Adrenoceptor stimulation suppresses endothelial IK(Ca)-channel hyperpolarization and associated dilatation in resistance arteries

BACKGROUND AND PURPOSE

In small arteries, small conductance Ca²⁺-activated K⁺ channels (SK(Ca)) and intermediate conductance Ca²⁺-activated K⁺ channels (IK(Ca)) restricted to the vascular endothelium generate hyperpolarization that underpins the NO- and PGI₂-independent, endothelium-derived hyperpolarizing factor response that is the predominate endothelial mechanism for vasodilatation. As neuronal IK(Ca) channels can be negatively regulated by PKA, we investigated whether β-adrenoceptor stimulation, which signals through cAMP/PKA, might influence endothelial cell hyperpolarization and as a result modify the associated vasodilatation.

EXPERIMENTAL APPROACH

Rat isolated small mesenteric arteries were pressurized to measure vasodilatation and endothelial cell [Ca²⁺]i , mounted in a wire myograph to measure smooth muscle membrane potential or dispersed into endothelial cell sheets for membrane potential recording.

KEY RESULTS

Intraluminal perfusion of β-adrenoceptor agonists inhibited endothelium-dependent dilatation to ACh (1 nM-10 μM) without modifying the associated changes in endothelial cell [Ca²⁺]i . The inhibitory effect of β-adrenoceptor agonists was mimicked by direct activation of adenylyl cyclase with forskolin, blocked by the β-adrenoceptor antagonists propranolol (non-selective), atenolol (β₁) or the PKA inhibitor KT-5720, but remained unaffected by ICI 118 551 (β₂) or glibenclamide (ATP-sensitive K⁺ channels channel blocker). Endothelium-dependent hyperpolarization to ACh was also inhibited by β-adrenoceptor stimulation in both intact arteries and in endothelial cells sheets. Blocking IK(Ca) {with 1 μM 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34)}, but not SK(Ca) (50 nM apamin) channels prevented β-adrenoceptor agonists from suppressing either hyperpolarization or vasodilatation to ACh.

CONCLUSIONS AND IMPLICATIONS

In resistance arteries, endothelial cell β₁-adrenoceptors link to inhibit endothelium-dependent hyperpolarization and the resulting vasodilatation to ACh. This effect appears to reflect inhibition of endothelial IK(Ca) channels and may be one consequence of raised circulating catecholamines.

β-Blockers

Objective: To review the pharmacology, pharmacokinetics, and pharmacodynamic properties of commonly used β-blockers (atenolol, carvedilol, metoprolol succinate, metoprolol tartrate, and nebivolol). Data Sources: A MEDLINE literature search (1966-May 2013) was performed using the following key terms: hypertension, β-blockers, atenolol, carvedilol, metoprolol tartrate, metoprolol succinate, nebivolol, pharmacology, pharmacodynamics, pharmacokinetics, blood pressure, metabolic, lipid, central aortic pressure, diabetes, and insulin resistance. References from publications reviewed were included. Study Selection and Data Extraction: English-language articles identified were reviewed. Animal studies and studies in patients for a primary diagnosis of coronary artery disease were excluded. Data Synthesis: β-Blockers are no longer recommended first-line therapy for primary hypertension, based on data showing that β-blockers are inferior to other antihypertensives and no better than placebo, in spite of provision of blood pressure reduction. Because atenolol is the β-blocker used in 75% of these studies, uncertainty about widespread application to all β-blockers exists. Different pharmacological and physiological properties, both within β-blockers and compared with other antihypertensives, may explain divergent effects. Evidence shows that β-blockers have a truncated effect on central aortic pressure, an independent predictor of cardiovascular events, compared with other antihypertensive classes; differences within the class may exist, but the evidence is inconclusive. Metabolic effects differ within the β-blocker class, with evidence that carvedilol causes less metabolic dysregulation. Conclusion: Emerging evidence reveals physiological differences within the β-blocker class and in comparison to other antihypertensives. These differences provide insight into the diverse clinical effects β-blockers provide in cardiovascular disease.

Effects of resveratrol and nebivolol on isolated vascular and cardiac tissues from young rats

The mechanisms by which resveratrol and nebivolol induce vasodilation are not clearly understood. It has been postulated that both agents stimulate the production of nitric oxide; however, this remains to be conclusively established. The major aim of this study was to examine the vasodilatory and antiarrhythmic effects of both resveratrol and nebivolol and to provide further insight into possible mechanisms of action. Cardiac and vascular tissues were isolated from healthy male rodents. Results indicate that resveratrol and nebivolol decrease the action potential duration and induce mild vasorelaxation in aortic and mesenteric segments. Relaxation induced by resveratrol was prevented by the addition of verapamil, N ω -nitro-L-arginine-methyl ester, and 4-aminopyridine. This suggests that nebivolol and resveratrol act as putative antiarrhythmic and vasodilatory agents in vitro through possible indirect nitric oxide mechanisms.

No evidence of nitrate tolerance caused by nebivolol

BACKGROUND

Continuous long-term treatment with nitrates may cause nitrate tolerance. Nebivolol is a highly selective beta1-adrenergic antagonist with additional nitric oxide (NO)-mediated vasodilatory effects. However, there have been no investigations into whether or not the long-term administration of nebivolol might cause nitrate tolerance.

METHODS

We performed a randomized, double-blind, placebo-controlled, cross-over study in 16 healthy men. Subjects received 5 mg nebivolol or placebo once daily for 8 days in random order divided by a drug-free interval of 2 weeks. Forearm blood flow (FBF) was measured by venous occlusion plethysmography 3 h after oral intake of the first and last doses of nebivolol and placebo, respectively. FBF was measured again following the intravenous administration of 4 μg nitroglycerin/kg body weight/min for 5 min.

RESULTS

Following 8 days of continuous intake of placebo, nitroglycerin increased FBF by 54% (p < 0.05), whereas nitroglycerin increased FBF by 96% (p < 0.01) following 8 days of continuous intake of nebivolol, and the increase after 8 days of nebivolol was significantly (p < 0.05) more pronounced than after 8 days of placebo.

CONCLUSIONS

These findings indicate no evidence of nitrate tolerance caused by long-term administration of nebivolol. On the contrary, long-term intake of nebivolol increases rather than decreases the NO-mediated vasodilating effects.

The effect of different β-blockers on vascular graft nitric oxide levels: comparison of nebivolol versus metoprolol

OBJECTIVES

The aim of this study was to investigate the effects of the vasodilating β-blocker nebivolol and the cardioselective β-blocker metoprolol on nitric oxide (NO) levels at vascular graft endothelium and vasa vasorum compared to controls in patients undergoing coronary artery bypass graft surgery.

METHODS

This was a prospective study. Fifty-five patients were divided into three groups: nebivolol group (group N, n = 23), metoprolol group (group M, n = 16), and control group (group A, n = 16). Group N received nebivolol 5 mg once daily, and group M received metoprolol 50 mg once daily for 15 days in the preoperative period. Control patients did not use β-blocker therapy. Tissue samples of both left internal mammary artery (LIMA) and saphenous vein grafts were investigated for NO activity using immunohistochemical methods.

RESULTS

Demographic characteristics and risk factors were similar between groups. We observed the highest NO activity in group N in both endothelial and vasa vasorum samples of LIMA and saphenous veins. NO activity of metoprolol group was similar to controls.

CONCLUSIONS

According to our results, we think that nebivolol may be safer and preferable in order to diminish graft spasm in patients undergoing coronary artery bypass graft surgery due to the NO-mediated vasodilating effect.