The effects of nebivolol on fibrinolytic parameters in mild and moderate hypertensive patients

Potential Protective Role of Blood Pressure-Lowering Drugs on the Balance between Hemostasis and Fibrinolysis in Hypertensive Patients at Rest and During Exercise

In patients with hypertension, the triad represented by endothelial dysfunction, platelet hyperactivity, and altered fibrinolytic function disturbs the equilibrium between hemostasis and fibrinolysis and translates into a hypercoagulable state, which underlies the risk of thrombotic complications. This article reviews the scientific evidence regarding some biological effects of antihypertensive drugs, which can protect patients from the adverse consequences of hypertensive disease, improving endothelial function, enhancing antioxidant activity, and restoring equilibrium between hemostatic and fibrinolytic factors. These protective effects appear not to be mediated through blood pressure reduction and are not shared by all molecules of the same pharmacological class.

Nebivolol, a β1-adrenergic blocker, protects from peritoneal membrane damage induced during peritoneal dialysis

Peritoneal dialysis (PD) is a form of renal replacement treatment, which employs the peritoneal membrane (PM) to eliminate toxins that cannot be removed by the kidney. The procedure itself, however, contributes to the loss of the PM ultrafiltration capacity (UFC), leading consequently to the technique malfunction. β-blockers have been considered deleterious for PM due to their association with loss of UFC and induction of fibrosis. Herein we analyzed the effects of Nebivolol, a new generation of β₁-blocker, on PM alterations induced by PD fluids (PDF).

In vitro: We found that mesothelial cells (MCs) express β₁-adrenergic receptor. MCs were treated with TGF-β to induce mesothelial-to-mesenchymal transition (MMT) and co-treated with Nebivolol. Nebivolol reversed the TGF-β effects, decreasing extracellular matrix synthesis, and improved the fibrinolytic capacity, decreasing plasminogen activator inhibitor-1 (PAI-1) and increasing tissue-type plasminogen activator (tPA) supernatant levels. Moreover, Nebivolol partially inhibited MMT and decreased vascular endothelial growth factor (VEGF) and IL-6 levels in supernatants.

In vivo: Twenty-one C57BL/6 mice were divided into 3 groups. Control group carried a catheter without PDF infusion. Study group received intraperitoneally PDF and oral Nebivolol during 30 days. PDF group received PDF alone. Nebivolol maintained the UFC and reduced PM thickness, MMT and angiogenesis promoted by PDF. It also improved the fibrinolytic capacity in PD effluents decreasing PAI-1 and IL-8 and increased tPA levels.

Conclusion: Nebivolol protects PM from PDF-induced damage, promoting anti-fibrotic, anti-angiogenic, anti-inflammatory and pro-fibrinolytic effects.

Pharmacological modulation of fibrinolytic response - In vivo and in vitro studies

Fibrinolysis is an action of converting plasminogen by its activators, like tissue- or urokinase-type plasminogen activators (t-PA, u-PA), to plasmin, which in turn cleaves fibrin, thereby causing clot dissolution and restoration of blood flow. Endothelial cells release t-PA, prostacyclin (PGI2) and nitric oxide (NO), the potent factors playing a crucial role in regulation of the fibrinolytic system. Since blood platelets can release not only prothrombotic, but also antifibrinolytic factors, like plasminogen activator inhibitor type-1 (PAI-1), they are involved in fibrynolysis regulation. Therefore agents enhancing fibrinolysis can be preferred pharmacologicals in many cardiovascular diseases. This review describes mechanisms by which major cardiovascular drugs (renin-angiotensin-aldosterone system inhibitors, statins, adrenergic receptors and calcium channel blockers, aspirin and 1-methylnicotinamide) influence fibrinolysis. The presented data indicate, that the influence of these drugs on endothelium-blood platelets interactions via NO/PGI2 pathway is fundamental for its antithrombotic and profibrinolytic action. We also described new approaches for intravital confocal real-time imaging as a tool useful to investigate mechanisms of thrombus formation and the effects of drugs affecting haemostasis and mechanisms of their action in the circulation.

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.

Anti-Inflammatory Effects of Hyptis albida Chloroform Extract on Lipopolysaccharide-Stimulated Peritoneal Macrophages

We examined the effects of a chloroform extract of Hyptis albida (CHA) on inflammatory responses in mouse lipopolysaccharide (LPS) induced peritoneal macrophages. Our findings indicate that CHA inhibits LPS-induced production of tumor necrosis factor (TNF- α ) and interleukin-6 (IL-6). During the process, levels of cyclooxygenase-2 (COX-2), nitric oxide synthase (iNOS), and nitric oxide (NO) increased in the mouse peritoneal macrophages; however, the extract suppressed them significantly. These results provide novel insights into the anti-inflammatory actions of CHA and support its potential use in the treatment of inflammatory diseases.

Differential effects of nebivolol and metoprolol on insulin sensitivity and plasminogen activator inhibitor in the metabolic syndrome

Early-generation β-blockers lower blood pressure and reduce cardiovascular morality in coronary artery disease and congestive heart failure but worsen glucose homeostasis and fibrinolytic balance. Nebivolol is a third-generation β-blocker that increases the bioavailability of nitric oxide. We compared the effect of nebivolol (5 mg/d) and the β(1)-selective antagonist metoprolol (100 mg/d) on glucose homeostasis and markers of fibrinolysis in 46 subjects with metabolic syndrome. Subjects underwent a frequently sampled IV glucose tolerance test after 3-week washout and placebo treatment and after randomized treatment with study drug. After 12-week treatment, nebivolol and metoprolol equivalently decreased systolic blood pressure, diastolic blood pressure, and heart rate. Neither drug affected β-cell function, disposition index, or acute insulin response to glucose. Metoprolol significantly decreased the insulin sensitivity index. In contrast, nebivolol did not affect insulin sensitivity, and the decrease in sensitivity was significantly greater after metoprolol than after nebivolol (-1.5±2.5×10(-4)×min(-1) per milliunit per liter versus 0.04±2.19×10(-4)×min(-1) per milliunit per liter after nebivolol; P=0.03). Circulating plasminogen activator inhibitor also increased after treatment with metoprolol (from 9.8±6.8 to 12.3±7.8 ng/mL) but not nebivolol (from 10.8±7.8 to 10.5±6.2 ng/mL; P=0.05 versus metoprolol). Metoprolol, but not nebivolol, increased F(2)-isoprostane concentrations. In summary, treatment with metoprolol decreased insulin sensitivity and increased oxidative stress and the antifibrinolytic plasminogen activator inhibitor 1 in patients with metabolic syndrome, whereas nebivolol lacked detrimental metabolic effects. Large clinical trials are needed to compare effects of nebivolol and the β(1) receptor antagonist metoprolol on clinical outcomes in patients with hypertension and the metabolic syndrome.

Effects of Pegylated Interferon α on Fibrinolytic Parameters in Patients With Chronic Hepatitis C

Interferon (IFN) interacts with endothelial cells and modulates the functions of these cells. In our study, we aimed to determine the effects of treatment with pegylated IFN-α (peg-IFN-α) on fibrinolytic parameters in patients with chronic hepatitis C. Fifteen patients with chronic hepatitis C were treated with peg-IFN-α once per week plus daily oral ribavirin. Euglobulin lysis time (ELT), plasma levels of d-dimer, tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1), and thrombin activatable fibrinolysis inhibitor (TAFI) were determined before treatment, 2 weeks, 1 month, and 3 months after the initiation of the treatment. Plasma levels of t-PA increased significantly 1 month and 3 months after the treatment ( P < .05). The PAI-1 and TAFI levels in 2 weeks, 1 month and 3 months after treatment were not statistically different as compared with pretreatment levels ( P > .05) No significant difference in plasma d-dimer levels was observed during peg-IFN-α treatment ( P > .05). There was a significant decrease in ELT 1 month and 3 months after the treatment ( P < .05). Our results indicated that treatment with peg-IFN-α may be associated with enhanced fibrinolysis,

Modified Si-Miao-San extract inhibits the release of inflammatory mediators from lipopolysaccharide-stimulated mouse macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Modified Si-Miao-San (mSMS) is a prescription modified from Si-Miao-San which is an ancient Chinese prescription used to treat various ailments.

AIM OF THE STUDY

Modified Si-Miao-San (mSMS) has been used for the treatment of infectious and inflammatory disorders in the clinic. This study was aimed to investigate its anti-inflammatory activity and underlying mechanism at cellular and molecular levels.

MATERIALS AND METHODS

We stimulated RAW264.7 cells with Lipopolysaccharide (LPS) and observed effects of mSMS on the release of inflammatory mediators such as: tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), NO, and relative gene expressions. Meanwhile, we also investigated the modulation of mSMS in inflammatory signal transduction mediated through extracellular signal-regulated protein kinase (ERK) and nuclear factor-kappaB (NF-kappaB) pathway.

RESULTS

Our findings demonstrated that mSMS significantly inhibited the excessive production of NO, TNF-alpha and IL-6 and the over expression of relative genes in LPS-stimulated macrophages. In addition, mSMS suppressed LPS-induced ERK1/2-phosphorylation and inhibited the activation of NF-kappaB by attenuation of I kappaB-alpha degradation.

CONCLUSIONS

Our results suggest that the anti-inflammatory properties of mSMS might result from the inhibition of inflammatory mediators, such as NO, TNF-alpha and IL-6, via suppression of ERK and NF-kappaB dependent pathways.

Nebivolol: the somewhat-different beta-adrenergic receptor blocker

Although its clinical use in Europe dates almost 10 years, nebivolol is a beta-blocker that has been only recently introduced in the U.S. market. Like carvedilol, nebivolol belongs to the third generation of beta-blockers, which possess direct vasodilator properties in addition to their adrenergic blocking characteristics. Nebivolol has the highest beta(1)-receptor affinity among beta-blockers and, most interestingly, it substantially improves endothelial dysfunction via its strong stimulatory effects on the activity of the endothelial nitric oxide synthase and via its antioxidative properties. Because impaired endothelial activity is attributed a major causal role in the pathophysiology of hypertension, coronary artery disease, and congestive heart failure, the endothelium-agonistic properties of nebivolol suggest that this drug might provide additional benefit beyond beta-receptor blockade. Although lesser beta-blocker-related side effects have been reported in patients with chronic obstructive pulmonary disease or impotence taking nebivolol, side effects and contraindications overlap those of other beta-blockers. Clinically, this compound has been proven to have antihypertensive and anti-ischemic effects as well as beneficial effects on hemodynamics and prognosis in patients with chronic congestive heart failure. Further studies are now necessary to compare the benefit of nebivolol with that of other drugs in the same class and, most importantly, its prognostic impact in patients with hypertension.

Effects of nebivolol on endothelial gene expression during oxidative stress in human umbilical vein endothelial cells

The endothelium plays a key role in the development of atherogenesis and its inflammatory and proliferative status influences the progression of atherosclerosis. The aim of this study is to compare the effects of two beta blockers such as nebivolol and atenolol on gene expression in human umbilical vein endothelial cells (HUVECs) following an oxidant stimulus. HUVECs were incubated with nebivolol or atenolol (10 micromol/L) for 24 hours and oxidative stress was induced by the addition of oxidized (ox)-LDL. Ox-LDL upregulated adhesion molecules (ICAM-1, ICAM-2, ICAM-3, E-selectin, and P-selectin); proteins linked to inflammation (IL-6 and TNFalpha), thrombotic state (tissue factor, PAI-1 and uPA), hypertension such as endothelin-1 (ET-1), and vascular remodeling such as metalloproteinases (MMP-2, MMP-9) and protease inhibitor (TIMP-1). The exposure of HUVECs to nebivolol, but not to atenolol, reduced these genes upregulated by oxidative stress both in terms of protein and RNA expression. The known antioxidant properties of the third generation beta blocker nebivolol seem to account to the observed differences seen when compared to atenolol and support the specific potential protective role of this beta blocker on the expression of a number of genes involved in the initiation and progression of atherosclerosis.