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

A Critical Review of Nebivolol and its Fixed-Dose Combinations in the Treatment of Hypertension

β-Adrenergic receptor blockers (β-blockers) are well-known useful and cost-effective drugs for managing hypertensive patients with coronary heart disease, stroke, and heart failure. However, it is often difficult to use β-blockers for patients with asthma or chronic obstructive pulmonary disease (COPD). Moreover, most β-blockers negatively influence glucose or lipid metabolism. Nebivolol is a third-generation lipophilic β-1 receptor-selective blocker with nitric oxide-mediated vasodilatory effects, metabolically neutral and usually well tolerated by patients with asthma or COPD. Nebivolol has significant effects of reduction in central blood pressure and improvements in endothelial dysfunction and arterial stiffness. To summarize the merits and demerits of nebivolol in different clinical situations, we conducted a review using the word 'nebivolol' on Pubmed and Embase, limiting the search to hypertension, clinical trials, and meta-analyses. This review summarizes the clinical studies on nebivolol itself and on the combination of nebivolol with other antihypertensive drugs, such as hydrochlorothiazide, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and amlodipine. Most studies showed the safety and well-tolerated profile of nebivolol and the combination of nebivolol with other antihypertensive drugs, which suggests that new fixed combinations of nebivolol with other antihypertensive drugs would be useful for patients who are unable to tolerate traditional β-blockers.

Beta-blockers: Historical Perspective and Mechanisms of Action

Beta-blockers are widely used molecules that are able to antagonize β-adrenergic receptors (ARs), which belong to the G protein-coupled receptor family and receive their stimulus from endogenous catecholamines. Upon β-AR stimulation, numerous intracellular cascades are activated, ultimately leading to cardiac contraction or vascular dilation, depending on the relevant subtype and their location. Three subtypes have been described that are differentially expressed in the body (β₁-, β₂- and β₃-ARs), β₁ being the most abundant subtype in the heart. Since their discovery, β-ARs have become an important target to fight cardiovascular disease. In fact, since their discovery by James Black in the late 1950s, β-blockers have revolutionized the field of cardiovascular therapies. To date, 3 generations of drugs have been released: nonselective β-blockers, cardioselective β-blockers (selective β₁-antagonists), and a third generation of these drugs able to block β₁ together with extra vasodilation activity (also called vasodilating β-blockers) either by blocking α₁- or by activating β₃-AR. More than 50 years after propranolol was introduced to the market due to its ability to reduce heart rate and consequently myocardial oxygen demand in the event of an angina attack, β-blockers are still widely used in clinics.

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.