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As prodrugs series of new sartan-derived molecules were designed, synthesized, and evaluated. Most of the synthesized compounds could decrease blood pressure efficiently in spontaneously hypertensive rats. It could be ratiocinated that the original drugs could be released from the prodrugs exactly at the connecting position catalyzed by the hydrolyzation enzymes. The maximal response of mean blood pressure (MBP) lowered 70.2 ± 5.0 mmHg (compound I1) and 61.2 ± 1.0 mmHg (compound II1) at 10 mg/kg after oral administration, and the antihypertensive effect lasted beyond 24 h, which performed better than Losartan and were similar with Telmisartan. Pharmacokinetics test results of I1 were consistent with its antihypertension effects in vivo. The safety was confirmed by the influence on the rats' heart rates and other symptoms which could not be observed during the whole process. Therefore, compounds I1 and II1 could be considered potential antihypertension drug candidates. [ABSTRACT FROM AUTHOR]

Growing evidence has highlighted that angiotensin-converting enzyme (ACE)-inhibitors (ACEi)/AT1 receptor blockers (ARBs) may influence the complex interplay between dopamine and the renin-angiotensin system in the nigrostriatal pathway, thus affecting the development of levodopa-induced dyskinesia in Parkinson's disease (PD). In the present study, we analyzed whether the use of this class of medication was associated with a reduced occurrence of levodopa-induced dyskinesia, using electronically-stored information of idiopathic PD patients enrolled at Novara University Hospital “Maggiore della Carità". We conducted a retrospective case-control study identifying PD patients with dyskinesias (PwD; n = 47) as cases. For each PwD we selected a non-dyskinetic control (NoD), nearly perfectly matched according to sex, Unified Parkinson's Disease Rating Scale (UPDRS) part III score, and duration of antiparkinsonian treatment. Binary logistic regression was used to evaluate whether dyskinesias were associated with ACEi/ARBs use. Ninety-four PD patients were included, aged 72.18 ± 9 years, with an average disease duration of 10.20 ± 4.8 years and 9.04 ± 4.9 years of antiparkinsonian treatment. The mean UPDRS part III score was 18.87 ± 7.6 and the median HY stage was 2. In the NoD group, 25 (53.2%) were users and 22 (46.8%) non-users of ACEi/ARBs. Conversely, in the PwD group, 11 (23.4%) were users and 36 non-users (76.6%) of this drug class (Pearson chi-square = 8.824, P = 0.003). Concerning general medication, there were no other statistically significant differences between groups. After controlling for tremor dominant phenotype, levodopa equivalent daily dose, HY 3-4, and disease duration, ACEi/ARBs use was a significant predictor of a lower occurrence of dyskinesia (OR = 0.226, 95% CI: 0.080-0.636, P = 0.005). Therefore, our study suggests that ACEi/ARBs may reduce levodopa-induced dyskinesia occurrence and, thanks to good tolerability and easy management, represent a feasible choice when dealing with the treatment of hypertension in PD patients. The study was approved by the Ethics Committee of Novara University Hospital “Maggiore della Carità” (CE 65/16) on July 27, 2016.

In the present work, a facile and efficient route for the synthesis of a series of N-substituted imidazole derivatives is described. Docking studies have revealed that N-substituted imidazole derivatives based on (E)-urocanic acid may be potential antihypertensive leads. Therefore, new AT1 receptor blockers bearing either the benzyl or the biphenylmethyl moiety at the N-1 or N-3 position, either the (E)-acrylate or the propanoate fragment and their related acids at the C-4 position as well as a halogen atom at the C-5 position of the imidazole ring, were synthesized. The newly synthesized analogues were evaluated for binding to human AT1 receptor. The biological results showed that this class of molecules possesses moderate or no activity, thus not always confirming high docking scores. Nonetheless, important conclusions can be derived for their molecular basis of their mode of action and help medicinal chemists to design and synthesize more potent ones. An aliphatic group as in losartan seems to be important for enhancing binding affinity and activity.

In the present work, a facile and efficient route for the synthesis of a series of N-substituted imidazole derivatives is described. Docking studies have revealed that N-substituted imidazole derivatives based on (E)-urocanic acid may be potential antihypertensive leads. Therefore, new AT1 receptor blockers bearing either the benzyl or the biphenylmethyl moiety at the N-1 or N-3 position, either the (E)-acrylate or the propanoate fragment and their related acids at the C-4 position as well as a halogen atom at the C-5 position of the imidazole ring, were synthesized. The newly synthesized analogues were evaluated for binding to human AT1 receptor. The biological results showed that this class of molecules possesses moderate or no activity, thus not always confirming high docking scores. Nonetheless, important conclusions can be derived for their molecular basis of their mode of action and help medicinal chemists to design and synthesize more potent ones. An aliphatic group as in losartan seems to be important for enhancing binding affinity and activity. [ABSTRACT FROM AUTHOR]

Abstract: A series of symmetrically bis-substituted imidazole analogs bearing at the N-1 and N-3 two biphenyl moieties ortho substituted either with tetrazole or carboxylate functional groups was designed based on docking studies and utilizing for the first time an extra hydrophobic binding cleft of AT1 receptor. The synthesized analogs were evaluated for their in vitro antagonistic activities (pA2 values) and binding affinities (–logIC50 values) to the Angiotensin II AT1 receptor. Among them, the potassium (–logIC50 = 9.04) and the sodium (–logIC50 = 8.54) salts of 4-butyl-N,N′-bis{[2′-(2H-tetrazol-5-yl)biphenyl-4-yl]methyl}imidazolium bromide (12a and 12b, respectively) as well as its free acid 11 (–logIC50 = 9.46) and the 4-butyl-2-hydroxymethyl-N,N′-bis{[2′-(2H-tetrazol-5-yl)biphenyl-4-yl]methyl}imidazolium bromide (14) (–logIC50 = 8.37, pA2 = 8.58) showed high binding affinity to the AT1 receptor and high antagonistic activity (potency). The potency was similar or even superior to that of Losartan (–logIC50 = 8.25, pA2 = 8.25). On the contrary, 2-butyl-N,N′-bis{[2′-[2H-tetrazol-5-yl)]biphenyl-4-yl]methyl}imidazolium bromide (27) (–logIC50 = 5.77) and 2-butyl-4-chloro-5-hydroxymethyl-N,N′-bis{[2′-[2H-tetrazol-5-yl)]biphenyl-4-yl]methyl}imidazolium bromide (30) (–logIC50 = 6.38) displayed very low binding affinity indicating that the orientation of the n-butyl group is of primary importance. Docking studies of the representative highly active 12b clearly showed that this molecule has an extra hydrophobic binding feature compared to prototype drug Losartan and it fits to the extra hydrophobic cavity. These results may contribute to the discovery and development of a new class of biologically active molecules through bis-alkylation of the imidazole ring by a convenient and cost effective synthetic strategy. [Copyright &y& Elsevier]

Background. The mechanisms of uraemia-induced atherosclerosis have not been fully delineated. The aims of this study were (i) to investigate the extent and the phenotype of atherosclerosis, including the activation of local renin–angiotensin system (RAS), in a mouse model of mild uraemia and (ii) to determine the effects of angiotensin II type1 (AT1) receptor blockade on the uraemic atherosclerosis, clarifying the mechanisms of its action.Methods. Mild uraemia was induced by 5/6 nephrectomy in 8-week-old apo E-deficient mice (apoE-KO). After nephrectomy, the animals received either treatment with candesartan or no treatment for 12-weeks. Sham-operated apoE-KO mice were used as controls.Results. Uraemia led to a two-fold increase in aortic plaque area. This was associated with a significant upregulation of aortic angiotensin-converting enzyme (ACE), AT1 receptor, connective tissue growth factor (CTGF), monocyte chemoattractant protein (MCP)-1 and vascular cell adhesion molecule (VCAM)-1. Candesartan significantly reduced aortic atherosclerosis, prevented the upregulation of the uraemia-induced genes and led to changes predicting greater stability of the plaques, without influencing blood pressure or serum lipids.Conclusions. This study indicates that uraemia leads to an acceleration of aortic atherosclerosis. The upregulation of aortic RAS and the reduced atherosclerosis following AT1 receptor blocker treatment highlights the pivotal role of the local RAS in the development and acceleration of atherosclerosis in uraemia. [ABSTRACT FROM AUTHOR]

Sanguinarine is an alkaloid found in many medicinal plants. It has diverse biological activities, including modulation of nuclear factor-κB and of several enzymes. It is also known to induce apoptosis, perturb microtubules, and to have antimicrobial effects. This article reviews its cardiovascular properties, including hypotensive, antiplatelet, and positive inotropic effects. Its pharmacokinetics, and toxicology, including its carcinogenic potential, are also discussed. Further pharmacological and toxicological studies with sanguinarine are needed before its therapeutic use can be considered. [ABSTRACT FROM AUTHOR]

Summary: Evidence that renin system blockade is useful in many patients with hypertension is overwhelming. Two recent lines of investigation have suggested that more complete blockade leads to improved clinical outcomes. One line of investigation involves the use of a combination of an angiotensin-converting enzyme inhibitor with an angiotensin-receptor blocker. The second line of investigation involves the use of very high dose angiotensin-receptor blocker. The interaction of renin with substrate is the rate-limiting step in the renin cascade; thus, the recent development of a powerful renin inhibitor also favors more complete blockade of the system. In many patients, this is likely to lead to improved treatment. [ABSTRACT FROM AUTHOR]

The angiotensin II (type 1) (AT1) receptor mediates many biological effects of the renin–angiotensin system (RAS), leading to remodelling of cardiac tissue. The present study was designed to analyse changes in the function and expression of the AT1 receptor as principal effector of the RAS in myocardium from type 2 diabetic patients compared with non-diabetic myocardium as control. In addition, we determined the effect of treatment with ACE inhibitors or AT1 receptor blockers on expression levels of the receptor in diabetic patients. Gene expression of the AT1 receptor was analysed by quantitative RT-PCR and protein expression was determined by immunoblot analysis in human right atrial myocardium. We investigated functional coupling of the receptors by measuring contractility in isolated trabeculae stimulated with increasing concentrations of angiotensin II. Diabetic myocardium showed a significant increase in protein expression (170 ± 16% of control) and median mRNA expression (186% of control) of the AT1 receptor. The additional receptors were functionally coupled, resulting in a stronger inotropic response upon stimulation with angiotensin II (89 ± 5.5% vs 29 ± 1.6% in controls), whereas receptor affinity was similar in both groups. However, myocardium from diabetic patients treated with ACE inhibitors or AT1 receptor blockers showed no increase in AT1 receptor expression. AT1 receptor expression in myocardium of type 2 diabetic patients is dynamic, depending on the level of glycaemic control and the activity of the RAS. These findings could at least in part explain the strong therapeutic benefit of RAS inhibition in diabetic patients. [ABSTRACT FROM AUTHOR]

Atherosclerotic plaque rupture is promoted by metalloproteinase (MMP)-2 and MMP-9, enzymes that degrade the fibrous cap leading to plaque erosion. MMP biosynthesis is mediated by prostaglandin (PG)E2, the product of cyclooxygenase (COX)-2/inducible PGE synthase (mPGES) activity. We have recently reported the overexpression of COX-2/mPGES-1 in vulnerable plaques as a basis of MMP-mediated plaque instability. Hypercholesterolemia and hypertension are two important risk factors for atherosclerosis. Recent trial showed that statins and AT1 receptor blockers significantly reduce the incidence of cardiovascular events in humans. Since anti-inflammatory effects have been reported in association to therapy with statins or AT1 receptor blockers, in two different studies we hypothesized that these drugs can stabilize atherosclerotic plaques through modulation of COX-2/mPGES-1-dependent MMP biosynthesis. Our data demonstrated the stabilizing effect of atherosclerotic plaques by simvastatin or irbesartan, that is due, at least in part, to the reduction of inflammatory burden and suppression of PGE2-dependent metalloproteinases release. [ABSTRACT FROM AUTHOR]

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Growing evidence has highlighted that angiotensin-converting enzyme (ACE)-inhibitors (ACEi)/AT1 receptor blockers (ARBs) may influence the complex interplay between dopamine and the renin-angiotensin system in the nigrostriatal pathway, thus affecting the development of levodopa-induced dyskinesia in Parkinson's disease (PD). In the present study, we analyzed whether the use of this class of medication was associated with a reduced occurrence of levodopa-induced dyskinesia, using electronically-stored information of idiopathic PD patients enrolled at Novara University Hospital "Maggiore della Carità". We conducted a retrospective case-control study identifying PD patients with dyskinesias (PwD; n = 47) as cases. For each PwD we selected a non-dyskinetic control (NoD), nearly perfectly matched according to sex, Unified Parkinson's Disease Rating Scale (UPDRS) part III score, and duration of antiparkinsonian treatment. Binary logistic regression was used to evaluate whether dyskinesias were associated with ACEi/ARBs use. Ninety-four PD patients were included, aged 72.18 ± 9 years, with an average disease duration of 10.20 ± 4.8 years and 9.04 ± 4.9 years of antiparkinsonian treatment. The mean UPDRS part III score was 18.87 ± 7.6 and the median HY stage was 2. In the NoD group, 25 (53.2%) were users and 22 (46.8%) non-users of ACEi/ARBs. Conversely, in the PwD group, 11 (23.4%) were users and 36 non-users (76.6%) of this drug class (Pearson chi-square = 8.824, P = 0.003). Concerning general medication, there were no other statistically significant differences between groups. After controlling for tremor dominant phenotype, levodopa equivalent daily dose, HY 3-4, and disease duration, ACEi/ARBs use was a significant predictor of a lower occurrence of dyskinesia (OR = 0.226, 95% CI: 0.080-0.636, P = 0.005). Therefore, our study suggests that ACEi/ARBs may reduce levodopa-induced dyskinesia occurrence and, thanks to good tolerability and easy management, represent a feasible choice when dealing with the treatment of hypertension in PD patients. The study was approved by the Ethics Committee of Novara University Hospital "Maggiore della Carità" (CE 65/16) on July 27, 2016., Competing Interests: None

• Series of new AT 1 antagonists were designed and synthesized. • 1g and 2a could lowered the blood pressure of SHR obviously over 24 h in vivo. • 1g and 2a may be considered as potent and long-lasting anti-hypertension drug candidates. A series of new fluoro-substituted benzimidazole derivatives were designed, synthesized and pharmacologically evaluated. All the target compounds were characterized by 1HNMR, 13CNMR, mass spectra and elemental analysis. The biological evaluation showed that most of the synthesized compounds displayed nanomolar affinity to the angiotensin II type 1 (AT 1) receptor and could decrease blood pressure efficiently in spontaneously hypertensive rats. The maximal response of mean blood pressure (MBP) lowered 74.5 ± 3.5 mmHg (1g) and 69.2 ± 0.9 mmHg (2a) at 10 g/kg after oral administration, and the antihypertensive effect lasted beyond 24 h, which performed better than both losartan and telmisartan. So, compounds 1g and 2a may be considered as potential antihypertension drug candidates. [ABSTRACT FROM AUTHOR]

A series of new 6-substituted aminocarbonyl benzimidazole derivatives with 1, 4-disubsituted or 1, 5-disubsituted indole moiety and benzoic acid moiety were designed, synthesized and pharmacologically evaluated. Most of the synthesized compounds could bind to the AT 1 receptor and decrease blood pressure significantly. Notably, 2e and 1h could obviously decrease MBP in a dose dependent manner. The maximal response lowered 57.9 ± 2.3 mmHg (2e) and 57.6 ± 1.9 mmHg (1h) of MBP at 10 mg/kg after oral administration, and the antihypertensive effect lasted beyond 24 h, which performed better than Losartan (Fig. 1). These results indicate that 2e and 1h are effective and long-lasting anti-hypertension drug candidates and deserve further investigation for therapeutic application. Compounds 1h and 2e have a high affinity to AT 1 receptor and efficient anti-hypertensive effect. Image 1 • A series of new 6-substituted aminocarbonyl benzimidazoles derivatives with 1, 4-disubsituted or 1, 5-disubsituted indole moiety and benzoic acid moiety were designed and synthesized. • Remarkably compounds 1h and 2e displayed the highest specific affinity to the AT 1 receptor with the IC 50 value of 2.3 ± 0.9 nM and the Ki value of 1.9 ± 0.8 nM. • Notably, 2e and 1h were much more potent compounds with maximal reducing response 57.9 ± 2.3 mmHg and 57.6 ± 1.9 mmHg of MBP separately at 10 mg/kg after oral administration. [ABSTRACT FROM AUTHOR]

NO produced by eNOS plays important roles in the cardiovascular system. Alterations in eNOS activity and expression occur in various cardiovascular disorders and eNOS constitutes a therapeutic target. In addition to posttranslational modifications of eNOS that affect eNOS activity, transcriptional and post-transcriptional regulation of eNOS expression also controls eNOS-derived NO production. Bradykinin is an important determinant of vascular function and participates in the regulation of eNOS activity and expression. A number of currently used drugs or investigational molecules targeting specific ion channels, enzymes or receptors, including dihydropyridine calcium channel blockers, angiotensin-converting enzyme inhibitors, statins, AT1 receptor blockers and angiotensin-(1-7), increase eNOS expression and activity. In this context, activation of bradykinin B2 receptors appears to be a common step for these drugs to promote eNOS expression, which certainly contributes to their therapeutic actions., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

In this review, we discuss the pharmacological and clinical properties of irbesartan, a noncompetitive angiotensin II receptor type 1 antagonist, successfully used for more than a decade in the treatment of essential hypertension. Irbesartan exerts its antihypertensive effect through an inhibitory effect on the pressure response to angiotensin II. Irbesartan 150-300 mg once daily confers a lasting effect over 24 hours, and its antihypertensive efficacy is further enhanced by the coadministration of hydrochlorothiazide. Additionally and partially beyond its blood pressure-lowering effect, irbesartan reduces left ventricular hypertrophy, favors right atrial remodeling in atrial fibrillation, and increases the likelihood of maintenance of sinus rhythm after cardioversion in atrial fibrillation. In addition, the renoprotective effects of irbesartan are well documented in the early and later stages of renal disease in type 2 diabetics. Furthermore, both the therapeutic effectiveness and the placebo-like side effect profile contribute to a high adherence rate to the drug. Currently, irbesartan in monotherapy or combination therapy with hydrochlorothiazide represent a rationale pharmacologic approach for arterial hypertension and early-stage and late-stage diabetic nephropathy in hypertensive type II diabetics.