The effect of angiotensin-converting enzyme inhibition on inflammatory and angiogenic factors in hypercholesterolemia

ACE inhibitors and their interaction with systems and molecules involved in metabolism

The main function of the renin-angiotensin-aldosterone system (RAAS) is the regulation of blood pressure; therefore, researchers have focused on its study to treat cardiovascular and renal diseases. One of the most widely used treatments derived from the study of RAAS, is the use of angiotensin-converting enzyme inhibitors (ACEi). Since it was discovered, the main target of ACEi has been the cardiovascular and renal systems. However, being the RAAS expressed locally in several specialized tissues and cells such as pneumocytes, hepatocytes, spleenocytes, enterocytes, adipocytes, and neurons the effect of inhibitors has expanded, because it is expected that RAAS has a role in the specific function of those cells. Many chronic degenerative diseases compromise the correct function of those organs, and in most of them, the RAAS is overactivated. Therefore, the use of ACEi must exert a benefit on an impaired system. Accordingly, the objective of this review is to present a brief overview of the cardiovascular and renal actions of ACEi and its effects in organs that are not the classic targets of ACEi that carry on glucose and lipid metabolism.

A Randomized, Multicenter, Double-blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of a Quadruple Combination of Amlodipine, Losartan, Rosuvastatin, and Ezetimibe in Patients with Concomitant Essential Hypertension and Dyslipidemia

BACKGROUND

Few data are available regarding the efficacy and safety of a single-pill combination (SPC) consisting of four medications in patients with concomitant hypertension and dyslipidemia.

OBJECTIVE

We aimed to determine the efficacy and tolerability of a fixed-dose SPC consisting of 5 mg amlodipine, 100 mg losartan, 20 mg rosuvastatin, and 10 mg ezetimibe (A/L/R/E) in patients with concomitant hypertension and dyslipidemia.

METHODS

This was a 14-week, randomized, multicenter, double-blind, placebo-controlled, phase III clinical trial. In total, 145 patients were randomized to receive A/L/R/E, A/L, or L/R/E. The primary endpoints were the average change in the low-density lipoprotein cholesterol (LDL-C) level in the A/L/R/E and A/L groups and the sitting systolic blood pressure (sitSBP) in the A/L/R/E and L/R/E groups. The numbers of patients with adverse drug reactions (ADRs) were compared as safety variables.

RESULTS

The average percentage change in the LDL-C level as the least squares mean (LSM) from the baseline LDL-C level at the end of the 8-week treatment was - 59.0% in the A/L/R/E group and 0.2% in the A/L group (LSM difference - 59.2, 95% confidence interval [CI] - 68.1 to - 50.4; p < 0.0001). The average change in the sitSBP as the LSM was - 15.8 mmHg in the A/L/R/E group and -4.7 mmHg in the L/R/E group (LSM difference - 11.1, 95% CI - 16.8 to - 5.4; p = 0.0002). No ADRs occurred in the A/L/R/E group.

CONCLUSIONS

A/L/R/E as an SPC could be an effective treatment for patients with hypertension and dyslipidemia without significant safety issues.

CLINICAL TRIALS REGISTRATION

NCT04074551 (registered 30 August 2019).

Effects of Thymoquinone Alone or in Combination with Losartan on the Cardiotoxicity Caused by Oxidative Stress and Inflammation in Hypercholesterolemia

Dietary cholesterol accelerates oxidative and pro-inflammatory processes, causing hypercholesterolemia and cardiovascular diseases. Thus, the purpose of the current study is to compare the protective effects of thymoquinone (TQ) alone or in combination with losartan (LT) against the heart damage caused by a high-cholesterol diet (HCD). HCD-fed rat groups revealed an elevated activity of indicators of cardiac enzymes in the serum. Serum and cardiac lipids were also found to be significantly higher in HCD-fed rat groups. Cardiac pro-inflammatory and oxidative markers were also increased in HCD-fed rat groups, whereas antioxidant indicators were decreased. However, all of these biochemical, inflammatory, antioxidant, and oxidative change indicators returned to levels similar to those of normal rats after treatment with TQ alone or in combination with LT administered to HCD-fed rat groups. Hypercholesterolemia considerably induced the lipid peroxidation product, thiobarbituric acid reaction substances (TBARs), and oxidative radicals in cardiac cells, which were attenuated by QT and LT treatments, particularly when combined. Finally, QT, LT, and their combination were able to reduce the histological changes changes brought on by cholesterol excess in cardiac tissues. In conclusion, administration of TQ in a combination with LT which has a better protective effect, significantly reduced the hypercholesterolemic-induced oxidative and inflammatory changes that occurred in cardiac tissue.

Renin angiotensin system blockage by losartan neutralize hypercholesterolemia-induced inflammatory and oxidative injuries

Objectives: This study explores the protective role of losartan (LT) against oxidative and inflammatory damages in different physiological systems including heart, liver, and kidney tissue in hypercholesterolemic rats.

Methods: After induction of hypercholesterolemia by high cholesterol diet for 6 weeks, LT was administered for 4 weeks. In serum, the levels of lipoproteins, aminotransferases, creatine kinases, urea, apoptosis, and inflammatory markers were measured. In cardiac, hepatic, and renal tissues, lipid peroxidation product and GSH as well as antioxidant enzymatic activities were assayed. Finally, histopathological assessment evaluated the structural damage in cardiac, hepatic, and renal tissues.

Results: Serum markers of cardiac, hepatic, and renal toxicities including creatine kinases, aminotransferases, and urea were attenuated by LT in hypercholesterolemic animals. Moreover, LT markedly corrected the elevated levels of lipoproteins, apoptosis, and inflammatory biomarkers. Hypercholesterolemia-induced lipid peroxidation, low GSH levels, and diminished activities of antioxidant enzymes were prominently improved in LT treated animals. Histopathological alterations by hypercholesterolemia in heart, liver, and kidney tissues were ameliorated by LT.

Conclusion: This study confirmed the pathological enrollment of renin–angiotensin system in hypercholesterolemia-associated metabolic alterations. LT had a significant cardiac, hepatic, and renal protective role against these impairments through down-regulation of oxidative damage, inflammation and necrosis.

Cardioprotective effects of Fenugreek (Trigonella foenum-graceum) seed extract in streptozotocin induced diabetic rats

Introduction: Inadequate control of diabetes mellitus (DM) leads to considerable cardiovascular implications like diabetic cardiomyopathy (DCM). Cardiomyocyte apoptosis is one of the main mechanisms of DCM pathogenesis associated with hyperglycemia, oxidative stress, inflammation, hyperlipidemia and several other factors. Trigonella foenum-graecum (Fenugreek) has been long used as a traditional medicine and has many therapeutic effects, including anti-diabetic, anti-hyperlipidemia, anti-inflammatory and anti-oxidant properties. The current study aimed to investigate cardioprotective effects of fenugreek seed on diabetic rats. Methods: Diabetes was induced in forty-two male rats by injection of streptozotocin (STZ) (60 mg/ kg). Diabetic animals were treated with three different doses of fenugreek seed extract (50, 100 and 200 mg/kg) or metformin (300 mg/kg) for six weeks by gavage. Nondiabetic rats served as controls. Glucose, cholesterol, and triglycerides levels were measured in the blood samples, and oxidative stress markers as well as gene expression of ICAM1 , Bax and Bcl2 were assessed in the cardiac tissues of the experimental groups. Results: Diabetic rats exhibited increased serum glucose, cholesterol and triglycerides levels, elevated markers of oxidative stress thiobarbituric acid-reacting substances (TBARS) levels , total thiol groups (SH), catalase (CAT) and superoxide dismutase (SOD) activity, and enhanced apoptosis cell death (ratio of Bax/Bcl2). Fenugreek seed extract considerably improved metabolism abnormalities, attenuated oxidative stress and diminished apoptosis index. Conclusion: Our study suggests that fenugreek seed may protect the cardiac structure in STZ-induced diabetic rats by attenuating oxidative stress and apoptosis.

Nigella sativa L. seed regulated eNOS, VCAM-1 and LOX-1 genes expression and improved vasoreactivity in aorta of diabetic rat

ETHNOPHARMACOLOGICAL RELEVANCE

Nigella sativa L. seed has been widely used in traditional medicine for the treatment of diabetes. The major reason for vascular complications in diabetic patients is endothelial dysfunction. However, the impact of N. sativa seed on endothelial dysfunction in diabetes remains unclear.

AIM OF THE STUDY

This study was conducted to evaluate the effect of the hydroalcoholic extract of N. sativa seed on eNOS, VCAM-1, and LOX-1 genes expression and the vasoreactivity of aortic rings to acetylcholine (Ach) in streptozotocin (STZ)-induced diabetic rat.

MATERIALS AND METHODS

Treated rats received N. sativa seed extract (100, 200, and 400 mg/kg) daily by gavage for 6 weeks. The fasting blood glucose and lipids were measured and atherogenic index of plasma (AIP) was calculated. The endothelium-dependent vasoreactivity responses of isolated aortic rings were evaluated in the presence of cumulative concentrations of Ach (10^-8-10^-5 M). eNOS, VCAM-1, and LOX-1 genes expression in aortic tissue was assessed by using real time polymerase chain reaction (PCR).

RESULTS

Male diabetic Wistar rats treated with N. sativa seed extract for six weeks reduced serum glucose and lipids and improved AIP. The vasorelaxant responses of aortic rings to Ach were markedly improved. N. sativa seed significantly increased eNOS in mRNA expression level and function, while it decreased VCAM-1 and LOX-1 expressions in vascular cells of aortic tissue which assessed only in mRNA level.

CONCLUSIONS

The results of this study showed that N. sativa seed more likely, has antidiabetic and antihyperlipidemic properties and improved vasoreactivity, endothelial dysfunction, and vascular inflammation in diabetic rats' aorta.

Angiotensin II induces the aggregation of native and oxidized low-density lipoprotein

Modifications of low-density lipoprotein (LDL), such as oxidation and aggregation, and angiotensin (Ang) peptides are involved in the pathogenesis of atherosclerosis. Here, we investigated the relationship between one of the Ang peptides, AngII, and two LDL modifications, oxidation and aggregation. Using polyacrylamide gel electrophoresis and aggregation assays, we noted that AngII markedly induced the aggregation of LDL and oxidized LDL (Ox-LDL), and bound to both the aggregated and non-aggregated forms. In contrast, a peptide (AngIII) formed by deletion of N-terminal Asp of AngII induced the aggregation of Ox-LDL but not LDL. From tyrosine fluorescence measurements, we noted that AngII interacted with two major lipid components in LDL and Ox-LDL, phosphatidylcholine (PC) and oxidized PC, while AngIII interacted with oxidized PC, but not with PC and lysophosphatidylcholine. Moreover, results from thiobarbituric acid-reactive substances assay proved that AngII did not induce oxidation of LDL. These results suggest that AngII can be involved in the pathogenesis of atherosclerosis by binding to LDL and Ox-LDL-especially to the major lipid components, PC and oxidized PC-followed by inducing the aggregation of LDL and Ox-LDL and that the N-terminal Asp of AngII is important for the binding and aggregation specificity of LDL and Ox-LDL.

Epidemiology and determinants of pruritus in pre-dialysis chronic kidney disease patients

PURPOSE

There are only a few small studies investigating chronic kidney disease-associated pruritus (CKD-P) in pre-dialysis chronic kidney disease (CKD). None of these has taken into account the associations of CKD-P with clinical features and laboratory data. We aimed to study prevalence of and clinical and laboratory associates of CKD-P in pre-dialysis CKD patients.

METHODS

A total of 402 consecutive stage 2-5 pre-dialysis CKD patients were included in this cross-sectional study. Pruritus was scored based on visual analog scale (VAS). Demographic and clinical features, comorbidities, smoking status and current medication use were recorded. 25 (OH) Vitamin D, urea, creatinine, uric acid, calcium, phosphorus, intact parathyroid hormone (PTH), magnesium, albumin, C-reactive protein (CRP), complete blood count and differential and other laboratory tests were studied for each participant.

RESULTS

This is the largest study conducted in pre-dialysis population with respect to pruritus and associated factors. The prevalence of CKD-P was 18.9%. Hemoglobin level was significantly lower, and eosinophil count and frequency of xerosis cutis were significantly higher in patients with CKD-P than those of patients without pruritus. However, there was no statistical difference between the pruritus and nonpruritus groups regarding vitamin D, PTH, calcium, phosphorus, neutrophil-to-lymphocyte ratio (NLR) and CRP.

CONCLUSIONS

CKD-P was almost present in one in every five pre-dialysis CKD patients. Interestingly, the prevalence was not affected by the stage of the CKD. For the first time, our results showed a significant association between CKD-P and peripheral eosinophilia and anemia. Besides this, xerosis cutis seems a determinant factor for CKD-P and its severity.