Angiotensin II receptor antagonists

Identification of angiotensin II-responsive circadian clock gene expression in adrenal zona glomerulosa cells and human adrenocortical H295R cells

The mammalian circadian timing system is organized in a hierarchy, with the master clock residing in the suprachiasmatic nucleus (SCN) of the hypothalamus and subsidiary peripheral clocks in peripheral tissues. Because of the diversity of peripheral tissues and cell-types in the body, the existence of autonomous clock and identification of its potential entrainment signals need to be empirically defined on a cell type-by-cell type basis. In this study, we characterized the basic circadian clock properties of the adrenal zona glomerulosa cells, or ZG cells. Using isolated adrenal explants from Per2Luc mice, dissociated ZG cells from Per2-dluc rats, and a related human adrenocortical cell line H295R, we showed that ZG cells possess genetically-encoded, self-sustained and cell-autonomous circadian clock. As to the potential entrainment signals, angiotensin II (Ang II) caused phase-dependent phase-shifts of adrenal ZG cells in cultured slices. Ang II treatment also drove initiation (or reset) of circadian clock gene expression in H295R cells with associated immediate up-regulation of PER1 and E4BP4 mRNA expression. We found that the type I Ang II receptor blocker CV11974, one of the most widely used clinical drugs for hypertensive diseases, caused attenuation of the phase resetting of H295R cells. Our in vitro data provide a basis to understand and argue for the adrenal gland ZG cells as a component of autonomous and entrainable peripheral clocks.

High-Throughput Screening for Prescribing Cascades Among Real-World Angiotensin-II Receptor Blockers (ARBs) Initiators

Objective

Angiotensin-II Receptor Blockers (ARBs) are commonly prescribed; however, their adverse events may prompt new drug prescription(s), known as prescribing cascades. We aimed to identify potential ARB-induced prescribing cascades using high-throughput sequence symmetry analysis.

Methods

Using claims data from a national sample of Medicare beneficiaries (2011-2020), we identified new ARB users aged ≥66 years with continuous enrollment ≥360 days before and ≥180 days after ARB initiation. We screened for initiation of 446 other (non-antihypertensive) 'marker' drug classes within ±90 days of ARB initiation, generating sequence ratios (SRs) reflecting proportions of ARB users starting the marker class after versus before ARB initiation. Adjusted SRs (aSRs) accounted for prescribing trends over time, and for significant aSRs, we calculated the naturalistic number needed to harm (NNTH); significant signals were reviewed by clinical experts for plausibility.

Results

We identified 320,663 ARB initiators (mean ± SD age 76.0 ± 7.2 years; 62.5% female; 91.5% with hypertension). Of the 446 marker classes evaluated, 17 signals were significant, and three (18%) were classified as potential prescribing cascades after clinical review. The strongest signals ranked by the lowest NNTH included benzodiazepine derivatives (NNTH 2130, 95% CI 1437-4525), adrenergics in combination with anticholinergics, including triple combinations with corticosteroids (NNTH 2656, 95% CI 1585-10074), and other antianemic preparations (NNTH 9416, 95% CI 6606-23784). The strongest signals ranked by highest aSR included other antianemic preparations (aSR 1.7, 95% CI 1.19-2.41), benzodiazepine derivatives (aSR 1.18, 95% CI 1.08-1.3), and adrenergics in combination with anticholinergics, including triple combinations with corticosteroids (aSR 1.12, 95% CI 1.03-1.22).

Conclusion

The identified prescribing cascade signals reflected known and possibly under-recognized ARB adverse events in this Medicare cohort. These hypothesis-generating findings require further investigation to determine the extent and impact of these prescribing cascades on patient outcomes.

Valsartan: An Angiotensin Receptor Blocker Modulates BDNF Expression and Provides Neuroprotection Against Cerebral Ischemic Reperfusion Injury

AT1 receptor blockers (ARBs) are commonly used drugs to treat cardiovascular disease and hypertension, but research on their impact on brain disorders is unattainable. Valsartan (VAL) is a drug that specifically blocks AT1 receptor. Despite the previous evidence for VAL to provide neuroprotection in case of ischemic reperfusion injury, evaluation of their potential in mitigating mitochondrial dysfunction that causes neuronal cell death and neurobehavioral impairment remains unknown. The aim of this study was to evaluate the therapeutic effect of repurposed drug VAL against ischemic reperfusion injury-induced neuronal alternation. tMCAO surgery was performed to induce focal cerebral ischemic reperfusion injury. Following ischemic reperfusion injury, we analyzed the therapeutic efficacy of VAL by measuring the infarct volume, brain water content, mitochondrial oxidative stress, mitochondrial membrane potential, histopathological architecture, and apoptotic marker protein. Our results showed that VAL administrations (5 and 10 mg/kg b.wt.) mitigated the brain damage, enhanced neurobehavioral outcomes, and alleviated mitochondrial-mediated oxidative damage. In addition to this, our findings demonstrated that VAL administration inhibits neuronal apoptosis by restoring the mitochondrial membrane potential. A follow-up investigation demonstrated that VAL induces BDNF expression and promoted ischemic tolerance via modulating the Akt/p-Creb signaling pathway. In summary, our results suggested that VAL administration provided neuroprotection, ameliorated mitochondrial dysfunction, preserved the integrity of neurons, and lead to functional improvement after ischemic reperfusion injury.

RENIN AND ANGIOTENSIN (1-7) OFFER PREDICTIVE VALUE IN PEDIATRIC SEPSIS: FINDINGS FROM PROSPECTIVE OBSERVATIONAL COHORTS

ABSTRACT

Background: Pediatric sepsis is a common and complex syndrome characterized by a dysregulated immune response to infection. Aberrations in the renin-angiotensin system (RAS) are factors in several infections of adults. However, the precise impact of RAS dysregulation in pediatric sepsis remains unclear. Methods: Serum samples were collected from a derivation cohort (58 patients with sepsis, 14 critically ill control subjects, and 37 healthy controls) and validation cohort (50 patients with sepsis, 37 critically ill control subjects, and 46 healthy controls). Serum RAS levels on day of pediatric intensive care unit admission were determined and compared with survival status and organ dysfunction. Results: In the derivation cohort, the serum renin concentration was significantly higher in patients with sepsis (3,678 ± 4,746) than that in healthy controls (635.6 ± 199.8) ( P < 0.0001). Meanwhile, the serum angiotensin (1-7) was significantly lower in patients with sepsis (89.7 ± 59.7) compared to that in healthy controls (131.4 ± 66.4) ( P < 0.01). These trends were confirmed in a validation cohort. Nonsurvivors had higher levels of renin (8,207 ± 7,903) compared to survivors (2,433 ± 3,193) ( P = 0.0001) and lower levels of angiotensin (1-7) (60.9 ± 51.1) compared to survivors (104.0 ± 85.1) ( P < 0.05). A combination of renin, angiotensin (1-7) and procalcitonin achieved a model for diagnosis with an area under the receiver operating curve of 0.87 (95% CI: 0.81-0.92). Conclusion: Circulating renin and angiotensin (1-7) have predictive value in pediatric sepsis.

Antihypertensive drug-associated adverse events in osteoarthritis: a study of a large real-world sample based on the FAERS database

Background

Hypertension is a common complication in patients with osteoarthritis (OA). There is increasing interest in the relationship between hypertension and OA. However, hypertension has been reported to negatively affect symptoms and quality of life in patients with OA. Therefore, treating hypertension is crucial for patients with OA. However, there is a lack of real-world studies on the effects of medications for treating hypertension on OA.

Methods

Data from the FAERS database from January 2004 to December 2023 were extracted for disproportionality analyses, and proportional reporting ratios (PRRs) were used to assess the association between medications for hypertension and all types of arthritis. Adverse event signals were identified and determined using reporting odds ratios (RORs) Adverse event signals were considered to have occurred if a drug-induced adverse event was recorded more than or equal to 3 and the lower limit of the ROR confidence interval was more than 1. We selected five classes of drugs including, calcium channel blockers (CCBs), angiotensin converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), thiazide diuretics and β-blockers and representative drugs were analysed for osteoarthritis-related adverse reactions, and age and gender subgroups were analysed for drugs of significance. We also analysed the occurrence of AEs in relation to time using the Weibull distribution.

Results

In terms of overall data, we found significant OA adverse reaction signals only for ARBs among the five drug classes.ARB AEs for spinal osteoarthritis (ROR 4.64, 95% CI 3.62-5.94), osteoarthritis (ROR 3.24 95% CI 2.82-3.72) and gouty arthritis (ROR 3.27 95% CI 1.22-8.75) were the three adverse reactions with the loudest signals. Next, we found that valsartan had strong osteoarthritis adverse reaction signals among the three ARBs, namely, irbesartan, cloxartan, and valsartan. We also analysed age and gender subgroups and found that osteoarthritis signals were strongest in the 18-65 and 65+ population, while females seem to be more prone to valsartan-related OA AEs.

Conclusion

ARBs, especially valsartan, have significant positive signals for OA AEs. Therefore, ARB drugs, especially valsartan, should be used with caution when treating patients with OA combined with hypertension.

Inhibitory Effects of Naringenin on LPS-Induced Skin Inflammation by NF-κB Regulation in Human Dermal Fibroblasts

Flavonoids are important natural compounds characterized by their extensive biological activities. Citrus flavonoids represent a significant segment of the broader flavonoid category. Naringenin, an integral part of this series, is recognized for its powerful anti-inflammatory and antioxidant properties. In addition, considering the lack of existing research on naringenin's potential effectiveness and intracellular mechanisms of action in skin-related applications, especially as a cosmetic ingredient, this study aimed to explore naringenin's role in reducing the fundamental generation of reactive oxygen species. This was achieved by examining its inhibitory effects on the expression levels of NADPH oxidase and iNOS, ultimately leading to a reduction in NO production. This research examined the anti-inflammatory and antioxidant capacities of naringenin by employing a cellular senescence model of LPS-induced HDFs. The evaluation of naringenin's efficacy was validated through several investigative procedures, including the NF-κB luciferase assay, ELISA assay, and qRT-PCR. To verify the anti-inflammatory effectiveness of naringenin, we measured the responsive elements of NF-κB using a luciferase reporter assay. This assessment revealed that naringenin could decrease the concentration of genes activated by NF-κB. Moreover, we found that naringenin inhibited the transcriptional expression of known NF-κB-regulated inflammatory cytokines, including IL-1β, IL-6, and IL-8. In addition, results from the qRT-PCR analysis indicated that naringenin facilitated a reduction in iNOS expression. Based on the data gathered and analyzed in this study, it can be conclusively inferred that naringenin possesses promising potential as a cosmetic ingredient, offering both anti-inflammatory and antioxidant benefits.

Efficacy and safety of azilsartan medoxomil in the treatment of hypertension: a systematic review and meta-analysis

Background

Angiotensin II receptor blockers (ARBs) are utilized for the management of hypertension and diabetes. Previous meta-analyses suggested that azilsartan medoxomil (AZL-M) improved blood pressure (BP) reduction, but there were no safety findings or suggestions for patients with hypertension or diabetes.

Methods

We performed an efficacy and safety meta-analysis of randomized controlled trials (RCTs) evaluating AZL-M therapy for reducing BP in patients with hypertension. Patients with hypertension complicated by diabetes were analyzed. The relevant literature was searched in English and Chinese databases for RCTs involving AZL-M in hypertension. Efficacy variables included the change from baseline in the 24-h mean systolic/diastolic BP measured by ambulatory BP monitoring, the change from baseline in clinic systolic/diastolic BP, and responder rates. Safety variables included total adverse events (AEs), serious AEs, AEs leading to discontinuation, and AEs related to the study drug. The raw data from the included studies were utilized to calculate the odds ratio (OR) for dichotomous data and the mean difference (MD) for continuous data, accompanied by 95% confidence intervals (CIs). Statistical analysis was performed using R software.

Results

A total of 11 RCTs met the inclusion criteria, representing 7,608 patients, 5 of whom had diabetes. Pooled analysis suggested a reduction in BP among patients randomized to 40 mg of AZL-M vs. control therapy [24-h ambulatory blood pressure monitoring (ABPM) mean systolic blood pressure (SBP) (MD: -2.85 mmHg), clinic SBP (MD: -3.48 mmHg), and clinic diastolic blood pressure (DBP) (MD: -1.96 mmHg)] and for 80 mg of AZL-M vs. control therapy [24-h ABPM mean SBP (MD: -3.59 mmHg), 24-h ABPM mean DBP (MD: -2.62 mmHg), clinic SBP (MD: -4.42 mmHg), clinic DBP (MD: -3.09 mmHg), and responder rate (OR: 1.46)]. There was no difference in the reduction of risks, except for dizziness (OR: 1.56) in the 80-mg AZL-M group or urinary tract infection (OR: 1.82) in the 40-mg AZL-M group. Analysis of patients with diabetes revealed that AZL-M can provide superior management, while safety and tolerability were similar to those of control therapy.

Conclusions

AZL-M appears to reduce BP to a greater extent than dose-control therapy and does not increase the risk of adverse events in patients with hypertension and diabetes compared with placebo.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=464284, identifier PROSPERO CRD42023464284.

Enhancing simultaneous determination of some angiotensin II receptor antagonists and amlodipine in plasma using HPTLC with fluorescence densitometry: Independent fluorescence detection of the co-administrative drugs in the mixture across various pH conditions

A novel and highly sensitive high-performance thin-layer chromatographic (HPTLC) method was developed and validated to quantify a combination of five pharmaceutical mixtures spiked to human plasma. The compounds comprised Amlodipine (AML) along with five angiotensin II receptor antagonist drugs (AIIRAs), namely Olmesartan (OLM), Telmisartan (TLM), Candesartan (CAN), Losartan (LOS), and Irbesartan (IRB). HPTLC was performed on silica gel 60 F254 plates using a mobile phase of Toluene: ethyl acetate: methanol: acetone: acetic acid (6:1.5:1:0.5:1, v/v/v/v/v). In a pioneering move, a reflectance/fluorescence detection mode was employed to identify two concurrently administered drugs at different pH levels for the first time. This method utilized the same chromatographic system, incorporating a specific measurement for AML at a neutral medium to achieve its maximum fluorescence at a 360 nm excitation wavelength, and measuring emission using a 540 nm optical filter. The process involved obtaining a very low fluorescence response from AIIRA. Subsequently, to enhance AIIRA's fluorescence, the plate was sprayed with perchloric acid to transition to a strong acidic medium, ultimately attaining the maximum fluorescence of AIIRA using various excitation wavelengths and a 400 nm emission filter. Through this strategic process, we could optimize the fluorescence signals of both drugs, thereby elevating the sensitivity of detection for this drug combination. AML demonstrated a linear range of 18-300 ng/band, while AIIRAs drugs exhibited a linear range of 6-150 ng/band. The method satisfied the International Conference on Harmonization (ICH) criteria for recovery, precision, repeatability, and robustness, showcasing exceptional sensitivity. The approach was successfully applied to quantify AML and AIIRAs drugs in both bulk drug and plasma samples, achieving high recovery percentages and minimal standard deviations.

Lipid Horizons: Recent Advances and Future Prospects in LBDDS for Oral Administration of Antihypertensive Agents

The lipid-based drug delivery system (LBDDS) is a well-established technique that is anticipated to bring about comprehensive transformations in the pharmaceutical field, impacting the management and administration of drugs, as well as treatment and diagnosis. Various LBDDSs verified to be an efficacious mechanism for monitoring hypertension systems are SEDDS (self-nano emulsifying drug delivery), nanoemulsion, microemulsions, vesicular systems (transferosomes and liposomes), and solid lipid nanoparticles. LBDDSs overcome the shortcomings that are associated with antihypertensive agents because around fifty percent of the antihypertensive agents experience a few drawbacks including short half-life because of hepatic first-pass metabolism, poor aqueous solubility, low permeation rate, and undesirable side effects. This review emphasizes antihypertensive agents that were encapsulated into the lipid carrier to improve their poor oral bioavailability. Incorporating cutting-edge technologies such as nanotechnology and targeted drug delivery, LBDDS holds promise in addressing the multifactorial nature of hypertension. By fine-tuning drug release profiles and enhancing drug uptake at specific sites, LBDDS can potentially target renin-angiotensin-aldosterone system components, sympathetic nervous system pathways, and endothelial dysfunction, all of which play crucial roles in hypertension pathophysiology. The future of hypertension management using LBDDS is promising, with ongoing reviews focusing on precision medicine approaches, improved biocompatibility, and reduced toxicity. As we delve deeper into understanding the intricate mechanisms underlying hypertension, LBDDS offers a pathway to develop next-generation antihypertensive therapies that are safer, more effective, and tailored to individual patient needs.

Structural insights into angiotensin receptor signaling modulation by balanced and biased agonists

The peptide hormone angiotensin II regulates blood pressure mainly through the type 1 angiotensin II receptor AT1 R and its downstream signaling proteins Gq and β-arrestin. AT1 R blockers, clinically used as antihypertensive drugs, inhibit both signaling pathways, whereas AT1 R β-arrestin-biased agonists have shown great potential for the treatment of acute heart failure. Here, we present a cryo-electron microscopy (cryo-EM) structure of the human AT1 R in complex with a balanced agonist, Sar1 -AngII, and Gq protein at 2.9 Å resolution. This structure, together with extensive functional assays and computational modeling, reveals the molecular mechanisms for AT1 R signaling modulation and suggests that a major hydrogen bond network (MHN) inside the receptor serves as a key regulator of AT1 R signal transduction from the ligand-binding pocket to both Gq and β-arrestin pathways. Specifically, we found that the MHN mutations N1113.35 A and N2947.45 A induce biased signaling to Gq and β-arrestin, respectively. These insights should facilitate AT1 R structure-based drug discovery for the treatment of cardiovascular diseases.

Development of a Non-Peptide Angiotensin II Type 1 Receptor Ligand by Structural Modification of Olmesartan as a Biased Agonist

As a biased agonist, peptide angiotensin II (Ang II) type 1 (AT₁) receptor ligand antagonizes Ang II-stimulated G protein signaling but stimulates several kinase pathways. Here, we developed a non-peptide AT₁ receptor compound as a biased ligand. We synthesized three non-peptide AT₁ receptor ligands (R239470, R781253, and R794847) as candidates of biased ligands. Extracellular signal-regulated kinase (ERK) 1/2 activation and inositol phosphate (IP) production were measured using a cell system that overexpressed AT₁ receptors (wild-type, L112A, Q257A, Y292A, and N295A receptors). We also examined the modes of receptor-ligand binding using a competition binding study. The K_d values of R239470, R781253, and R794847 for the AT₁ wild-type receptor were 0.8, 21, and 48 nM, respectively, as assessed in a competition binding study. Those of R239470, R781253, and R794847 for the L112A receptor were 37, 23, and 31 nM, respectively. R781253 and R794847 decreased and increased IP production, respectively, whereas R239470 did not change IP production. R781253 and R794847, but not R239470, activated ERK1/2. In conclusion, R239470, R781253, and R794847 act as a neutral antagonist, an inverse agonist, and an agonist with regard to IP production, respectively. On the other hand, R781253 and R794847, but not R239470, are agonists toward ERK1/2 activation. Thus, we developed a non-peptide AT₁ receptor compound as a biased ligand.

Structural, spectroscopic, molecular docking, ADME, molecular dynamics studies of Val-Trp dipeptide

Hypertension is a significant risk factor for various diseases, especially heart, brain, and kidney diseases. It is known that many peptides have the property of lowering blood pressure and determine as ACE inhibitors. The purpose of this study is to obtain information about the molecular structure of Val-Trp (L-valyl-L-tryptophan), which is one of the antihypertensive peptides, by molecular mechanical, quantum mechanical, and spectroscopic methods (FT-IR and Raman). Also, it is aimed to investigate the interactions of Val-Trp dipeptide with receptors related to hypertension and to determine the pharmacokinetic profile due to the potential of the peptide to be a drug candidate. The peptide structure was optimized by DFT/B3LYP/6-311++G(d,p) basis set, then vibrational wavenumbers, molecular electrostatic potential (MEP), HOMO-LUMO (highest occupied molecular orbital- lowest unoccupied molecular orbital), NBO (natural bond orbital) analyzes were performed. The assignment of fundamental theoretical vibration wavenumbers was carried out with potential energy distribution analysis (PED). After the structural analyzes of the peptide were performed, the interactions of the peptide with Angiotensin-converting enzyme (ACE), Angiotensin II Receptor Type 1 (AT1R) and Renin were investigated by molecular docking study. Then, the molecular dynamic (MD) simulation of the peptide-ACE complex with the best binding affinity in the molecular docking studies was carried out for 50 ns. ADME (absorption, distribution, metabolism, and excretion) analysis of Val-Trp dipeptide was performed. In support of the studies carried out, enlightening information about the feasibility of the antihypertensive drug of Val-Trp dipeptide with the help of the ADME profile was presented to the literature.Communicated by Ramaswamy H. Sarma.

Pharmacological Utility of PPAR Modulation for Angiogenesis in Cardiovascular Disease

Peroxisome proliferator activated receptors, including PPARα, PPARβ/δ, and PPARγ, are ligand-activated transcription factors belonging to the nuclear receptor superfamily. They play important roles in glucose and lipid metabolism and are also supposed to reduce inflammation and atherosclerosis. All PPARs are involved in angiogenesis, a process critically involved in cardiovascular pathology. Synthetic specific agonists exist for all PPARs. PPARα agonists (fibrates) are used to treat dyslipidemia by decreasing triglyceride and increasing high-density lipoprotein (HDL) levels. PPARγ agonists (thiazolidinediones) are used to treat Type 2 diabetes mellitus by improving insulin sensitivity. PPARα/γ (dual) agonists are supposed to treat both pathological conditions at once. In contrast, PPARβ/δ agonists are not in clinical use. Although activators of PPARs were initially considered to have favorable effects on the risk factors for cardiovascular disease, their cardiovascular safety is controversial. Here, we discuss the implications of PPARs in vascular biology regarding cardiac pathology and focus on the outcomes of clinical studies evaluating their benefits in cardiovascular diseases.

Vascular Relaxation and Blood Pressure Lowering Effects of Prunus mume in Rats

Prunus mume Siebold et Zuccarini is mainly consumed as processed fruits in beverages, vinegar, alcohol, or fruit syrup; studies have reported various functional effects. Many pharmacological and functional studies exist on fruit extracts or processed foods using fruits, however, efficacy studies on various parts of P. mume, including the bark, branches, flowers, and leaves, have not been sufficiently conducted. A previous study revealed that a 70% ethanol extract of P. mume branches induced vascular endothelium-dependent vasorelaxant effects in rat thoracic aortic rings. Therefore, we hypothesized that various parts (the fruits, flowers, leaves, and bark) might have vasorelaxant effects. We evaluated the effects of P. mume extracts on the vascular relaxation of isolated rat thoracic aorta and hypotensive effects in spontaneous hypertensive rats (SHR). A 70% ethanol extract of P. mume bark (PBaE) was the most effective, thus, we investigated its vasorelaxant mechanisms and hypotensive effects. PBaE lowered the blood pressure in SHR and induced the vascular endothelium-dependent relaxation of isolated rat aortic rings via the NO/sGC/cGMP and the PGI₂ pathways in the vascular smooth muscle. Potassium channels, such as K_Ca, K_ATP, K_V, and K_ir, were partially associated with a PBaE-induced vasorelaxation. Therefore, PBaE might help prevent and treat hypertension.

An insight into the role of telmisartan as PPAR-γ/α dual activator in the management of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common hepatic disease. It is rapidly emerging as the frequent cause for liver transplantation with the risk of disease recurrence, even after transplantation. Clinical evidence showed an abnormally altered expression of different peroxisome proliferator-activated receptor (PPAR) isotypes (PPAR-α/γ/δ) in NAFLD with an involvement in the induction of insulin resistance, hepatic steatosis, reactive oxygen species (ROS) formation, and hepatic inflammation. Recently, several dual PPAR-γ/α agonists were developed to simultaneously achieve the insulin-sensitizing effect of PPAR-γ as well as lipid catabolizing effect of PPAR-α. PPAR-α activation could counterbalance the steatogenic and adipogenic effects of PPAR-γ. But most of the drugs were ended in the initial level itself due to harmful adverse effects. In the present review, we discuss the possible mechanism of telmisartan, a typical angiotensin receptor blocker with excellent safety and pharmacokinetic profile, as a PPAR-γ/α dual agonist in the treatment of NAFLD.

Diminished antiproteinuric effect of the angiotensin receptor blocker losartan during high potassium intake in patients with CKD

Background

Angiotensin II type 1 receptor blockers (ARBs) lower blood pressure (BP) and proteinuria and reduce renal disease progression in many-but not all-patients. Reduction of dietary sodium intake improves these effects of ARBs. Dietary potassium intake affects BP and proteinuria. We set out to address the effect of potassium intake on BP and proteinuria response to losartan in non-diabetic proteinuric chronic kidney disease (CKD) patients.

Methods

We performed a post hoc analysis of a placebo-controlled interventional cross-over study in 33 non-diabetic proteinuric patients (baseline mean arterial pressure and proteinuria: 105 mmHg and 3.8 g/day, respectively). Patients were treated for 6 weeks with placebo, losartan and losartan/hydrochlorothiazide (HCT), combined with a habitual (∼200 mmol/day) and low-sodium (LS) diet (<100 mmol/day), in randomized order. To analyse the effects of potassium intake, we categorized patients based on median split of 24-h urinary potassium excretion, reflecting potassium intake.

Results

Mean potassium intake was stable during all six treatment periods. Losartan and losartan/HCT lowered BP and proteinuria in all treatment groups. Patients with high potassium intake showed no difference in the BP effects compared with patients with low potassium intake. The antiproteinuric response to losartan monotherapy and losartan combined with HCT during the habitual sodium diet was significantly diminished in patients with high potassium intake (20% versus 41%, P = 0.011; and 48% versus 64%, P = 0.036). These differences in antiproteinuric response abolished when shifting to the LS diet.

Conclusions

In proteinuric CKD patients, the proteinuria, but not BP-lowering response to losartan during a habitual high-sodium diet was hampered during high potassium intake. Differences disappeared after sodium status change by LS diet.

Biologically active metabolites in drug discovery

Biologically active metabolites are a valuable resource for development of drug candidates and lead structures for drug design. This digest highlights a selection of biologically active metabolites that have been used as new chemical entities for development or as lead structures for drug design.

The determination of two analogues of 4-(azidomethyl)-1,1'-biphenyl as potential genotoxic impurities in the active pharmaceutical ingredient of several sartans containing a tetrazole group

4'-(azidomethyl)-[1,1'-biphenyl]-2-carbonitrile (GTI-azide-1) and 5-(4'-(azidomethyl)-[1,1'-biphenyl]-2-yl)-1H-tetrazole (GTI-azide-2) are potentially genotoxic impurities that can be present at trace levels in the active pharmaceutical ingredients and drug products of sartans containing a tetrazole group. A method of high-performance liquid chromatography coupled with mass spectrometry, that allows the determination of those genotoxic impurities at sub-ppm level relative to the active pharmaceutical ingredient, was developed. The method utilises a very efficient liquid chromatograph Waters Acquity I-Class coupled with a highly sensitive tandem mass spectrometer Xevo TQ-XS. The separation was achieved on a column Acquity UPLC BEH Shield RP18 1.7 μm employing a linear elution gradient. The mass spectrometer was used with a heated electrospray ionization. The method was found to be sufficient in terms of sensitivity, linearity, precision, accuracy, selectivity and robustness and is easily applicable in the pharmaceutical quality control environment. The method allows for accurate quantification of both impurities GTI-azide-1 and GTI-azide-2 at levels below 1/10^th of the specification limit, which is crucial in the context of pharmaceutical analysis. The limit of quantification was determined to be 0.033 ppm and 0.025 ppm for GTI-azide-1 and GTI-azide-2, respectively.

Serum anti-AP3D1 antibodies are risk factors for acute ischemic stroke related with atherosclerosis

Atherosclerosis has been considered as the main cause of morbidity, mortality, and disability worldwide. The first screening for antigen markers was conducted using the serological identification of antigens by recombinant cDNA expression cloning, which has identified adaptor-related protein complex 3 subunit delta 1 (AP3D1) as an antigen recognized by serum IgG antibodies of patients with atherosclerosis. Serum antibody levels were examined using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) using a recombinant protein as an antigen. It was determined that the serum antibody levels against AP3D1 were higher in patients with acute ischemic stroke (AIS), transient ischemic attack, diabetes mellitus (DM), cardiovascular disease, chronic kidney disease (CKD), esophageal squamous cell carcinoma (ESCC), and colorectal carcinoma than those in the healthy donors. The area under the curve values of DM, nephrosclerosis type of CKD, and ESCC calculated using receiver operating characteristic curve analysis were higher than those of other diseases. Correlation analysis showed that the anti-AP3D1 antibody levels were highly associated with maximum intima-media thickness, which indicates that this marker reflected the development of atherosclerosis. The results of the Japan Public Health Center-based Prospective Study indicated that this antibody marker is deemed useful as risk factors for AIS.

The emerging field of non-human leukocyte antigen antibodies in transplant medicine and beyond

The major medical advances in our knowledge of the human leukocyte antigen (HLA) system have allowed us to uncover several gaps in our understanding of alloimmunity. Although the non-HLA system has long sparked the interest of the transplant community, recognition of the role of immunity to non-HLA antigenic targets has only emerged recently. In this review, we will provide a comprehensive summary of the paradigm-changing concept of immunity to the non-HLA angiotensin II type 1 receptor (AT1R), discovered by Duška Dragun et al., that began from careful bedside clinical observations, to validated detection of anti-AT1R antibodies and lead to clinical intervention. This scientific approach has also allowed the recognition of broader pathogenicity of anti-AT1R antibodies across multiple organ transplants and in other human diseases, the integration of both non-HLA and HLA systems to understand their immunologic effects on organ allografts, and the identification of future directions for therapeutic intervention to modulate immunity to AT1R. Rationally designed successful interventions to target AT1R system provide an exemplar for other non-HLA antibodies to cross borders between medical specialties, will generate new avenues in translational research beyond transplantation, and will foster the development of new and reliable tools to improve our understanding of non-HLA immunity and ultimately allow us to improve patient care.

The Therapeutic Potential of Targeting the Angiotensin Pathway as a Novel Therapeutic Approach to Ameliorating Post-Surgical Adhesions

BACKGROUND

Post-surgical adhesion is a common complication after abdominal or pelvic surgeries. Despite improvements in surgical techniques or the application of physical barriers, little improvements have been achieved. It causes bowel obstruction, pelvic pain, and infertility in women and has an adverse effect on the quality of life. Renin-Angiotensin System (RAS) is traditionally considered as a blood pressure regulator. However, recent studies also indicate that the RAS plays a vital role in other processes, including oxidative stress, fibrosis, proliferation, inflammation, and the wound healing process. Angiotensin II (Ang II) is the main upstream effector of the RAS that can bind to the AT1 receptor (ATIR). A growing body of evidence has revealed that targeting Angiotensin-Converting Enzyme Inhibitors (ACEIs), Angiotensin II type 1 Receptor Blockers (ARBs), and Direct Renin Inhibitors (DRIs) can prevent post-surgical adhesions. Here we provide an overview of the therapeutic effect of RAS antagonists for adhesion.

METHODS

PubMed, EMBASE, and the Cochrane library were reviewed to identify potential agents targeting the RAS system as a potential approach for post-surgical adhesion.

RESULTS

Available evidence suggests the involvement of the RAS signaling pathway in inflammation, proliferation, and fibrosis pathways as well as in post-surgical adhesions. Several FDA-approved drugs are being used for targeting the RAS system. Some of them are being tested in different models to reduce fibrosis and improve adhesion after surgery, including Telmisartan, valsartan, and enalapril.

CONCLUSION

Identification of the pathological causes of post-surgical adhesion and the potential role of targeting Renin-Angiotensin System may help prevent this problem. Based on the pathological function of RAS signaling after surgeries, the administration of ARBs may be considered as a novel and efficient approach to prevent postsurgical adhesions. Pre-clinical and clinical studies should be carried out to have better information on the clinical significance of this therapy against post-surgical adhesion formation.

Development of a Sensitive Headspace Gas Chromatography-Mass Spectrometry Method for the Simultaneous Determination of Nitrosamines in Losartan Active Pharmaceutical Ingredients

Nitrosamine impurities in angiotensin II receptor antagonists (sartans) containing a tetrazole group represent an urgent concern for active pharmaceutical ingredient (API) manufacturers and global regulators. Regarding safety, API manufacturers must develop methods to monitor the levels of each nitrosamine impurity before individual batch release. In this study, we developed and validated a sensitive, selective, and high-throughput method based on headspace gas chromatography-mass spectrometry (HS-GC-MS) for the simultaneous determination of four nitrosamines in losartan potassium API with simple sample preparation. N-Nitrosodimethylamine (NDMA, m/z 74), N-nitrosodiethylamine (NDEA, m/z 102), N-nitrosoethylisopropylamine (EIPNA, m/z 116), and N-nitrosodiisopropylamine (DIPNA, m/z 130) levels were quantified using an electron impact, single quadrupole mass spectrometer under a selected-ion-monitoring acquisition method. The method was validated according to the Q2(R1) ICH guidelines. The calibration curves of the assay ranged from 25 to 5000 ng/mL with limits of quantitation of 25 ppb for NDMA and NDEA and 50 ppb for DIPNA and EIPNA. The accuracy of the developed method ranged from -7.04% to 7.25%, and the precision %CV was ≤11.5. Other validation parameters, including specificity, stability, carryover, and robustness, met the validation criteria. In conclusion, the developed method was successfully applied for the determination of nitrosamines in losartan potassium APIs.

Mechanisms of anthracycline-mediated cardiotoxicity and preventative strategies in women with breast cancer

While anthracyclines (ACs) are a class of chemotherapeutic agents that have improved the prognosis of many women with breast cancer, it is one of the most cardiotoxic agents used to treat cancer. Despite their reported dose-dependent cardiotoxicity, AC-based chemotherapy has become the mainstay of breast cancer therapy due to its efficacy. Elucidating the mechanisms of anthracycline-mediated cardiotoxicity and associated therapeutic interventions continue to be the main focus in the field of cardio-oncology. Herein, we summarized the current literature surrounding the mechanisms of anthracycline-induced cardiotoxicity, including the role of topoisomerase II inhibition, generation of reactive oxygen species, and elevations in free radicals. Furthermore, this review highlights the molecular mechanisms of potential cardioprotective interventions in this setting. The benefits of pharmaceuticals, including dexrazoxane, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, statins, and antioxidants in this setting, are reviewed. Finally, the mechanisms of emerging preventative interventions within this patient population including nutraceuticals and aerobic exercise are explored.

Design, Synthesis and Anticancer Activity of New Polycyclic: Imidazole, Thiazine, Oxathiine, Pyrrolo-Quinoxaline and Thienotriazolopyrimidine Derivatives

In this article, we showed the synthesis of new polycyclic aromatic compounds, such as thienotriazolopyrimidinones, N-(thienotriazolopyrimidine) acetamide, 2-mercapto-thienotriazolo-pyrimidinones, 2-(((thieno-triazolopyrimidine) methyl) thio) thieno-triazolopyrimidines, thieno-pyrimidotriazolo-thiazines, pyrrolo-triazolo-thienopyrimidines, thienopyrimido-triazolopyrrolo-quinoxalines, thienopyrimido-triazolo-pyrrolo-oxathiino-quinoxalinones, 1,4-oxathiino-pyrrolo- triazolothienopyrimidinones, imidazopyrrolotriazolothienopyrimidines and 1,2,4-triazoloimidazo- pyrrolotriazolothienopyrimidindiones, based on the starting material 2,3-diamino-6-benzoyl-5- methylthieno[2,3-d]pyrimidin-4(3H)-one (3). The chemical structures were confirmed using many spectroscopic ways (IR, 1H, 13C, -NMR and MS) and elemental analyses. A series of thiazine, imidazole, pyrrole, thienotriazolopyrimidine derivatives were synthesized and evaluated for their antiproliferative activity against four human cancer cell lines, i.e., CNE2 (nasopharyngeal), KB (oral), MCF-7 (breast) and MGC-803 (gastric) carcinoma cells. The compounds 20, 19, 17, 16 and 11 showed significant cytotoxicity against types of human cancer cell lines.

Extemporaneous Compounding and Physiological Modeling of Amlodipine/Valsartan Suspension

Method

Amlodipine/valsartan extemporaneous suspension was prepared from available commercial tablets such as Valzadepine^®. The dissolution profiles for the extemporaneous preparation and the commercial tablet were determined in different pH media. The physical, chemical, and microbial stability of the compounded formulation was evaluated over one-month period at room temperature. Moreover, in silico modeling using GastroPlus™ software was used to build absorption models for both drugs based on the in vitro dissolution data. The simulated plasma profiles for both active ingredients were compared with the in vivo plasma profiles to examine the similarity of the extemporaneous suspension and the commercial tablets.

Results

The amlodipine/valsartan extemporaneous suspension was successfully prepared with acceptable organoleptic properties. The suspension was stable for four-week period preserving its physical and chemical features. The release profiles of valsartan and amlodipine from the suspension were similar to those from source tablet Valzadepine^®. In silico modeling predicted the similarity of the extemporaneous suspension and the commercial tablets.

Conclusion

Amlodipine/valsartan extemporaneous suspension could be prepared from available commercial tablets. Moreover, GastroPlus™ can be applied along with the in vitro dissolution in order to affirm similarity in extemporaneous compounding situations.

Development of a novel [18 F]fluorobenzyl derivative of the AT1 receptor antagonist Candesartan

Candesartan is a clinically approved angiotensin II type 1 receptor (AT1 R)-blocker that selectively binds AT1 Rs in high affinity. We report here the radiosynthesis and automation of the novel [18 F]fluorobenzyl derivative of Candesartan using the Sonogashira cross-coupling reaction. [18 F]Fluorobenzyl-Candesartan ([18 F]7) was developed from 4-[18 F]fluoroiodobenzene ([18 F]FIB) that was conjugated with alkyne-trityl-candesartan with the assistance of a Pd (PPh3 )4 /CuI catalyst followed by acid deprotection. The three-step two-reactor 2-HPLC purification process was automated resulting in >90% pure [18 F]7 in a RCY of 4.6 ± 1.1% (decay corrected from EOB) and molar activities of 1,406-5,513 GBq/mmol. [18 F]FIB was reproducibly obtained by direct radiofluorination of the mono-iodinated triphenylsulfonium salt in the presence of K222/K2 CO3 in an ~30% yield (decay-corrected). [18 F]7 was stable (>97%) up to 4 h in solution and up to 1 h in rat plasma at 37°C. However, the use of Sonogashira cross-coupling reaction to produce [18 F]7 in high yields and molar activities was found to be challenging for routine use in radiochemistry labs.

Differential Effects of Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers on COVID-19

Background:

The effect of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs) on the coronavirus disease 2019 (COVID-19) remains controversial from clinic evidence.

Objectives:

The objectives of this study were to report the major characteristics and clinical outcomes of COVID-19 patients treated with ACEIs and ARBs and compare the different effects of the two drugs for outcomes of COVID-19 patients.

Methods:

This is a retrospective, two-center case series of 198 consecutive COVID-19 patients with a history of hypertension.

Results:

Among 198 patients, 58 (29.3%) and 16 (8.1%) were on ARB and ACEI, respectively. Patients who were on ARB or ACEI/ARB had a significantly lower rate of severe illness and acute respiratory distress syndrome (ARDS) when compared with patients treated with ACEI alone or not receiving RAAS blocker (P < 0.05). The Kaplan–Meier survival curve showed that patients with ARB in their antihypertensive regimen had a trend toward a higher survival rate when compared with individuals without ARB (adjusted hazard ratio, 0.27; 95% confidence interval [CI], 0.07–1.02; P = 0.054). The occurrence rates of severe illness, ARDS, and death were similar in the two groups regardless of receiving ACEI. The Cox regression analyses showed a better survival in the ARB group than the ACEI group (adjusted hazard ratio, 0.03; 95% CI, 0.00–0.58; P = 0.02).

Conclusions:

Our data may provide that some evidence of using ARB, but not ACEI, was associated with a reduced rate of severe illness and ARDS, indicating their potential protective impact in COVID-19. Further large sample sizes and multiethnic populations are warranted to confirm our findings.

ACE2: from protection of liver disease to propagation of COVID-19

Twenty years ago, the discovery of angiotensin-converting enzyme 2 (ACE2) was an important breakthrough dramatically enhancing our understanding of the renin-angiotensin system (RAS). The classical RAS is driven by its key enzyme ACE and is pivotal in the regulation of blood pressure and fluid homeostasis. More recently, it has been recognised that the protective RAS regulated by ACE2 counterbalances many of the deleterious effects of the classical RAS. Studies in murine models demonstrated that manipulating the protective RAS can dramatically alter many diseases including liver disease. Liver-specific overexpression of ACE2 in mice with liver fibrosis has proved to be highly effective in antagonising liver injury and fibrosis progression. Importantly, despite its highly protective role in disease pathogenesis, ACE2 is hijacked by SARS-CoV-2 as a cellular receptor to gain entry to alveolar epithelial cells, causing COVID-19, a severe respiratory disease in humans. COVID-19 is frequently life-threatening especially in elderly or people with other medical conditions. As an unprecedented number of COVID-19 patients have been affected globally, there is an urgent need to discover novel therapeutics targeting the interaction between the SARS-CoV-2 spike protein and ACE2. Understanding the role of ACE2 in physiology, pathobiology and as a cellular receptor for SARS-CoV-2 infection provides insight into potential new therapeutic strategies aiming to prevent SARS-CoV-2 infection related tissue injury. This review outlines the role of the RAS with a strong focus on ACE2-driven protective RAS in liver disease and provides therapeutic approaches to develop strategies to prevent SARS-CoV-2 infection in humans.

Renin-angiotensin system impairs macrophage lipid metabolism to promote age-related macular degeneration in mouse models

Metabolic syndrome, a condition involving obesity and hypertension, increases the risk of aging-associated diseases such as age-related macular degeneration (AMD). Here, we demonstrated that high-fat diet (HFD)-fed mice accumulated oxidized low-density lipoprotein (ox-LDL) in macrophages through the renin–angiotensin system (RAS). The ox-LDL-loaded macrophages were responsible for visual impairment in HFD mice along with a disorder of the retinal pigment epithelium (RPE), which is required for photoreceptor outer segment renewal. RAS repressed ELAVL1, which reduced PPARγ, impeding ABCA1 induction to levels that are sufficient to excrete overloaded cholesterol within the macrophages. The ox-LDL-loaded macrophages expressed inflammatory cytokines and attacked the RPE. An antihypertensive drug, angiotensin II type 1 receptor (AT1R) blocker, resolved the decompensation of lipid metabolism in the macrophages and reversed the RPE condition and visual function in HFD mice. AT1R signaling could be a future therapeutic target for macrophage-associated aging diseases, such as AMD.

Nagai et al. show that mice fed high-fat diet (HFD) accumulate oxidized low-density lipoprotein in macrophages through the renin–angiotensin system, which impairs visual function. They find that angiotensin II type 1 receptor (AT1R) improves the visual function of HFD mice, suggesting AT1R signaling as a potential therapeutic target for age-related macular degeneration.

Losartan Treatment Could Improve the Outcome of TBI Mice

Traumatic brain injury frequently leads to serious mortality and physical disability, yet effective treatments remains insufficient. TBI always leads to a series of secondary brain injuries including neuronal apoptosis, continuous inflammation, endoplasmic reticulum stress, and disruption of the blood-brain barrier. Sartans that block angiotensin II type 1 receptors are strongly neuroprotective, neurorestorative and anti-inflammatory. However, whether losartan, a FDA-approved and widely used drug for regulating blood pressure, is beneficial for improving the prognosis of TBI need more evidence. Through a controlled cortical impact injury mice model, we confirmed that losartan treatment could ameliorate CCI-induced secondary brain injury. We found that losartan treatment decreased brain lesion volume, neuronal apoptosis and ER stress protein ATF4 and eIF2α. Moreover, our results showed that losartan also improved neurological and motor function. It is worth pointing out that losartan increased the expression of tight junction proteins ZO-1 and alleviated brain edema and blood brain barrier leakage. Additionally, losartan inhibited pro-inflammatory factor TNF-α and improve anti-inflammatory factor IL-10. Taken together, our data demonstrated that losartan could improve the prognosis of TBI and may be a promising therapeutic method for mitigating TBI.

Protective Effects of Statin and Angiotensin Receptor Blocker in a Rat Model of Doxorubicin- and Trastuzumab-Induced Cardiomyopathy

BACKGROUND

Chemotherapy has led to improved survival in patients with breast cancer; however, it is associated with an increased risk of cardiac dysfunction and heart failure. We investigated the protective effects of rosuvastatin and candesartan, alone and in combination, in a doxorubicin- and trastuzumab-induced rat model of cardiomyopathy.

METHODS

Forty-two rats were allocated into six groups (G1-G6): G1, control; G2, doxorubicin only; G3, doxorubicin + trastuzumab; G4, doxorubicin + trastuzumab + rosuvastatin; G5, doxorubicin + trastuzumab + candesartan; and G6, doxorubicin + trastuzumab + rosuvastatin + candesartan. Doxorubicin and trastuzumab were sequentially administered for 28 days. Left ventricular end-systolic dimension and longitudinal strain (LS) were assessed via echocardiography. Left ventricular (LV) performance was evaluated using a microcatheter in the LV apex on day 28. Blood for biomarker analysis was collected from the inferior vena cava before sacrifice.

RESULTS

Doxorubicin in combination with trastuzumab increased the LV end-systolic dimension but worsened LS compared with the control group (all P < .05). The level of C-reactive protein was lower in the rosuvastatin treatment group (P = .007) than in the controls but not in the candesartan treatment group. Both rosuvastatin and candesartan attenuated the increase in glutathione. Candesartan treatment improved +dP/dt (P = .011), whereas rosuvastatin did not. In the combination treatment group, the worsening of LS was significantly attenuated compared with that in either the rosuvastatin or candesartan group (all P < .05).

CONCLUSIONS

In a rat model of doxorubicin- and trastuzumab-induced cardiomyopathy, rosuvastatin alleviated systemic inflammation, while candesartan improved LV performance. Combination therapy with rosuvastatin and candesartan demonstrated additional preventive effects on myocardial strain. The protective mechanisms of rosuvastatin and candesartan appear to be different but complementary in chemotherapy-induced cardiomyopathy.

Should Angiotensin-Converting Enzyme Inhibitors ever Be Used for the Management of Hypertension?

Purpose of Review

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are commonly used anti-hypertensive medications in a number of clinical settings. They are often used interchangeably, but we pose the provocative question as to whether they should be. We review the literature to evaluate for any differences in efficacy between the two classes in order to determine if the greater side effects associated with angiotensin-converting enzyme inhibitors are offset by any advantageous effects on outcomes to warrant their use over angiotensin receptor blockers.

Recent Findings

In many clinical scenarios, the data supports similar efficacy between ACE inhibitors and ARBs, while in a minority of others, there are murky signals from previous trials that suggest ACE inhibitors may be better. However, when reviewing the literature in its entirety, and taking into account recently published pooled analysis and head to head trials, it is reasonable to conclude that ACE inhibitors and ARBs have similar efficacy. This is in contrast to data on adverse effects, which consistently favors the use of ARBs.

Summary

From the available data, it is reasonable to conclude that ACE inhibitors and ARBs have equal efficacy yet unequal adverse effects. It is in this context that we take the provocative stance that ACE inhibitors should not be used to treat hypertension.

Effects of ACEi and ARB on post-exercise hypotension induced by exercises conducted at different times of day in hypertensive men

BACKGROUND

Post-exercise hypotension (PEH) is greater after evening than morning exercise, but antihypertensive drugs may affect the evening potentiation of PEH. Objective: To compare morning and evening PEH in hypertensives receiving angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARB).

METHODS

Hypertensive men receiving ACEi (n = 14) or ARB (n = 15) underwent, in a random order, two maximal exercise tests (cycle ergometer, 15 watts/min until exhaustion) with one conducted in the morning (7 and 9 a.m.) and the other in the evening (8 and 10 p.m.). Auscultatory blood pressure (BP) was assessed in triplicate before and 30 min after the exercises. Changes in BP (post-exercise - pre-exercise) were compared between the groups and the sessions using a two-way mixed ANOVA and considering P < .05 as significant.

RESULTS

In the ARB group, systolic BP decrease was greater after the evening than the morning exercise, while in the ACEi group, it was not different after the exercises conducted at the different times of the day. Additionally, after the evening exercise, systolic BP decrease was lower in the ACEi than the ARB group (ARB = -11 ± 8 vs -6 ± 6 and ACEi = -6 ± 7 vs. -8 ± 5 mmHg, evening vs. morning, respectively, P for interaction = 0.014).

CONCLUSIONS

ACEi, but not ARB use, blunts the greater PEH that occurs after exercise conducted in the evening than in the morning.

A Brief Review of Cardiovascular Diseases, Associated Risk Factors and Current Treatment Regimes

Cardiovascular diseases (CVDs) are the leading cause of premature death and disability in humans and their incidence is on the rise globally. Given their substantial contribution towards the escalating costs of health care, CVDs also generate a high socio-economic burden in the general population. The underlying pathogenesis and progression associated with nearly all CVDs are predominantly of atherosclerotic origin that leads to the development of coronary artery disease, cerebrovascular disease, venous thromboembolism and, peripheral vascular disease, subsequently causing myocardial infarction, cardiac arrhythmias or stroke. The aetiological risk factors leading to the onset of CVDs are well recognized and include hyperlipidaemia, hypertension, diabetes, obesity, smoking and, lack of physical activity. They collectively represent more than 90% of the CVD risks in all epidemiological studies. Despite high fatality rate of CVDs, the identification and careful prevention of the underlying risk factors can significantly reduce the global epidemic of CVDs. Beside making favorable lifestyle modifications, primary regimes for the prevention and treatment of CVDs include lipid-lowering drugs, antihypertensives, antiplatelet and anticoagulation therapies. Despite their effectiveness, significant gaps in the treatment of CVDs remain. In this review, we discuss the epidemiology and pathology of the major CVDs that are prevalent globally. We also determine the contribution of well-recognized risk factors towards the development of CVDs and the prevention strategies. In the end, therapies for the control and treatment of CVDs are discussed.

Potential pharmacodynamic and pharmacokinetic interactions of Nigella Sativa and Trigonella Foenum-graecum with losartan in L-NAME induced hypertensive rats

The objective of this investigation was to study whether Nigella Sativa and Trigonella Foenum-graecum, could modulate the losartan pharmacodynamic (PD) and pharmacokinetic (PK) in experimental L-NAME induced hypertensive rats. For in vivo study, the systolic blood pressure (SBP) of rats was measured by the “tail-cuff system” after the treatment of rats with herb alone and herb + losartan in hypertensive rats. The SBP of rats treated with L-NAME + losartan also recorded. For the PK study, blood samples were obtained for up to 12 h to determine the concentrations of the drug, and various PK parameters were calculated. The data displayed that the SBP was significantly (p < 0.05) decreased in the rats when administered with L-NAME + N. Sativa or L-NAME + T. Foenum-graecum in contrast to the rats administered with L-NAME alone. A more prominent decline (p < 0.05) in SBP was detected in rats administered with L-NAME + N. Sativa + losartan and L-NAME + T. Foenum-graecum + losartan. In a PK study, higher losartan C_max and AUC_0-t were noted in rats treated with N. Sativa + losartan and T. Foenum-graecum + losartan, although the difference was not significant in contrast to the control group. This study proposed that the interaction between N. Sativa & losartan and T. Foenum-graecum & losartan could take place on concurrent administration; consequently, the dose of losartan may need to be accustomed when they are utilized simultaneously.

Comparisons of Staphylococcus aureus infection and other outcomes between users of angiotensin-converting-enzyme inhibitors and angiotensin II receptor blockers: lessons for COVID-19 from a nationwide cohort study

Background: Mice receiving angiotensin converting enzyme inhibitor (ACEI) drugs show increased susceptibility to infection by Staphylococcus aureus ( S. aureus). We sought to investigate whether humans using ACEI were at increased risk of S. aureus infection, comparing them to users of Angiotensin II Receptor Blockers (ARB) with multiple control outcomes to assess the potential for residual confounding.

Methods: Using the UK Clinical Practice Research Datalink linked to Hospital Episode Statistics between 1997 and 2017, we identified adults starting ACEI or ARB (as an active comparator drug). We regarded prescription of ACEI or ARB as time-dependent exposure and used a Cox regression model to compare incidence of first hospitalisation with infection due to S. aureus in periods with ACEI to periods with ARB prescriptions. We repeated the analysis using control outcomes that we did not expect to be associated with use of ACEI versus ARB (Gram-negative sepsis, hip fracture and herpes zoster) and one that we did (dry cough).

Results: We identified 445,341 new users of ACEI (mean age 64.0±14.0, male 51.7%) and 41,824 new users of ARB (mean age 64.1±14.0, male 45.5%). The fully adjusted hazard ratio for S. aureus infection (ACEI vs. ARB) was 1.18 (95% CI 1.10–1.27), consistent across sensitivity analyses. However, we also found associations with all control outcomes; rates of Gram-negative sepsis, hip fracture and dry cough were also increased during periods of time treated with ACEI compared to ARB while herpes zoster was more common during time treated with ARB.

Conclusions: Our results suggest that although ARB users appear an ideal control for analyses of ACEI effects, there is residual confounding even after multivariable adjustment. This has implications for observational analyses comparing users of these drug classes, in particular the effect of these drugs in relation to COVID-19 infection.

Novel feature extraction approach for achieving potential spectral resolution: Green analytical application on zofenopril calcium and hydrochlorothiazide in their spectrally overlapping binary mixture

A novel and green spectrophotometric method, namely constant extraction, based on extracting a spectral feature value (constant ratio) has been developed and validated for simultaneous estimation of a binary mixture of zofenopril calcium (ZOF) and hydrochlorothiazide (HCT) in their bulk and marketable formulation. A comparative study between this newly developed method and four long-established ones; ratio difference, ratio subtraction coupled with constant multiplication, advanced amplitude modulation and absorbance subtraction has been carried out giving very promising results. Various analytical performance parameters like linearity, accuracy, precision, and robustness were investigated in accordance with ICH (Q2B). Satisfying optimized instrumental parameters; absorbance of ZOF and HCT were linearly increased for the previously mentioned methods in a concentration range 5.0-35.0 and 3.0-20.0 μg/mL, respectively showing correlation coefficients ≥0.9990. Moreover, specificity has been checked through analyzing synthetic mixtures of the studied analytes. Feasibility has been successfully assessed by simultaneous quantification of both analytes in the commercially available formulation. As well, validity was examined and no interference from common excipients was noticed. Observed data has been statistically compared with those of the published one concluding that no significant variations between both results have been indicated. Furthermore, greenness profile of these methods was assessed by analytical Eco-Scale and found superior to that of the reported HPLC method as an even greener approach for the simultaneous analysis of ZOF and HCT.

Angioedemas associated with renin-angiotensin system blocking drugs: Comparative analysis of spontaneous adverse drug reaction reports

INTRODUCTION

Angioedema is a subcutaneous swelling typically affecting the face, larynx or pharynx. It is a known adverse drug reaction (ADR) of ACE inhibitors (ACEi), angiotensin-II-receptor blockers (ARBs) and aliskiren (renin inhibitor). Several studies have reported pathophysiological mechanisms and risk factors of ACEi-associated angioedemas, whereas little is known for ARBs and aliskiren. The aim of the study was to analyze comparatively ACEi versus ARBs and aliskiren angioedema reports contained in the European ADR database EudraVigilance with regard to reported risk factors and clinical phenotypes.

METHODS

All spontaneous angioedema reports received between 01/2010-06/2017 reporting either an ACEi, ARB, or aliskiren as "suspected/interacting" drug were identified using the Standardized MedDRA Query "angioedema (narrow)". In order to perform a comparative analysis, odds ratios (ORs) were calculated for angioedema reports of ACEi (n = 3.194) versus ARBs (n = 687) and aliskiren (n = 162).

RESULTS

More patients with a history of allergy were included in angioedema reports of ARBs (6.8%) and aliskiren (13.6%) versus ACEi (4.3%). "Urticaria" as an ADR was reported more frequently in angioedema reports of ARBs (18.5%) and aliskiren (9.0%) versus ACEi (5.0%). ACEi-associated angioedemas were more often designated as "life-threatening" compared to ARBs (OR 2.2 [1.6-2.9]) and aliskiren-associated angioedemas (OR 14.2 (3.5-57.4). Concomitant therapy with mTOR inhibitors (OR 4.3 [1.0-17.9]) and fibrinolytics (OR 7.8 [1.1-57.2]) was reported more often in ACEi versus ARBs angioedema reports.

CONCLUSION

The reported clinical phenotypes differed between ACEi versus ARBs and aliskiren angioedema reports. Differences between the patient populations as observed in our study or differences with regard to underlying pathomechanisms could account for this finding. Due to the methodological limitations of spontaneous reporting systems, we cannot draw a firm conclusion in this regard. Hence, further research is necessary to confirm our observation and elucidate the underyling causes.

Systematic characterization of AT1 receptor antagonists with label-free dynamic mass redistribution assays

INTRODUCTION

In the drug discovery field, the binding affinities and binding kinetics of drug candidates are very important. Angiotensin II type 1 (AT1) receptor antagonists, e.g., candesartan, telmisartan, irbesartan, losartan and valsartan, show high affinities and long-lasting bindings to the receptor, making them preferred medications for hypertension treatment. However, the molecular binding properties of AT1 receptor antagonists are controversial.

METHODS

In this work, we established a profile to study the phenotypic properties of AT1 receptor antagonists with label-free dynamic mass redistribution (DMR) assays in native human cells. With noninvasive features, DMR assay were conducted in multiple formats. Eleven antagonists were systematically evaluated with angiotensin II as an agonist probe in the Hep G2 cell line, which endogenously expresses the AT1 receptor.

RESULTS

The IC₅₀ values to the AT1 receptor of individual antagonist varied with different incubation times. The antagonists showed competitive behavior with angiotensin II. Schild analysis was used to analyze the competitive behavior of the antagonist. All of the antagonist showed long-lasting possession of the AT1 receptor, except telmisartan. The systematic evaluation of the antagonists implied that 11 antagonists showed high binding affinity but distinct binding modes to AT1 receptor.

DISCUSSION

This study demonstrated that the DMR assay has great potential for determining the pharmacological parameters of ligands. This work may serve as guidance for other receptor and ligand assays.

Biological Activity-Based Prioritization of Pharmaceuticals in Wastewater for Environmental Monitoring: G Protein-Coupled Receptor Inhibitors

Pharmaceuticals raise concerns for aquatic species owing to their biological activities. It is estimated that nearly 40% of marketed pharmaceuticals target G protein-coupled receptors (GPCRs). Using an in vitro transforming growth factor-α (TGFα) shedding assay, we previously detected antagonistic activities of GPCR-acting pharmaceuticals against angiotensin (AT1), dopamine (D2), acetylcholine (M1), adrenergic family members (β1), and histamine (H1) receptors at up to μg-antagonist-equivalent quantities/L in wastewater in England and Japan. However, which pharmaceuticals were responsible for biological activities in wastewater remained unclear. Here, we used (1) the consumption of GPCR-acting pharmaceuticals, particularly antagonists, as calculated from prescriptions, (2) their urinary excretion, and (3) their potency measured by the TGFα shedding assay to prioritize them for analysis in wastewater in England and Japan. We calculated predicted activities of 48 GPCR-acting pharmaceuticals in influents in England and Japan and identified which were mainly responsible for antagonistic activities in wastewater against each GPCR. Mixtures of pharmaceuticals tested in this study were confirmed to behave additively. The combination of consumption and potency is useful in prioritizing pharmaceuticals for environmental monitoring and toxicity testing.

Pneumoperitoneum in laparoscopy and preoperative antihypertensive agents: A retrospective study

The purpose of the current study was to investigate the effects of preoperative antihypertensive agents on blood pressure (BP) changes after intraperitoneal CO₂ insufflation during laparoscopic surgery. The medical records of patients (≥50 years old) undergoing laparoscopic colon surgery were retrospectively analyzed (n=342). The patients were divided into four groups: normotensive group (group N), monotherapy with angiotensin receptor blockers (ARBs) (group A), monotherapy with calcium channel blockers (CCBs) (group C), and combination therapy with ARBs and CCBs (group AC). The systolic BP changes were investigated, and their correlations with preoperative pulse pressure were analyzed. The degree of increase from baseline BP to that after CO₂ insufflation was significantly lower in groups A [difference vs. group N, 17.8; 95% confidence interval (CI), 7.8-27.8; P=0.001) and AC (18.2; 95% CI, 8.7-27.7; P<0.001] compared with groups N and C. The incidence of intraoperative hypotension was not significantly different among the groups. In groups A and AC, the preoperative pulse pressure showed a strong correlation (r=0.73 and 0.83, respectively) with the increase in BP after CO₂ insufflation. In conclusion, patients with hypertension who received ARBs before surgery showed a strong correlation between the preoperative pulse pressure and BP fluctuation immediately after CO₂ insufflation. Small BP fluctuations are suggested to indicate the positive role of ARBs. Large randomized controlled trials are required to validate these results and assess the effect of each antihypertensive agent. This trial was registered (Trial registration: http://www.who.int/ictrp/network/cris2/en/; CRIS; KCT0002595) on the 23 November 2017.

Effect of angiotensin II receptor blocker and salt supplementation on short-term blood pressure variability in type 2 diabetes

High blood pressure variability (BPV) has been associated with increased cardiovascular (CV) risk. The effect of dietary salt and renin-angiotensin-aldosterone system (RAAS) activity on short-term BPV in type 2 diabetes mellitus (T2DM) is not well characterised. We aimed to determine the effect of dietary salt (sodium chloride, NaCl) supplementation on 24-h mean arterial BPV (24hBPV) during angiotensin II receptor blocker (telmisartan) use and to evaluate the effects of age, sex, plasma renin activity (PRA) and serum aldosterone on 24hBPV. In a randomised, double-blind, crossover study, patients with T2DM (n = 28), treated with telmisartan received NaCl (100 mmol/24 h) or placebo capsules during 2 weeks of telmisartan. Following a 6-week washout, the protocol was repeated in reverse. 24hBPV was evaluated as a co-efficient of variation [CV (%) = mean/standard deviation] × 100). Twenty-four hour urinary sodium excretion, ambulatory BP and biochemical tests were performed at each phase. Results were analysed using a linear mixed model to generate predicted values for 24hBPV. Predicted 24hBPV was higher with telmisartan vs baseline (p = 0.01), with a trend towards reduced 24hBPV with salt (p = 0.052). Predicted 24hBPV was lower in females (p = 0.017), increasing age (p = 0.001) and increasing PRA (p = 0.011). In patients with T2DM, predicted 24hBPV increased from baseline with telmisartan, but there was no additional increase in predicted 24hBPV with salt supplementation. This suggests that in the short-term, salt supplementation has no apparent deleterious effects on 24hBPV. Long-term studies are required to evaluate the effect of 24hBPV on CV outcomes in patients with T2DM.

Antihypertensive and Target-Organ Protective Properties of Telmisartan and Hydrochlorothiazide Single-Pill Combination

The most important result of the revision of the European and Russian guidelines for the management of arterial hypertension (AH) was a special focus on initializing antihypertensive treatment with single-pill combinations (SPCs) in majority patients with AH. Combination of the angiotensin II receptor blocker and thiazide diuretic is one of the possible first line SPCs in the absence of specific clinical conditions according to the new guidelines. In this regard, SPC of telmisartan and hydrochlorothiazide (HCT), worth special noticing in the classes of sartans and thiazide diuretics, since both drugs have a long clinical experience and large body of evidence of antihypertensive efficacy and safety, as well as telmisartan also has a number of superior target-organ protective and metabolic properties distinguishing it from other members of the class. In real clinical practice TANDEM study telmisartan and its SPC with HCT showed high antihypertensive efficacy and good tolerability in patients with all AH grades and with isolated systolic AH and allowed to achieve target blood pressure levels in the most of patients. Long-lasting effect is another essential characteristic of telmisartan, this feature allows to control blood pressure throughout the day, including the morning surge, which is the most “dangerous” in terms of cardiovascular risk. Telmisartan also provide powerful target-organ protection realized at the level of all AH target-organs. Finally, another unique pharmacological property of telmisartan and its combination with HCT is a favourable effect on the carbohydrate and lipid profile, which comprises of increasing tissue sensitivity to insulin, normalizing blood glucose levels, reducing blood total cholesterol, low-density lipoprotein cholesterol and triglycerides and thereby reducing risk of atherosclerosis development and progression. Telmisartan/HCT SPC should be recommended for wide use in hypertensive patients to control blood pressure, protect end-organs, improve prognosis and reduce cardiovascular risk due to its high antihypertensive efficacy, the ability to provide the large target-organ protection and a beneficial metabolic effect.

Early Experience With Sacubitril/Valsartan in Adult Patients With Congenital Heart Disease

Background:

Heart failure (HF) is the leading cause of hospitalizations and death in patients with adult congenital heart disease (ACHD). Sacubitril/valsartan is a new agent in the treatment of HF, but its effects have not been assessed in ACHD.

Methods:

We retrospectively studied all 15 patients with ACHD at our center who were prescribed sacubitril/valsartan between June 2017 and June 2018. We assessed baseline characteristics and clinical and laboratory changes after initiation of sacubitril/valsartan. Adverse events, including renal function, medication intolerance, and worsening HF were documented.

Results:

The median age was 53.2 (27.6-83.6) years, with a median follow-up duration of 69 (8-419) days. At baseline, all patients had refractory HF despite guideline-directed medical therapy, with ten (67%) patients as New York Heart Association (NYHA) class II, and five (33%) patients NYHA class III. The medication was discontinued in one (7%) patient secondary to worsening kidney function. No patients reported clinical deterioration; four NYHA class III patients with complex CHD, pulmonary hypertension, and cyanosis reported significant improvement to NYHA class II. Baseline creatinine was 1.1 (0.9-1.7) and two weeks after starting sacubitril/valsartan it was 1.3 (0.8-2.5, P = .22).

Conclusions:

Sacubitril/valsartan seems to be well tolerated in patients with ACHD who present with refractory HF symptoms. Patients with complex CHD associated with cyanosis and pulmonary hypertension could benefit the most, but larger studies are needed to assess the safety as well as the effectiveness of sacubitril/valsartan in this patient population.