Clinical pharmacokinetics and selective pharmacodynamics of new angiotensin converting enzyme inhibitors: an update

Drug administration via feeding tubes-a procedure that carries risks: systematic identification of critical factors based on commonly administered drugs in a cohort of stroke patients

PURPOSE

Drug administration via feeding tubes is considered a process with many uncertainties. This review aimed to give a comprehensive overview of data available on feeding tube application and to carry out risk assessments for drug substances commonly administered to stroke patients.

METHODS

Drugs frequently administered via feeding tubes were identified through a retrospective analysis of discharge letters from a stroke unit. Physicochemical, pharmacokinetic, and stability properties of these drugs and data on drug-enteral nutrition interactions were systematically searched for in the European Pharmacopoeia, Hagers Handbook of Pharmaceutical Practice, Birchers clinical-pharmacological data compilation, and the Martindale Complete Drug Reference, as well as from databases including DrugBank, DrugDex, PubChem, Google Scholar, and PubMed.

RESULTS

Of the drugs most commonly administered via feeding tubes in the present stroke patient cohort, bisoprolol, candesartan, and ramipril could be considered the least critical due to their overall favourable properties. Acetylsalicylic acid, amlodipine, hydrochlorothiazide, omeprazole and esomeprazole, simvastatin, and torasemide pose risks based on pH or light-dependent instability or proposed food effects. The most critical drugs to be administered via feeding tubes are considered to be furosemide, levodopa, and levothyroxine as they show relevant instabilities under administration conditions and substantial food effects; the latter two even possess a narrow therapeutic index. However, little information is available on drug-tube and drug-formula interactions.

CONCLUSION

Feeding tube administration of medications turned out to be a highly complex process with several unmet risks. Therefore, investigations that systematically assess these risk factors using clinically relevant model systems are urgently needed.

Discontinuation vs. continuation of renin-angiotensin system inhibition before non-cardiac surgery: the SPACE trial

BACKGROUND AND AIMS

Haemodynamic instability is associated with peri-operative myocardial injury, particularly in patients receiving renin-angiotensin system (RAS) inhibitors (angiotensin-converting-enzyme inhibitors/angiotensin II receptor blockers). Whether stopping RAS inhibitors to minimise hypotension, or continuing RAS inhibitors to avoid hypertension, reduces peri-operative myocardial injury remains unclear.

METHODS

From 31 July 2017 to 1 October 2021, patients aged ≥60 years undergoing elective non-cardiac surgery were randomly assigned to either discontinue or continue RAS inhibitors prescribed for existing medical conditions in six UK centres. Renin-angiotensin system inhibitors were withheld for different durations (2-3 days) before surgery, according to their pharmacokinetic profile. The primary outcome, masked to investigators, clinicians, and patients, was myocardial injury [plasma high-sensitivity troponin-T (hs-TnT) ≥ 15 ng/L within 48 h after surgery, or ≥5 ng/L increase when pre-operative hs-TnT ≥15 ng/L]. Pre-specified adverse haemodynamic events occurring within 48 h of surgery included acute hypertension (>180 mmHg) and hypotension requiring vasoactive therapy.

RESULTS

Two hundred and sixty-two participants were randomized to continue (n = 132) or stop (n = 130) RAS inhibitors. Myocardial injury occurred in 58 (48.3%) patients randomized to discontinue, compared with 50 (41.3%) patients who continued, RAS inhibitors [odds ratio (for continuing): 0.77; 95% confidence interval (CI) 0.45-1.31]. Hypertensive adverse events were more frequent when RAS inhibitors were stopped [16 (12.4%)], compared with 7 (5.3%) who continued RAS inhibitors [odds ratio (for continuing): 0.4; 95% CI 0.16-1.00]. Hypotension rates were similar when RAS inhibitors were stopped [12 (9.3%)] or continued [11 (8.4%)].

CONCLUSIONS

Discontinuing RAS inhibitors before non-cardiac surgery did not reduce myocardial injury, and could increase the risk of clinically significant acute hypertension. These findings require confirmation in future studies.

Simultaneously Predicting the Pharmacokinetics of CES1-Metabolized Drugs and Their Metabolites Using Physiologically Based Pharmacokinetic Model in Cirrhosis Subjects

Hepatic carboxylesterase 1 (CES1) metabolizes numerous prodrugs into active ingredients or direct-acting drugs into inactive metabolites. We aimed to develop a semi-physiologically based pharmacokinetic (semi-PBPK) model to simultaneously predict the pharmacokinetics of CES1 substrates and their active metabolites in liver cirrhosis (LC) patients. Six prodrugs (enalapril, benazepril, cilazapril, temocapril, perindopril and oseltamivir) and three direct-acting drugs (flumazenil, pethidine and remimazolam) were selected. Parameters such as organ blood flows, plasma-binding protein concentrations, functional liver volume, hepatic enzymatic activity, glomerular filtration rate (GFR) and gastrointestinal transit rate were integrated into the simulation. The pharmacokinetic profiles of these drugs and their active metabolites were simulated for 1000 virtual individuals. The developed semi-PBPK model, after validation in healthy individuals, was extrapolated to LC patients. Most of the observations fell within the 5th and 95th percentiles of simulations from 1000 virtual patients. The estimated AUC and Cmax were within 0.5-2-fold of the observed values. The sensitivity analysis showed that the decreased plasma exposure of active metabolites due to the decreased CES1 was partly attenuated by the decreased GFR. Conclusion: The developed PBPK model successfully predicted the pharmacokinetics of CES1 substrates and their metabolites in healthy individuals and LC patients, facilitating tailored dosing of CES1 substrates in LC patients.

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.

Atomistic simulations suggest dietary flavonoids from Beta vulgaris (beet) as promising inhibitors of human angiotensin-converting enzyme and 2-alpha-adrenergic receptors in hypertension

Motivation

Beta vulgaris (beet) is extensively reported for its antihypertensive activity. However, the mechanismunderpinning its antihypertensive activity is not well understood. In this study, we evaluated the in silico interactionsof 70 compounds derived from beta vulgaris against the active sites of angiotensin-converting enzyme (ACE) and alpha-adrenergic receptor (AR).

Results

Structure-based virtual screening against angiotensin-converting enzyme revealed that, Cochliophilin A (-9.0 Kcal/mol), Miraxanthin (-8.3 Kcal/mol), and quercimeritrin (-9.7 Kcal/mol) had lower docking scores than the reference lisinopril (-7.9 Kcal/mol). These compounds exhibited dual binding tendency as they also ranked top compounds upon screening against adrenergic receptor. The thermodynamic parameters computed from the resulting trajectories obtained from the 100 ns full atomistic molecular dynamics simulation revealed structural stability and conformational flexibility of the ligand-receptor complexes as indicated by the RMSD, RMSF, RoG, SASA, and H-bond calculations. The molecular mechanics with generalized Born and surface area solvation binding energy calculations revealed that the proteins exhibit considerable binding energy with the phytochemicals in a dynamic environment. Furthermore, the hit compounds possess good physicochemical properties and drug-likeness. Overall, cochliophilin and quercimeritrin are promising dual-target directed flavonoids from Beta vulgaris; and are suggested for further experimental and preclinical evaluation.

Availability and implementation

All data was provided in the manuscript.

Angiotensin-converting enzyme inhibitor induced cough compared with placebo, and other antihypertensives: A systematic review, and network meta-analysis

Studies have shown that angiotensin converting enzyme inhibitors (ACEIs) are superior in primary and secondary prevention for cardiac mortality and morbidity to angiotensin receptor blocker (ARBs). One of the common side effects from ACEI is dry cough. The aims of this systematic review, and network meta-analysis are to rank the risk of cough induced by different ACEIs and between ACEI and placebo, ARB or calcium channel blockers (CCB). We performed a systematic review, and network meta-analysis of randomized controlled trials to rank the risk of cough induced by each ACEI and between ACEI and placebo, ARB or CCB. A total of 135 RCTs with 45,420 patients treated with eleven ACEIs were included in the analyses. The pooled estimated relative risk (RR) between ACEI and placebo was 2.21 (95% CI: 2.05-2.39). ACEI had more incidences of cough than ARB (RR 3.2; 95% CI: 2.91, 3.51), and pooled estimated of RR between ACEI and CCB was 5.30 (95% CI: 4.32-6.50) Moexipril ranked as number one for inducing cough (SUCRA 80.4%) and spirapril ranked the least (SUCRA 12.3%). The order for the rest of the ACEIs are as follows: ramipril (SUCRA 76.4%), fosinopril (SUCRA 72.5%), lisinopril (SUCRA 64.7%), benazepril (SUCRA 58.6%), quinapril (SUCRA 56.5%), perindopril (SUCRA 54.1%), enalapril (SUCRA 49.7%), trandolapril (SUCRA 44.6%) and, captopril (SUCRA 13.7%). All ACEI has the similar risk of developing a cough. ACEI should be avoided in patients who have risk of developing cough, and an ARB or CCB is an alternative based on the patient's comorbidity.

Dosing time optimization of antihypertensive medications by including the circadian rhythm in pharmacokinetic-pharmacodynamic models

Blood pressure (BP) follows a circadian variation, increasing during active hours, showing a small postprandial valley and a deeper decrease during sleep. Nighttime reduction of 10–20% relative to daytime BP is defined as a dipper pattern, and a reduction of less than 10%, as a non-dipper pattern. Despite this BP variability, hypertension’s diagnostic criteria and therapeutic objectives are usually based on BP average values. Indeed, studies have shown that chrono-pharmacological optimization significantly reduces long-term cardiovascular risk if a BP dipper pattern is maintained. Changes in the effect of antihypertensive medications can be explained by circadian variations in their pharmacokinetics (PK) and pharmacodynamics (PD). Nevertheless, BP circadian variation has been scarcely included in PK-PD models of antihypertensive medications to date. In this work, we developed PK-PD models that include circadian rhythm to find the optimal dosing time (Ta) of first-line antihypertensive medications for dipper and non-dipper patterns. The parameters of the PK-PD models were estimated using global optimization, and models were selected according to the lowest corrected Akaike information criterion value. Simultaneously, sensitivity and identifiability analysis were performed to determine the relevance of the parameters and establish those that can be estimated. Subsequently, Ta parameters were optimized to maximize the effect on BP average, BP peaks, and sleep-time dip. As a result, all selected models included at least one circadian PK component, and circadian parameters had the highest sensitivity. Furthermore, Ta with which BP>130/80 mmHg and a dip of 10–20% are achieved were proposed when possible. We show that the optimal Ta depends on the therapeutic objective, the medication, and the BP profile. Therefore, our results suggest making chrono-pharmacological recommendations in a personalized way.

Predictors of hypotension during anesthesia induction in patients with hypertension on medication: a retrospective observational study

Background

Hypotension during anesthesia induction is a common event, and occurs more frequently in patients with hypertension than in healthy individuals. Intraoperative hypotension in non-cardiac surgery is reportedly associated with various postoperative complications. However, the predictors of hypotension during anesthesia induction in patients with hypertension have not yet been ascertained. Therefore, we aimed to determine the predictors of hypotension during anesthesia induction in patients with hypertension on medication focusing on the half-life of the medication used.

Methods

In this retrospective observational study, we enrolled patients with hypertension on medication who underwent general anesthesia for oral and maxillofacial surgery between January 1, 2013, and December 31, 2019. Multivariable logistic regression analysis was conducted to test for associations between clinical factors and hypotension during anesthesia induction in patients with hypertension on medication.

Results

A total of 395 patients were included in this study. The risk factors for hypotension during anesthesia induction in patients with hypertension on medication were pre-induction mean arterial blood pressure (adjusted unit odds ratio, 0.96 [95% confidence interval, 0.94 to 0.98]), female sex (adjusted odds ratio [aOR], 1.63 [1.03 to 2.57]), regular use of angiotensin receptor blockers (ARBs)/angiotensin-converting enzyme inhibitors (ACE-Is) with a long half-life (vs. no regular use of ARBs/ACE-Is aOR, 4.02 [1.77 to 9.12]; vs. regular use of ARBs/ACE-Is with a short-to-middle half-life aOR, 3.17 [1.46 to 6.85]), and regular use of beta blockers (aOR, 2.45 [1.19 to 5.04]). Regular use of calcium channel blockers (aOR, 0.44 [0.25 to 0.77]) was a suppressive factor for hypotension during anesthesia induction in patients with hypertension.

Conclusions

In patients with hypertension on medication, regular use of ARBs/ACE-Is with a long half-life, regular use of beta blockers, low pre-induction mean arterial blood pressure, and female sex were risk factors for hypotension during anesthesia induction. Notably, regular use of ARBs/ACE-Is with a long half-life was a high-risk factor for hypotension during anesthesia induction in patients with hypertension on medication even after a 24-h preoperative withdrawal period.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01899-9.

Bioequivalence evaluation and food effect assessment of Lisinopril/amlodipine tablets in healthy Chinese subjects under fasting and fed conditions

PURPOSE

The combination of lisinopril and amlodipine has a marked additional effect on blood pressure and fewer side effects than individual monotherapy. This study was conducted to compare the pharmacokinetic parameters and evaluate the bioequivalence between two Lisinopril/amlodipine tablets in healthy Chinese subjects.

METHODS

A single center, randomized, open-label, single-dose, two-period crossover bioequivalence study was designed in healthy Chinese subjects under both fasting and fed conditions. Blood samples were collected before drug administration and at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 24, 36, 48, 72, 96, 144, 168 h after administration. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to determine the plasma concentration of lisinopril and amlodipine. Maximum concentration (C_max) and area under the concentration-time curve (AUC) were used to evaluate bioequivalence. Adverse events were recorded.

RESULTS

Ninety-two healthy subjects were enrolled, and 75 completed the study. The 90% confidence intervals (CIs) of the ratio of geometric means (GMRs) of C_max, AUC_0-t, and AUC_0-∞ of lisinopril and amlodipine under both fasting and fed conditions fell within the conventional bioequivalence criteria of 0.80-1.25. A high-fat meal appeared to decrease the C_max and AUC of lisinopril. No severe adverse events were observed.

CONCLUSION

The trial demonstrated that the test and the reference lisinopril/amlodipine tablets were bioequivalent and well tolerated in Chinese people under fasting and fed conditions.

TRIAL REGISTRATION

Clinical Trails.gov identifier, NCT04885660 (retrospectively registered in 13/05/ 2021).

Transcriptional Regulation of Carboxylesterase 1 in Human Liver: Role of the Nuclear Receptor Subfamily 1 Group H Member 3 and Its Splice Isoforms

Carboxylesterase 1 (CES1) is the predominant carboxylesterase in the human liver, involved in metabolism of both xenobiotics and endogenous substrates. Genetic or epigenetic factors that alter CES1 activity or expression are associated with changes in drug response, lipid, and glucose homeostasis. However, the transcriptional regulation of CES1 in the human liver remains uncertain. By applying both the random forest and Sobol's Sensitivity Indices (SSI) to analyze existing liver RNA expression microarray data (GSE9588), we identified nuclear receptor subfamily 1 group H member 3 (NR1H3) liver X receptor (LXR)α as a key factor regulating constitutive CES1 expression. This model prediction was validated using small interfering RNA (siRNA) knockdown and CRISPR-mediated transcriptional activation of NR1H3 in Huh7 and HepG2 cells. We found that NR1H3's activation of CES1 is splice isoform-specific, namely that increased expression of the NR1H3-211 isoform increased CES1 expression whereas NR1H3-201 did not. Also, in human liver samples, expression of NR1H3-211 and CES1 are correlated, whereas NR1H3-201 and CES1 are not. This trend also occurs during differentiation of induced pluripotent stem cells (iPSCs) to hepatocytes, where only expression of the NR1H3-211 isoform parallels expression of CES1 Moreover, we found that treatment with the NR1H3 agonist T0901317 in HepG2 cells had no effect on CES1 expression. Overall, our results demonstrate a key role of NR1H3 in maintaining the constitutive expression of CES1 in the human liver. Furthermore, our results support that the effect of NR1H3 is splice isoform-specific and appears to be ligand independent. SIGNIFICANCE STATEMENT: Despite the central role of carboxylesterase 1 (CES1) in metabolism of numerous medications, little is known about its transcriptional regulation. This study identifies nuclear receptor subfamily 1 group H member 3 as a key regulator of constitutive CES1 expression and therefore is a potential target for future studies to understand interperson variabilities in CES1 activity and drug metabolism.

Once- Versus Twice-Daily Angiotensin-Converting Enzyme Inhibitors for Blood Pressure Control in Adult Patients With Hypertension

This review aimed to assess the efficacy and safety of once- versus twice-daily administration of angiotensin-converting enzyme (ACE) inhibitors for the management of hypertension. A literature search on PubMed and Google Scholar was performed (January 1980 to June 2020) using the following search terms: ACE inhibitors, lisinopril, enalapril, fosinopril, trandolapril, ramipril, perindopril, captopril, benazepril, ambulatory blood pressure, hypertension, twice-daily dosing, once-daily dosing. Reference lists from retrieved articles were examined for additional reports. Relevant English-language studies or those conducted in humans were considered. Overall, six studies were included that compared the efficacy of once-daily to twice-daily dosing of ACE inhibitors. Similar blood pressure-lowering effects, and, in some studies, greater blood pressure lowering has been noted in the twice-daily administration arm than once-daily administration of ACE inhibitors. ACE inhibitors' pharmacokinetic and pharmacodynamic properties play an integral role in determining the expected blood pressure-lowering outcome. It is noteworthy that adherence issues may arise when transitioning from a once-daily regimen to a twice-daily regimen. There appear to be no added safety concerns between twice-daily and once-daily administration of ACE inhibitors regarding safety outcomes. After reviewing the available literature, twice-daily dosing of ACE inhibitors may promote added blood pressure-lowering effects, with the advantages of reducing cost, reducing the risk of drug-drug interactions, reducing polypharmacy, and reducing patient confusion about their medications. Recommendations for twice-daily administration of ACE -inhibitors should be made via shared decision-making with the patient, and clinician judgment, to drive treatment selection.

A novel angiotensin I-converting enzyme inhibitory peptide derived from the trypsin hydrolysates of salmon bone proteins

When fish are processed, fish bone becomes a key component of the waste, but to date very few researchers have sought to use fish bone to prepare protein hydrolysates as a means of adding value to the final product. This study, therefore, examines the potential of salmon bone, through an analysis of the benefits of its constituent components, namely fat, moisture, protein, and ash. In particular, the study seeks to optimize the process of enzymatic hydrolysis of salmon bone with trypsin in order to produce angiotensin-I converting enzyme (ACE) inhibitory peptides making use of response surface methodology in combination with central composite design (CCD). Optimum hydrolysis conditions concerning DH (degree of hydrolysis) and ACE-inhibitory activity were initially determined using the response surface model. Having thus determined which of the salmon bone protein hydrolysates (SBPH) offered the greatest level of ACE-inhibitory activity, these SBPH were duly selected to undergo ultrafiltration for further fractionation. It was found that the greatest ACE-inhibitory activity was achieved by the SBPH fraction which had a molecular weight lower than 0.65 kDa. This fraction underwent further purification using RP-HPLC, revealing that the F7 fraction offered the best ACE-inhibitory activity. For ACE inhibition, the ideal peptide in the context of the F7 fraction comprised eight amino acids: Phe-Cys-Leu-Tyr-Glu-Leu-Ala-Arg (FCLYELAR), while analysis of the Lineweaver-Burk plot revealed that the FCLYELAR peptide can serve as an uncompetitive ACE inhibitor. An examination of the molecular docking process showed that the FCLYELAR peptide was primarily able to provide ACE-inhibitory qualities as a consequence of the hydrogen bond interactions taking place between ACE and the peptide. Furthermore, upon isolation form the SBPH, the ACE-inhibitory peptide demonstrated ACE-inhibitory capabilities in vitro, underlining its potential for applications in the food and pharmaceutical sectors.

Inhibition of Angiotensin-I Converting Enzyme by Ginsenosides: Structure-Activity Relationships and Inhibitory Mechanism

Ginseng (Panax ginseng C. A. Meyer) extract has been reported to inhibit the angiotensin converting enzyme (ACE); however, the possible inhibitory action of most of its constituents (ginsenosides) against ACE remains unknown. Thus, in this study, we investigated ginsenoside derivatives' inhibitory effect on ACE. We assessed the activities of 22 ginsenosides, most of which inhibited ACE significantly. Notably, protopanaxatriol, protopanaxadiol, and ginsenoside Rh2 exhibited the most potent ACE inhibitory potential, with IC₅₀ values of 1.57, 2.22, and 5.60 μM, respectively. Further, a kinetic study revealed different modes of inhibition against ACE. Molecular docking studies have confirmed that ginsenosides inhibit ACE via many hydrogen bonds and hydrophobic interactions with catalytic residues and zinc ion of C- and N-domain ACE that block the catalytic activity of ACE. In addition, we found that the active ginsenosides stimulated glucose uptake in insulin-resistant C2C12 skeletal muscle cells in a dose-dependent manner. Moreover, the most active ginsenosides' reactive oxygen species (ROS) and peroxynitrite (ONOO^-) scavenging properties were evaluated, in which IC₅₀ values ranged from 1.44-43.83 to 2.36-39.56 μM in ONOO^- and ROS, respectively. The results derived from these computational and in vitro experiments provide additional scientific support for the anecdotal use of ginseng in traditional medicine to treat cardiovascular diseases such as hypertension.

Molecules and Mechanisms to Overcome Oxidative Stress Inducing Cardiovascular Disease in Cancer Patients

Reactive oxygen species (ROS) are molecules involved in signal transduction pathways with both beneficial and detrimental effects on human cells. ROS are generated by many cellular processes including mitochondrial respiration, metabolism and enzymatic activities. In physiological conditions, ROS levels are well-balanced by antioxidative detoxification systems. In contrast, in pathological conditions such as cardiovascular, neurological and cancer diseases, ROS production exceeds the antioxidative detoxification capacity of cells, leading to cellular damages and death. In this review, we will first describe the biology and mechanisms of ROS mediated oxidative stress in cardiovascular disease. Second, we will review the role of oxidative stress mediated by oncological treatments in inducing cardiovascular disease. Lastly, we will discuss the strategies that potentially counteract the oxidative stress in order to fight the onset and progression of cardiovascular disease, including that induced by oncological treatments.

COVID's Razor: RAS Imbalance, the Common Denominator Across Disparate, Unexpected Aspects of COVID-19

A modern iteration of Occam's Razor posits that "the simplest explanation is usually correct." Coronavirus Disease 2019 involves widespread organ damage and uneven mortality demographics, deemed unexpected from what was originally thought to be "a straightforward respiratory virus." The simplest explanation is that both the expected and unexpected aspects of COVID-19 share a common mechanism. Silent hypoxia, atypical acute respiratory distress syndrome (ARDS), stroke, olfactory loss, myocarditis, and increased mortality rates in the elderly, in men, in African-Americans, and in patients with obesity, diabetes, and cancer-all bear the fingerprints of the renin-angiotensin system (RAS) imbalance, suggesting that RAS is the common culprit. This article examines what RAS is and how it works, then from that baseline, the article presents the evidence suggesting RAS involvement in the disparate manifestations of COVID-19. Understanding the deeper workings of RAS helps one make sense of severe COVID-19. In addition, recognizing the role of RAS imbalance suggests potential routes to mitigate COVID-19 severity.

Review on druggable targets of key age-associated properties regulated by therapeutic agents

Aging is a biological process which accounts for the deterioration of effective physiological functions. The malfunctioning of vital organ systems leads to the onset of neurodegenerative, cardiovascular, and immunomodulatory diseases in the elder population. Age-dependent mitochondrial dysfunctions trigger the production of reactive oxygen species, which serve as a major contributing factor for the onset of age-associated diseases. The increasing burden of age-related pathologies explicates the relevance of identifying novel therapeutic agents with enhanced potency and bioavailability. Key information on the biological mechanisms of significant age-related diseases aids in understanding relevant druggable targets essential for the initiation and progression of the disease. This review provides detailed insights into the druggable targets of key anti-aging properties of therapeutic agents such as anti-oxidant, immunomodulation, cardioprotection, anti-melanogenic, and anti-elastase properties. This information aids in the development of novel therapeutic agents/ supplements with enhanced efficacy.

Risks of ACE Inhibitor and ARB Usage in COVID-19: Evaluating the Evidence

Concerns have been raised regarding the safety of angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in patients with coronavirus disease of 2019 (COVID‐19), based on the hypothesis that such medications may raise expression of ACE2, the receptor for severe acute respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2). We conducted a literature review of studies (n = 12) in experimental animals and human subjects (n = 12) and evaluated the evidence regarding the impact of administration of ACEIs and ARBs on ACE2 expression. We prioritized studies that assessed ACE2 protein expression data, measured directly or inferred from ACE2 activity assays. The findings in animals are inconsistent with respect to an increase in ACE2 expression in response to treatment with ACEIs or ARBs. Control/sham animals show little to no effect in the plurality of studies. Those studies that report increases in ACE2 expression tend to involve acute injury models and/or higher doses of ACEIs or ARBs than are typically administered to patients. Data from human studies overwhelmingly imply that administration of ACEIs/ARBs does not increase ACE2 expression. Available evidence, in particular, data from human studies, does not support the hypothesis that ACEI/ARB use increases ACE2 expression and the risk of complications from COVID‐19. We conclude that patients being treated with ACEIs and ARBs should continue their use for approved indications.

Synthesis of chiral α-substituted α-amino acid and amine derivatives through Ni-catalyzed asymmetric hydrogenation

Highly efficient Ni-catalyzed asymmetric hydrogenation of cyclic N-sulfonyl ketimino esters was, for the first time, successfully developed, providing various chiral α-monosubstituted α-amino acid derivatives with excellent results (97-99% yields, 90 to >99% ee). Cyclic N-sulfonyl ketimines were also hydrogenated well to afford chiral amine derivatives with 98-99% yields and 97 to >99% ee. The gram-scale asymmetric hydrogenation was performed well with 85% yield and 99% ee using only 0.2 mol% catalyst.

Considerations for Docking of Selective Angiotensin-Converting Enzyme Inhibitors

The angiotensin-converting enzyme (ACE) is a two-domain dipeptidylcarboxypeptidase, which has a direct involvement in the control of blood pressure by performing the hydrolysis of angiotensin I to produce angiotensin II. At the same time, ACE hydrolyzes other substrates such as the vasodilator peptide bradykinin and the anti-inflammatory peptide N-acetyl-SDKP. In this sense, ACE inhibitors are bioactive substances with potential use as medicinal products for treatment or prevention of hypertension, heart failures, myocardial infarction, and other important diseases. This review examined the most recent literature reporting ACE inhibitors with the help of molecular modeling. The examples exposed here demonstrate that molecular modeling methods, including docking, molecular dynamics (MD) simulations, quantitative structure-activity relationship (QSAR), etc, are essential for a complete structural picture of the mode of action of ACE inhibitors, where molecular docking has a key role. Examples show that too many works identified ACE inhibitory activities of natural peptides and peptides obtained from hydrolysates. In addition, other works report non-peptide compounds extracted from natural sources and synthetic compounds. In all these cases, molecular docking was used to provide explanation of the chemical interactions between inhibitors and the ACE binding sites. For docking applications, most of the examples exposed here do not consider that: (i) ACE has two domains (nACE and cACE) with available X-ray structures, which are relevant for the design of selective inhibitors, and (ii) nACE and cACE binding sites have large dimensions, which leads to non-reliable solutions during docking calculations. In support of the solution of these problems, the structural information found in Protein Data Bank (PDB) was used to perform an interaction fingerprints (IFPs) analysis applied on both nACE and cACE domains. This analysis provides plots that identify the chemical interactions between ligands and both ACE binding sites, which can be used to guide docking experiments in the search of selective natural components or novel drugs. In addition, the use of hydrogen bond constraints in the S₂ and S₂′ subsites of nACE and cACE are suggested to guarantee that docking solutions are reliable.

Screening of cardiovascular agents in plasma with LC-MS/MS: A valuable tool for objective drug adherence assessment

Adherence to cardiovascular preventive agents is important to prevent short and long term cardiovascular events. Recently, qualitatively compound screening using liquid chromatography-tandem mass spectrometry (LC-MS/MS) has gained interest for drug adherence assessment in patients at high risk of cardiovascular events. Therefore, we developed and tested an assay including 52 compounds and metabolites, covering over 95% of the antihypertensive and antithrombotic agents available worldwide. Trichloroacetic acid was used as simple and fast method for protein precipitation. The assay was validated for lower limit of quantification (LLOQ), linearity, stability for freeze/thaw, room temperature, autosampler and matrix effects. The LLOQ for each compound was targeted under the population trough concentration (PTC) as reported in literature to assure high sensitivity for adherence detection. This was accomplished for 50 of 52 compounds with a LLOQ equal or lower compared to the PTC. Linearity was confirmed for all compounds (r² > 0.995), except for acetylsalicylic acid (r² = 0.991). For room temperature stability, 12 compounds showed degradation over 20% after 20 h. 3 compounds suffer from matrix effect with recoveries < 50%. After analytical validation, blood samples from 91 patients with difficult-to-treat hypertension were analyzed. Patients were unaware of adherence assessment. Adherence varied largely per agent and per concentration ratio (CR) (ratio of the detected concentration with LC-MS/MS and the PTC) cut-off value. Additionally, stratification by adherence group showed that the percentage of patients classified as non-adherent increased from 6.6% for qualitative analysis (pos/neg) to 19.8% for a CR cut-off of 0.5. The data imply that using the CR cut off values has a significant and relevant effect on patient adherence classification.

Syndrome of inappropriate secretion of antidiuretic hormone associated with angiotensin-converting enzyme inhibitor therapy in the perioperative period

Introduction:

Angiotensin-converting enzyme (ACE) inhibitors are one of the most commonly used medications for hypertension. Rarely, ACE inhibitors have the potential to cause a syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

Case presentation:

A 70-year-old woman with > 10 years ACE inhibitor therapy with normonatremia suddenly developed severe SIADH when she took a liquid diet in the uneventful perioperative period, with hemodynamic stability and no surgical complications. She promptly recovered from SIADH subsequent to discontinuing the ACE inhibitor therapy and changing her diet. Therefore, it was assumed that excess antidiuretic hormone secretion due to an ACE inhibitor and free water load from the liquid diet contributed to hyponatremia in our patient.

Conclusion:

Patients treated with an ACE inhibitor can latently experience inappropriate secretion of antidiuretic hormone, and rapidly develop severe hyponatremia together with additional factors affecting water or salt homeostasis regardless of the length of the administration duration. Clinicians should monitor serum sodium levels in such patients not only just after the initiation of ACE inhibitors but also upon the appearance of those factors.

A Comparative Effectiveness Study of Renal Parameters Between Imidapril and Amlodipine in Patients with Hypertension: A Retrospective Cohort Study

Introduction

Imidapril is an angiotensin converting enzyme inhibitor (ACEI) that is frequently used as an antihypertensive drug in Japan. Although ACEIs are known to have adverse effects of decreasing glomerular filtration rate (GFR) and causing hyperkalemia, there are very few clinical data on the long-term effect of imidapril on glomerular function. We conducted a retrospective cohort study using a clinical database to evaluate and compare the long-term effects of imidapril and amlodipine on renal parameters in Japanese hypertensive patients in routine clinical practice.

Methods

We identified cohorts of new users of imidapril (n = 57) and a propensity score-matched group with an equal number of new users of amlodipine (n = 57). We used a multivariable regression model to evaluate and compare the effects of the drugs on laboratory parameters including serum levels of creatinine, potassium, sodium, blood urea nitrogen, and estimated GFR (eGFR) between imidapril users and amlodipine users up to 12 months after the initiation of study drug administration. The mean exposure of imidapril and amlodipine was 226.2 and 235.2 days, respectively.

Results

We found a significant increase of serum creatinine and potassium levels and a decrease of eGFR in imidapril users from the baseline period to the exposure period. The reduction of eGFR and the increase of serum creatinine and potassium levels in imidapril users were significantly greater than those in amlodipine users.

Conclusions

Our study showed that imidapril decreased eGFR and increases the serum levels of creatinine and potassium compared with amlodipine, at least during 1 year of administration.

Regulatory effects of genomic translocations at the human carboxylesterase-1 (CES1) gene locus

OBJECTIVE

CES1 encodes carboxylesterase-1, an important drug-metabolizing enzyme with high expression in the liver. Previous studies have reported a genomic translocation of the 5' region from the poorly expressed pseudogene CES1P1, to CES1, yielding the structural variant CES1VAR. The aim of this study was to characterize this translocation and its effect on CES1 expression in the human liver.

MATERIALS AND METHODS

Experiments were conducted in human liver tissues and cell culture (HepG2). The promoter and exon 1 of CES1 were sequenced by Sanger and Ion Torrent sequencing to identify gene translocations. The effects of CES1 5'UTRs on mRNA and protein expression were assessed by quantitative real-time PCR, allelic ratio mRNA analysis by primer extension (SNaPshot), quantitative targeted proteomics, and luciferase reporter gene assays.

RESULTS

Sequencing of CES1 identified two translocations: first, CES1VAR (17% minor allele frequency) comprising the 5'UTR, exon 1, and part of intron 1. A second shorter translocation, CES1SVAR, was observed excluding exon 1 and intron 1 regions (<0.01% minor allele frequency). CES1VAR is associated with 2.6-fold decreased CES1 mRNA and ∼1.35-fold lower allelic mRNA. Luciferase reporter constructs showed that CES1VAR decreases luciferase activity 1.5-fold, whereas CES1SVAR slightly increases activity. CES1VAR was not associated with CES1 protein expression or metabolism of the CES1 substrates enalapril, clopidogrel, or methylphenidate in the liver.

CONCLUSION

The frequent translocation variant CES1VAR reduces mRNA expression of CES1 in the liver by ∼30%, but protein expression and metabolizing activity in the liver were not detectably altered - possibly because of variable CES1 expression masking small allelic effects. Whether drug therapies are affected by CES1VAR will require further in-vivo studies.

Pharmacokinetic profile of defibrotide in patients with renal impairment

Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (VOD/SOS), is an unpredictable, potentially life-threatening complication of hematopoietic stem cell transplant conditioning. Severe VOD/SOS, generally associated with multiorgan dysfunction (pulmonary or renal dysfunction), may be associated with >80% mortality. Defibrotide, recently approved in the US, has demonstrated efficacy treating hepatic VOD/SOS with multiorgan dysfunction. Because renal impairment is prevalent in patients with VOD/SOS, this Phase I, open-label, two-part study in adults examined the effects of hemodialysis and severe or end-stage renal disease (ESRD) on defibrotide pharmacokinetics (PK). Part 1 compared defibrotide PK during single 6.25 mg/kg doses infused with and without dialysis. Part 2 assessed defibrotide plasma PK after multiple 6.25 mg/kg doses in nondialysis-dependent subjects with severe/ESRD versus healthy matching subjects. Among six subjects enrolled in Part 1, percent ratios of least-squares mean and 90% confidence intervals (CIs) on dialysis and nondialysis days were 109.71 (CI: 97.23, 123.78) for maximum observed plasma concentration (C_max); 108.39 (CI: 97.85, 120.07) for area under the concentration–time curve to the time of the last quantifiable plasma concentration (AUC_0–t); and 109.98 (CI: 99.39, 121.70) for AUC extrapolated to infinity (AUC_0–∞). These ranges were within 80%–125%, indicating no significant effect of dialysis on defibrotide exposure/clearance. In Part 2, defibrotide exposure parameters in six subjects with severe/ESRD after multiple doses (AUC_0–t, 113 µg·h/mL; AUC over dosing interval, 113 µg·h/mL; C_max, 53.8 µg/mL) were within 5%–8% of parameters after the first dose (AUC_0–t, 117 µg·h/mL; AUC_0–∞, 118 µg·h/mL; C_max, 54.9 µg/mL), indicating no accumulation. Defibrotide peak and extent of exposures in those with severe/ESRD were ~35%–37% and 50%–60% higher, respectively, versus controls, following single and multiple doses. One adverse event (vomiting, possibly drug-related) was reported. These findings support defibrotide prescribing guidance stating no dose adjustment is necessary for hemodialysis or severe/ESRD.

Antihypertensive drugs metabolism: an update to pharmacokinetic profiles and computational approaches

Drug discovery and development is a high-risk enterprise that requires significant investments in capital, time and scientific expertise. The studies of xenobiotic metabolism remain as one of the main topics in the research and development of drugs, cosmetics and nutritional supplements.

Antihypertensive drugs are used for the treatment of high blood pressure, which is one the most frequent symptoms of the patients that undergo cardiovascular diseases such as myocardial infraction and strokes. In current cardiovascular disease pharmacology, four drug clusters - Angiotensin Converting Enzyme Inhibitors, Beta-Blockers, Calcium Channel Blockers and Diuretics - cover the major therapeutic characteristics of the most antihypertensive drugs. The pharmacokinetic and specifically the metabolic profile of the antihypertensive agents are intensively studied because of the broad inter-individual variability on plasma concentrations and the diversity on the efficacy response especially due to the P450 dependent metabolic status they present.

Several computational methods have been developed with the aim to: (i) model and better understand the human drug metabolism; and (ii) enhance the experimental investigation of the metabolism of small xenobiotic molecules. The main predictive tools these methods employ are rule-based approaches, quantitative structure metabolism/activity relationships and docking approaches.

This review paper provides detailed metabolic profiles of the major clusters of antihypertensive agents, including their metabolites and their metabolizing enzymes, and it also provides specific information concerning the computational approaches that have been used to predict the metabolic profile of several antihypertensive drugs.

How to design a potent, specific, and stable angiotensin-converting enzyme inhibitor

Angiotensin-converting enzyme inhibitors (ACE-Is) are a valuable class of antihypertensive drugs used in the treatment of cardiovascular system-related diseases. Hence, constant research into, and the development of, such compounds remain within the priorities of modern medical sciences. In this respect, a thorough understanding of their chemistry and biology is an important aspect of drug design; therefore, we present here available data on the pharmaceutical properties of ACE-Is. We also review the structural and biochemical features of the molecular target of ACE-Is and demonstrate several known enzyme-inhibitor complexes. Finally, we attempt to create a mathematical model describing the relation between the potency and/or stability of ACE-Is and their structural characteristics using quantitative structure-activity relation (QSAR), and quantitative structure-property relation (QSPR) techniques.

The Evaluation of Dipeptidyl Peptidase (DPP)-IV, α-Glucosidase and Angiotensin Converting Enzyme (ACE) Inhibitory Activities of Whey Proteins Hydrolyzed with Serine Protease Isolated from Asian Pumpkin (Cucurbita ficifolia)

In the present study, whey protein concentrate (WPC-80) and β-lactoglobulin were hydrolyzed with a noncommercial serine protease isolated from Asian pumpkin (Cucurbita ficifolia). Hydrolysates were further fractionated by ultrafiltration using membranes with cut-offs equal 3 and 10 kDa. Peptide fractions of molecular weight lower than 3 and 3-10 kDa were further subjected to the RP-HPLC. Separated preparations were investigated for their potential as the natural inhibitors of dipeptidyl peptidase (DPP-IV), α-glucosidase and angiotensin converting enzyme (ACE). WPC-80 hydrolysate showed higher inhibitory activities against the three tested enzymes than β-lactoglobulin hydrolysate. Especially high biological activities were exhibited by peptide fractions of molecular weight lower than 3 kDa, with ACE IC50 <0.64 mg/mL and DPP-IV IC50 <0.55 mg/mL. This study suggests that peptides generated from whey proteins may support postprandial glycemia regulation and blood pressure maintenance, and could be used as functional food ingredients in the diet of patients with type 2 diabetes.

Effects of imidapril treatment on aquaporin-2 expression in the kidneys and excretion in the urine of hypertensive rats

Renal aquaporin-2 (AQP2) is critical for maintaining water balance and is associated with hypertension. Anti-hypertensive drugs, including imidapril, improve kidney function; however, it remains unclear whether these effects are mediated through the regulation of AQP2. In this study, the effects of imidapril on AQP2 expression in the kidneys and excretion in urine were assessed in hypertensive rats. Hypertension was induced in 24 rats, which were randomized into a control group, treated with water only, and an imidapril treatment group (n=12 per group). Blood and urine samples were collected from all rats to determine blood pressure (BP), serum Na+, urine volume and urine osmolality after 8 weeks of treatment. Molecular and immunological techniques were used to measure the expression of AQP2 in the kidneys. Urine AQP2 concentration was detected by indirect enzyme-linked immunosorbent assay (ELISA). The concentration of plasma arginine vasopressin (AVP), a regulator of AQP2 was detected by radioimmunoassay (RIA). Hypertensive rats treated with imidapril exhibited reduced BP and 24-h urine osmolality, with a concomitant increase in 24-h urine volume, compared with control hypertensive rats (P<0.05). Additionally, the expression of Aqp2 mRNA, detected by RT-PCR, and AQP2 protein, detected by immunohistochemistry and western blotting, in renal tissue significantly decreased (P<0.05). Finally, urine AQP2 concentration increased while plasma AVP concentration decreased following imidapril treatment (P<0.05). These findings indicate that imidapril reduces the expression level of AQP2 in renal tissue and accelerates its excretion.

Pharmacological and Clinical Profile of Moexipril: A Concise Review

Angiotensin-converting enzyme (ACE) inhibitors are effective and safe antihypertensive drugs, with the exception of the rare occasion of angioedema. These drugs have demonstrated additional cardiovascular protective effects to their blood pressure lowering, and their combination with the diuretic hydrochlorothiazide potentiates their antihypertensive effectiveness. Moexipril is a long-acting ACE inhibitor suitable for once-daily administration, and like some ACE inhibitors, moexipril is a prodrug and needs to be hydrolyzed in the liver into its active carboxylic metabolite, moexiprilat, to become effective. Moexipril alone and in combination with low-dose hydrochlorothiazide has been shown in clinical trials to be effective in lowering blood pressure and be well tolerated and safe given in single daily doses. In this review, the pharmacological profile of this drug and its clinical usefulness are discussed.

The effects of the combined use of a PDE5 inhibitor and medications for hypertension, lower urinary tract symptoms and dyslipidemia on corporal tissue tone

ED is closely associated with its comorbidities (hypertension, dyslipidemia and lower urinary tract symptoms (LUTS)). Therefore, several drugs have been prescribed simultaneously with PDE5 inhibitors. If a specific medication for ED comorbidities has enhancing effects on PDE5 inhibitors, it offers alternative combination therapy in nonresponders to monotherapy with PDE5 inhibitors and allows clinicians to treat ED and its comorbidities simultaneously. To establish theoretical basis of choosing an appropriate medication for ED and concomitant disease, we examined the effects combining a PDE5 inhibitor with representative drugs for hypertension, dyslipidemia and LUTS on relaxing the corpus cavernosum of rabbits using the organ-bath technique. The effect of mirodenafil on relaxing phenylephrine-induced cavernosal contractions was significantly enhanced by the presence of 10(-4) M losartan, 10(-6) M nifedipine, 10(-6) M amlodipine, 10(-7) M doxazosin and 10(-9) M tamsulosin (P<0.05). The maximum relaxation effects were 47.2±3.8%, 57.6±2.6%, 64.0±3.7%, 76.1±5.7% and 71.7±5.4%, respectively. Enalapril and simvastatin had no enhancing effects. The relaxation induced by sodium nitroprusside alone (39.0±4.0%) was significantly enhanced in the presence of the 10(-4) M losartan (66.0±6.0%, P<0.05). Tetraethylammonium (1 mM) significantly inhibited the enhancement effects of tamsulosin and doxazosin on mirodenafil-induced relaxation (doxazosin: 76.1±5.7% vs 45.3±2.3%; tamsulosin: 71.7±5.4% vs 48.1±3.5%). On the basis of these findings, losartan seemed to induce synergistic effects through an interaction with nitric oxide. In addition, K(+) channel activation could be one of the mechanisms for the synergistic effect of combining mirodenafil with doxazosin or tamsulosin. We believe that the combination of a PDE5 inhibitor with losartan, nifedipine, amlodipine, doxazosin or tamsulosin could be a pharmacologic strategy for simultaneously treating ED and its comorbidities and increasing response rates to PDE5 inhibitors.

High-risk prescribing and incidence of frailty among older community-dwelling men

Evidence about the association between treatment with high-risk medicines and frailty in older individuals is limited. We investigated the relationship between high-risk prescribing and frailty at baseline, as well as 2-year incident frailty, in 1,662 men ≥70 years of age. High-risk prescribing was defined as polypharmacy (≥5 medicines), hyperpolypharmacy (≥10 medicines), and by the Drug Burden Index (DBI), a dose-normalized measure of anticholinergic and sedative medicines. At baseline, frail participants had adjusted odds ratios (ORs) of 2.55 (95% confidence interval, CI: 1.69-3.84) for polypharmacy, 5.80 (95% CI: 2.90-11.61) for hyperpolypharmacy, and 2.33 (95% CI: 1.58-3.45) for DBI exposure, as compared with robust participants. Of the 1,242 men who were robust at baseline, 6.2% developed frailty over two years. Adjusted ORs of incident frailty were 2.45 (95% CI: 1.42-4.23) for polypharmacy, 2.50 (95% CI: 0.76-8.26) for hyperpolypharmacy, and 2.14 (95% CI: 1.25-3.64) for DBI exposure. High-risk prescribing may contribute to frailty in community-dwelling older men.

Complementary mechanisms of action and rationale for the fixed combination of perindopril and indapamide in treating hypertension - update on clinical utility

Although reducing blood pressure is the most important approach to reduce cardiovascular outcomes in the hypertensive population, the majority of patients fail to attain the targets. Most patients with hypertension need at least 2 antihypertensive agents to achieve blood pressure goals. The 2007 European hypertension guidelines state that combined therapy is needed when monotherapy does not attain blood pressure objectives and as a first-line treatment in high-risk patients. This point has been reinforced in the 2009 update of the European guidelines. The advantages of combination therapy are well documented with the potential for increased antihypertensive efficacy as a result of different mechanisms of action, and a lower incidence of adverse effects because of the lower doses used and the possible compensatory responses. Moreover, the use of fixed dose combinations are specially recommended as they facilitate treatment compliance. The inhibition of the renin-angiotensin system appears to be very beneficial in the treatment of patients with hypertension along the cardiovascular continuum and the combination of a renin-angiotensin system inhibitor and a diuretic is particularly recommended. Many clinical trials have demonstrated the benefits of the fixed combination perindopril/indapamide in the treatment of hypertension. The aim of this manuscript is to update the published data on the efficacy and safety of this fixed combination.

Transcriptional regulation of human carboxylesterase 1A1 by nuclear factor-erythroid 2 related factor 2 (Nrf2)

Human carboxylesterase (CES) 1A, which is predominantly expressed in liver and lung, plays an important role in the hydrolysis of endogenous compounds and xenobiotics. CES1A is reported to be induced in human hepatocytes by butylated hydroxyanisole, ticlopidine and diclofenac, and the induction is assumed to be caused by oxidative stress. However, the molecular mechanism remains to be determined. In this study, we sought to investigate whether CES1A is regulated by nuclear factor-erythroid 2 related factor 2 (Nrf2), which is a transcriptional factor activated by oxidative stress, and clarify the molecular mechanism. Real-time reverse transcription-PCR assays revealed that CES1A1 mRNA was significantly induced by tert-butylhydroquinone (tBHQ) and sulforaphane (SFN), which are representative activators of Nrf2 in HepG2, Caco-2 and HeLa cells. The induction was completely suppressed with small interfering RNA for Nrf2. In HepG2 cells, the CES1A protein level and imidapril hydrolase activity, which is specifically catalyzed by CES1A, were also significantly induced by tBHQ and SFN. Luciferase assays revealed that the antioxidant response element (ARE) at -2025 in the CES1A1 gene was responsible for the transactivation by Nrf2. In addition, electrophoretic mobility shift assays and chromatin immunoprecipitation assays revealed that Nrf2 binds to the ARE in the CES1A1 gene. These findings clearly demonstrated that human CES1A1 is induced by Nrf2. This is the first study to demonstrate the molecular mechanism of the inducible regulation of human CES1A1.

Inhibition of renin-angiotensin system in experimental acute pancreatitis in rats: a new therapeutic target?

OBJECTIVE

Pancreatic renin-angiotensin system has been implied to play a role in the regulation of pancreatic functions and could be a new therapeutic target in acute pancreatitis. The aim of this study was to evaluate the therapeutic potential of angiotensin-converting-enzyme inhibition by captopril and angiotensin II type 1 receptor inhibition by L-158809 and losartan experimentally in acute pancreatitis.

DESIGN

Rats were randomly divided into 15 groups. Acute edematous pancreatitis was induced by injection of cerulein 20microg/kg SC four times at hourly intervals. Severe necrotizing pancreatitis was induced by retrograde injection of 3% taurocholate into the biliary-pancreatic duct.

INTERVENTIONS

Captopril, L-158809 and losartan were given intraperitoneally. Main outcome features: pancreatic pathology, pancreatic myeloperoxidase activity and serum amylase activity were assessed.

RESULTS

Captopril decreased serum amylase (10,809+/-1867 vs. 4085+/-1028U/L, p<0.01), myeloperoxidase activity (3.5+/-0.5 vs. 1.5+/-0.1, p<0.05) and histopathological score (5.0+/-0.4 vs. 1.1+/-0.5, p<0.01) in acute edematous pancreatitis. In taurocholate induced severe necrotizing pancreatitis captopril ameliorated histopathological score (10.1+/-1.2 vs. 3.4+/-0.5, p<0.01), pancreatic parenchymal necrosis (4.5+/-0.6 vs. 0.0+/-0.0, p<0.001), fatty necrosis (2.8+/-0.9 vs. 0.1+/-0.1, p<0.01) and edema (2.1+/-0.3 vs. 1.4+/-0.3, p<0.05). However, L-158809 did not have similar beneficial effects on acute pancreatitis in rats while losartan decreased pancreatic parenchymal necrosis and neutrophil infiltration.

CONCLUSIONS

This study not only demonstrated the differential effects of captopril, losartan and L-158809 in acute pancreatitis but also showed that there is still much to investigate about pancreatic renin-angiotensin system. Inhibition of angiotensin-converting enzyme should be evaluated carefully as a potential new therapeutic target in acute pancreatitis.

Update on the use of trandolapril in the management of cardiovascular disorders

Trandolapril is a well known angiotensin converting enzyme (ACE) inhibitor with many cardiovascular (CV) indications. The objectives of this article are to review the pharmacokinetics and pharmacodynamics properties of trandolapril and to focus on its clinical relevance in cardiovascular medicine. Various populations have been studied in large clinical trials including patients with congestive heart failure (CHF) after an acute myocardial infarction (AMI), diabetics, patients with hypertension (HTN), stable coronary artery disease (CAD) and prevention of proteinuria. Long-term treatment with trandolapril in patients with reduced left ventricular function soon after AMI significantly reduced the risk of overall mortality, mortality from CV causes, sudden death, and the development of severe CHF. Treatment with trandolapril after AMI complicated by left ventricular dysfunction appears to be of considerable importance in patients with diabetes mellitus by saving lives and substantially reducing the risk of progression to severe CHF as well. Moreover, trandolapril reduces progression to proteinuria in high-risk patients. Some of the advantages of trandolapril over other ACE inhibitors are the wide spectrum of patient populations studied, the well established dosage and its proven trough-to-peak effect ratios permitting a safe once-a-day administration.