Enalapril

Enalapril (MK-421) is an orally active angiotensin-converting enzyme inhibitor. Enalapril blocks the conversion of angiotensin I to angiotensin II, regulates the renin-angiotensin system, reduces preload and afterload, and decreases plasma angiotensin II levels. Enalapril inhibits apoptosis, reduces nitric oxide metabolite levels, stabilizes endothelial cells, enhances endothelial antioxidant defense, scavenges reactive oxygen species (ROS), and alleviates neuronal damage. Enalapril attenuates glutathione depletion, protein/lipid oxidation, tissue damage, and type III collagen immunolabeling in organs of diabetic rats. Enalapril reduces systolic blood pressure and urinary albumin excretion, and delays the progression of diabetic cardiac/renal injury. Enalapril is used in research related to asymptomatic left ventricular dysfunction, congestive heart failure, Alzheimer's disease, diabetes mellitus, acute myocardial infarction, atrial fibrillation, hypertension, cerebral ischemia, chronic heart failure, and single-ventricle physiology^{[1][2][3][4][5][6][7][8][9][10]}. In Vitro:Pretreatment with enalapril (50 µM; 24 h) significantly reduces AD serum-induced apoptosis in HUVECs, whereas post-treatment with the same concentration and duration does not provide this protective effect^[3].
Enalapril (0.1-100.0 μM; 24 h) dose-dependently inhibits staurosporine-induced apoptosis in primary chick embryo telencephalon neurons, with significant reductions in apoptotic neuron percentages observed at all tested concentrations^[8].
Both pretreatment and post-treatment with enalapril (50 µM; 24 h) significantly reduces elevated nitrite levels in HUVEC culture supernatants induced by exposure to AD patient sera^[3].
Enalapril when incorporated with 10-20% (w/w) stearic acid into microcrystalline cellulose pellets as enalapril maleate significantly improves enalapril stability under accelerated 40°C/75% RH conditions for 91 days, reducing formation of the degradation products enalaprilate and diketopiperazine more effectively than conventional enalapril maleate or enalapril sodium salt pellets, while stearic acid destabilizes enalapril when combined with enalapril sodium salt in pellets^[7].
Enalapril as enalapril maleate shows no significant interaction with stearic acid in 1:1 (w/w) binary mixtures, but as enalapril sodium salt interacts with stearic acid to reduce its thermal stability, lowering the onset temperature for diketopiperazine formation by ~22°C^[7].
Enalapril when incorporated with 5% (w/w) crospovidone into microcrystalline cellulose pellets containing 10% (w/w) stearic acid enables enalapril release of 89.51% at 30 min, meeting USP immediate-release criteria^[7].
Enalapril (0.1-100.0 μM; 24 h) dose-dependently protects primary chick embryo telencephalon neurons from glutamate- and Fe²⁺/³⁺-induced damage, with significant reductions in damaged neuron percentages observed at concentrations ≥0.1 μM for glutamate and ≥10.0 μM for Fe²⁺/^3+[8].
Enalapril (0.1-100.0 μM; 3 h (Fe²⁺/³⁺, staurosporine); 1 h (glutamate)) dose-dependently reduces Fe²⁺/³⁺-, glutamate-, and staurosporine-induced mitochondrial reactive oxygen species generation in primary chick embryo telencephalon neurons, with significant reductions observed at concentrations ≥1.0 μM for all treatments^[8]. In Vivo:Enalapril (20 mg/L; p.o.; continuous; 8 months) attenuates oxidative stress and reduces heart, kidney, and liver tissue damage in streptozotocin-induced diabetic rats, including an 86% reduction in heart fibrosis scores^[4].
Enalapril (0.03 mg/kg; i.p.; single dose; 1 hour before permanent middle cerebral artery occlusion) significantly reduces cortical infarct area in male NMRI mice^[8].