Could signal peptide complement C1r/C1s, Uegf, and Bmp1, and epidermal growth factor-containing protein 1 be a therapeutic target in the pathogenesis of preeclampsia?

OBJECTIVE: Determination of biomolecules that play a role in the etiopathogenesis of preeclampsia and their application as therapeutic targets may increase surveillance in this patient group. The aim of this study was to investigate the relationship between signal peptide complement C1r/C1s, Uegf, and Bmp1, and epidermal growth factor-containing protein 1, a marker of endothelial dysfunction and platelet activation, and the development of preeclampsia. METHODS: In this observational cross-sectional study conducted between April 2021 and December 2022, 73 consecutive pregnant women with preeclampsia and 73 healthy pregnant women were included. Blood samples were taken from all patients with preeclampsia to measure signal peptide complement C1r/C1s, Uegf, and Bmp1, and epidermal growth factor-containing protein 1 levels at the time of hospitalization. Excluded from the study were pregnant women with certain medical conditions or treatments, and the signal peptide complement C1r/C1s, Uegf, and Bmp1, and epidermal growth factor-containing protein 1 levels of the groups were compared according to the development of preeclampsia. RESULTS: Signal peptide complement C1r/C1s, Uegf, and Bmp1, and epidermal growth factor-containing protein 1 levels were significantly higher in the preeclampsia group than in the controls (p<0.001). In multivariate analysis, signal peptide complement C1r/C1s, Uegf, and Bmp1, and epidermal growth factor-containing protein 1 was determined as an independent predictor for preeclampsia (OR: 1.678, 95%CI 1.424-1.979, p<0.001). Receiver operating characteristic curve analysis showed that the best cutoff value of signal peptide complement C1r/C1s, Uegf, and Bmp1, and epidermal growth factor-containing protein 1 at 3.25 ng/mL predicted the development of preeclampsia with 71% sensitivity and 68% specificity (area under the curve, 0.739; 95% confidence interval (95%CI), 0.681-0.798, p<0.001). CONCLUSION: Signal peptide complement C1r/C1s, Uegf, and Bmp1, and epidermal growth factor-containing protein 1 is significantly elevated in pregnant women with preeclampsia compared with healthy controls.

Evaluation of the anti-inflammatory effect of 1,4-dihydropyridine derivatives.

INTRODUCTION: Inflammation is a physiological event that protects the organism against different factors that lead to loss of tissue homeostasis. Dihydropyridine (DHP) derivatives are heterocyclic compounds known for their different biological activities, including anti-inflammatory activities. OBJECTIVE: To evaluate the anti-inflammatory activity of 1,4-dihydropyridine (1,4-DHP) derivatives using anti-inflammatory models in vitro, in RAW264.7 cells induced by lipopolysaccharide (LPS) and in vivo using the acute lung injury (ALI) model in mice. RESULTS: Fifteen compounds derived from 1,4-DHP were tested in RAW264.7 cells for their cytotoxic effect and cell viability. Thereafter, only the six compounds that showed the highest cell viability were tested for the production or inhibition of the pro-inflammatory cytokine interleukin 6 (IL-6). The best compound (compound 4) was tested for its anti-inflammatory effects in vitro and in vivo, showing inhibition of nitric oxide (NO), pro-inflammatory cytokines, increased phagocytic activity, and an increase in IL-10 in vitro. In in vivo tests, compound 4 also reduces the levels of NO, myeloperoxidase (MPO) activity, leukocyte migration, and exudation, as well as reducing the levels of tumor necrosis factor-alpha (TNF-α) and IL-6 and preventing the loss in the lung architecture. CONCLUSION: This compound showed important anti-inflammatory activity, with a significant ability to reduce the production of pro-inflammatory mediators and increase the phagocytic activity of macrophages and anti-inflammatory mediator secretion (IL-10). These findings led us to hypothesize that this compound can repolarize the macrophage response to an anti-inflammatory profile (M2). Moreover, it was also able to maintain its anti-inflammatory activity in vivo experiments.

Synthesis, Cytotoxic Activity and In Silico Study of Novel Dihydropyridine Carboxylic Acids Derivatives.

To aid the possible prevention of multidrug resistance in tumors and cause lower toxicity, a set of sixteen novel dihydropyridine carboxylic acids derivatives 3a-p were produced; thus, the activation of various ynones with triflic anhydride was performed, involving a nucleophilic addition of several bis(trimethylsilyl) ketene acetals, achieving good yields requiring easy workup. The target molecules were unequivocally characterized by common spectroscopic methods. In addition, two of the tested compounds (3a, and 3b) were selected to perform in silico studies due to the highest cytotoxic activity towards the HCT-15 cell line (7.94 ± 1.6 µM and 9.24 ± 0.9 µM, respectively). Employing theoretical calculations with density functional theory (DFT) using the B3LYP/6-311++G(d,p) showed that the molecular parameters correlate adequately with the experimental results. In contrast, predictions employing Osiris Property Explorer showed that compounds 3a and 3b present physicochemical characteristics that would likely make it an orally active drug. Moreover, the performance of Docking studies with proteins related to the apoptosis pathway allowed a proposal of which compounds could interact with PARP-1 protein. Pondering the obtained results (synthesis, in silico, and cytotoxic activity) of the target compounds, they can be judged as suitable antineoplastic agent candidates.

Current Status on 1,4-Dihydropyridine Derivatives against Human Pathogenic Parasites.

Infections provoked by parasites are among the most prevalent diseases worldwide and generate important health and socioeconomic problems. Despite the enormous amount of work done, the chemotherapy for most of them remains unsolved. Usually, treatments are based on no specific drugs associated, in several cases, with long-term treatments and severe side effects. In addition, drug resistance and different strains' susceptibility are further drawbacks of the existing chemotherapy. Considering that 1,4-dihydropyridines derivatives constitute an important class of compounds for new drug development, we present in this review an in-depth overview of the work done so far on 1,4-dihydropyridines and their antiparasitic activities. The development of new derivatives or the application of known drugs used for other diseases is described in terms of their potential usefulness for drug design.

Ene-adducts from 1,4-dihydropyridines and α,ß-unsaturated nitriles: asynchronous transition states displaying aromatic features.

Hydride transfer reactions involving 1,4-dihydropyridines play a central role in bioorganic chemistry as they represent an important share of redox metabolism. For this class of reactions, direct hydride transfer is the commonly accepted mechanism; however, an Alder-Ene-like pathway has been proposed as a plausible alternative. The reaction between 1,4-ditrimethylsilyl-1,4-dihydropyridine and α,ß-unsaturated nitriles is a solid candidate for this latter pathway. In this work, we perform high level ab initio and density functional theory computations to characterize the mechanism of this reaction, taking into account diverse reaction paths, and evaluating the effect of solvent polarity and variations in the chemical structure. Our analysis explains the stereochemical aspects of the reaction, characterizing the up to now unresolved spatial configurations of the predominant products, and may contribute to the understanding of enzymatic reactions involving NADP(H). The reactions are found to proceed in an asynchronous fashion, with transition states that display significant aromatic features. With this observation in mind, Alder-Ene and direct hydride transfer pathways can be understood as two extremes of a continuous mechanistic spectrum for this kind of reaction, with the analyzed systems located approximately equidistant from both ends.

JM-20, a Benzodiazepine-Dihydropyridine Hybrid Molecule, Inhibits the Formation of Alpha-Synuclein-Aggregated Species.

Studies showed that JM-20, a benzodiazepine-dihydropyridine hybrid molecule, protects against rotenone and 6-hydroxydopamine neurotoxicity. However, its protective effects against cytotoxicity induced by endogenous neurotoxins involved in Parkinson's disease (PD) pathogenesis have never been investigated. In this study, we evaluated the ability of JM-20 to inhibit alpha-synuclein (aSyn) aggregation. We also evaluated the interactions of JM-20 with aSyn by molecular docking and molecular dynamics and assessed the protective effect of JM-20 against aminochrome cytotoxicity. We demonstrated that JM-20 induced the formation of heterogeneous amyloid fibrils, which were innocuous to primary cultures of mesencephalic cells. Moreover, JM-20 reduced the average size of aSyn positive inclusions in H4 cells transfected with SynT wild-type and synphilin-1-V5, but not in HEK cells transfected with synphilin-1-GFP. In silico studies showed the interaction between JM-20 and the aSyn-binding site. Additionally, we showed that JM-20 protects SH-SY5Y cells against aminochrome cytotoxicity. These results reinforce the potential of JM-20 as a neuroprotective compound for PD and suggest aSyn as a molecular target for JM-20.

Fluorinated dihydropyridines as candidates to block L-type voltage-dependent calcium channels.

Voltage-gated calcium (Cav) channels malfunction may lead to Alzheimer's and cardiovascular disorders, thus a critical protein target for drug development and treatment against several diseases. Indeed, dihydropyridines (DHPs) as nifedipine and amlodipine are top-selling pharmaceuticals and, respectively, the 121st and 5th most prescribed drugs in the United States that have been used as successful selective blockers for L-type Ca2+ channels (LCC) and may be helpful model structures to compare with new DHP analogs. In this context, we have performed a structure-based drug design (SBDD) study of several fluorinated DHPs by using homology modeling, molecular docking, quantitative structure activity relationship (QSAR) and molecular dynamics calculations. Such approaches combined with molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) interaction energy results and screening of ADMET (absorption, distribution, metabolism, excretion and toxicity) properties indicate that all ligands in this study are potential new candidates to be tested experimentally for inhibition of LCC and may have higher affinities than the commonly used drugs, being convenient synthetic routes proposed for 11-16, which are among the ligands that showed the best theoretical results concerning LCC inhibition. Furthermore, the ligand interactions with the binding site were carefully examined using the topological noncovalent interactions (NCI) method, which highlighted specifically responsible amino acid residues that increase the spontaneity of the new proposed DHP ligands.Communicated by Ramaswamy H. Sarma.

Exploratory Study on Lercanidipine Hydrochloride Polymorphism: pH-Dependent Solubility Behavior and Simulation of its Impact on Pharmacokinetics.

This work describes an exploratory experimental and in silico study of the influence of polymorphism, particle size, and physiology on the pharmacokinetics of lercanidipine hydrochloride (LHC). Equilibrium and kinetic solubility studies were performed on LHC forms I and II, as a function of pH and buffer composition. GastroPlus® was used to evaluate the potential effect of solubility differences due to polymorphism, particle size, and physiological conditions, on the drug pharmacokinetics. The results indicated that solubilities of LHC polymorphs are strongly dependent on the composition and pH of the buffer media. The concentration ratio (CI/CII) is particularly large for chloride buffer (CI/CII = 3.3-3.9) and exhibits a slightly decreasing tendency with the pH increase for all other buffers. Based on solubility alone, a higher bioavailability of form I might be expected. However, exploratory PBPK simulations suggested that (i) under usual fasted (pH 1.3) and fed (pH 4.9) gastric conditions, the two polymorphs have similar bioavailability, regardless of the particle size; (ii) at high gastric pH in the fasted state (e.g., pH 3.0), the bioavailability of form II can be considerably lower than that of form I, unless the particle size is < 20 µm. This study demonstrates the importance of investigating the effect of the buffer nature when evaluating the solubility of ionizable polymorphic substances. It also showcases the benefits of using PBPK simulations, to assess the risk and pharmacokinetic relevance of different solubility and particle size between crystal forms, for diverse physiological conditions.

Bioenergetics impairment of Trypanosoma cruzi by the antihypertensive manidipine: A drug repurposing strategy.

Considering the lack of effective and safe therapy for the treatment of Chagas disease, the antihypertensive drug manidipine (MDP) was in vitro evaluated against Trypanosoma cruzi. The bioenergetics of trypomastigotes was studied in the presence of the drug using fluorimetric and luminescent assays. Manidipine showed a potent antiparasitic activity, with IC50 values of 0.1 µM (intracellular amastigotes) and 3 µM (trypomastigotes), resulting in a promising selectivity index against the amastigotes (>1459). Using fluorimetric analysis, the drug showed depolarisation of the electric potential of the plasma membrane with no alteration of the permeability. A decrease in ATP levels suggested a bioenergetic alteration of the mitochondria, which was confirmed by the depolarisation of the mitochondrial membrane potential and a slight increase of the ROS levels. This is the first study to show the promising in vitro effectiveness of the antihypertensive MDP against T. cruzi, which may represent a candidate for future investigations in animal models.

Long-chain fatty dihydropyridines: Docking calcium channel studies and antihypertensive activity.

AIMS: From the synthesis of 43 lipophilic dihydropyridines, the aim of this study was to verify whether the new dihydropyridines have calcium channel affinity using coupling studies and to determine antihypertensive and antioxidant properties, as well as toxicology and toxicity nifedipine and three new compounds, were chosen from the previous results. MATERIALS AND METHODS: The animals were treated for 56 days, 28 days with N (ω) -nitro-L-arginine methyl ester to induce hypertension, and then treated for another 28 days with the new di- hydropyridine and the standard drug nifedipine. Throughout the treatment the animals had their blood pressure measured and their heart rate checked by pletysmography. After treatment the animals were euthanised, blood samples were collected for creatine kinase and urea analysis, and the brain, heart and liver were collected for oxidative status analysis (quantification of reactive oxygen species, total antioxidant capacity, and lipid peroxidation). KEY FINDINGS: Compounds 2c, and 9a, and nifedipine significantly reduced blood pressure to control group levels. The tachycardia caused by the induction of hypertension was reversed by 2c and 9a compounds. Regarding oxidative stress analyzes, the compounds that had the best performances were also 2c and 9a. Overall the results demonstrate that two of the three new dihydropyridines tested demonstrated performance equal to or superior to the standard drug nifedipine. SIGNIFICANCE: In this study, for the first time, docking was applied to analyse 43 fatty dihydropyridines regarding their calcium channel binding. Afterwards, three fatty dihydropyridines were chosen and their antihypertensive and antioxidant properties.

Effect of Lercanidipine on the Pharmacokinetics-Pharmacodynamics of Carvedilol Enantiomers in Patients With Chronic Kidney Disease.

This study evaluates the carvedilol-lercanidipine drug interaction, and the influence of chronic kidney disease (CKD) on both drugs. Patients with high blood pressure (8 with normal renal function [control] and 8 with CKD with estimated glomerular filtration rate categories of G3b to G5 [12-38 mL/min/1.73 m2 ]) were included and prescribed 3 different treatment regimens, a single oral dose of racemic carvedilol 25 mg (CAR), a single oral dose of racemic lercanidipine 20 mg (LER), and single oral doses of CAR plus LER. Blood samples were collected and variations in heart rate were assessed (using isometric exercise with handgrip) for up to 32 hours. Lercanidipine pharmacokinetics were not enantioselective, and were not affected by carvedilol and CKD. Carvedilol pharmacokinetics (data presented as median) were enantioselective with higher plasma exposure of (R)-(+)-carvedilol in both control (103.5 vs 46.0 ng ∙ h/mL) and CKD (190.6 vs 98.9 ng ∙ h/mL) groups. Lercanidipine increased the area under the plasma concentration-time curve of only (R)-(+)-carvedilol in the CKD group (190.6 vs 242.2 ng ∙ h/mL) but not in the control group (103.5 vs 98.7 ng ∙ h/mL). CKD increased plasma exposure (46.0 vs 98.9 ng ∙ h/mL) and effect-compartment exposure (5.5 vs 20.9 ng ∙ h/mL) to (S)-(-)-carvedilol, resulting in higher ß-adrenergic inhibition (10.0 vs 6.1 bpm). Therefore, carvedilol dose titration in CKD patients with estimated glomerular filtration rate categories of G3b to G5 should be initiated, with no more than half the dose used for patients with normal renal function.

The Protective Effect of Lercanidipine on Indomethacin-Induced Gastric Ulcers in Rats

Abstract Nonsteroidal anti-inflammatory drugs (NSAID) are among the aggressive factors causing gastric ulcer. They cause oxidative damage in the gastric tissue and lead to intracellular calcium deposition. Lercanidipine is a calcium channel blocker derived from the third generation dihydropyridine. The aim of this study is to analyse the effect of lercanidipine on indomethacin-induced gastric ulcers. A total of 24 albino Wistar male rats were divided into four groups; those who received indomethacin 25 mg/kg (IND), 5 mg mg/kg lercanidipine +25 mg/kg indomethacin (LC-5), 10 mg/kg lercanidipine+25mg/kg indomethacin (LC-10) and healthy rats who received 0.5 mL distilled water. Six hours after the application of indomethacin, the animals were sacrificed by high dose thiopental sodium. The stomachs of the animals were excised to perform a macroscopic analysis and the ulcerous region was measured on millimeter paper. All the stomachs were subjected to a biochemical analysis. Macroscopic analysis revealed hyperaemia on the gastric surface of the indomethacin group. Ulcerous tissues formed by oval, circular or irregular mucosal defects in varying diameters and depths were observed on the whole surface of the stomach. Hyperaemia was lower and ulcerous region was smaller in groups LC-5 and LC-10 compared to IND group. Malondialdehyde and myeloperoxidase levels were significantly lower and total glutathione and cyclooxygenase-1 activity were higher in groups LC-5 and LC-10. Lercanidipine did not change the cyclooxygenase-2 activity. Lercanidipine in doses 10 mg/kg is more effective compared to 5 mg/kg. Lercanidipinine can be useful in the treatment of NSAID-induced gastric damage.

Synthesis and antioxidant activity of new lipophilic dihydropyridines.

Dihydropyridines (DHPs) obtained from Hantzsch multicomponent reactions are an important pharmaceutical class of compounds marketed as antihypertensive (e.g., nifedipine, nitrendipine, and amlodipine) drugs. This study synthesized new symmetrical and unsymmetrical long-chain fatty DHPs using multicomponent reactions under metal-free conditions with sulfamic acid as a catalyst. The DHPs were tested for antioxidant activity using three different methods. The insertion of a long chain into the DHP core contributed to antioxidant potential, and compounds derived from nitro aldehydes have better antioxidant potential than the antihypertensive drug nifedipine. In addition, fatty analogs to nifedipine derived from palmitic and oleic chains showed similar antioxidant activity to the common standards butylated hydroxytoluene and vitamin E. These results showed that our new synthesized products may find novel applications as antioxidant additives or for tools for use in drug discovery.

Relationship between Hammett's parameters and in silico density functional with tandem mass ESI-CID fragmentation: Dihydropyridines as prototypes.

Over the years, with the instrumental analysis evolution, the relationships between the carried-out results with the data of theoretical analysis in silico and the Hammett's parameters have been reported. They have been very useful for chemical characterization of small organic molecules. Thus, this work aims at showing the feasibility and limitations for Hammett's and density functional theory applications in electrospray ionization-collision-induced dissociation (ESI-CID) fragmentation provision. For this, 13 dihydropyrimidinones para, meta, and orto monosubstituted were studied using ESI and CID in positive mode. As a result, it was observed that the main fragmentation includes the isocyanate and ethanol loses at low energy. Nevertheless, at higher energies, radical ions formed by McLafferty rearrangement were observed. The Hammett plots were correlated fragmentation profiles, showing good linearity for the [M + H]+ , which does not occur to radical ions and carbocation's. These tendencies had demonstrated that the stability of protonate and activation energy of secondary ions changes with the pKa. The density functional theory studies indicated that, both nitrogen atoms in the dihydropyrimidinone's prototypes are capable of being protonated. However, the activation energy of fragmentation products is not changed. Therefore, this work has shown information, which can be useful to understand tandem mass spectrometry in ESI-CID conditions for small organic molecules series. This is the first step for normalization of fragmentation pathway.

Anti-cancer activity of a new dihydropyridine derivative, VdiE-2N, in head and neck squamous cell carcinoma.

This study aims to examine the effects of a new 1,4-dihydropyridine derivative, VdiE-2N, on cell signaling pathways and mitochondrial events in head and neck squamous cell carcinoma (HNSCC) cells, and on a mice model of xenograft tumor growth/cell proliferation. Four HNSCC cell lines (HN13, HN12, HN6, and CAL27), HEK293 cells (human embryonic kidney 293 cells), and human oral healthy mucosa fibroblasts (OHMF) were used for in vitro assessment of cell viability (resazurin assay) and invasion capacity (modified Boyden chamber assay), and mitochondrial membrane potential (JC-1 fluorescence assay), morphology (transmission electron microscopy), and number of mitochondria (MitoTracker® imaging). SET and pDRP1 proteins were analyzed by immunofluorescence, and proteins involved in cell death/survival pathways were analyzed by Western blotting. HN12 xenograft tumors were established in the flank of Balb/c nude mice, and their characteristics and sensitivity to VdiE-2N were determined by immunohistochemistry and histology. VdiE-2N decreased cell viability in HNSCC cells (IC50 = 9.56 and 22.45µM for HN13 and HN12 cells, respectively) more strongly than it decreased cell viability in OHMF and HEK293 cells (IC50 = 32.90 and > 50µM, respectively). In HN13 cells, VdiE-2N dissipated mitochondrial membrane potential and altered the mitochondria size, shape, and number in a concentration-dependent manner, as well as it induced apoptosis and reduced their invasion capacity. Treatment of mice bearing xenograft tumors with VdiE-2N significantly diminished proliferation of cancer cells. Therefore, VdiE-2N induces HNSCC cell death in vitro through mitochondria-mediated apoptotic pathways and dampens tumor growth in vivo, thus supporting a potential anti-cancer effect.

Platelet-activating factor increases reactive oxygen species-mediated microbicidal activity of human macrophages infected with Leishmania (Viannia) braziliensis.

Platelet-activating factor (PAF) is produced by macrophages during inflammation and infections. We evaluated whether PAF is able to modulate the infection of human macrophages by Leishmania braziliensis, the main Leishmania sp. in Brazil. Monocyte-derived macrophages were incubated with promastigote forms in absence or presence of exogenous PAF. We observed that the treatment of macrophages with low concentrations of PAF prior to infection increased the phagocytosis of L. braziliensis. More importantly, exogenous PAF reduced the parasitism when it was added before, during or after infection. In addition, treatment with a PAF antagonist (PCA 4248) resulted in a significant increase of macrophage infection in a concentration-dependent manner, suggesting that endogenous PAF is important to control L. braziliensis infection. Mechanistically, while exogenous PAF increased production of reactive oxygen species (ROS) treatment with PCA 4248 reduced oxidative burst during L. braziliensis infection. The microbicidal effects of exogenous PAF were abolished when macrophages were treated with apocynin, an NADPH oxidase inhibitor. The data show that PAF promotes the production of ROS induced by L. braziliensis, suggesting that this lipid mediator may be relevant to control L. braziliensis infection in human macrophages.

Synthesis and in vitro evaluation of Ca2+ channel blockers 1,4-dihydropyridines analogues against Trypanosoma cruzi and Leishmania amazonensis: SAR analysis.

Drugs containing the1,4-dihydropyridine (DHP) core have recently attracted attention concerning their antiparasitic effect against various species of Leishmania and Trypanosoma. This approach named drugs repositioning led to interesting results, which have prompted us to prepare 21 DHP's analogues. The 1,4-DHP scaffold was decorated with different function groups at tree points including the nitrogen atom (NH and N-phenyl), the aryl group attached to C-4 (various substituted aryl residues) and the carbon atoms 2 and 6 (bearing Ph or Me groups). Moreover, the products were evaluated for their cytotoxicity on three cancer and a non-tumoral cell lines. Only 6 of them were antiproliferative and their weak effect (CC50 comprised between 27 and 98µM) suggested these DHPs as good candidates against the intracellular amastigote forms of L. amazonensis and T. cruzi. L. amazonensis was sensitive to DHPs 5, 11 and 15 (IC50 values at 15.11, 45.70 and 53.13µM, respectively) while 12 of them displayed significant to moderate trypanocidal activities against T. cruzi. The best trypanocidal activities were obtained with compounds 2, 18 and 21 showing IC50 values at 4.95, 5.44, and 6.64µM, respectively. A part of the N-phenylated DHPs showed a better selectivity than their NH analogues towards THP-1 cells. 4-Chlorophenyl, 4-nitrophenyl and 3-nitrophenyl residues attached to the carbon atom 4 turned to be important sub-structures for the antitrypanosomal activity.

The cytotoxic effects of VE-3N, a novel 1,4-dihydropyridine derivative, involve the mitochondrial bioenergetic disruption via uncoupling mechanisms.

Several 1,4-dihydropyridine derivatives overcome the multidrug resistance in tumors, but their intrinsic cytotoxic mechanisms remain unclear. Here we addressed if mitochondria are involved in the cytotoxicity of the novel 1,4-dihydropyridine derivative VE-3N [ethyl 6-chloro-5-formyl-2-methyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3-carboxylate] towards cancer cells by employing hepatic carcinoma (HepG2) cells and isolated rat liver mitochondria. In HepG2 cells, VE-3N induced mitochondrial membrane potential dissipation, ATP depletion, annexin V/propidium iodide double labeling, and Hoechst staining; events indicating apoptosis induction. In isolated rat liver mitochondria, VE-3N promoted mitochondrial uncoupling by exerting protonophoric actions and by increasing membrane fluidity. Mitochondrial uncoupling was evidenced by an increase in resting respiration, dissipation of mitochondrial membrane potential, inhibition of Ca2+ uptake, stimulation of Ca2+ release, decrease in ATP synthesis, and swelling of valinomycin-treated organelles in hyposmotic potassium acetate media. Furthermore, uncoupling concentrations of VE-3N in the presence of Ca2+ plus ruthenium red induced the mitochondrial permeability transition process. These results indicate that mitochondrial uncoupling is potentially involved in the VE-3N cytotoxic actions towards HepG2 cells. Considering that hepatocellular carcinoma is the most common form of liver cancer, our findings may open a new avenue for the development of VE-3N-based cancer therapies, and help to unravel the cytotoxic mechanisms of 1,4-dihydropyridines towards cancer cells.

Reduced density gradient as a novel approach for estimating QSAR descriptors, and its application to 1, 4-dihydropyridine derivatives with potential antihypertensive effects.

The relationship between the chemical structure and biological activity (log IC50) of 40 derivatives of 1,4-dihydropyridines (DHPs) was studied using density functional theory (DFT) and multiple linear regression analysis methods. With the aim of improving the quantitative structure-activity relationship (QSAR) model, the reduced density gradient s( r) of the optimized equilibrium geometries was used as a descriptor to include weak non-covalent interactions. The QSAR model highlights the correlation between the log IC50 with highest molecular orbital energy (E HOMO), molecular volume (V), partition coefficient (log P), non-covalent interactions NCI(H4-G) and the dual descriptor [Δf(r)]. The model yielded values of R 2=79.57 and Q 2=69.67 that were validated with the next four internal analytical validations DK=0.076, DQ=-0.006, R P =0.056, and R N=0.000, and the external validation Q 2boot=64.26. The QSAR model found can be used to estimate biological activity with high reliability in new compounds based on a DHP series. Graphical abstract The good correlation between the log IC50 with the NCI (H4-G) estimated by the reduced density gradient approach of the DHP derivatives.