RESUMEN
Introduction: Cystic echinococcosis (CE) is a chronic zoonotic parasitic disease caused by the larvae of the Echinococcus granulosus sensu lato (s.l.) cluster. The current existing drugs have limited therapeutic efficacy against cystic echinococcosis, and thus, there is an urgent need to develop new drugs. Methods: In this study, 7 harmine (HM) derivatives were screened and the effects of HM derivatives on E. granulosus sensu stricto (s.s.) were evaluated by in vitro and mouse experiments. The safety of the HM derivatives was assessed by cytotoxicity assays, acute toxicity study in animals and subacute toxicity study. Results: These results show that the HM derivatives H-2-168 and DH-004 exhibited more significant antiparasitic effects at an initial concentration of 40 µM. The results of further studies showed that H-2-168 and DH-004 had dose-dependent effects against protoscoleces and had satisfactory therapeutic outcomes in vivo. Electron microscopy observations demonstrated that H-2-168 and DH-004 caused severe disruption of the parasite ultrastructure. Notably, the results of the acute toxicity and subchronic toxicity studies showed that H-2-168 and DH-004 had significantly improved safety. In addition, we found that H-2-168 and DH-004 induced DNA damage in E. granulosus s.s., which may be the mechanism by which these drugs produce their therapeutic effects. Discussion: Overall, the data from this work demonstrate that H-2-168 and DH-004 are highly effective candidate compounds with low toxicity for the treatment of CE and will provide a new therapeutic strategy for CE pharmacological treatment.
Asunto(s)
Equinococosis , Echinococcus granulosus , Animales , Ratones , Harmina/farmacología , Equinococosis/tratamiento farmacológico , Antiparasitarios , Daño del ADNRESUMEN
A computational study was carried out to develop quantitative-structure activity relationship (QSAR), pharmacophore, molecular docking and molecular dynamics simulations of a series of N9-substituted harmine derivatives in order to investigate the structural factors involved in the cytotoxic activity and thus design new active derivatives. A valid 3 D-QSAR (R2= 0.89, q2=0.67, R2pred = 0.72) and 2 D-QSAR (R2= 0.81, q2=0.69, R2pred = 0.76) models were obtained correlating the cytotoxic activity with hydrophobic and hydrogen bond acceptor (HBA) features for 3 D-QSAR and SlogP and a_acc descriptors for 2 D-QSAR. Analysis of the selected descriptors for both models highlighted that lipophilicity and hydrogen bonding acceptor atoms remain the crucial properties and those on which cytotoxic activity depends. Also, these findings are in agreement with the characteristics of the generated pharmacophore. Furthermore, molecular docking revealed that the binding energy (-9.74 kcal/mol) and inhibition constant (0.071 µmol) correlate with the activity of the most active compound that forms hydrophobic interactions and two hydrogen bonds with the the dual specificity tyrosine phosphorylation regulated kinase 1 A (DYRK1A). The molecular dynamics simulations revealed that the protein-ligand equilibrium is stable after 100000 fs of trajectories. Based on these results, we designed new N9-substituted harmine derivatives with improved properties: predicted cytotoxic activities, estimated binding energies, estimated inhibition constants and interaction modes with amino acid residues of DYRK1A, compared to the best compound in the studied dataset. Additionally, these newly designed inhibitors showed promising results in the preliminary in silico Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) evaluations.Communicated by Ramaswamy H. Sarma.
Asunto(s)
Antineoplásicos , Harmina , Antineoplásicos/química , Antineoplásicos/farmacología , Harmina/farmacología , Ligandos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Relación Estructura-Actividad CuantitativaRESUMEN
SerB2 is an essential phosphoserine phosphatase (PSP) that has been shown to be involved in Mycobacterium tuberculosis (Mtb) immune evasion mechanisms, and a drug target for the development of new antitubercular agents. A highly similar (91.0%) orthologous enzyme exists in the surrogate organism Mycobacterium marinum (Mma) and could have acquired similar properties. By homology modeling, we show that the two PSPs are expected to exhibit almost identical architectures. MmaSerB2 folds into a homodimer formed by two intertwined subunits including two ACT regulatory domains followed by a catalytic core typical of HAD (haloacid dehalogenase) phosphatases. Their in vitro catalytic properties are closely related as MmaSerB2 also depends on Mg2+ for the dephosphorylation of its substrate, O-phospho-l-serine (PS), and is most active at neutral pH and temperatures around 40 °C. Moreover, an enzyme kinetics study revealed that the enzyme is inhibited by PS as well, but at lower concentrations than MtbSerB2. Substrate inhibition could occur through the binding of PS in the second active site and/or at the ACT domains interface. Finally, previously described beta-carboline MtbSerB2 inhibitors also decrease the phosphatase activity of MmaSerB2. Altogether, these results provide useful information when M.marinum is used as a model to study immune evasion in tuberculosis.
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Proteínas Bacterianas/metabolismo , Mycobacterium marinum/metabolismo , Monoéster Fosfórico Hidrolasas/metabolismo , Regulación Alostérica , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Humanos , Modelos Moleculares , Infecciones por Mycobacterium no Tuberculosas/microbiología , Mycobacterium marinum/química , Mycobacterium tuberculosis/química , Mycobacterium tuberculosis/metabolismo , Monoéster Fosfórico Hidrolasas/química , Fosfoserina/metabolismo , Conformación Proteica , Multimerización de Proteína , Especificidad por SustratoRESUMEN
Mycobacterium tuberculosis is still the deadliest bacterial pathogen worldwide and the increasing number of multidrug-resistant tuberculosis cases further complicates this global health issue. M. tuberculosis phosphoserine phosphatase SerB2 is a promising target for drug design. Besides being a key essential metabolic enzyme of the pathogen's serine pathway, it appears to be involved in immune evasion mechanisms. In this work, a malachite green-based phosphatase assay has been used to screen 122 compounds from an internal chemolibrary. Trisubstituted harmine derivatives were found among the best hits that inhibited SerB2 activity. Synthesis of an original compound helped to discuss a brief structure activity relationship evaluation. Kinetics experiments showed that the most potent derivatives inhibit the phosphatase in a parabolic competitive fashion with apparent inhibition constants ( K i ) values in the micromolar range. Their interaction modes with the enzyme were investigated through induced fit docking experiments, leading to results consistent with the experimental data. Cellular assays showed that the selected compounds also inhibited M. tuberculosis growth in vitro. Those promising results may provide a basis for the development of new antimycobacterial agents targeting SerB2.
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Reposicionamiento de Medicamentos , Inhibidores Enzimáticos/farmacología , Harmina/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Monoéster Fosfórico Hidrolasas/antagonistas & inhibidores , Antituberculosos/síntesis química , Antituberculosos/química , Antituberculosos/farmacología , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/análisis , Inhibidores Enzimáticos/síntesis química , Harmina/síntesis química , Harmina/química , Cinética , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Monoéster Fosfórico Hidrolasas/metabolismo , TermodinámicaRESUMEN
A series of N(9)-substituted harmine derivatives were synthesized and evaluated for their anticancer activity on a panel of cancer cell lines, their apoptosis induction and their cell cycle effects. The results showed that N(9)-substituted harmine derivatives had anticancer effects. In particular, N(9)-haloalkyl derivatives 9a-9c and N(9)-acyl harmine derivatives 11c and 11d, with IC50 values less than 1µM, were more potent than doxorubicin against A-549 and/or MCF-7 cell lines. Moreover, structure-activity relationships (SARs) indicated that introducing a haloalkyl or benzenesulfonyl group in the N(9)-position of harmine could significantly increase the anticancer activity. The most active compound (11d) caused cell cycle arrest in the G2/M phase, and induced cell apoptosis in a dose-dependent manner.
Asunto(s)
Antineoplásicos/síntesis química , Harmina/química , Células A549 , Antineoplásicos/química , Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Harmina/síntesis química , Harmina/toxicidad , Humanos , Puntos de Control de la Fase M del Ciclo Celular/efectos de los fármacos , Células MCF-7 , Relación Estructura-ActividadRESUMEN
Apolar trisubstituted derivatives of harmine show high antiproliferative activity on diverse cancer cell lines. However, these molecules present a poor solubility making these compounds poorly bioavailable. Here, new compounds were synthesized in order to improve solubility while retaining antiproliferative activity. First, polar substituents have shown a higher solubility but a loss of antiproliferative activity. Second, a Comparative Molecular Field Analysis (CoMFA) model was developed, guiding the design and synthesis of eight new compounds. Characterization has underlined the in vitro antiproliferative character of these compounds on five cancerous cell lines, combining with a high solubility at physiological pH, making these molecules druggable. Moreover, targeting glioma treatment, human intestinal absorption and blood brain penetration have been calculated, showing high absorption and penetration properties.