RESUMO
The purpose of this investigation is to contribute to the development of new anticonvulsant drugs to treat patients with refractory epilepsy. We applied a virtual screening protocol that involved the search into molecular databases of new compounds and known drugs to find small molecules that interact with the open conformation of the Nav1.2 pore. As the 3D structure of human Nav1.2 is not available, we first assembled 3D models of the target, in closed and open conformations. After the virtual screening, the resulting candidates were submitted to a second virtual filter, to find compounds with better chances of being effective for the treatment of P-glycoprotein (P-gp) mediated resistant epilepsy. Again, we built a model of the 3D structure of human P-gp, and we validated the docking methodology selected to propose the best candidates, which were experimentally tested on Nav1.2 channels by patch clamp techniques and in vivo by the maximal electroshock seizure (MES) test. Patch clamp studies allowed us to corroborate that our candidates, drugs used for the treatment of other pathologies like Ciprofloxacin, Losartan, and Valsartan, exhibit inhibitory effects on Nav1.2 channel activity. Additionally, a compound synthesized in our lab, N, N'-diphenethylsulfamide, interacts with the target and also triggers significant Na1.2 channel inhibitory action. Finally, in vivo studies confirmed the anticonvulsant action of Valsartan, Ciprofloxacin, and N, N'-diphenethylsulfamide.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Anticonvulsivantes/química , Epilepsia/tratamento farmacológico , Canal de Sódio Disparado por Voltagem NAV1.2/química , Bloqueadores do Canal de Sódio Disparado por Voltagem/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Anticonvulsivantes/farmacologia , Ciprofloxacina/química , Ciprofloxacina/farmacologia , Bases de Dados de Compostos Químicos , Células HEK293 , Humanos , Losartan/química , Losartan/farmacologia , Masculino , Camundongos , Conformação Molecular , Simulação de Acoplamento Molecular , Canal de Sódio Disparado por Voltagem NAV1.2/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologia , Valsartana/química , Valsartana/farmacologia , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologiaRESUMO
We report herein the design and optimization of a novel series of sulfamides and sulfamates derived from amino esters with anticonvulsant properties. The structures were designed based on the pharmacophoric pattern previously proposed, with the aim of improving the anticonvulsant action. The compounds were obtained by a new synthetic procedure with microwave assisted heating and the use of adsorbents in the isolation process. All the derivatives showed protection against the maximal electroshock seizure test (MES test) in mice at the lowest dose tested (30 mg/kg) but they did not show significant protection against the chemical induced convulsion by pentylenetetrazole. These results verify the ability of the computational model for designing new anticonvulsants structures with anti-MES activity. Additionally, we evaluated the capacity of the synthesized structures to bind to the benzodiazepine binding site (BDZ-bs) of the γ-aminobutiric acid receptor (GABAA receptor). Some of them showed medium to low affinity for the BDZ-bs.
Assuntos
Amidas/química , Anticonvulsivantes/síntese química , Anticonvulsivantes/farmacologia , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/farmacologia , Ácidos Sulfônicos/síntese química , Ácidos Sulfônicos/farmacologia , Animais , Anticonvulsivantes/química , Anticonvulsivantes/uso terapêutico , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/uso terapêutico , Anidrases Carbônicas/química , Anidrases Carbônicas/metabolismo , Domínio Catalítico , Técnicas de Química Sintética , Ésteres , Masculino , Camundongos , Modelos Moleculares , Convulsões/tratamento farmacológico , Ácidos Sulfônicos/química , Ácidos Sulfônicos/uso terapêuticoRESUMO
Steviol glycosides are natural constituents of Stevia rebaudiana (Bert.) Bert. (Asteraceae) that have recently gained worldwide approval as nonnutritive sweeteners by the Joint Food and Agriculture Organization/World Organization Expert Committee on Food Additives. Cheminformatic tools suggested that the aglycone steviol and several of its phase I metabolites were predicted as potential anticonvulsant agents effective in the seizure animal model maximal electroshock seizure (MES) test. Thus, aqueous infusion from S. rebaudiana was tested in the MES test (mice, intraperitoneal administration), confirming dose-dependent anticonvulsant effect. Afterward, isolated stevioside and rebaudioside A were tested in the MES test, with positive results. Though drug repositioning most often focuses on known therapeutics, this article illustrates the possibilities of this strategy to find new functionalities and therapeutic indications for food constituents and natural products.
Assuntos
Anticonvulsivantes/farmacologia , Diterpenos do Tipo Caurano/farmacologia , Glucosídeos/farmacologia , Adoçantes não Calóricos/farmacologia , Algoritmos , Animais , Biologia Computacional , Simulação por Computador , Relação Dose-Resposta a Droga , Eletrochoque , Ensaios de Triagem em Larga Escala , Camundongos , Modelos Moleculares , Convulsões/tratamento farmacológico , Stevia/química , Relação Estrutura-AtividadeRESUMO
In spite of remarkable advances in the knowledge on Trypanosoma cruzi biology, no medications to treat Chagas disease have been approved in the last 40 years and almost 8 million people remain infected. Since the public sector and non-profit organizations play a significant role in the research efforts on Chagas disease, it is important to implement research strategies that promote translation of basic research into the clinical practice. Recent international public-private initiatives address the potential of drug repositioning (i.e. finding second or further medical uses for known-medications) which can substantially improve the success at clinical trials and the innovation in the pharmaceutical field. In this work, we present the computer-aided identification of approved drugs clofazimine, benidipine and saquinavir as potential trypanocidal compounds and test their effects at biochemical as much as cellular level on different parasite stages. According to the obtained results, we discuss biopharmaceutical, toxicological and physiopathological criteria applied to decide to move clofazimine and benidipine into preclinical phase, in an acute model of infection. The article illustrates the potential of computer-guided drug repositioning to integrate and optimize drug discovery and preclinical development; it also proposes rational rules to select which among repositioned candidates should advance to investigational drug status and offers a new insight on clofazimine and benidipine as candidate treatments for Chagas disease. One Sentence Summary: We present the computer-guided drug repositioning of three approved drugs as potential new treatments for Chagas disease, integrating computer-aided drug screening and biochemical, cellular and preclinical tests.
Assuntos
Reposicionamento de Medicamentos/métodos , Tripanossomicidas/farmacologia , Animais , Clofazimina/metabolismo , Clofazimina/farmacologia , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Di-Hidropiridinas/metabolismo , Di-Hidropiridinas/farmacologia , Feminino , Masculino , Camundongos , Simulação de Acoplamento Molecular , Conformação Proteica , Proteínas de Protozoários , Saquinavir/metabolismo , Saquinavir/farmacologia , Tripanossomicidas/metabolismo , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/enzimologiaRESUMO
P-glycoprotein (P-gp) is involved in the transport of xenobiotic compounds and responsible for the decrease of the drug accumulation in multi-drug-resistant cells. In this investigation we compare several docking algorithms in order to find the conditions that are able to discriminate between P-gp binders and nonbinders. We built a comprehensive dataset of binders and nonbinders based on a careful analysis of the experimental data available in the literature, trying to overcome the discrepancy noticeable in the experimental results. We found that Autodock Vina flexible docking is the best choice for the tested options. The results will be useful to filter virtual screening results in the rational design of new drugs that are not expected to be expelled by P-gp.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Simulação de Acoplamento Molecular , Algoritmos , Animais , Cristalografia por Raios X , Humanos , Camundongos , Curva ROC , Saquinavir/química , Saquinavir/metabolismo , Homologia Estrutural de ProteínaRESUMO
ABC efflux transporters are polyspecific members of the ABC superfamily that, acting as drug and metabolite carriers, provide a biochemical barrier against drug penetration and contribute to detoxification. Their overexpression is linked to multidrug resistance issues in a diversity of diseases. Breast cancer resistance protein (BCRP) is the most expressed ABC efflux transporter throughout the intestine and the blood-brain barrier, limiting oral absorption and brain bioavailability of its substrates. Early recognition of BCRP substrates is thus essential to optimize oral drug absorption, design of novel therapeutics for central nervous system conditions, and overcome BCRP-mediated cross-resistance issues. We present the development of an ensemble of ligand-based machine learning algorithms for the early recognition of BCRP substrates, from a database of 262 substrates and nonsubstrates compiled from the literature. Such dataset was rationally partitioned into training and test sets by application of a 2-step clustering procedure. The models were developed through application of linear discriminant analysis to random subsamples of Dragon molecular descriptors. Simple data fusion and statistical comparison of partial areas under the curve of ROC curves were applied to obtain the best 2-model combination, which presented 82% and 74.5% of overall accuracy in the training and test set, respectively.
Assuntos
Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos , Modelos Moleculares , Proteínas de Neoplasias/química , Proteínas de Neoplasias/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Feminino , Humanos , Curva ROC , Especificidade por SubstratoRESUMO
The synthesis and anticonvulsant activity of novel heterocycles N-derivative-1,2,3-oxathiazolidine-4-one-2,2-dioxides, bioisosteres of trimethadione (TMD, oxazolidine-2,4-dione) and phenytoin (PHE), are described. TMD is an anticonvulsant drug widely used against absences seizures in the early 80's and PHE is an antiepileptic drug with a wide spectrum activity. The intermediates of synthesis of N-derivative-1,2,3-oxathiazolidine-4-one-2,2-dioxides, α-hydroxyamides, were obtained using microwave assisted synthesis. Anticonvulsant screening was performed in mice after intraperitoneal administration in the maximal electroshock seizure test (MES) and subcutaneous pentylenetetrazole seizures test (scPTZ). These new compounds showed a wide spectrum activity and were no neurotoxic in the RotoRod test. α-Hydroxyamides and N-derivative-1,2,3-oxathiazolidine-4-one-2,2-dioxides were 3-4700 times more potent than valproic acid in the MES test. Quantification of anticonvulsant protection was calculated (ED(50)) for the most active candidates; α-hydroxyamides 3a-c and 3e, and N-derivative-oxathiazolidine-4-one-2,2-dioxides 5a-c with ED(50) values of 9.1, 53.9, 44.6, 25.2, 15.1, 91.1 and 0.06mg/kg, respectively, in the MES test.
Assuntos
Amidas/química , Anticonvulsivantes/síntese química , Tiazolidinas/química , Trimetadiona/química , Animais , Anticonvulsivantes/química , Anticonvulsivantes/toxicidade , Comportamento Animal/efeitos dos fármacos , Masculino , Camundongos , Micro-Ondas , Fenitoína/química , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Relação Estrutura-Atividade , Trimetadiona/síntese química , Trimetadiona/toxicidadeRESUMO
A set of sulfamides and sulfamates were synthesized and tested against several isoforms of carbonic anhydrase: CA I, CA II, CA VII, CA XII and CA XIV. The biological assays showed a broad range of inhibitory activity, and interesting results were found for several compounds in terms of activity (Ki <1µm) and selectivity: some aromatic sulfamides are active against CA I, CA II and/or CA VII; while they are less active in CA XII and CA XIV. On the other hand, bulky sulfamides are selective to CA VII. To understand the origin of the different inhibitory activity against each isozyme we used molecular modeling techniques such as docking and molecular dynamic simulations.
Assuntos
Inibidores da Anidrase Carbônica/química , Anidrases Carbônicas/química , Sulfonamidas/química , Sítios de Ligação , Anidrase Carbônica I/antagonistas & inibidores , Anidrase Carbônica I/metabolismo , Anidrase Carbônica II/antagonistas & inibidores , Anidrase Carbônica II/metabolismo , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/metabolismo , Anidrases Carbônicas/metabolismo , Domínio Catalítico , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Sulfonamidas/síntese química , Sulfonamidas/metabolismoRESUMO
A virtual screening campaign was conducted in order to discover new anticonvulsant drug candidates for the treatment of refractory epilepsy. To this purpose, a topological discriminant function to identify antiMES drugs and a sequential filtering methodology to discriminate P-glycoprotein substrates and nonsubstrates were jointly applied to ZINC 5 and DrugBank databases. The virtual filters combine an ensemble of 2D classifiers and docking simulations. In the light of the results, 10 structurally diverse compounds were acquired and tested in animal models of seizure and the rotorod test. All 10 candidates showed some level of protection against MES test.
Assuntos
Anticonvulsivantes/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Epilepsia/tratamento farmacológico , Interface Usuário-Computador , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Anticonvulsivantes/uso terapêutico , Humanos , Camundongos , Modelos Moleculares , Conformação Proteica , Falha de TratamentoRESUMO
We describe the opportunities posed by computer-assisted drug design in the light of two aspects of the current drug discovery scenario: the decline of innovation due to high attrition rates at clinical stage of development and the combinatorial explosion emerging from exponential growth of feasible small molecules and genome and proteome exploration. We present an overview of recent reports from our group in the field of rational drug development, by using topological descriptors (either alone, or in combination with different 3D approaches) and a diversity of modeling techniques such as Linear Discriminant Analysis and the Replacement Method. Modeling efforts aimed at the integrated prediction of several significant molecular properties in the field of drug discovery, such as pharmacological activity, aqueous solubility, human intestinal permeability and affinity to P-glycoprotein (ABCB1, MDR1) are reviewed. The suitability of conformation-independent descriptors to explore large chemical repositories is highlighted, as well as the opportunities posed by in silico guided drug repurposing.