RESUMO
Chagas disease, caused by Trypanosoma cruzi (T. cruzi), is one of the most important neglected diseases in Latin America. The limited use of the current nitro-derivative-based chemotherapy highlights the need for alternative drugs and the identification of their molecular targets. In this study, we investigated the trypanocidal effect of the sesquiterpene lactone dehydroleucodine (DhL) and its derivatives, focusing on the antioxidative defense of the parasites. DhL and two derivatives, at lesser extent, displayed antiproliferative effect on the parasites. This effect was blocked by the reducing agent glutathione (GSH). Treated parasites exhibited increased intracellular ROS concentration and trypanothione synthetase activity, accompanied by mitochondrial swelling. Although molecular dynamics studies predicted that GSH would not interact with DhL, 1H-NMR analysis confirmed that GSH could protect parasites by interacting with the lactone. When parasites overexpressing mitochondrial tryparedoxin peroxidase were incubated with DhL, its effect was attenuated. Overexpression of cytosolic tryparedoxin peroxidase also provided some protection against DhL. These findings suggest that DhL induces oxidative imbalance in T. cruzi, offering new insights into potential drug targets against this parasite.
Assuntos
Lactonas , Espécies Reativas de Oxigênio , Sesquiterpenos , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/metabolismo , Sesquiterpenos/farmacologia , Lactonas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Tripanossomicidas/farmacologia , Glutationa/metabolismo , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Proteínas de Protozoários/metabolismo , Animais , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Amida SintasesRESUMO
Neglected Tropical Diseases are a significant concern as they encompass various infections caused by pathogens prevalent in tropical regions. The limited and often highly toxic treatment options for these diseases necessitate the exploration of new therapeutic candidates. In the present study, the lignan methylpiperitol was isolated after several chromatographic steps from Persea fulva L.â E. Koop (Lauraceae) and its leishmanicidal and trypanocidal activities were evaluated using inâ vitro and inâ silico approaches. The chemical structure of methylpiperitol was defined by NMR and MS spectral data analysis. The antiprotozoal activity of methylpiperitol was determined inâ vitro and indicated potency against trypomastigote forms of Trypanosoma cruzi (EC50 of 4.5±1.1â mM) and amastigote forms of Leishmania infantum (EC50 of 4.1±0.5â mM), with no mammalian cytotoxicity against NCTC cells (CC50>200â mM). Molecular docking studies were conducted using six T. cruzi and four Leishmania. The results indicate that for the molecular target hypoxanthine phosphoribosyl transferase in T. cruzi and piteridine reductase 1 of L. infatum, the methylpiperitol obtained better results than the crystallographic ligand. Therefore, the lignan methylpiperitol, isolated from P. fulva holds potential for the development of new prototypes for the treatment of Neglected Tropical Diseases, especially leishmaniasis.
Assuntos
Leishmania infantum , Lignanas , Simulação de Acoplamento Molecular , Trypanosoma cruzi , Lignanas/farmacologia , Lignanas/isolamento & purificação , Lignanas/química , Trypanosoma cruzi/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Testes de Sensibilidade Parasitária , Antiprotozoários/farmacologia , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Animais , Relação Estrutura-Atividade , Estrutura Molecular , Relação Dose-Resposta a Droga , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/isolamento & purificaçãoRESUMO
Chagas disease, a silent but widespread disease that mainly affects a socioeconomically vulnerable population, lacks innovative safe drug therapy. The available drugs, benznidazole and nifurtimox, are more than fifty years old, have limited efficacy, and carry harmful side effects, highlighting the need for new therapeutics. This study presents two new series of pyrazole-thiadiazole compounds evaluated for trypanocidal activity using cellular models predictive of efficacy. Derivatives 1c (2,4-diCl) and 2k (4-NO2) were the most active against intracellular amastigotes. Derivative 1c also showed activity against trypomastigotes, with the detachment of the flagellum from the parasite body being a predominant effect at the ultrastructural level. Analogs have favorable physicochemical parameters and are predicted to be orally available. Drug efficacy was also evaluated in 3D cardiac microtissue, an important target tissue of Trypanosoma cruzi, with derivative 2k showing potent antiparasitic activity and a significant reduction in parasite load. Although 2k potentially reduced parasite load in the washout assay, it did not prevent parasite recrudescence. Drug combination analysis revealed an additive profile, which may lead to favorable clinical outcomes. Our data demonstrate the antiparasitic activity of pyrazole-thiadiazole derivatives and support the development of these compounds using new optimization strategies.
Assuntos
Pirazóis , Tiadiazóis , Tripanossomicidas , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Tiadiazóis/química , Tiadiazóis/farmacologia , Tiadiazóis/síntese química , Pirazóis/farmacologia , Pirazóis/química , Pirazóis/síntese química , Tripanossomicidas/farmacologia , Tripanossomicidas/síntese química , Tripanossomicidas/química , Animais , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , HumanosRESUMO
Aim: Benznidazole (BNZ), a class-II drug, is the primary treatment for Chagas disease, but its low aqueous solubility presents challenges in formulation and efficacy. Nanosuspensions (NS) could potentially address these issues.Methods: BNZ-NS were prepared using a simple, organic solvents-free nano-milling approach. Physicochemical characterizations were conducted on both NS and lyophilized solid-state BNZ-nanocrystals (NC).Results: BNZ-NS exhibited particle size <500 nm, an acceptable polydispersity index (0.23), high Z-potential, and physical stability for at least 90 days. BNZ-NC showed tenfold higher solubility than pure BNZ. Dissolution assays revealed rapid BNZ-NS dissolution. BNZ-NC demonstrated biocompatibility on an eukaryotic cell and enhanced BNZ efficacy against trypomastigotes of Trypanosoma cruzi.Conclusion: BNZ-NS offers a promising alternative, overcoming limitations associated with BNZ for optimized pharmacotherapy.
[Box: see text].
Assuntos
Doença de Chagas , Nanopartículas , Nitroimidazóis , Tamanho da Partícula , Solubilidade , Tripanossomicidas , Trypanosoma cruzi , Nitroimidazóis/química , Nitroimidazóis/administração & dosagem , Doença de Chagas/tratamento farmacológico , Trypanosoma cruzi/efeitos dos fármacos , Nanopartículas/química , Tripanossomicidas/administração & dosagem , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Animais , Humanos , Suspensões , Estabilidade de Medicamentos , Química Farmacêutica/métodos , Solventes/química , LiofilizaçãoRESUMO
BACKGROUND: The current treatments for Chagas disease (CD) include benznidazole and nifurtimox, which have limited efficacy and cause numerous side effects. Triazoles are candidates for new CD treatments due to their ability to eliminate T. cruzi parasites by inhibiting ergosterol synthesis, thereby damaging the cell membranes of the parasite. METHODS: Eleven synthetic analogs of the kinase inhibitor SRPIN340 containing a triazole core (compounds 6A-6K) were screened in vitro against the Tulahuen strain transfected with ß-galactosidase, and their IC50, CC50, and selectivity indexes (SI) were calculated. Compounds with an SI > 50 were further evaluated in mice infected with the T. cruzi Y strain by rapid testing. RESULTS: Eight compounds were active in vitro with IC50 values ranging from 0.5-10.5 µg/mL. The most active compounds, 6E and 6H, had SI values of 125.2 and 69.6, respectively. These compounds also showed in vivo activity, leading to a reduction in parasitemia at doses of 10, 50, and 250 mg/kg/day. At doses of 50 and 250 mg/kg/day, parasitemia was significantly reduced compared to infected untreated animals, with no significant differences between the effects of 6E and 6H. CONCLUSIONS: This study identified two new promising compounds for CD chemotherapy and confirmed their activity against T. cruzi.
Assuntos
Doença de Chagas , Triazóis , Tripanossomicidas , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Animais , Triazóis/farmacologia , Doença de Chagas/tratamento farmacológico , Tripanossomicidas/farmacologia , Camundongos , Concentração Inibidora 50 , Testes de Sensibilidade Parasitária , TiazóisRESUMO
Bromodomains are structural folds present in all eukaryotic cells that bind to other proteins recognizing acetylated lysines. Most proteins with bromodomains are part of nuclear complexes that interact with acetylated histone residues and regulate DNA replication, transcription, and repair through chromatin structure remodeling. Bromodomain inhibitors are small molecules that bind to the hydrophobic pocket of bromodomains, interfering with the interaction with acetylated histones. Using a fluorescent probe, we have developed an assay to select inhibitors of the bromodomain factor 2 of Trypanosoma cruzi (TcBDF2) using fluorescence polarization. Initially, a library of 28,251 compounds was screened in an endpoint assay. The top 350-ranked compounds were further analyzed in a dose-response assay. From this analysis, seven compounds were obtained that had not been previously characterized as bromodomain inhibitors. Although these compounds did not exhibit significant trypanocidal activity, all showed bona fide interaction with TcBDF2 with dissociation constants between 1 and 3 µM validating these assays to search for bromodomain inhibitors.
Assuntos
Polarização de Fluorescência , Ensaios de Triagem em Larga Escala , Proteínas de Protozoários , Tripanossomicidas , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/metabolismo , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/metabolismo , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Ensaios de Triagem em Larga Escala/métodos , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismoRESUMO
Chagas disease is a tropical neglected disease that affects millions of people worldwide, still demanding a more effective and safer therapy, especially in its chronic phase which lacks a treatment that promotes substantial parasitological cure. The technical note of Romanha and collaborators published in 2010 aimed establish a guideline with the set of minimum criteria and decision gates for the development of new agents against Trypanosoma cruzi with the focus on developing new antichagasic drugs. In this sense, the present review aims to update this technical note, bringing the state of the art and new advances on this topic in recent years.
Assuntos
Doença de Chagas , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Tripanossomicidas , Trypanosoma cruzi , Doença de Chagas/tratamento farmacológico , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Animais , Trypanosoma cruzi/efeitos dos fármacos , Humanos , Desenvolvimento de MedicamentosRESUMO
The development of new compounds to treat Chagas disease is imperative due to the adverse effects of current drugs and their low efficacy in the chronic phase. This study aims to investigate nitroisoxazole derivatives that produce oxidative stress while modifying the compounds' lipophilicity, affecting their ability to fight trypanosomes. The results indicate that these compounds are more effective against the epimastigote form of T. cruzi, with a 52 ± 4% trypanocidal effect for compound 9. However, they are less effective against the trypomastigote form, with a 15 ± 3% trypanocidal effect. Additionally, compound 11 interacts with a higher number of amino acid residues within the active site of the enzyme cruzipain. Furthermore, it was also found that the presence of a nitro group allows for the generation of free radicals; likewise, the large size of the compound enables increased interaction with aminoacidic residues in the active site of cruzipain, contributing to trypanocidal activity. This activity depends on the size and lipophilicity of the compounds. The study recommends exploring new compounds based on the nitroisoxazole skeleton, with larger substituents and lipophilicity to enhance their trypanocidal activity.
Assuntos
Isoxazóis , Tripanossomicidas , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/síntese química , Isoxazóis/química , Isoxazóis/farmacologia , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/antagonistas & inibidores , Relação Estrutura-Atividade , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Animais , Domínio Catalítico , Estrutura MolecularRESUMO
Human African trypanosomiasis (HAT, sleeping sickness) and American trypanosomiasis (Chagas disease) are endemic zoonotic diseases caused by genomically related trypanosomatid protozoan parasites (Trypanosoma brucei and Trypanosoma cruzi, respectively). Just a few old drugs are available for their treatment, with most of them sharing poor safety, efficacy, and pharmacokinetic profiles. Only fexinidazole has been recently incorporated into the arsenal for the treatment of HAT. In this work, new multifunctional Ru(II) ferrocenyl compounds were rationally designed as potential agents against these pathogens by including in a single molecule 1,1'-bis(diphenylphosphino)ferrocene (dppf) and two bioactive bidentate ligands: pyridine-2-thiolato-1-oxide ligand (mpo) and polypyridyl ligands (NN). Three [Ru(mpo)(dppf)(NN)](PF6) compounds and their derivatives with chloride as a counterion were synthesized and fully characterized in solid state and solution. They showed in vitro activity on bloodstream T. brucei (EC50 = 31-160 nM) and on T. cruzi trypomastigotes (EC50 = 190-410 nM). Compounds showed the lowest EC50 values on T. brucei when compared to the whole set of metal-based compounds previously developed by us. In addition, several of the Ru compounds showed good selectivity toward the parasites, particularly against the highly proliferative bloodstream form of T. brucei. Interaction with DNA and generation of reactive oxygen species (ROS) were ruled out as potential targets and modes of action of the Ru compounds. Biochemical assays and in silico analysis led to the insight that they are able to inhibit the NADH-dependent fumarate reductase from T. cruzi. One representative hit induced a mild oxidation of low molecular weight thiols in T. brucei. The compounds were stable for at least 72 h in two different media and more lipophilic than both bioactive ligands, mpo and NN. An initial assessment of the therapeutic efficacy of one of the most potent and selective candidates, [Ru(mpo)(dppf)(bipy)]Cl, was performed using a murine infection model of acute African trypanosomiasis. This hit compound lacks acute toxicity when applied to animals in the dose/regimen described, but was unable to control parasite proliferation in vivo, probably because of its rapid clearance or low biodistribution in the extracellular fluids. Future studies should investigate the pharmacokinetics of this compound in vivo and involve further research to gain deeper insight into the mechanism of action of the compounds.
Assuntos
Compostos Ferrosos , Rutênio , Tripanossomicidas , Trypanosoma cruzi , Compostos Ferrosos/química , Compostos Ferrosos/farmacologia , Compostos Ferrosos/síntese química , Trypanosoma cruzi/efeitos dos fármacos , Ligantes , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/síntese química , Animais , Rutênio/química , Rutênio/farmacologia , Camundongos , Metalocenos/química , Metalocenos/farmacologia , Metalocenos/síntese química , Trypanosoma brucei brucei/efeitos dos fármacos , Testes de Sensibilidade Parasitária , Estrutura Molecular , Compostos Organometálicos/farmacologia , Compostos Organometálicos/química , Compostos Organometálicos/síntese química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese químicaRESUMO
Sterol 14-demethylase (CYP51) inhibitors, encompassing new chemical entities and repurposed drugs, have emerged as promising candidates for Chagas disease treatment, based on preclinical studies reporting anti-Trypanosoma cruzi activity. Triazoles like ravuconazole (RAV) and posaconazole (POS) progressed to clinical trials. Unexpectedly, their efficacy was transient in chronic Chagas disease patients, and their activity was not superior to benznidazole (BZ) treatment. This paper aims to summarize evidence on the global activity of CYP51 inhibitors against T. cruzi by applying systematic review strategies, risk of bias assessment, and meta-analysis from in vivo studies. PubMed and Embase databases were searched for original articles, obtaining fifty-six relevant papers meeting inclusion criteria. Characteristics of animal models, parasite strain, treatment schemes, and cure rates were extracted. Primary outcomes such as maximum parasitaemia values, survival, and parasitological cure were recorded for meta-analysis, when possible. The risk of bias was uncertain in most studies. Animals treated with itraconazole, RAV, or POS survived significantly longer than the infected non-treated groups (RR = 4.85 [3.62, 6.49], P < 0.00001), and they showed no differences with animals treated with positive control drugs (RR = 1.01 [0.98, 1.04], P = 0.54). Furthermore, the overall analysis showed that RAV or POS was not likely to achieve parasitological cure when compared with BZ or NFX treatment (OD = 0.49 [0.31, 0.77], P = 0.002). This systematic review contributes to understanding why the azoles had failed in clinical trials and, more importantly, how to improve the animal models of T. cruzi infection by filling the gaps between basic, translational, and clinical research.