Complexos imínicos de cobre com atividade antiparasitária frente à doença de chagas / Imine copper complexes with antiparasitic activity against Chagas disease

Neste trabalho foram sintetizados e caracterizados três complexos de cobre com ligantes imínicos, com o objetivo de avaliar sua atividade tripanocida. Esses complexos foram caracterizados por diversas técnicas espectroscópicas, como UV-Vis, Infravermelho e EPR, além de análise elementar e espectrometria de massa. Juntamente com outros complexos similares previamente sintetizados pelo nosso grupo, tiveram suas atividades avaliadas frente à forma tripomastigota do parasita T. cruzi, responsável pela fase aguda da doença de Chagas, por ensaios de viabilidade celular, com determinação do valor de seus IC50, concentração em que observamos a morte de 50% da cultura celular, pela metodologia denominada MTT. Todos os complexos mostraram-se eficientes frente a tripomastigotas, apresentando valores de IC50 abaixo de 10 µM, com quatro deles obtendo índice de seletividade maior que 10, fator importante para definir agentes promissores antichagásicos. Complexos selecionados também tiveram sua atividade verificada frente à forma amastigota do parasita, responsável pela fase crônica da doença, utilizando método de imageamento por microscópio de fluorescência e contagem celular. Estudos de inibição da cruzaína, uma cisteíno-protease importante para o metabolismo do parasita foram conduzidos em colaboração com o laboratório do Prof. Wagner Alves de Souza Júdice, da Universidade de Mogi das Cruzes. Quatro dos compostos testados apresentaram atividade inibitória frente a cruzaína, sendo dois de cobre, um de zinco e um ligante livre. Os estudos também permitiram diferenciar os mecanismos de inibição dos compostos, com os complexos de cobre apresentando um mecanismo de inibição clássico e o composto de zinco e o ligante livre apresentando o mecanismo de inibição competitiva parabólica com cooperatividade

In this work, three copper complexes with iminic ligands were synthesized and characterized, with the objective of evaluating their trypanocidal activity. These complexes were characterized by several spectroscopic techniques, such as UV-Vis, Infrared and EPR, in addition to elementary analysis and mass spectrometry. Together with other similar complexes previously synthesized by our group, their activities were evaluated against the trypomastigote form of the parasite T. cruzi, responsible for the acute phase of Chagas disease, by cell viability tests, with determination of the value of their IC50, concentration in that we observed the death of 50% of the cell culture, by the methodology called MTT, all presenting IC50 values below 10 µM, with four of them obtaining a selectivity index greater than 10, important factor for defining promising antichagasic agents. Selected complexes also had their activity verified against the amastigote form of the parasite, responsible for the chronic phase of the disease, using a fluorescence microscope and cell counting imaging method. Inhibition studies of cruzain, a cysteine protease important for the metabolism of the parasite, were conducted in collaboration with the laboratory of Professor Wagner Alves de Souza Júdice at the University of Mogi das Cruzes. Four of the tested compounds showed inhibitory activity against cruzain, two of copper, one of zinc and a free ligand. The studies also allowed to differentiate the mechanisms of inhibition of the compounds, with the copper complexes presenting a classic inhibition mechanism and the zinc compound and the free ligand presenting the competitive parabolic inhibition mechanism with cooperativity

Chagas disease. The use of serology to establish drug efficacy. Value and limitations

Presented at the "Consultative Meeting on the Strategic and Operational Aspects for the Clinical Development of Trypanocidal Drugs for Chagas Disease, 23-24 April 2007, Buenos Aires, Argentina.", sponsored by TDR, WHO.

Follow-up of dairy cattle naturally infected by Trypanosoma vivax after treatment with isometamidium chloride / Acompanhamento de bovinos leiteiros naturalmente infectados com Trypanosoma vivax após tratamento com cloreto de isometamidium

Abstract Trypanosoma vivax infections cause nonspecific clinical signs in cattle associated with aparasitemic intervals, making disease diagnosis a challenge. In Brazil, diminazene aceturate and isometamidium chloride (ISM) are available to treat bovine trypanosomosis. The objective of this study was to follow-up, by molecular and serological techniques, dairy cattle naturally infected by T. vivax after ISM treatment. Thirty cattle naturally infected with T. vivax received two applications of ISM, at a dosage of 1.0 mg/kg intramuscularly, on days 0 and 150. For T. vivax diagnosis, EDTA-blood and serum samples were evaluated on 0, 7, 15, 30, 60, 90, 120, 150, 180, 210, and 240 days after treatment PCR, Loop-mediated isothermal amplification (LAMP) and ELISA. Animals with persistent detection of T. vivax DNA by both PCR and LAMP were found and continuous detection of anti-T. vivax IgG antibodies by ELISA, suggesting the presence of T. vivax resistance to ISM. The combination of LAMP and ELISA tests can prevent misdiagnosis of the parasite clearance in treated cattle, contributing to better disease control. This is the first experiment that demonstrates the persistence infection of T. vivax under ISM treatment in a natural infected herd and evidence of ISM chemotherapy-resistant T. vivax in Brazil.

Resumo Em bovinos, infecções por Trypanosoma vivax geram sinais clínicos inespecíficos que, associados a intervalos aparasitêmicos, faz com que o diagnóstico da enfermidade seja desafiador. No Brasil, somente aceturato de diaminazeno e cloridrato de isometamidum (ISM) estão disponíveis para o tratamento da tripanossomose bovina. Este trabalho teve como objetivo acompanhar bovinos leiteiros naturalmente infectados por T. vivax, após o tratamento com ISM por meio de técnicas moleculares e sorológica. Foram utilizados 30 bovinos naturalmente infectados com T. vivax, sendo estes tratados com duas aplicações de ISM, na dosagem de 1,0 mg/kg por via intramuscular profunda, nos dias 0 e 150. Foram avaliadas, para diagnóstico de T. vivax, amostras de sangue acrescido de EDTA e soro, colhidas nos 0, 7, 15, 30, 60, 90, 120, 150, 180, 210 e 240 dias após os tratamentos pela reação em cadeia da polimerase (PCR), amplificação circular isotérmica do DNA (LAMP) e ensaio de imunoabsorção enzimático (ELISA). Verificou-se a presença de animais com persistência na detecção de DNA de T. vivax pela PCR e LAMP, bem como detecção contínua de anticorpos IgG anti-T. vivax pelo método de ELISA, sugerindo a presença de resistência de T. vivax ao ISM. A combinação dos testes LAMP e ELISA pode evitar falsos diagnósticos da eliminação do parasita nos bovinos tratados, contribuindo para um melhor controle da doença. Este é o primeiro experimento que demonstra infecção persistente do T. vivax em rebanho naturalmente infectado, tratado com ISM, e evidencia possível resistência ao quimioterápico no Brasil.

Characterization of adverse reactions to benznidazole in patients with Chagas disease in the Federal District, Brazil

Abstract INTRODUCTION: Benznidazole is used for treating Chagas disease (CD). This cross-sectional study aimed to characterize the adverse drug reactions (ADRs) of benznidazole at a public hospital in Brazil's Federal District. METHODS: Medical records were analyzed and ADRs were categorized by type, intensity, seriousness, and causality. RESULTS: Of the 62 patients who started benznidazole treatment for CD, 41 (66%) presented with 105 ADRs; 23 (37%) discontinued the treatment. Most reactions were classified as probable (81%), severe (63%), serious (67%), and dose-dependent (56%). CONCLUSIONS: The high incidence of ADRs because of treatment withdrawal revealed the need for safer alternatives for CD treatment.

Efficacy of the Benznidazole+Posaconazole combination therapy in parasitemia reduction: An experimental murine model of acute Chagas

Abstract INTRODUCTION: Benznidazole (BZL) and Nifurtimox (NFX) are the pharmacological treatment for acute phase Chagas Disease (CD); however, therapy resistance and residual mortality development remain important unresolved issues. Posaconazole (POS) has shown a trypanocidal effect in vivo and in vitro. Thus, this study aimed at comparing the T. Cruzi parasitic load-reducing effect of the combination of BZL+POS against that of monotherapy with either, during acute phase CD, in an experimental murine model. METHODS Nineteen Wistar rats were randomly allocated to four groups and inoculated with the trypomastigotes of T. cruzi strain´s JChVcl1. The rats were administered anti-parasites from day 20-29 post-infection. The Pizzi and Brener method was used for parasitemia measurement. Longitudinal data analysis for the continuous outcome of repeated measures was performed using parasitemia as the outcome measured at days 20, 22, 24, 27, and 29 post-infection. RESULTS All four groups had similar parasitic loads (p=0.143) prior to therapy initiation. Among the three treatment groups, the BZL+POS (n=5) group showed the highest mean parasitic load reduction (p=0.000) compared with the control group. Likewise, the BZL+POS group rats showed an earlier therapeutic effect and were the only ones without parasites in their myocardial samples. CONCLUSIONS: Treatment of acute phase CD with BZL+POS was more efficacious at parasitemia and myocardial injury reduction, compared with monotherapy with either.

Chagas congénito en atención primaria de la salud en la Provincia de Santa Fe / Congenital Chagas disease in primary health care in Santa Fe province

Actualmente, la transmisión transplacentaria es la vía más frecuente de infección por Trypanosoma cruzi. El diagnóstico y tratamiento temprano de hijos infectados evita el riesgo de desarrollar miocardiopatía y las niñas dejan de ser potenciales fuentes de transmisión congénita. En este estudio se evaluó el seguimiento de hijos de mujeres infectadas por T. cruzi en Centros de Salud de la provincia de Santa Fe. Se estudiaron 19 madres y sus 51 hijos. 45% (23/51) de los hijos no habían sido estudiados previamente, y de éstos 21/23 resultaron negativos mientras que dos niñas de 3 y 7 años estaban infectadas. Los 28 niños restantes ya habían sido estudiados en los Centros de Salud, siendo positivas dos gemelas de 22 meses y una niña de 9 años; los otros 25/28 hijos no estaban infectados. Un 47% (9/19) de las madres tenían como único antecedente la serología materna positiva, y de las 4 mujeres que transmitieron la infección, tres pertenecían a este grupo. La edad promedio de diagnóstico fue: 20±6 años en las madres y 7,4±6,7 años en los hijos. Se requieren estrategias sanitarias que favorezcan el estudio para la infección por T. cruzi en mujeres antes del embarazo y el seguimiento de todos los hijos para no perder la oportunidad de tratamiento

Transplacental transmission is currently the most frequent route of infection by Trypanosoma cruzi. Early diagnosis and treatment of infected children avoids the risk of developing cardiomyopathy, and girls are no longer potential sources of congenital transmission. This study evaluated the follow-up of children of women infected with T. cruzi in Primary Care Centres of the province of Santa Fe. Nineteen mothers and their 51 children were studied. Among the 51 children, 23 had no previous diagnosis (45%). Of these, 21 were negative while 2 girls, ages 3 and 7, were infected. The remaining 28 children already had a diagnosis at the Health Centres, with 2 twins of 22 months and a 9-year-old girl who were positive; the other 25 children were not infected. Among the 19 mothers, 9 (47%) had the positive maternal serology as the only antecedent. Of the 4 women who transmitted the infection, 3 belonged to this group. The average age of diagnosis was: 20 ± 6 years in mothers and 7.4 ± 6.7 years in children. Health strategies are required to promote the detection of infected women before pregnancy and the monitoring of all children so as not to miss the opportunity for treatment

Antiparasitic and anti-inflammatory activities of ß-lapachone-derived naphthoimidazoles in experimental acute Trypanosoma cruzi infection

BACKGROUND Chagas disease, which is caused by the protozoan Trypanosoma cruzi, is endemic to Latin America and mainly affects low-income populations. Chemotherapy is based on two nitrocompounds, but their reduced efficacy encourages the continuous search for alternative drugs. Our group has characterised the trypanocidal effect of naphthoquinones and their derivatives, with naphthoimidazoles derived from β-lapachone (N1, N2 and N3) being the most active in vitro. OBJECTIVES In the present work, the effects of N1, N2 and N3 on acutely infected mice were investigated. METHODS in vivo activity of the compounds was assessed by parasitological, biochemical, histopathological, immunophenotypical, electrocardiographic (ECG) and behavioral analyses. FINDINGS Naphthoimidazoles led to a decrease in parasitaemia (8 dpi) by reducing the number of bloodstream trypomastigotes by 25-50% but not by reducing mortality. N1 protected mice from heart injury (15 dpi) by decreasing inflammation. Bradycardia was also partially reversed after treatment with N1 and N2. Furthermore, the three compounds did not reverse hepatic and renal lesions or promote the improvement of other evaluated parameters. MAIN CONCLUSION N1 showed moderate trypanocidal and promising immunomodulatory activities, and its use in combination with benznidazole and/or anti-arrhythmic drugs as well as the efficacy of its alternative formulations must be investigated in the near future.

Cardiac Evaluation in the Acute Phase of Chagas' Disease with Post-Treatment Evolution in Patients Attended in the State of Amazonas, Brazil / Avaliação Cardíaca na Fase Aguda da Doença de Chagas com Evolução Pós-Tratamento em Pacientes Atendidos no Estado do Amazonas, Brasil

Abstract Background: In the past two decades, a new epidemiological profile of Chagas' disease (CD) has been registered in the Brazilian Amazon where oral transmission has been indicated as responsible for the increase of acute cases. In the Amazonas state, five outbreaks of acute CD have been registered since 2004. The cardiac manifestations in these cases may be characterized by diffuse myocarditis, with alteration in the electrocardiogram (ECG) and transthoracic echocardiogram (TTE). Objective: To perform a cardiac evaluation in autochthonous patients in the acute phase and at least one year after submitted to treatment for acute CD and evaluate the demographic variables associated with the presence of cardiac alterations. Methods: We evaluated patients diagnosed with acute CD through direct parasitological or serological (IgM) methods from 2007 to 2015. These patients were treated with benznidazole and underwent ECG and TTE before and after treatment. We assumed a confidence interval of 95% (CI 95%, p < 0.05) for all variables analyzed. Results: We observed 63 cases of an acute CD in which oral transmission corresponded to 75%. Cardiac alterations were found in 33% of the cases, with a greater frequency of ventricular repolarization alteration (13%), followed by pericardial effusion (10%) and right bundle branch block and left anterior fascicular block (2%). The follow-up occurred in 48 patients with ECG and 25 with TTE for a mean period of 15.5 ± 4.1 months after treatment. Of these, 8% presented normalization of the cardiac alterations in ECG, 62.5% remained with the normal exams. All of the patients presented normal results in TTE in the post-treatment period. As for the demographic variables, isolated cases presented more cardiac alterations than outbreaks (p = 0.044) as well as cases from Central Amazonas mesoregion (p = 0.020). Conclusions: Although cardiac alterations have not been frequent in most of the studied population, a continuous evaluation of the clinical-epidemiological dynamics of the disease in the region is necessary in order to establish preventive measures.

Resumo Fundamento: Nas últimas duas décadas, um novo perfil epidemiológico da Doença de Chagas (DC) foi registrado na Amazônia brasileira, onde a transmissão oral foi indicada como responsável pelo aumento dos casos agudos. No estado do Amazonas, foram registrados cinco surtos da doença desde 2004. As manifestações cardíacas nesses casos podem ser caracterizadas por miocardite difusa, com alteração nos resultados eletrocardiograma (ECG) e ecocardiografia transtorácica (ETT). Objetivo: avaliar parâmetros cardíacos em pacientes autóctones com DC na fase aguda e em um ano ou mais após tratamento, e avaliar as variáveis demográficas associadas com a presença de alterações cardíacas. Métodos: Avaliamos os pacientes diagnosticados com DC aguda por método direto parasitológico e exame sorológico (IgM) entre 2007 e 2015. Os pacientes foram tratados com benzonidazol e submetidos à ECG e ETT antes e após tratamento. Assumimos um intervalo de confiança de 95% (p < 0,05) para todas as variáveis analisadas. Resultados: Observamos 63 casos de DC aguda em que a transmissão oral ocorreu em 75% dos casos. Alterações cardíacas foram encontradas em 33% dos casos, com maior frequência de repolarização ventricular (13%), seguida de derrame pericárdico (10%), e bloqueio do ramo direito e bloqueio fascicular anterior esquerdo (2%). O acompanhamento foi realizado com 48 pacientes com ECG e 25 com ETT por um período médio de 15,5±4,1 meses após o tratamento. Desses pacientes, observou-se normalização das alterações eletrocardiográficas em 8% dos pacientes, e 62,5% continuaram com os parâmetros normais. Todos os pacientes apresentaram resultados da ETT normais no período pós-tratamento. Quanto às variáveis demográficas, os casos isolados apresentaram mais alterações cardíacas em comparação aos casos de surtos (p=0,044) e os casos identificados na mesorregião do Amazonas Central (p = 0,020). Conclusões: Apesar de as alterações cardíacas não terem sido frequentes na maioria da população do estudo, é necessária uma avaliação contínua da dinâmica clínica-epidemiológica da doença na região para se estabelecer medidas preventivas.

First report of treatment failure in a patient with cutaneous leishmaniasis infected by Leishmania (Viannia) naiffi carrying Leishmania RNA virus: a fortuitous combination?

Abstract We report the case of a 32-year-old man from Rio de Janeiro, who was infected in the Amazon region of Brazil by Leishmania (Viannia) naiffi. Generally, patients with L. naiffi cutaneous leishmaniasis exhibit a good therapeutic response to either pentavalent antimonials or pentamidine. However, after pentamidine treatment, this patient's infection evolved to therapeutic failure. To understand this clinical outcome, we investigated the presence of the Leishmania RNA virus (LRV) in parasites isolated from the cutaneous lesion; herein, we discuss the possible association between a poor response to pentamidine therapy and the presence of the LRV.

In vitro genotoxicity of nitroimidazoles as a tool in the search of new trypanocidal agents

BACKGROUND Only benznidazole (Bnz) (1) and nifurtimox (Nfx) (2) are licensed for the treatment of Chagas disease although their safety and efficacy profile are far from ideal. Farmanguinhos from Fiocruz has developed seven nitroimidazole compounds (4-10) analogs of megazol (3). OBJECTIVES To evaluate whether the genotoxic effect of 3 was abolished in the seven nitroimidazoles (4-10) analogs using the in vitro alkaline comet assay (CA) and the in vitro cytokinesis-block micronucleus assay (CBMN) in whole human blood cells (WHBC) and correlate this effect with their trypanocidal activity using bloodstream trypomastigote forms of Trypanosoma cruzi. METHODS The toxicity of 3-10 to WHBC in the in vitro CA was determined using the fluorescein diacetate/ethidium bromide assay. DNA damage in the in vitro CA was evaluated according to tail size in four classes (0-3) and methyl methane-sulfonate (MMS) was used as a positive control. The cytotoxicity of 3-10 to WHBC in the CBMN was measured using the cytokinesis-block proliferation index and the replication index. The number of the micronucleate cells in 2,000 binucleate cells by experimental group was determined. Mitomycin C and N-deacetyl-N-methylcolchicine were used as positive controls. FINDINGS Compound 3 showed a significant DNA strand break effect through the in vitro CA and highly significant clastogenic and/or aneugenic effect in the CBMN. Compounds 5, 6, 8, 9 and 10 showed negative results in the CBMN and positive results in the in vitro CA, while the inverse effect was observed for 4 and 7. MAIN CONCLUSIONS Compound 10 was the most promising to proceed with the development as a drug candidate in the treatment of Chagas disease showing absence of chromosomal cytogenetic damage and high activity against T. cruzi, about two times higher than 3 and the clinical drug 1.

Reactivation of Chagas disease in a heart transplant patient infected by sylvatic trypanosoma cruzi discrete typing unit I

Abstract Heart transplantation is an effective treatment for Chagas disease patients with severe cardiomyopathy. However, Trypanosoma cruzi reactivation is of great concern. The T. cruzi parasite is classified into six discrete typing units (DTUs identified as TcI-TcVI). It is unknown whether there is an association between T. cruzi genetic lineages and the different clinical manifestations of the disease. We report the case of a 51-year-old man who received a heart transplantation and presented with a reactivation of the disease. The molecular characterization of the parasite showed that the reactivation was related to specific infection by a DTU I (TcISYL) parasite.

Chagas cardiomyopathy associated with serological cure after trypanocidal treatment during childhood

Abstract Chagas disease is a chronic parasitological disease, which could cause cardiac manifestations in approximately one-third of affected individuals. Benznidazole and nifurtimox are used to treat this parasitological infection caused by Trypanosoma cruzi. Conventionally, the criterion for cure is consistently negative serological tests after treatment. We report a case of a patient who was treated when she was 13 years old and achieved T. cruzi negative seroconversion but developed Chagas disease cardiomyopathy as an adult.

Trypanosoma cruzi: analysis of two different strains after piplartine treatment

ABSTRACT The hemoflagellate protozoan, Trypanosoma cruzi, mainly transmitted by triatomine insects through blood transfusion or from mother-to-child, causes Chagas' disease. This is a serious parasitic disease that occurs in Latin America, with considerable social and economic impact. Nifurtimox and benznidazole, drugs indicated for treating infected persons, are effective in the acute phase, but poorly effective during the chronic phase. Therefore, it is extremely urgent to find innovative chemotherapeutic agents and/or effective vaccines. Since piplartine has several biological activities, including trypanocidal activity, the present study aimed to evaluate it on two T. cruzi strains proteome. Considerable changes in the expression of some important enzymes involved in parasite protection against oxidative stress, such as tryparedoxin peroxidase (TXNPx) and methionine sulfoxide reductase (MSR) was observed in both strains. These findings suggest that blocking the expression of the two enzymes could be potential targets for therapeutic studies.

Response to different benznidazole doses in animal models of chronic phase Chagas disease: a critical review

Abstract Chagas disease is a protozoan infection that was identified over a century ago. No drugs are available to treat the indeterminate and determinate chronic phases of the disease. Success of a drug design is dependent on correct biological evaluation. Concerning new drug designs for Chagas disease, it is essential to first identify the most effective, existing, experimental chronic protocols that can be used for comparison purposes. Here, we present a literature review regarding experimental models with chronic Chagas disease to evaluate the efficacy of benznidazole (BZN). We searched literature published in PubMed and Web of Science databases, using these keywords: animal model, BZN, Chagas disease, T. cruzi, and chronic phase, with no timeframe limitations. We excluded articles involving acute phase animal models and/or those without BZN treatment. The selected studies were conducted using different BZN concentrations (10mg-100mg) involving several different periods (5-70 days). Concentrations and durations of use are directly related to side effects, but do not prevent chronic tissue lesions. BZN use during the late/chronic phases of Chagas disease is unable to eliminate amastigote forms present in infected tissues. This study suggests the administration of a lower BZN concentration (<100mg/kg/day) during the chronic phase of the animal model, as this had been reported to result in fewer side effects.

Evaluation of in vitro anti-Trypanosoma cruzi activity of medications benznidazole, amiodarone hydrochloride, and their combination

Abstract INTRODUCTION: Approximately seven to eight million people worldwide have Chagas disease. In Brazil, benznidazole is the most commonly used active drug against Trypanosoma cruzi; however, its efficacy is limited, and side effects are frequent. Recent studies suggest that amiodarone may be beneficial in the treatment of this disease, by exerting anti-T. cruzi action. This study evaluated changes in T. cruzi cell count in in vitro cultures subjected to different doses of benznidazole, amiodarone, and their combination. METHODS: T. cruzi (Y strain) cultures containing approximately 100,000 cells were treated with either 100mg, 50mg, 25mg, 12.5mg, or 10mg of benznidazole, amiodarone, or their combination. On the 4th day, cell count was compared to the baseline data. RESULTS: On the 4th day, no parasites were observed in any of the treated cultures. CONCLUSIONS: Benznidazole and amiodarone were equally effective in eliminating T. cruzi in culture. The combination of the two drugs was also equally effective, but our data cannot demonstrate synergism, as similar results were obtained when the drugs were tested individually or in combination. It is suggested that this study be repeated with other T. cruzi strains to determine whether similar results can be obtained again.

From Medicinal Chemistry to Human Health: Current Approaches to Drug Discovery for Cancer and Neglected Tropical Diseases

ABSTRACT Scientific and technological breakthroughs have compelled the current players in drug discovery to increasingly incorporate knowledge-based approaches. This evolving paradigm, which has its roots attached to the recent advances in medicinal chemistry, molecular and structural biology, has unprecedentedly demanded the development of up-to-date computational approaches, such as bio- and chemo-informatics. These tools have been pivotal to catalyzing the ever-increasing amount of data generated by the molecular sciences, and to converting the data into insightful guidelines for use in the research pipeline. As a result, ligand- and structure-based drug design have emerged as key pathways to address the pharmaceutical industry's striking demands for innovation. These approaches depend on a keen integration of experimental and molecular modeling methods to surmount the main challenges faced by drug candidates - in vivo efficacy, pharmacodynamics, metabolism, pharmacokinetics and safety. To that end, the Laboratório de Química Medicinal e Computacional (LQMC) of the Universidade de São Paulo has developed forefront research on highly prevalent and life-threatening neglected tropical diseases and cancer. By taking part in global initiatives for pharmaceutical innovation, the laboratory has contributed to the advance of these critical therapeutic areas through the use of cutting-edge strategies in medicinal chemistry.

Overexpression of eukaryotic initiation factor 5A (eIF5A) affects susceptibility to benznidazole in Trypanosoma cruzi populations

Eukaryotic initiation factor 5A (eIF5A) is a conserved protein with an essential role in translation elongation. Using one and two-dimensional western blotting, we showed that the eIF5A protein level was 2-fold lower in benznidazole (BZ)-resistant (BZR and 17LER) Trypanosoma cruzi populations than in their respective susceptible counterparts (BZS and 17WTS). To confirm the role of eIF5A in BZ resistance, we transfected BZS and 17WTS with the wild-type eIF5A or mutant eIF5A-S2A (in which serine 2 was replaced by alanine). Upon overexpressing eIF5A, both susceptible lines became approximately 3- and 5-fold more sensitive to BZ. In contrast, the eIF5A-S2A mutant did not alter its susceptibility to BZ. These data suggest that BZ resistance might arise from either decreasing the translation of proteins that require eIF5A, or as a consequence of differential levels of precursors for the hypusination reactions (e.g., spermidine and trypanothione), both of which alter BZ's effects in the parasite.

Therapeutic drug monitoring of benznidazole and nifurtimox: a systematic review and quality assessment of published clinical practice guidelines

Abstract The pharmacological management of adults with chronic-phase Chagas disease is challenging despite it being the recent focus of extensive research. One of the challenges in the current clinical practice guidelines (CPGs) landscape is the existence of non-evidence-based recommendations for the use of laboratory tests in treatment monitoring. This study aimed to systematically assess the quality and consistency of recommendations of CPGs on the pharmacological management of adults with chronic-phase Chagas disease. Systematic literature searches were conducted in MEDLINE, EMBASE, SciELO and Google to identify all published CPGs relevant to the pharmacological management of Chagas disease, between January 2010 and March 2016. Three independent reviewers assessed the quality of each CPG using the Appraisal of Guidelines Research and Evaluation (AGREE) II instrument. A total of five CPGs were included and the overall quality of the guidelines for therapeutic drug monitoring of Chagas disease was moderate-to-low. There was considerable variation in the quality of the CPGs across the AGREE II domains. The domains of scope/purpose, stakeholder involvement, and clarity of presentation were rated well, and the domains of applicability and editorial independence received poor ratings. This review showed that the methodological quality of CPGs for Chagas disease was generally inappropriate, and there was no explicit link between the best available evidence and current recommendations.