Synthesis and activity of benzimidazole N-Acylhydrazones against Trypanosoma cruzi, Leishmania amazonensis and Leishmania infantum.

In this study, we present the design, synthesis, and cytotoxic evaluation of a series of benzimidazole N-acylhydrazones against strains of T. cruzi (Y and Tulahuen) and Leishmania species (L. amazonensis and L. infantum). Compound (E)-N'-((5-Nitrofuran-2-yl)methylene)-1H-benzo[d]imidazole-2-carbohydrazide demonstrated significant activity against both trypomastigote and amastigote forms (Tulahuen strain), with an IC50/120 h of 0.033 µM and a selectivity index (SI) of 7680. This represents a potency 46 times greater than that of benznidazole (IC50/120 h = 1.520 µM, SI = 1390). Another compound (E)-N'-(2-Hydroxybenzylidene)-1H-benzo[d]imidazole-2-carbohydrazide showed promising activity against both trypomastigote and amastigote forms (Tulahuen strain), with an IC50/120 h of 3.600 µM and an SI of 14.70. However, its efficacy against L. infantum and L. amazonensis was comparatively lower. These findings provide valuable insights for the development of more effective treatments against Trypanosoma cruzi.

New drug discovery strategies for the treatment of benznidazole-resistance in Trypanosoma cruzi, the causative agent of Chagas disease.

INTRODUCTION: Benznidazole, the drug of choice for treating Chagas Disease (CD), has significant limitations, such as poor cure efficacy, mainly in the chronic phase of CD, association with side effects, and parasite resistance. Understanding parasite resistance to benznidazole is crucial for developing new drugs to treat CD. AREAS COVERED: Here, the authors review the current understanding of the molecular basis of benznidazole resistance. Furthermore, they discuss the state-of-the-art methods and critical outcomes employed to evaluate the efficacy of potential drugs against T. cruzi, aiming to select better compounds likely to succeed in the clinic. Finally, the authors describe the different strategies employed to overcome resistance to benznidazole and find effective new treatments for CD. EXPERT OPINION: Resistance to benznidazole is a complex phenomenon that occurs naturally among T. cruzi strains. The combination of compounds that inhibit different metabolic pathways of the parasite is an important strategy for developing a new chemotherapeutic protocol.

New 2-nitroimidazole-N-acylhydrazones, analogs of benznidazole, as anti-Trypanosoma cruzi agents.

Chagas disease is a neglected tropical parasitic disease caused by the protozoan Trypanosoma cruzi. Worldwide, an estimated 8 million people are infected with T. cruzi, causing more than 10,000 deaths per year. Currently, only two drugs, nifurtimox and benznidazole (BNZ), are approved for its treatment. However, both are ineffective during the chronic phase, show toxicity, and produce serious side effects. This work aimed to obtain and evaluate novel 2-nitroimidazole-N-acylhydrazone derivatives analogous to BNZ. The design of these compounds used the two important pharmacophoric subunits of the BNZ prototype, the 2-nitroimidazole nucleus and the benzene ring, and the bioisosterism among the amide group of BNZ and N-acylhydrazone. The 27 compounds were obtained by a three-step route in 57%-98% yields. The biological results demonstrated the potential of this new class of compounds, since eight compounds were potent and selective in the in vitro assay against T. cruzi amastigotes and trypomastigotes using a drug-susceptible strain of T. cruzi (Tulahuen) (IC50 = 4.3-6.25 µM) and proved to be highly selective with low cytotoxicity on L929 cells. The type I nitroreductase (TcNTR) assay suggests that the new compounds may act as substrates for this enzyme.

Assessment of potential transthyretin amyloid cardiomyopathy cases in the Brazilian public health system using a machine learning model.

OBJECTIVES: To identify and describe the profile of potential transthyretin cardiac amyloidosis (ATTR-CM) cases in the Brazilian public health system (SUS), using a predictive machine learning (ML) model. METHODS: This was a retrospective descriptive database study that aimed to estimate the frequency of potential ATTR-CM cases in the Brazilian public health system using a supervised ML model, from January 2015 to December 2021. To build the model, a list of ICD-10 codes and procedures potentially related with ATTR-CM was created based on literature review and validated by experts. RESULTS: From 2015 to 2021, the ML model classified 262 hereditary ATTR-CM (hATTR-CM) and 1,581 wild-type ATTR-CM (wtATTR-CM) potential cases. Overall, the median age of hATTR-CM and wtATTR-CM patients was 66.8 and 59.9 years, respectively. The ICD-10 codes most presented as hATTR-CM and wtATTR-CM were related to heart failure and arrythmias. Regarding the therapeutic itinerary, 13% and 5% of hATTR-CM and wtATTR-CM received treatment with tafamidis meglumine, respectively, while 0% and 29% of hATTR-CM and wtATTR-CM were referred to heart transplant. CONCLUSION: Our findings may be useful to support the development of health guidelines and policies to improve diagnosis, treatment, and to cover unmet medical needs of patients with ATTR-CM in Brazil.

Assessment of potential transthyretin amyloid cardiomyopathy cases in the Brazilian public health system using a machine learning mode

OBJECTIVES: To identify and describe the profile of potential transthyretin cardiac amyloidosis (ATTR-CM) cases in the Brazilian public health system (SUS), using a predictive machine learning (ML) model. METHODS: This was a retrospective descriptive database study that aimed to estimate the frequency of potential ATTR-CM cases in the Brazilian public health system using a supervised ML model, from January 2015 to December 2021. To build the model, a list of ICD-10 codes and procedures potentially related with ATTR-CM was created based on literature review and validated by experts. RESULTS: From 2015 to 2021, the ML model classified 262 hereditary ATTR-CM (hATTR-CM) and 1,581 wild-type ATTR-CM (wtATTR-CM) potential cases. Overall, the median age of hATTR-CM and wtATTR-CM patients was 66.8 and 59.9 years, respectively. The ICD-10 codes most presented as hATTR-CM and wtATTR-CM were related to heart failure and arrythmias. Regarding the therapeutic itinerary, 13% and 5% of hATTR-CM and wtATTR-CM received treatment with tafamidis meglumine, respectively, while 0% and 29% of hATTR-CM and wtATTR-CM were referred to heart transplant. CONCLUSION: Our findings may be useful to support the development of health guidelines and policies to improve diagnosis, treatment, and to cover unmet medical needs of patients with ATTR-CM in Brazil.

What are the barriers and facilitators to participation of people with Down syndrome? A scoping review.

AIM: To determine the barriers and facilitators of active community participation of children, adolescents, and adults with Down syndrome. METHOD: Searches were completed in five electronic databases to identify original studies about participation of children, adolescents (ages < 18 years), and adults (ages 18-59 years) with Down syndrome. Barriers and facilitators to participation were categorized into four factors: personal, social, environmental, and policy and programme. Findings were analysed and validated by a young adult with Down syndrome and a family member, using the public and patient involvement strategy. RESULTS: Fourteen studies were included: eight with children and adolescents and six with adults. Of the 14 studies, 10 were qualitative and four quantitative. Most studies (n = 9) investigated participation in physical activities, while only a few examined participation in community/social activities (n = 3), daily activities (n = 2), and leisure activities (n = 1). The most commonly cited barriers and facilitators were the availability of programmes and specialized professionals, transportation, as well as attitudes and behaviours. Physical and psychological characteristics of people with Down syndrome and facilities were also frequently mentioned as barriers. On the other hand, the desire to stay active and personal interest in the activity were among the most frequently reported facilitators. INTERPRETATION: The participation of people with Down syndrome is mainly influenced by physical or psychological factors, the support and attitudes of parents/caregivers, and the availability of specialized programmes. Given the scarcity of research investigating the participation of people with Down syndrome in community activities, daily activities, and leisure, especially in adults, more studies are still needed.

Aminopyrimidine Derivatives as Multiflavivirus Antiviral Compounds Identified from a Consensus Virtual Screening Approach.

Around three billion people are at risk of infection by the dengue virus (DENV) and potentially other flaviviruses. Worldwide outbreaks of DENV, Zika virus (ZIKV), and yellow fever virus (YFV), the lack of antiviral drugs, and limitations on vaccine usage emphasize the need for novel antiviral research. Here, we propose a consensus virtual screening approach to discover potential protease inhibitors (NS3pro) against different flavivirus. We employed an in silico combination of a hologram quantitative structure-activity relationship (HQSAR) model and molecular docking on characterized binding sites followed by molecular dynamics (MD) simulations, which filtered a data set of 7.6 million compounds to 2,775 hits. Lastly, docking and MD simulations selected six final potential NS3pro inhibitors with stable interactions along the simulations. Five compounds had their antiviral activity confirmed against ZIKV, YFV, DENV-2, and DENV-3 (ranging from 4.21 ± 0.14 to 37.51 ± 0.8 µM), displaying aggregator characteristics for enzymatic inhibition against ZIKV NS3pro (ranging from 28 ± 7 to 70 ± 7 µM). Taken together, the compounds identified in this approach may contribute to the design of promising candidates to treat different flavivirus infections.

Translation and validation of the audiovisual version of the Montreal cognitive assessment in older adults in Brazil.

BACKGROUND: The use of a reliable remote cognitive screening test for older adults is crucial for the diagnosis of cognitive impairment. This study aimed to translate and validate the audiovisual Montreal Cognitive Assessment (MoCA)for older adults in Brazil. METHODS: One hundred and fourteen older adults were recruited from the community and demographic, functional, mood, and cognitive data were collected. Participants were classified into two groups: cognitively healthy or mild cognitive impairment (MCI). Statistical analyses were performed in order to assess the validity of the test and the cutoff score. RESULTS: The psychometric properties of the audiovisual MoCA showed good convergent validity. The audiovisual MoCA was represented as a unifactorial adjusted model, the composite reliability value was acceptable and a cutoff point of ≥23 reached adequate sensitivity and specificity at 0.77 and 0.92, respectively. CONCLUSIONS: The translated audiovisual MoCA is a valid and reliable cognitive screening test that can be administered remotely in older adults in Brazil. The test demonstrated a great ability to discriminate older adults with MCI from cognitively healthy adults. Future studies should focus on validating the audiovisual MoCA using other target population groups in order to expand the use of this remote screening test.

New anti-SARS-CoV-2 aminoadamantane compounds as antiviral candidates for the treatment of COVID-19.

Here, the antiviral activity of aminoadamantane derivatives were evaluated against SARS-CoV-2. The compounds exhibited low cytotoxicity to Vero, HEK293 and CALU-3 cells up to a concentration of 1,000 µM. The inhibitory concentration (IC50) of aminoadamantane was 39.71 µM in Vero CCL-81 cells and the derivatives showed significantly lower IC50 values, especially for compounds 3F4 (0.32 µM), 3F5 (0.44 µM) and 3E10 (1.28 µM). Additionally, derivatives 3F5 and 3E10 statistically reduced the fluorescence intensity of SARS-CoV-2 protein S from Vero cells at 10 µM. Transmission microscopy confirmed the antiviral activity of the compounds, which reduced cytopathic effects induced by the virus, such as vacuolization, cytoplasmic projections, and the presence of myelin figures derived from cellular activation in the face of infection. Additionally, it was possible to observe a reduction of viral particles adhered to the cell membrane and inside several viral factories, especially after treatment with 3F4. Moreover, although docking analysis showed favorable interactions in the catalytic site of Cathepsin L, the enzymatic activity of this enzyme was not inhibited significantly in vitro. The new derivatives displayed lower predicted toxicities than aminoadamantane, which was observed for either rat or mouse models. Lastly, in vivo antiviral assays of aminoadamantane derivatives in BALB/cJ mice after challenge with the mouse-adapted strain of SARS-CoV-2, corroborated the robust antiviral activity of 3F4 derivative, which was higher than aminoadamantane and its other derivatives. Therefore, aminoadamantane derivatives show potential broad-spectrum antiviral activity, which may contribute to COVID-19 treatment in the face of emerging and re-emerging SARS-CoV-2 variants of concern.

Integration of biophysical and biological approaches to validate fragment-like compounds targeting l,d-transpeptidases from Mycobacterium tuberculosis.

Tuberculosis is one of the major causes of death worldwide; more than a million people die every year because of this infection. The constant emergency of Mycobacterium tuberculosis resistant strains against the most used treatments also contributes to the burden caused by this disease. Consequently, the development of new alternative therapies against this disease is constantly required. In recent years, only a few molecules have reached the market as new antituberculosis agents. The mycobacterial cell wall biosynthesis is for a longstanding considered an important target for drug development. Particularly, in M. tuberculosis, the peptidoglycan cross-links are predominantly formed by nonclassical bridges between the third residues of adjacent tetrapeptides. The responsible enzymes for these reactions are ld-transpeptidases (Ldts), for which M. tuberculosis has five paralogues. Although these enzymes are distinct from the penicillin-binding proteins (PBPs), they can also be inactivated by ß-lactam antibiotics, but since M. tuberculosis has a chromosomal ß-lactamase, most of the antibiotics of these classes can be degraded. Thus, to identify alternative scaffolds for the development of new antimicrobials against tuberculosis, we have integrated several fragment-based drug discovery techniques. Based on that, we identified and validated a number of small molecules that could be the starting point in the synthesis of more potent inhibitors against at least two Ldts from M. tuberculosis, LdtMt2 and LdtMt3. Eight identified molecules inhibited the Ldts activity in at least 20%, and three of them have antimycobacterial activity. The cell ultrastructural analysis suggested that one of the best compounds induced severe effects on the septum and cell wall morphologies, which corroborates our target-based approach to identifying new Ldts hits.

Porcine milk exosomes modulate the immune functions of CD14+ monocytes in vitro.

Exosomes mediate near and long-distance intercellular communication by transferring their molecular cargo to recipient cells, altering their biological response. Milk exosomes (MEx) are internalized by immune cells and exert immunomodulatory functions in vitro. Porcine MEx can accumulate in the small intestine, rich in macrophages. No information is available on the immunomodulatory ability of porcine MEx on porcine monocytes, which are known precursors of gut macrophages. Therefore, this study aims at (1) assessing the in vitro uptake of porcine MEx by porcine monocytes (CD14+), and (2) evaluating the in vitro impact of porcine MEx on porcine monocytes immune functions. MEx were purified by ultracentrifugation and size exclusion chromatography. The monocytes' internalization of PKH26-labeled MEx was examined using fluorescence microscopy. Monocytes were incubated with increasing exosome concentrations and their apoptosis and viability were measured. Lastly, the ability of MEx to modulate the cells' immune activities was evaluated by measuring monocytes' phagocytosis, the capacity of killing bacteria, chemotaxis, and reactive oxygen species (ROS) production. MEx were internalized by porcine monocytes in vitro. They also decreased their chemotaxis and phagocytosis, and increased ROS production. Altogether, this study provides insights into the role that MEx might play in pigs' immunity by demonstrating that MEx are internalized by porcine monocytes in vitro and exert immunomodulatory effects on inflammatory functions.

Repertório ocupacional de pessoas idosas em cenário pandêmico: olhares sobre trajetórias em (re)construção / Occupational repertoire of older people in a pandemic scenario: views on trajectories in (re)construction / Repertorio ocupacional de las personas mayores en un escenario pandémico: puntos de vista sobre las trayectorias en (re)construcción

Introdução: A pandemia do coronavírus impôs interrupções e/ou mudanças no modo de executar diversas ocupações. Muitas delas, fazem parte do cotidiano das pessoas idosas, e que podem repercutir na saúde e no bem-estar. Objetivo: Compreender as vivências das pessoas idosas na pandemia do coronavírus e suas repercussões no repertório ocupacional. Métodos: Trata-se de um estudo transversal descritivo, de abordagem qualitativa. Participaram da pesquisa 148 pessoas idosas, entrevistadas por chamada de vídeo. Desta forma, discorreram livremente sobre as vivências cotidianas na pandemia, seus significados e suas repercussões no repertório ocupacional. Os dados foram tratados pela técnica de análise de conteúdo. Resultados: Duas categorias temáticas representam as vivências das pessoas idosas: negativas e positivas. Nas vivências negativas, as alterações emocionais promoveram restrição à participação social ou até mesmo o desengajamento ocupacional. Por outro lado, a categoria das vivências positivas, mostrou pessoas idosas que utilizaram o cenário pandêmico para melhorar o autocuidado, se engajar em novos projetos de vida ou resgatar aqueles que estavam esquecidos, e reconhecer a importância da solidariedade e empatia diante das adversidades do adoecimento. Conclusão: As vivências foram ambivalentes. Os participantes declararam como a pandemia despertou afetos negativos que culminaram em interrupções de atividades rotineiras e significativas. No entanto, muitos demonstraram a capacidade de superar as adversidades, refletir sobre os aspectos positivos e se adaptar para se manter engajados em ocupações. (AU)

Introduction: The coronavirus pandemic has imposed interruptions and/or changes in the way of performing various occupations that are part of the everyday life of older people and that can have repercussions on their health and well-being. Objective: To understand the experiences of the elderly in the coronavirus pandemic and its repercussions on the occupational repertoire. Methods: This is a cross-sectional descriptive study with a qualitative approach. A total of 148 older people participated in the research and were interviewed by video call. They were asked to talk freely about their daily experiences in the pandemic period, their meanings, and their repercussions on their occupational repertoire. The data were analyzed by the content analysis technique. Results: Two thematic categories represent the experiences of older people: negative and positive. In the negative experiences, the emotional changes promoted restricted social participation or even occupational disengagement. On the other hand, the category of positive experiences showed older people who used the pandemic scenario to improve self-care, engage in new life projects or rescue those that were forgotten, and recognize the importance of solidarity and empathy in the face of the adversities of illness. Conclusion: The experiences were ambivalent. The participants stated how the pandemic awakened negative affections that culminated in interruptions of routine and meaningful activities, however, many demonstrated the ability to overcome adversity, reflect on the positive aspects and adapt to stay engaged in occupations. (AU)

Introducción: La pandemia de coronavirus ha impuesto interrupciones y/o cambios en la forma de realizar diversas ocupaciones que forman parte de la vida cotidiana de las personas mayores y que pueden repercutir en la salud y el bienestar. Objetivo: Conocer las experiencias de las personas mayores en la pandemia de coronavirus y sus repercusiones en el repertorio ocupacional. Métodos: Se trata de un estudio descriptivo transversal con un enfoque cualitativo. Un total de 148 personas mayores participaron en la encuesta y fueron entrevistadas por videollamada. Se les invitó a hablar libremente sobre sus experiencias cotidianas en la pandemia, sus significados y sus repercusiones en su repertorio ocupacional. Los datos se trataron mediante la técnica de análisis de contenido. Resultados: Dos categorías temáticas representan las experiencias de las personas mayores: negativas y positivas. En las experiencias negativas, las alteraciones emocionales promovían la restricción a la participación social o incluso la desvinculación ocupacional. Por otro lado, la categoría de experiencias positivas mostró a personas mayores que utilizaron el escenario pandémico para mejorar el autocuidado, emprender nuevos proyectos de vida o rescatar a los que estaban olvidados y reconocer la importancia de la solidaridad y la empatía ante las adversidades de la enfermedad. Conclusión: Las experiencias fueron ambivalentes. Los participantes declararon que la pandemia provocó un afecto negativo que culminó en la interrupción de las actividades rutinarias y significativas; sin embargo, muchos demostraron la capacidad de superar la adversidad, reflexionar sobre los aspectos positivos y adaptarse para seguir participando en sus ocupaciones. (AU)

Using machine learning to assess potential cases of transthyretin cardiac amyloidosis in Brazil: a retrospective database approach

INTRODUCTION: Amyloidosis is a group of protein misfolding disorders leading to organ damage due to insoluble amyloid fibril deposits • The two primary types of cardiac amyloidosis are light-chain amyloid (AL) and transthyretin (TTR) cardiac amyloidosis • TTR amyloidosis can be hereditary (hATTR) or age-related (wtATTR). It is an often-overlooked cause of heart failure in older adults • Recent studies reveal its prevalence in various patient groups: up to 13% in HFpEF, 16% in aortic stenosis patients undergoing valve replacement, 7-8% in carpal tunnel release surgery, and 17% in some other contexts • ATTR-CM is significant in the context of cardiovascular diseases, a leading global cause of death. OBJECTIVE: This study aimed to identify and describe the profile of potential transthyretin cardiac amyloidosis (ATTR-CM) cases in the Brazilian public health system (SUS), using a predictive machine learning (ML) model. MATERIALS AND METHODS: This was a retrospective descriptive database study that aimed to estimate the frequency of potential ATTR-CM cases in the Brazilian public health system (Figure 1) using a supervised machine learning (Figure 2) model, with data extracted from DATASUS outpatient and inpatient datasets from January 2015 to December 2021 • To build the model, a list of ICD-10 codes and procedures potentially related with ATTR-CM was created based on literature review and validated by experts (Figure 3). RESULTS: From 2015 to 2021, the ML model classified 262 hATTR-CM (213 reference hATTR-CIM and 49 hATTR-CM-like) and 1,581 wtATTR-CM (203 reference wtATTR-CM and 1,378 wtATTR-CM-like). Overall, the median age of hATTR-CM and wtATTR-CM patients was 66.8 and 59.9 years, respectively • The ICD-10 codes most presented as hATTR-CM and wtATTR-CM were related to heart failure and arrythmias, with similar procedures performed (Figure 4). Regarding healthcare utilization, hATTR-CM and hATTR-CM-like had similar profiles on proportion of patients with outpatient visits (hATTR-CM 98.0% vs. 92.0% hATTR-CM-like) and different profile related to proportion of hospitalized patients (hATTR-CM 94.4% vs. 32.7% hATTR-CM-like) (Figure 5) • In wtATTR-CM groups, although both proportions on outpatient visits and hospitalizations were similar, the length of stay (LOS) on hospitalizations was different in wtATTR-CM-like (wtATTR-CM median LOS 5.0 (IQR:2.0 - 10.0] vs. median LOS 7.0 [IQR:3.0 - 14.0]). CONCLUSIONS: Our findings may be useful to support decreasing the uncertainties on ATTR-CM population size in Health Technology Assessment appraisals and in the development of healthcare guidelines and policies to address patients' unmet needs and to improve early diagnosis and access to treatment for patients with ATTR-CM in Brazil This study puts a spotlight on the ATTR-CM underdiagnosis in Brazil using a machine learning approach, which can be used as an important tool to support diagnosis improvement.

Discovery and structural optimization of a new series of N-acyl-2-aminobenzothiazole as inhibitors of Zika virus.

Zika virus infection is associated to severe diseases such as congenital microcephaly and Zika fever causing serious harm to humans and special concern to health systems in low-income countries. Currently, there are no approved drugs against the virus, and the development of anti-Zika virus drugs is thus urgent. The present investigation describes the discovery and hit expansion of a N-acyl-2-aminobenzothiazole series of compounds against Zika virus replication. A structure-activity relationship study was obtained with the synthesis and evaluation of anti-Zika virus activity and cytotoxicity on Vero cells of nineteen derivatives. The three optimized compounds were 2.2-fold more potent than the initial hit and 20.9, 7.7 and 6.4-fold more selective. Subsequent phenotypic and biochemical assays were performed to evidence whether non-structural proteins, such as the complex NS2B-NS3pro, are related to the mechanism of action of the most active compounds.

Real-world treatment patterns of rheumatoid arthritis in Brazil: analysis of DATASUS national administrative claims data for pharmacoepidemiology studies (2010-2020).

Our study assessed DATASUS as a potential source for pharmacoepidemiologic studies in rheumatoid arthritis (RA) in the Brazilian population focusing on treatment patterns and determinants of initiating or switching to a novel therapy. This was a descriptive database study of RA patients with at least one claim of RA and ≥ 2 claims of disease-modifying anti-rheumatic drug (DMARD); conventional synthetic (cs), biologic (b) or targeted synthetic (ts) DMARD with more than 6 months of follow-up from 01-Jan-2010 to 31-Dec-2020. Analyses were stratified for SUS-exclusive and SUS+ private user cohorts. We identified 250,251 patients with RA in DATASUS: mean age of 58.4 years, majority female (83%) and white (58%). 62% were SUS-exclusive and 38% SUS+ private. Most common bDMARDs were adalimumab and etanercept. Age (adjusted odds ratio 1.78 [50+]; 95% CI 1.57-2.01), SUS exclusive status (0.53; 0.47-0.59), distance to clinic [160+ km] (0.57; 0.45-0.72), and pre-index csDMARD claims (1.23; 1.08-1.41) were independent predictors of initiating a novel oral tsDMARD. Switching from bDMARD to tsDMARD, associations were similar, except for the direction of associations for SUS exclusive status (adjusted hazard ratio 1.10; 1.03-1.18), distance to clinic (1.18; 1.03-1.35), and number of previous bDMARD (0.15; 0.14-0.16). DATASUS is a source suitable for treatment-related analyses in RA reflecting the public health system in Brazil.

Evaluating Known Zika Virus NS2B-NS3 Protease Inhibitor Scaffolds via In Silico Screening and Biochemical Assays.

The NS2B-NS3 protease (NS2B-NS3pro) is regarded as an interesting molecular target for drug design, discovery, and development because of its essential role in the Zika virus (ZIKV) cycle. Although no NS2B-NS3pro inhibitors have reached clinical trials, the employment of drug-like scaffolds can facilitate the screening process for new compounds. In this study, we performed a combination of ligand-based and structure-based in silico methods targeting two known non-peptide small-molecule scaffolds with micromolar inhibitory activity against ZIKV NS2B-NS3pro by a virtual screening (VS) of promising compounds. Based on these two scaffolds, we selected 13 compounds from an initial library of 509 compounds from ZINC15's similarity search. These compounds exhibited structural modifications that are distinct from previously known compounds yet keep pertinent features for binding. Despite promising outcomes from molecular docking and initial enzymatic assays against NS2B-NS3pro, confirmatory assays with a counter-screening enzyme revealed an artifactual inhibition of the assessed compounds. However, we report two compounds, 9 and 11, that exhibited antiviral properties at a concentration of 50 µM in cellular-based assays. Overall, this study provides valuable insights into the ongoing research on anti-ZIKV compounds to facilitate and improve the development of new inhibitors.

Molecular targets for Chagas disease: validation, challenges and lead compounds for widely exploited targets.

INTRODUCTION: Chagas disease (CD) imposes social and economic burdens, yet the available treatments have limited efficacy in the disease's chronic phase and cause serious adverse effects. To address this challenge, target-based approaches are a possible strategy to develop new, safe, and active treatments for both phases of the disease. AREAS COVERED: This review delves into target-based approaches applied to CD drug discovery, emphasizing the studies from the last five years. We highlight the proteins cruzain (CZ), trypanothione reductase (TR), sterol 14 α-demethylase (CPY51), iron superoxide dismutase (Fe-SOD), proteasome, cytochrome b (Cytb), and cleavage and polyadenylation specificity factor 3 (CPSF3), chosen based on their biological and chemical validation as drug targets. For each, we discuss its biological relevance and validation as a target, currently related challenges, and the status of the most promising inhibitors. EXPERT OPINION: Target-based approaches toward developing potential CD therapeutics have yielded promising leads in recent years. We expect a significant advance in this field in the next decade, fueled by the new options for Trypanosoma cruzi genetic manipulation that arose in the past decade, combined with recent advances in computational chemistry and chemical biology.

Structure-based discovery of thiosemicarbazones as SARS-CoV-2 main protease inhibitors.

Aim: Discovery of novel SARS-CoV-2 main protease (Mpro) inhibitors using a structure-based drug discovery strategy. Materials & methods: Virtual screening employing covalent and noncovalent docking was performed to discover Mpro inhibitors, which were subsequently evaluated in biochemical and cellular assays. Results: 91 virtual hits were selected for biochemical assays, and four were confirmed as reversible inhibitors of SARS CoV-2 Mpro with IC50 values of 0.4-3 µM. They were also shown to inhibit SARS-CoV-1 Mpro and human cathepsin L. Molecular dynamics simulations indicated the stability of the Mpro inhibitor complexes and the interaction of ligands at the subsites. Conclusion: This approach led to the discovery of novel thiosemicarbazones as potent SARS-CoV-2 Mpro inhibitors.

Design and synthesis of new 1,2,3-triazoles derived from eugenol and analogues with in vitro and in vivo activity against Trypanosoma cruzi.

Chagas disease (CD) is a neglected tropical disease endemic in 21 countries and affects about 8 million people around the world. The pharmacotherapy for this disease is limited to two drugs (Benznidazole and Nifurtimox) and both are associated with important limitations, as low cure rate in the chronic phase of the disease, high toxicity and increasing resistance by Trypanosoma cruzi. Recently, we reported a bioactive 1,2,3-triazole (compound 35) active in vitro (IC50 42.8 µM) and in vivo (100 mg/kg) against T. cruzi Y strains and preliminary in silico studies suggested the cysteine protease cruzain as a possible target. Considering these initial findings, we describe here the design and synthesis of new 1,2,3-triazoles derivatives of our hit compound (35). The triazoles were initially evaluated against healthy cells derived from neonatal rat cardiomyoblasts (H9c2 cells) to determine their cytotoxicity and against epimastigotes forms of T. cruzi Y strain. The most active triazoles were compounds 26 (IC50 19.7 µM) and 27 (IC50 7.3 µM), while benznidazole was active at 21.6 µM. Derivative 27 showed an interesting selectivity index considering healthy H9c2 cells (>77). Promising activities against trypomastigotes forms of the parasite were also observed for triazoles 26 (IC50 20.74 µM) and 27 (IC50 8.41 µM), mainly 27 which showed activity once again higher than that observed for benznidazole (IC50 12.72 µM). While docking results suggested cruzain as a potential target for these compounds, no significant enzyme inhibition was observed in vitro, indicating that their trypanocidal activity is related to another mode of action. Considering the promising in vitro results of triazoles 26 and 27, the in vivo toxicity was initially verified based on the evaluation of behavioral and physiological parameters, mortality, effect in body weight gain, and through the measurement of AST/ALT enzymes, which are markers of liver toxicity. All these evaluations pointed to a good tolerability of the animals, especially considering triazole 27. A reduction in parasitemia was observed among animals treated with triazole 27, but not among those treated with derivative 26. Regarding the dosage, derivative 27 (100 mg/kg) was the most active sample against T. cruzi infection, showing a 99.4% reduction in parasitemia peak. Triazole 27 at a dosage of 100 mg/kg influenced the humoral immune response and reduced myocarditis in the animals, bringing antibody levels closer to those observed among healthy mice. Altogether, our results indicate compound 27 as a new lead for the development of drug candidates to treat Chagas disease.

Structure-based discovery of novel cruzain inhibitors with distinct trypanocidal activity profiles.

Over 110 years after the first formal description of Chagas disease, the trypanocidal drugs thus far available have limited efficacy and several side effects. This encourages the search for novel treatments that inhibit T. cruzi targets. One of the most studied anti-T. cruzi targets is the cysteine protease cruzain; it is associated with metacyclogenesis, replication, and invasion of the host cells. We used computational techniques to identify novel molecular scaffolds that act as cruzain inhibitors. First, with a docking-based virtual screening, we identified compound 8, a competitive cruzain inhibitor with a Ki of 4.6 µM. Then, aided by molecular dynamics simulations, cheminformatics, and docking, we identified the analog compound 22 with a Ki of 27 µM. Surprisingly, despite sharing the same isoquinoline scaffold, compound 8 presented higher trypanocidal activity against the epimastigote forms, while compound 22, against the trypomastigotes and amastigotes. Taken together, compounds 8 and 22 represent a promising scaffold for further development of trypanocidal compounds as drug candidates for treating Chagas disease.