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In previous studies, we developed anti-trypanosome tubulin inhibitors with promising in vitro selectivity and activity against Human African Trypanosomiasis (HAT). However, for such agents, oral activity is crucial. This study focused on further optimizing these compounds to enhance their ligand efficiency, aiming to reduce bulkiness and hydrophobicity, which should improve solubility and, consequently, oral bioavailability. Using Trypanosoma brucei brucei cells as the parasite model and human normal kidney cells and mouse macrophage cells as the host model, we evaluated 30 new analogs synthesized through combinatorial chemistry. These analogs have fewer aromatic moieties and lower molecular weights than their predecessors. Several new analogs demonstrated IC50s in the low micromolar range, effectively inhibiting trypanosome cell growth without harming mammalian cells at the same concentration. We conducted a detailed structure-activity relationship (SAR) analysis and a docking study to assess the compounds' binding affinity to trypanosome tubulin homolog. The results revealed a correlation between binding energy and anti-Trypanosoma activity. Importantly, compound 7 displayed significant oral activity, effectively inhibiting trypanosome cell proliferation in mice.
Assuntos
Tripanossomicidas , Trypanosoma brucei brucei , Animais , Trypanosoma brucei brucei/efeitos dos fármacos , Tripanossomicidas/farmacologia , Tripanossomicidas/síntese química , Tripanossomicidas/química , Relação Estrutura-Atividade , Camundongos , Humanos , Administração Oral , Proliferação de Células/efeitos dos fármacos , Estrutura Molecular , Simulação de Acoplamento Molecular , Tubulina (Proteína)/metabolismo , Testes de Sensibilidade Parasitária , Relação Dose-Resposta a Droga , Moduladores de Tubulina/farmacologia , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Tripanossomíase Africana/tratamento farmacológicoRESUMO
Chagas disease is one of the world's neglected tropical diseases, caused by the human pathogenic protozoan parasite Trypanosoma cruzi. There is currently a lack of effective and tolerable clinically available therapeutics to treat this life-threatening illness and the discovery of modern alternative options is an urgent matter. T. cruzi glucokinase (TcGlcK) is a potential drug target because its product, d-glucose-6-phosphate, serves as a key metabolite in the pentose phosphate pathway, glycolysis, and gluconeogenesis. In 2019, we identified a novel cluster of TcGlcK inhibitors that also exhibited anti-T. cruzi efficacy called the 3-nitro-2-phenyl-2H-chromene analogues. This was achieved by performing a target-based high-throughput screening (HTS) campaign of 13,040 compounds. The selection criteria were based on first determining which compounds strongly inhibited TcGlcK in a primary screen, followed by establishing on-target confirmed hits from a confirmatory assay. Compounds that exhibited notable in vitro trypanocidal activity over the T. cruzi infective form (trypomastigotes and intracellular amastigotes) co-cultured in NIH-3T3 mammalian host cells, as well as having revealed low NIH-3T3 cytotoxicity, were further considered. Compounds GLK2-003 and GLK2-004 were determined to inhibit TcGlcK quite well with IC50 values of 6.1 µM and 4.8 µM, respectively. Illuminated by these findings, we herein screened a small compound library consisting of thirteen commercially available 3-nitro-2-phenyl-2H-chromene analogues, two of which were GLK2-003 and GLK2-004 (compounds 1 and 9, respectively). Twelve of these compounds had a one-point change from the chemical structure of GLK2-003. The analogues were run through a similar primary screening and confirmatory assay protocol to our previous HTS campaign. Subsequently, three in vitro biological assays were performed where compounds were screened against (a) T. cruzi (Tulahuen strain) infective form co-cultured within NIH-3T3 cells, (b) T. brucei brucei (427 strain) bloodstream form, and (c) NIH-3T3 host cells alone. We report on the TcGlcK inhibitor constant determinations, mode of enzyme inhibition, in vitro antitrypanosomal IC50 determinations, and an assessment of structure-activity relationships. Our results reveal that the 3-nitro-2-phenyl-2H-chromene scaffold holds promise and can be further optimized for both Chagas disease and human African trypanosomiasis early-stage drug discovery research.
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Benzopiranos , Glucoquinase , Tripanossomicidas , Trypanosoma cruzi , Animais , Humanos , Camundongos , Benzopiranos/farmacologia , Benzopiranos/química , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Descoberta de Drogas/métodos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Glucoquinase/metabolismo , Glucoquinase/antagonistas & inibidores , Ensaios de Triagem em Larga Escala , Simulação de Acoplamento Molecular , Células NIH 3T3 , Relação Estrutura-Atividade , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/enzimologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Folk medicine is widely used in Angola, even for human African trypanosomiasis (sleeping sickness) in spite of the fact that the reference treatment is available for free. Aiming to validate herbal remedies in use, we selected nine medicinal plants and assessed their antitrypanosomal activity. A total of 122 extracts were prepared using different plant parts and solvents. A total of 15 extracts from seven different plants exhibited in vitro activity (>70% at 20 µg/mL) against Trypanosoma brucei rhodesiense bloodstream forms. The dichloromethane extract of Nymphaea lotus (leaves and leaflets) and the ethanolic extract of Brasenia schreberi (leaves) had IC50 values ≤ 10 µg/mL. These two aquatic plants are of particular interest. They are being co-applied in the form of a decoction of leaves because they are considered by local healers as male and female of the same species, the ethnotaxon "longa dia simbi". Bioassay-guided fractionation led to the identification of eight active molecules: gallic acid (IC50 0.5 µg/mL), methyl gallate (IC50 1.1 µg/mL), 2,3,4,6-tetragalloyl-glucopyranoside, ethyl gallate (IC50 0.5 µg/mL), 1,2,3,4,6-pentagalloyl-ß-glucopyranoside (IC50 20 µg/mL), gossypetin-7-O-ß-glucopyranoside (IC50 5.5 µg/mL), and hypolaetin-7-O-glucoside (IC50 5.7 µg/mL) in B. schreberi, and 5-[(8Z,11Z,14Z)-heptadeca-8,11,14-trienyl] resorcinol (IC50 5.3 µg/mL) not described to date in N. lotus. Five of these active constituents were detected in the traditional preparation. This work provides the first evidence for the ethnomedicinal use of these plants in the management of sleeping sickness in Angola.
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Antiprotozoários , Nymphaea , Tripanossomíase Africana , Humanos , Animais , Angola , Sementes , Antiprotozoários/farmacologia , Extratos Vegetais/farmacologiaRESUMO
Parasitic diseases still compromise human health. Some of the currently available therapeutic drugs have limitations considering their adverse effects, questionable efficacy, and long treatment, which have encouraged drug resistance. There is an urgent need to find new, safe, effective, and affordable antiparasitic drugs. Marine-derived cyclic peptides have been increasingly screened as candidates for developing new drugs. Therefore, in this review, a systematic analysis of the scientific literature was performed and 25 marine-derived cyclic peptides with antiparasitic activity (1-25) were found. Antimalarial activity is the most reported (51%), followed by antileishmanial (27%) and antitrypanosomal (20%) activities. Some compounds showed promising antiparasitic activity at the nM scale, being active against various parasites. The mechanisms of action and targets for some of the compounds have been investigated, revealing different strategies against parasites.
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Antiprotozoários , Leishmaniose , Doenças Parasitárias , Humanos , Antiparasitários/química , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/uso terapêutico , Leishmaniose/tratamento farmacológico , Antiprotozoários/química , Doenças Parasitárias/tratamento farmacológicoRESUMO
Nagana and Human African Trypanosomiasis (HAT), caused by (sub)species of Trypanosoma, are diseases that impede human and animal health, and economic growth in Africa. The few drugs available have drawbacks including suboptimal efficacy, adverse effects, drug resistance, and difficult routes of administration. New drugs are needed. A series of 20 novel quinolone compounds with affordable synthetic routes was made and evaluated inâ vitro against Trypanosoma brucei and HEK293 cells. Of the 20â compounds, 12 had sub-micromolar potencies against the parasite (EC50 values=0.051-0.57â µM), and most were non-toxic to HEK293 cells (CC50 values>5â µM). Two of the most potent compounds presented sub-micromolar activities against other trypanosome (sub)species (T. cruzi and T. b. rhodesiense). Although aqueous solubility is poor, both compounds possess good logD values (2-3), and either robust or poor microsomal stability profiles. These varying attributes will be addressed in future reports.
Assuntos
Testes de Sensibilidade Parasitária , Quinolonas , Tripanossomicidas , Trypanosoma brucei brucei , Humanos , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/síntese química , Células HEK293 , Trypanosoma brucei brucei/efeitos dos fármacos , Relação Estrutura-Atividade , Quinolonas/química , Quinolonas/farmacologia , Quinolonas/síntese química , Estrutura Molecular , Hidrazinas/química , Hidrazinas/farmacologia , Hidrazinas/síntese química , Trypanosoma cruzi/efeitos dos fármacos , Relação Dose-Resposta a DrogaRESUMO
Due to the proximity of humans to the countryside and the progressive increase in populations of invasive species, such as wild boars (Sus scrofa), the risk of disease spread is also exacerbated, some of which are zoonoses caused by protozoa. In the present study, 75 tissue/organ samples from 25 wild boars obtained from authorized hunting in the northern region of Rio Grande do Sul were evaluated to investigate the presence of Trypanosoma spp. using conventional PCR with specific primers and amplification of the ITS1 region for Leishmania spp. detection and species differentiation, multiplex PCR with kDNA minicircle amplification was performed. Trypanosoma spp. DNA was detected in 11 out of 25 hearts, representing 44% of the culled animals. Regarding the detection of Leishmania DNA, L. infantum was detected in one spleen sample, accounting for 4%, and L. amazonensis in one liver sample from the same animal, also representing 4% (1/25) of the samples. It is important to note that this wild boar, with detection for both L. amazonensis and L. infantum, also had Trypanosoma spp. DNA detected in a heart sample, indicating the potential of this species to have multiple infections with these agents. Furthermore, this is the first reported case of multiple infection in a wild boar with these agents. Therefore, the results obtained reinforce the risk posed by invasive species, especially wild boars, as potential sources of infectious agent dissemination and their role as possible reservoirs for numerous diseases.
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Leishmania , Trypanosoma , Animais , Humanos , Suínos , Leishmania/genética , DNA , Espécies Introduzidas , Trypanosoma/genética , Sus scrofaRESUMO
According to the World Health Organization, Chagas disease (CD) is the most prevalent poverty-promoting neglected tropical disease. Alarmingly, climate change is accelerating the geographical spreading of CD causative parasite, Trypanosoma cruzi, which additionally increases infection rates. Still, CD treatment remains challenging due to a lack of safe and efficient drugs. In this work, we analyze the viability of T. cruzi Akt-like kinase (TcAkt) as drug target against CD including primary structural and functional information about a parasitic Akt protein. Nuclear Magnetic Resonance derived information in combination with Molecular Dynamics simulations offer detailed insights into structural properties of the pleckstrin homology (PH) domain of TcAkt and its binding to phosphatidylinositol phosphate ligands (PIP). Experimental data combined with Alpha Fold proposes a model for the mechanism of action of TcAkt involving a PIP-induced disruption of the intramolecular interface between the kinase and the PH domain resulting in an open conformation enabling TcAkt kinase activity. Further docking experiments reveal that TcAkt is recognized by human inhibitors PIT-1 and capivasertib, and TcAkt inhibition by UBMC-4 and UBMC-6 is achieved via binding to TcAkt kinase domain. Our in-depth structural analysis of TcAkt reveals potential sites for drug development against CD, located at activity essential regions.
Assuntos
Doença de Chagas , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Trypanosoma cruzi , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/efeitos dos fármacos , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Ligação ProteicaRESUMO
Chagas disease (CD) is a typical tropical illness caused by Trypanosoma cruzi. The objective of this study was to assess the prevalence of Chagas disease in communities in two states of the Brazilian Amazon. Data collection occurred in July in the Alto Juruá region of Acre and in December in the communities of Humaitá, Amazonas, in 2019. A total of 477 participants were included in the study. In the communities of Alto Juruá, triatomine collections and analyses of T. cruzi infection were also carried out. All confirmed cases were found in the state of Acre, resulting in a total prevalence of 1.67. Of these eight cases, seven underwent ECG, all of which were concluded as normal by the physician team's cardiologists. Seventeen triatomine bugs, all belonging to the Rhodnius genus, were captured. The natural infection rate by T. cruzi was 25% in the Nova Cintra community and 66.67% in the Boca do Moa community (Alto Juruá). This research found that more than 1% of the studied population exhibited positive serological results for Chagas disease in the riverine communities during the study period, representing a small portion of cases among those who have not yet been diagnosed.
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Kinetoplastids are the causative agents for a spectrum of vector-borne diseases including Leishmaniasis, Chagas disease and Trypanosomiasis that affect millions of people worldwide. In the absence of safe and effective vaccines, chemotherapy, in conjunction with vector control, remain the most significant control approach for kinetoplastid diseases. However, commercially available treatment for these neglected tropical diseases frequently ends up with toxic side effects and increasing resistance. To meet the rising need for innovative medications, alternative chemotherapeutic agents are required. Moreover, insights into target-based mode of action of chemotherapeutic agents are required if novel drugs that may outwit resistance to commercially available drugs are to be developed. Tryptophan has been implicated in a variety of diseases and disorders due to its fundamental role as a precursor to several bioactive metabolites, as well as its importance in the improvement of health and nutrition, diagnostics, and therapeutics. The regulation of tryptophan metabolism plays a fundamental role in the growth of kinetoplastids. Moreover, the levels of tryptophan may serve as a biomarker to distinguish between the stages of kinetoplastids making it an important amino acid to explore for drug targets. The main aim of this review is thus to provide a comprehensive literature synthesis of tryptophan derivatives to explore as potential anti-kinetoplastids. Here we highlight the role of tryptophan derivatives as chemotherapeutic agents against kinetoplastids. The reviewed compounds provide insights into potential new drug interventions that may combat the increasing problem of anti-kinetoplastid resistance.
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BACKGROUND: Multi-factorial reasons are an induction to cause cancer. Different infections and infestations with viruses, bacteria, and parasites have been detected for many years to be related to human carcinogenesis. PURPOSE: The study aimed to review all ideas of tumor carcinogenesis and its associations with parasitic infections and infestations. METHODS: We reviewed several articles (published and imprinted) by selecting, extracting, and synthesizing data about the relationship between cancers and parasites. RESULTS: Several helminths infections as schistosomiasis, are highly carcinogenic agents for bladder cancer, whereas trypanosomiasis has a bi-model role in cancer development. Leishmaniasis may be a cause of hepatocarcinoma, skin cancer, and lymphomas. In addition, malaria appears to be causative in the carcinogenesis of some cancers; as Burkitt lymphoma. Also, data from previous studies suggested that Strongyloides stercoralis may be a relevant co-factor in lymphomas. CONCLUSION: There are different mechanisms of parasitic infection to be enhancing in carcinogenesis of cancer in human.
Assuntos
Carcinogênese , Neoplasias , Humanos , Animais , Neoplasias/complicações , Doenças Parasitárias/complicações , Doenças Parasitárias/parasitologiaRESUMO
Trypanosomiasis is associated with tissue damage and may trigger an immunological response. These tissue lesions are linked to metabolic issues and oxidative stress. The current study aimed to investigate the immunological, antioxidant, and metabolic changes that may be connected to camel trypanosomiasis. Blood samples were collected from 54 camels and allocated into two groups: The control group (35 camels) and the infected group (19 camels). The genes TLR2, TLR5, IL-17, MARCHF3, RASGRP1, EPS15L1, PPIE, ASB16, CMPK2, LPCAT1, FPGT, GPHN, TNNI3K, DIO3, keap1, and OXSR1 were significantly up-regulated in trypanosomiasis camels. However, down-regulation was observed for the genes Nrf2, PRDX6, and NDUFS5. PCR-DNA sequencing was used to identify nucleotide sequence polymorphisms in the immune (TLR2, TLR5, IL-17, MARCHF3, RASGRP1, and EPS15L1), metabolic (PPIE, ASB16, CMPK2, LPCAT1, FPGT, GPHN, TNNI3K, and DIO3), and antioxidant (Nrf2, Keap1, PRDX6, NDUFS5, and OXSR1) genes between healthy and trypanosomiasis-affected camels. Exploring the serum profile also showed a significant (P Ë 0.05) increase in Hp, SAA, Cp, IL-1ß, IL-6, IL 10, TNF-α, and MDA, with significant (P Ë 0.05) reduction in the serum levels of CAT, SOD, GSH, T3, and T4 in diseased camels compared with healthy ones. Our findings confirm the significance of nucleotide variations, gene expression patterns, and the biochemical profile of the investigated markers as indicators for the susceptibility of trypanosomiasis in dromedary camels and may be utilized to create management strategies.
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Studies have shown that depending on the substitution pattern, microtubule (MT)-targeting 1,2,4-triazolo[1,5-a]pyrimidines (TPDs) can produce different cellular responses in mammalian cells that may be due to these compounds interacting with distinct binding sites within the MT structure. Selected TPDs are also potently bioactive against the causative agent of human African trypanosomiasis, Trypanosoma brucei, both inâ vitro and inâ vivo. So far, however, there has been no direct evidence of tubulin engagement by these TPDs in T. brucei. Therefore, to enable further investigation of anti-trypanosomal TPDs, a TPD derivative amenable to photoaffinity labeling (PAL) was designed, synthesized, and evaluated in PAL experiments using HEK293 cells and T. brucei. The data arising confirmed specific labeling of T. brucei tubulin. In addition, proteomic data revealed differences in the labeling profiles of tubulin between HEK293 and T. brucei, suggesting structural differences between the TPD binding site(s) in mammalian and trypanosomal tubulin.
Assuntos
Tripanossomicidas , Trypanosoma brucei brucei , Tripanossomíase Africana , Animais , Humanos , Tubulina (Proteína)/metabolismo , Células HEK293 , Proteômica , Tripanossomíase Africana/tratamento farmacológico , Trypanosoma brucei brucei/metabolismo , Pirimidinas/química , Tripanossomicidas/química , Mamíferos/metabolismoRESUMO
Despite multiple screening efforts to identify exposures to Trypanosoma cruzi, in dogs across southern USA, no published studies could be found involving client owned dogs in the North Texas Metroplex area. Therefore, a limited screen was conducted for client owned dogs, seeking routine or preventative care, from participating veterinary practices in the greater Dallas-Fort Worth (DFW) Metroplex from 2019 to 2021. Participants, with owner consent, ranged in age, breed, and length of time at recorded residence. Ninety-nine samples were acquired from participating veterinary practices, initially assessed with the Chagas StatPak, and positive samples were confirmed with IFA (indirect fluorescent antibody test) at the Texas Veterinary Medical Diagnostic Lab (TVMDL), College Station, Texas. Six samples were positive with the StatPak and only two were confirmed positive with IFA. Both animals were senior (10 and 8 years) with no owner reports of previous cardiac issues. The results appear reasonable within the context of previous studies and the seropositivity rate of 2% (n = 99) for client owned dogs included in this study are lower than previously reported rates for shelter dogs from the North Texas area.
Assuntos
Doença de Chagas , Doenças do Cão , Trypanosoma cruzi , Animais , Cães , Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Doença de Chagas/veterinária , Texas/epidemiologia , Habitação , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologiaRESUMO
Alpine swifts (Tachymarptis melba) are sub-Saharan migratory birds, which, in Switzerland, nest in colonies that have been continuously monitored for over 40 years. In the summer of 2022, despite favourable environmental conditions, an unexpectedly high number of sudden mortalities (30-80%) occurred in 20 to 45-day-old nestlings from several nesting sites, of which 3 were monitored in detail. Nestlings submitted for post-mortem analysis (n = 5) were in good body condition but exhibited extensive subcutaneous haematomas (n = 5), myocardial petechiae (n = 2) and stunted growth of primary feathers (n = 1). In all birds, 4-5 µm large, amastigote-like protozoans were identified in skeletal and cardiac muscle sections. These tissues tested positive in a PCR targeting the 18S-rRNA gene of Trypanosoma spp. Amplified sequences showed 99.63% identity with sequences of Trypanosoma corvi (JN006854 and AY461665) and Trypanosoma sp. (AJ620557, JN006841). 72 blood smears of 45-day-old nestlings from two colonies were assessed, of which 20 contained trypomastigote forms, some with high parasitaemia (highest average of 56.4 in 10 high power fields, 400x magnification). Trypomastigote morphometrics (n = 36; mean total length = 30.0 µm; length of free flagellum = 5.8 µm) were consistent with those of T. bouffardi. These findings suggest that an avian trypanosomiasis causing mass nestling mortality could be an emerging disease in Swiss Alpine swift populations.
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Protozoan parasites are major hazards to human health, society, and the economy, especially in equatorial regions of the globe. Parasitic diseases, including leishmaniasis, malaria, and others, contribute towards majority of morbidity and mortality. Around 1.1 million people die from these diseases annually. The lack of licensed vaccinations worsens the worldwide impact of these diseases, highlighting the importance of safe and effective medications for their prevention and treatment. However, the appearance of drug resistance in parasites continuously affects the availability of medications. The demand for novel drugs motivates global antiparasitic drug discovery research, necessitating the implementation of many innovative ways to maintain a continuous supply of promising molecules. Drug repurposing has come out as a compelling tool for drug development, offering a cost-effective and efficient alternative to standard de novo approaches. A thorough examination of drug repositioning candidates revealed that certain drugs may not benefit significantly from their original indications. Still, they may exhibit more pronounced effects in other disorders. Furthermore, certain medications can produce a synergistic effect, resulting in enhanced therapeutic effectiveness when given together. In this chapter, we outline the approaches employed in drug repurposing (sometimes referred to as drug repositioning), propose novel strategies to overcome these hurdles and fully exploit the promise of drug repurposing. We highlight a few major human protozoan diseases and a range of exemplary drugs repurposed for various protozoan infections, providing excellent outcomes for each disease.
Assuntos
Reposicionamento de Medicamentos , Infecções por Protozoários , Humanos , Animais , Infecções por Protozoários/tratamento farmacológico , Antiprotozoários/uso terapêutico , Antiprotozoários/farmacologiaRESUMO
Over a hundred years ago after the discovery of Chagas disease (CD) in Brazil, the World Health Organization estimates a number of 6 to 7 million people infected by Trypanosoma cruzi worldwide. Therefore, the goal of this work was to identify variables related to the spread of infection by T. cruzi in humans living in rural areas, seeking predictor variables. A systematic review of the literature has been conducted, with a search in the Scopus platform, using the search string "Chagas disease" and "rural", resulting in 85 valid and analyzed scientific studies (1977 and 2022). Twenty-seven predictor variables have been acquired, and 19 of them have been grouped, such as: socioeconomic and educational, housing, environmental, sanitary, and cultural; and 8 variables related to T. cruzi seropositive individuals. The predictor variables yielded significant results (p-value < 0.05) in 59.5% of the cases (195/328), with a median of 66.7%. In other words, studies relating to 50% of the 27 variables showed significance equal to or greater than 66.7% of the time. The independent variables with the highest proportion of significant data (p-value < 0.05) were Education (87.6%), Intradomicile building (70%), Domestic animals (69.6%), and Triatomines (69.2%) in the households. Some variables reached 100%; however, few articles were found, indicating the need for further research, especially for Sanitation and Culture. It has been concluded that, in the several contexts found, the social vulnerability and lack of information led the individual to living in environments where inhabitability is inadequate, to perform limited work activity and develop habits and behaviors which impair them in an environmental insalubrity situation, favorable to the access of vectors and pathogens of anthropozoonoses such as CD.
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In response to invading parasites, one of the principal arms of innate immunity is oxidative stress, caused by reactive oxygen species (ROS). However, oxidative stresses play dual functions in the disease, whereby free radicals promote pathogen removal, but they can also trigger inflammation, resulting in tissue injuries. A growing body of evidence has strongly supported the notion that nuclear factor erythroid 2-related factor 2 (NRF) signaling is one of the main antioxidant pathways to combat this oxidative burst against parasites. Given the important role of NRF2 in oxidative stress, in this review, we investigate the activation mechanism of the NRF2 antioxidant pathway in different parasitic diseases, such as malaria, leishmaniasis, trypanosomiasis, toxoplasmosis, schistosomiasis, entamoebiasis, and trichinosis.
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The need for new drugs to treat human infections is a global health concern. Diseases like tuberculosis, trypanosomiasis, amoebiasis, and AIDS remain significant problems, especially in developing countries like Mexico. Despite existing treatments, issues such as resistance and adverse effects drive the search for new alternatives. Herein, we introduce the NUATEI research consortium, made up of experts from the Institute of Biomedical Research at UNAM, who identify and obtain natural and synthetic compounds and test their effects against human pathogens using in vitro and in vivo models. The consortium has evaluated hundreds of natural extracts and compounds against the pathogens causing tuberculosis, trypanosomiasis, amoebiasis, and AIDS, rendering promising results, including a patent with potential for preclinical studies. This paper presents the rationale behind the formation of this consortium, as well as its objectives and strategies, emphasizing the importance of natural and synthetic products as sources of antimicrobial compounds and the relevance of the diseases studied. Finally, we briefly describe the methods of the evaluation of the compounds in each biological model and the main achievements. The potential of the consortium to screen numerous compounds and identify new therapeutic agents is highlighted, demonstrating its significant contribution to addressing these infectious diseases.
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Chagas disease affects around 8 million people globally, with Latin America bearing approximately 10,000 deaths each year. Combatting the disease relies heavily on vector control methods, necessitating the identification of new targets. Within insect genomes, genes harboring small open reading frames (smORFs - < 100 amino acids) present numerous potential candidates. In our investigation, we elucidate the pivotal role of the archetypal smORF-containing gene, mille-pattes/polished-rice/tarsalless (mlpt/pri/tal), in the post-embryonic development of the kissing bug Rhodnius prolixus. Injection of double-stranded RNA targeting mlpt (dsmlpt) during nymphal stages yields a spectrum of phenotypes hindering post-embryonic growth. Notably, fourth or fifth stage nymphs subjected to dsmlpt do not undergo molting. These dsmlpt nymphs display heightened mRNA levels of JHAMT-like and EPOX-like, enzymes putatively involved in the juvenile hormone (JH) pathway, alongside increased expression of the transcription factor Kr-h1, indicating changes in the hormonal control. Histological examination reveals structural alterations in the hindgut and external cuticle of dsmlpt nymphs compared to control (dsGFP) counterparts. Furthermore, significant changes in the vector's digestive physiology were observed, with elevated hemozoin and glucose levels in the posterior midgut of dsmlpt nymphs. Importantly, dsmlpt nymphs exhibit impaired metacyclogenesis of Trypanosoma cruzi, the causative agent of Chagas disease, underscoring the crucial role of proper gut organization in parasite differentiation. Thus, our findings constitute the first evidence of a smORF-containing gene's regulatory influence on vector physiology, parasitic cycle, and disease transmission.
Assuntos
Proteínas de Insetos , Muda , Ninfa , Rhodnius , Animais , Rhodnius/genética , Rhodnius/fisiologia , Rhodnius/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/genética , Ninfa/fisiologia , Muda/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Hormônios Juvenis/metabolismo , Fases de Leitura Aberta , DigestãoRESUMO
During the opening of diplomatic relations in the 1990s, South Africa gifted 20 southern white rhinoceros (Ceratotherium simum simum) to Kenya. The species is not indigenous to Kenya, and management of the introduction was not clearly addressed in the legislation. Responsibility was left to the private sector and local authorities. Ten of the animals were introduced to land contiguous with the Maasai Mara National Reserve, an area with tsetse-trypanosomiasis challenges, and with rare cases of human sleeping sickness. Mortalities had been previously documented when indigenous naïve black rhinoceros were introduced to areas with tsetse; hence there was no consensus on the management of this introduction. Feasibility was only explored once before with the introduction of two animals in a monitored and managed translocation from Lewa Downs, Laikipia in 1992-1994. Ultimately, Kenyan experts were co-opted to address risk after trypanosomiasis occurred in many animals. Unfortunately, this finding was followed by gradual mortalities of most rhinoceros with only a few being saved by removal to highland private sanctuaries. This event was complicated by many factors. Samples were only sporadically collected, and mainly from sick animals. With no clear responsibility by government agencies, a collaboration between veterinarians and researchers resulted in characterization of the disease challenge, and when invited, assessment of health status. Laboratory diagnostics revealed common and sometimes severe infections with Trypanosoma brucei, a normally infrequent trypanosome. Infection was associated with disturbances in erythropoiesis, especially anemia. Symptoms varied from sudden death associated with intestinal atony, to a semiparalyzed animal that was partially responsive to treatment for trypanosomes. This event should be used as a caution to future movements of this species that are planned or ongoing in Africa, for conservation or other purposes.