Search Results (668)

Chagas disease, caused by Trypanosoma cruzi, affects a significant proportion of patients who develop digestive and cardiac complications, including megaviscera. This pathogenesis has been associated with autoimmune mechanisms mediated by molecular mimicry. In this study, an in silico evaluation of the potential structural basis of cross-reactivity of β-tubulin 1.9 of T. cruzi and the human β-4A tubulin isoform 3 was conducted. Using bioinformatics tools, homologous regions were identified and potentially immunogenic epitopes were predicted, considering their structural modeling and molecular docking. The proteins shared 87% sequence identity and 95% similarity, with an almost identical structural overlap, RMSD 0.291 Å. Three epitopes, VPFPRLHFF, NDLVSEYQQYQDATI, and GQSGAGNNWAKGHYTEGAELIDS, exhibited high predicted antigenicity, with the 9-mer and 16-mer peptides displaying structurally compatible docking poses within the binding grooves of MHC class I and class II molecules, respectively, while B-cell epitope potential was inferred from sequence-based property predictions. Normal mode analysis, used as an exploratory approach, suggested comparable flexibility profiles for the parasitic- and human-derived peptide–MHC complexes. These findings provide an exploratory structural framework supporting a potential role of β-tubulin epitopes in molecular mimicry processes implicated in the development of chagasic megaviscera. Full article

Introduction: Chagas disease, caused by the protozoan Trypanosoma cruzi, remains a major public health concern due to the limited effectiveness of current treatments, especially in the chronic stage. Objective: Here, we wanted to advance a library of 30 N,N′-disubstituted diamines as promising antichagasic agents and gain insight into the mechanism of action. Methods: The library was evaluated for activity against the T. cruzi amastigote stage and trypanocidal efficacy. In addition, selected compounds were tested as potential polyamine transport inhibitors, and a fluorescent analog was employed to investigate compound internalization. Results: Five compounds exhibited potent activity (pIC₅₀ > 6.0), particularly those with short aliphatic linkers (3–6 carbon atoms), suggesting a structure–activity relationship favouring shorter chains. Mechanistic studies showed that compound 3c strongly inhibited polyamine transport, a vital pathway in T. cruzi, though this was not a universal mechanism among active hits, indicating the potential for multiple targets. A fluorescent analog confirmed intracellular uptake in amastigotes but lacked antiparasitic activity, likely due to disrupted pharmacophoric features. Importantly, none of the compounds demonstrated trypanocidal activity in long-term assays, and some showed cytotoxicity, particularly in the benzyloxy-substituted series. Conclusions: These findings position N,N′-disubstituted diamines as a viable scaffold for Chagas disease drug discovery. However, further optimization is required to enhance selectivity, achieve trypanocidal effects, and better understand the underlying mechanisms of action. Full article

Trypanosoma cruzi is the protozoan parasite responsible for Chagas disease, a neglected tropical disease caused by trypanosomatids. Its success as pathogen relies on remarkable metabolic adaptability, stress tolerance, and complex interactions with mammalian hosts. Among the proteins contributing to these processes, nucleoside diphosphate kinases (NDPKs) and arginine kinase (AK) have emerged as central enzymes for parasite metabolism. NDPKs, beyond their canonical role in nucleotide homeostasis, are implicated in DNA repair and oxidative stress responses and are also secreted enzymes. AK, on the other hand, serves as a unique energy-buffering system absent in mammals, supporting parasite growth and adaptation to oxidative and metabolic stresses, including modulation of host immunity. Both enzymes display distinct subcellular localizations all along the parasite and through the life cycle, linking them to multiple roles important for parasite biology and survival. Recent studies have highlighted the impact of interfering these enzymes with several compounds on the viability of the organisms, suggesting new avenues to explore them as drug targets. This review provides a general overview of NDPKs and AK in T. cruzi, aiming to underline their relevance to a broader context of trypanosomatids. Their study not only broadens our understanding of parasite biology but also opens perspectives for applied research, including therapeutic alternatives for Chagas and related diseases. Full article

Chagas disease remains a significant neglected tropical disease that predominantly affects vulnerable populations in rural, low-income areas of Latin America. The management of this condition is severely hindered by the limitations of current therapies, which are characterized by substantial toxicity, diminished efficacy during the chronic phase, and the emergence of parasitic resistance. Given the promising activity of SB-83 (a 2-aminothiophenic derivative) against Leishmania spp., the present study sought to evaluate its trypanocidal activity against Trypanosoma cruzi. The results showed that SB-83 exhibited potent inhibitory effects on the epimastigote forms of T. cruzi (IC₅₀ = 6.23 ± 0.84 μM), trypomastigotes (EC₅₀ = 7.31 ± 0.52 μM) and intracellular amastigotes (EC₅₀ = 5.12 ± 0.49 μM). Furthermore, the cellular proliferation assay results indicated CC₅₀ values of 77.80 ± 2.05 µM for LLC-MK2 CCL-7 and 24.21 ± 1.2 µM for Vero CCL-87, with a selectivity index above 10 for LLC-MK2 cells. In addition, the compound increased TNF-α, IL-12, nitric oxide, and ROS while decreasing IL-10. Moreover, in silico and in vitro assays confirmed its binding to trypanothione reductase, disrupting redox balance. Flow cytometry further revealed apoptosis induction in trypomastigotes, whereas electron microscopy showed cellular disruption and organelle disorganization. Therefore, SB-83 demonstrated potent activity against the TcI-resistant strain linked to Chagas cardiomyopathy at non-toxic concentrations for host cells, supporting its potential as a therapeutic candidate. Full article

Background: Chagas disease, caused by Trypanosoma cruzi, remains endemic throughout Latin America but is increasingly reported in urban areas due to migration and vector adaptation. The cardiac form is the most severe manifestation, associated with arrhythmia, mural thrombus formation, and a high risk of cardioembolic events. Stroke secondary to Chagas cardiomyopathy is uncommon and poses diagnostic and therapeutic challenges. Case Presentation: A 58-year-old woman with serologic evidence of T. cruzi infection presented with sudden-onset dyspnea, oppressive chest pain, and left-sided weakness. Neurological examination revealed left brachiocrural hemiparesis and mild dysarthria (NIHSS = 9). Non-contrast cranial CT showed an acute infarct in the right middle cerebral artery territory (ASPECTS = 7). Electrocardiography demonstrated typical atrial flutter with variable conduction, and transthoracic echocardiography revealed a markedly dilated left atrium containing a mural thrombus and a left ventricular ejection fraction of 45%. Intravenous thrombolysis with alteplase (0.9 mg/kg) was administered within 4.5 h of symptom onset. Pharmacologic rhythm control was achieved using intravenous and oral amiodarone, followed by oral anticoagulation with warfarin (target INR 2.0–3.0) after excluding hemorrhagic transformation. The patient showed rapid neurological improvement (NIHSS reduction from 9 to 2) and was discharged on day 10 with minimal residual deficit (mRS = 1), sinus rhythm, and stable hemodynamics. Conclusions: This case highlights the rare coexistence of Chagas cardiomyopathy, atrial flutter, and cardioembolic stroke due to left atrial thrombus. Early recognition, adherence to evidence-based guidelines, and multidisciplinary management were key to achieving a favorable outcome. Timely diagnosis and intervention remain crucial to preventing severe complications in patients with Chagas disease. Full article

Background/Objectives: Chagas disease remains a major unmet medical need due to the limited efficacy and safety of current therapies. Here, we investigated sixteen thiosemicarbazone (TSC) derivatives as cruzain inhibitors using an integrated in silico/in vitro workflow. Methods: Docking against cruzain (PDB 3KKU) guided hit prioritization and correlated with enzyme inhibition; validation by redocking supported the protocol’s reliability. Results: The top compounds—H7, H10 and H11—showed potent cruzain inhibition (IC₅₀ = 0.306, 0.512 and 0.412 µM, respectively) and low-micromolar trypanocidal activity, with negligible cytotoxicity in human fibroblasts (CC₅₀ > 64 µM) and favorable selectivity. Structure–activity insights highlighted the role of expanded aromatic systems and electron-donating groups in enhancing binding within S2/S1′ subsites, while nitro substituents were associated with higher cytotoxicity. In silico ADMET parameters supported oral drug-likeness and acceptable metabolic liabilities. Conclusions: Overall, these data position TSCs as promising anti-T. cruzi leads and underscore the value of rational design against cruzain. Full article

Chagas disease remains a major public health challenge due to the limited effectiveness and considerable side effects of existing treatments, particularly during the chronic stage. Açaí (Euterpe oleracea) seeds have gained increasing attention as a source of bioactive compounds with potential therapeutic applications. In this study, hydroalcoholic extracts and solvent fractions obtained from açaí seeds were chemically characterized by ESI/MS and HPLC–MS/MS and evaluated for their cytotoxicity and antiparasitic activity against different developmental stages of Trypanosoma cruzi (Y strain). Chemical profiling revealed a predominance of phenolic compounds, particularly catechins and procyanidins, which were identified as major constituents of the hydroalcoholic extract and the ethyl acetate fraction. Cytotoxicity assays performed on murine peritoneal macrophages demonstrated low toxicity, with CC₅₀ values exceeding 500 µg/mL for most samples, indicating a favorable in vitro safety profile. Antiparasitic assays showed weak activity against epimastigote forms; however, significant inhibitory effects were observed against bloodstream trypomastigotes, cell culture-derived trypomastigotes, and intracellular amastigotes. Notably, the hydroalcoholic extract exhibited the highest selectivity against intracellular amastigotes, with a selectivity index greater than 10, fulfilling key criteria proposed by the Drugs for Neglected Diseases initiative (DNDi) for early-stage hit compounds. Flow cytometry analysis showed that both the hydroalcoholic extract and the ethyl acetate fraction induced parasite cell death through late apoptosis-like and necrosis. Together, these findings highlight the antiparasitic potential of E. oleracea seed extracts, particularly against clinically relevant stages of T. cruzi, and support further investigation of these bioproducts as promising candidates for the development of new therapeutic strategies for Chagas disease. Full article

Trypanosoma cruzi is the causative agent of Chagas disease, which affects 6–7 million people worldwide. Although the possibility of oral transmission was first scientifically suggested in 1913, it was not until 1968 that the first confirmed cases of human infection via food consumption were reported. This long gap contributed to the widespread perception that oral transmission was a rare or incidental event. Over the past two decades, significant advances have been made in understanding the biological and clinical aspects of oral transmission, including the molecular mechanisms by which metacyclic trypomastigotes establish infection via the digestive route. Experimental studies in murine models have further deepened our knowledge of the biology and pathogenesis of oral infection. Concurrently, multiple outbreaks of T. cruzi infection through contaminated food and beverages have been reported across Latin America, providing valuable insights into the molecular epidemiology and clinical characteristics of this transmission route. Moreover, experimental evidence has shown that the consumption of meat from animals infected during the acute phase can also lead to T. cruzi infection, highlighting carnivory as a potential alternative transmission mechanism. This review aims to comprehensively analyze oral infection by T. cruzi, considering clinical and epidemiological data, parasite biology, and findings from murine experimental models. Strategies for controlling foodborne transmission of Chagas disease are also discussed. Full article

Inonotus obliquus (Chaga) is a medicinal basidiomycete fungus with diverse bioactive compounds and pharmacological properties. This study systematically compared green extraction techniques: maceration, ultrasound-assisted extraction (UAE), and combined supercritical CO₂-pressurized liquid extraction (ScCO₂-PLE), using solvents of varying polarity (water, 50%, and 70% ethanol). Chaga extracts were analyzed for phytochemical composition (HPLC-Orbitrap Exploris 120) and antioxidant activity toward DPPH and hydroxyl (^•OH) radicals using EPR spectroscopy. The results revealed that both solvent polarity and extraction technique significantly influenced extraction efficiency and antioxidant potential. The UAE extraction method achieved the highest overall recovery of phenolic and triterpenoid compounds, with extracts obtained using 50% and 70% ethanol exhibiting the most pronounced and well-balanced radical scavenging activity (>98% toward DPPH, >91% toward ^•OH). Correlation and PCA analyses identified phenolic and triterpenoid compounds, including fungal-specific polyphenols such as hispidin and hispolon, as key contributors to antioxidant activity. Among the extracts obtained using different solvents, the extracts with the highest overall antioxidant potential were encapsulated into liposomes and evaluated for their DPPH and ^•OH radical scavenging. Encapsulation effectively preserved the antioxidant activity of ethanol-derived extracts, demonstrating that Chaga liposomes can maintain bioactivity while offering the advantages of controlled delivery. Combining optimized extraction with liposomal encapsulation thus represents a promising strategy to enhance the stability and practical applicability of Chaga antioxidants in nutraceutical or therapeutic contexts. Full article

Mushroom coffee—blends of coffee with “functional” mushroom powders—has surged in popularity, yet its hemostatic effects are poorly appreciated in perioperative care. We report a postoperative hemorrhage likely potentiated by a commercial mushroom coffee. A 62-year-old man with HIV, hepatitis C, and insulin-treated diabetes underwent colostomy reversal. On postoperative day 9, he developed brisk bleeding at the colonic anastomosis requiring angiography and embolization. Recurrent hemorrhage prompted a detailed supplement history, revealing daily use of mushroom coffee for two months preoperatively. The product’s labeled ingredients include an organic mushroom blend of cordyceps, lion’s mane (Hericium), reishi (Ganoderma), shiitake, turkey tail, and king trumpet, combined with arabica coffee, MCT oil, and coconut milk. Several constituents—reishi, cordyceps, lion’s mane, and chaga (Inonotus obliquus, used in some mushroom blends)—have published antiplatelet or antithrombotic activity in vitro and/or in vivo. After counseling, the patient discontinued mushroom coffee; no further bleeding occurred, and he recovered without additional intervention. This case highlights a clinically important but underrecognized risk: mushroom-based beverages can exert antiplatelet effects comparable to herbal supplements traditionally flagged in preoperative screening. We recommend that preoperative medication reconciliation explicitly query mushroom coffees and “adaptogenic” blends and that such products be held similarly to other agents with antiplatelet properties. Greater awareness among surgeons, anesthesiologists, and internists is needed as functional foods proliferate. Controlled studies are warranted to quantify bleeding risk from multi-mushroom products and to inform evidence-based perioperative guidance Full article

Vector-borne parasites might be transmitted through transfusion, notably Plasmodium spp. and Trypanosoma cruzi. Prevention strategies include blood donor screening, deferral, and blood unit treatment by pathogen inactivation methods. At the end of 2015, in line with European guidelines, Italian legislation introduced a questionnaire to identify donors at risk and their screening by serological methods. In early 2016, the Laboratory of Parasitology at Pisa University Hospital started the serological analysis of donors at risk, referring to Transfusion Services located in northwestern Tuscany. The aim of the present study was to describe the prevalence of seropositive donors observed during 8 years of screening. Donors at risk of transmitting malaria were screened by ELISA (Enzyme Linked Immunosorbent Assay). The DRG ELISA kit was employed until 2020, when it was substituted by the Euroimmun ELISA kit based on the results of a comparative evaluation of available commercial kits. Seropositive donors were offered the possibility of Plasmodium DNA testing by Loop-Mediated AMPlification (LAMP) to exclude current infection. Donors at risk of transmitting Chagas disease were screened by ICT employing recombinant antigen until 2021, when it was substituted by ELISA employing lysate antigen because of its higher accuracy. Seropositive donors were further tested by CLIA, and WB was performed in case of discordant results, according to WHO guidelines for diagnosis of chronic Chagas disease. A total of 3754 donors were tested for anti-Plasmodium antibodies, revealing a 6.8% (95% CI = 6.1–7.7%) seroprevalence. Seropositivity was higher among donors from Sub-Saharan Africa (42.9%; 95% CI = 36.1–49.9%) and Southeast Asia (10.6%; 95% CI = 6.7–16.4%). A lower seropositivity was observed when employing Euroimmun ELISA (4.8; 95% CI = 3.8–5.9%) than DRG ELISA (8.2%; 95% CI = 7.1–9.3%). Seropositivity dropped to 3.6% (95% CI = 2.4–5.6) in 2020, likely because of travel restrictions during the COVID-19 pandemic. None of the tested seropositive donors (n = 20) tested positive for Plasmodium DNA LAMP testing. A high proportion of seroreversion was observed after one year of testing. Among 4285 donors tested for anti-T. cruzi antibodies seroprevalence was 0.7% (95% CI = 0.5–1.1%), a higher value than what was observed in a recent national survey. All seropositive donors were born in Europe or Latin America. Seropositivity was apparently lower with ELISA (0.5%, 95% CI = 0.2–1.2%) than ICT (0.8%, 95% CI = 0.6–1.2%), possibly due to ELISA’s higher specificity, although the difference is not significant. No confirmed cases of chronic Chagas disease were identified. The study emphasizes the importance of defining the serological test employed for screening and the need to confirm seropositive results with further testing. The high seroreversion observed in the study suggests repeating seropositive donor screening after a year to minimize deferral and blood unit loss. Full article

Chagas disease is caused by the protozoan Trypanosoma cruzi, and its current treatment is limited to the use of two nitroderivatives, benznidazole (Bz) and nifurtimox; however, their toxicity often leads to discontinuation, justifying the search for new therapeutic options. The biological activity of quinones has long shown efficacy towards pathogenic microorganisms. In our previous investigations, two naphthoquinones combining ortho- and para-quinoidal moieties exhibited remarkable trypanocidal activity and presented low toxicity to host cells. Here, these two active compounds were further assessed. On trypomastigotes and epimastigotes, brominated (NQ1) and chlorinated (NQ2) nor-beta-lapachone-derived 1,2,3-triazoles were more active than Bz, presenting IC₅₀/24 h values in the range of 0.8 to 3.1 µM. NQ1-treated epimastigotes showed a mitochondrial impairment and reactive oxygen species (ROS) production under electron microscopy and flow cytometry. The in vitro evaluation of both combinations of compounds with Bz indicated an additive interaction. In vivo, oral treatment with NQ1 reduced parasitemia in an acute model, with no evidence of toxicity. The treatment also led to a reduction in myocarditis, decreasing the PR interval in electrocardiographic analysis and reversing the sinus bradycardia caused by infection. These data suggest that T. cruzi mitochondrion are part of the NQ1 mechanism of action. In vivo, this compound presented moderate trypanocidal and promising anti-inflammatory activity. Its combination with Bz could enhance current therapeutic protocols and should be better explored in the future. Full article

Background/Objectives: Chagas disease, caused by Trypanosoma cruzi, remains a major neglected tropical disease with limited therapeutic options restricted to benznidazole and nifurtimox, both associated with significant toxicity and reduced efficacy during chronic infection. Seeking novel, safe, and sustainable chemotherapeutic candidates, two new saturated cardanol-derived phospholipid analogs—LDT10 and LDT119—were rationally designed based on the molecular scaffold of miltefosine and biosourced from cashew nut shell liquid (CNSL). This study aimed to evaluate the pharmacokinetic properties of these compounds in silico and assess their antiparasitic activity, cytotoxicity, and morphological and ultrastructural effects on all developmental forms of T. cruzi in vitro. Materials and Methods: In silico ADMET predictions (SwissADME, pkCSM) were performed to determine bioavailability, pharmacokinetic behavior, CYP inhibition, mutagenicity, and hepatotoxicity. Antiproliferative activity was evaluated in epimastigotes, trypomastigotes, and intracellular amastigotes using dose–response assays and flow cytometry. Cytotoxicity was assessed in HEPG2 and HFF-1 cells using resazurin-based viability assays. Morphological and ultrastructural alterations were investigated through scanning (SEM) and transmission (TEM) electron microscopy. Reactive oxygen species (ROS) generation was quantified with H₂DCFDA after 4 h and 24 h of exposure. Results: In silico analyses indicated favorable drug-like profiles, high intestinal absorption (>89%), absence of mutagenicity or hepatotoxicity, and non-penetration of the blood–brain barrier. LDT10 was not a P-gp substrate, and LDT119 acted as a P-gp inhibitor, suggesting reduced efflux and higher intracellular retention. Both compounds inhibited epimastigote proliferation with low IC₅₀ values (LDT10: 0.81 µM; LDT119: 1.2 µM at 48 h) and reduced trypomastigote viability (LD₅₀ LDT10: 2.1 ± 2 µM; LDT119: 1.8 ± 0.8 µM). Intracellular amastigotes were highly susceptible (IC₅₀ LDT10: 0.48 µM; LDT119: 0.3 µM at 72 h), with >90% inhibition at higher concentrations. No cytotoxicity was observed in mammalian cells up to 20 µM. SEM revealed membrane wrinkling, pore-like depressions, rounded cell bodies, and multiple flagella, indicating cell division defects. TEM showed Golgi disorganization, autophagic vacuoles, mitochondrial vesiculation, and abnormal kinetoplast replication, while host cells remained structurally preserved. Both compounds induced significant ROS production in trypomastigotes after 24 h in a dose-dependent manner. Conclusions: LDT10 and LDT119 exhibited potent and selective in vitro activity against all developmental stages of T. cruzi, with low micromolar to submicromolar IC₅₀/LD₅₀ values, minimal mammalian cytotoxicity, and extensive morphological and ultrastructural damage consistent with disruption of phospholipid biosynthesis pathways. Combined with favorable in silico pharmacokinetic predictions, these CNSL-derived phospholipid analogs represent promising candidates for future Chagas disease chemotherapy and warrant further in vivo evaluation. Full article

Chagas disease (CD) remains a major global health challenge and requires standardized, multidisciplinary, and evidence-based clinical approaches. This article aims to present and systematize the model of clinical routines developed at the Clinical Research Laboratory on Chagas Disease (Lapclin-Chagas), INI/Fiocruz, for the initial evaluation and longitudinal follow-up of patients with chronic CD. The proposal is intended to serve as a replicable and adaptable framework for referral centers in both endemic and non-endemic settings. Using a descriptive qualitative design, institutional protocols, national and international guidelines, and expert consultations were analyzed to construct a comprehensive care model. The resulting protocol integrates diagnostic pathways (including dual serological confirmation and clinical staging), criteria for etiological treatment, and coordinated multidisciplinary follow-up involving cardiology, gastroenterology, pharmaceutical care, nutrition, psychology, and social support. Specific pathways are also presented for Trypanosoma cruzi (T. cruzi)/HIV coinfection, laboratory accidents, and monitoring of adverse reactions to benznidazole. By consolidating more than three decades of institutional experience into operational workflows, this proposal offers an innovative contribution to the organization of CD care and provides actionable guidance for health systems seeking to improve diagnostic accuracy, therapeutic adherence, patient safety, and long-term outcomes. Full article

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, continues to be a significant global health issue, especially in Latin America, with increasing international prevalence due to migration. Despite advancements in diagnosis and treatment, it remains a neglected tropical disease characterized by significant morbidity and mortality, mainly influenced by the complex interaction between parasite diversity and host immune responses. Importantly, the remarkable genetic diversity of T. cruzi lineages also contributes to clinical heterogeneity, influencing immune evasion, therapeutic responses, and vaccine feasibility. This review analyzes the impact of immunogenetics on host–parasite interactions in Chagas disease and explores its implications for personalized therapy approaches. Recent research, particularly over the last decade, has indicated that processes including antigenic variation, extracellular vesicle-mediated regulation, and disruption of host signaling pathways facilitate parasite persistence. Host genetic variables significantly influence susceptibility, disease development, and treatment outcomes, including changes in Human Leukocyte Antigen (HLA) genes, cytokine gene polymorphisms, and immunogenetic determinants of cardiac pathology. These findings underscore the potential of immunogenetic markers as tools for prognosis and as targets for personalized therapies. However, there are still considerable research deficiencies. Inadequate comprehension of gene–environment interactions, lack of representation of varied populations, and inconsistencies in study design limit the use of immunogenetic findings in therapeutic settings. At present, the concept of personalized medicine in Chagas disease remains largely aspirational, better understood as a framework for precision public health or stratified interventions guided by host immunogenetic and parasite lineage data. Addressing these issues necessitates comprehensive genomic research, mechanistic investigations of host–parasite interactions, and clinical validation of genetic markers. This study emphasizes the necessity of incorporating immunogenetics into personalized patient management strategies based on existing evidence. This integration has the potential to improve diagnosis, enhance treatment efficacy, and inform preventive interventions, thereby advancing personalized therapy for Chagas disease. Full article