Search Results (40)

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

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

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

Background/Objectives: Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, remains a major neglected tropical disease, with over six million cases concentrated, primarily in Latin America. Despite decades of research, treatment continues to rely on two outdated drugs—benznidazole and nifurtimox—both of which exhibit limited efficacy and are associated with severe side effects. In this context, drug repurposing presents a promising strategy to accelerate the development of safer and more effective therapies. Nitroxoline, a hydroxyquinoline compound widely used in Europe to treat bacterial urinary tract infections, has recently garnered attention for its broad-spectrum antimicrobial and anticancer activities. This study evaluated the antitrypanosomal potential of nitroxoline against both epimastigote and intracellular amastigote forms of T. cruzi, demonstrating significantly greater efficacy than benznidazole. Methods: In addition to its antiparasitic activity, we investigated the mechanism of parasite death and found that nitroxoline induces hallmarks of programmed cell death, including chromatin condensation, mitochondrial membrane depolarization, ATP depletion, reactive oxygen species accumulation, and increased membrane permeability. These cellular events are critical for minimizing host tissue inflammation and suggest a safer therapeutic profile. Results: The nitroxoline was shown to induce greater activity than the reference treatment, benznidazole, in addition to triggering events related to apoptotic or silent cell death. Conclusions: Given its established clinical use and favorable safety data, nitroxoline emerges as a strong candidate for further investigation as a repurposed treatment for Chagas disease. Future work should focus on in vivo efficacy, pharmacokinetics, and drug delivery strategies to enhance systemic bioavailability. Full article

Chagas disease is a neglected disease caused by the parasite Trypanosoma cruzi, a public health problem in both endemic and non-endemic countries. In Mexico, the southern region is considered endemic, and cases are frequently reported; however, in the northwestern region, only a few cases are confirmed annually. This study describes, for the first time, the Discrete Typing Unit (DTU) of Trypanosoma cruzi in a volunteer blood donor rejected for being reactive in the northwestern region of Mexico. Seroreactivity was confirmed using “in-house” ELISAs which employed three different antigens: total extract from Trypanosoma cruzi isolated from a vector (Triatoma rubida) from Sonora (strain T1), strain H1 and CL-Brener. The molecular characterization of Trypanosoma cruzi was conducted by amplifying satellite DNA by qPCR and posterior sequencing of the mini-exon gene, using Next Generation Sequencing (NGS) to enhance the accuracy of genetic characterization. The results show that the reactive status of this blood donor was confirmed using our in-house ELISAs, and the presence of Trypanosoma cruzi by detecting TcI DTU confirmed the infection status. Full article

Chagas disease, caused by the protozoan Trypanosoma cruzi, affects millions globally, with limited treatment options available. Current therapies, such as benznidazole and nifurtimox, present challenges, including their toxicity, side effects, and inefficacy in the chronic phase. This study explores the potential of drug repurposing as a strategy to identify new treatments for T. cruzi, focusing on compounds from the Medicines for Malaria Venture (MMV) COVID Box. An initial screening of 160 compounds identified eight with trypanocidal activity, with almitrine and bortezomib showing the highest efficacy. Both compounds demonstrated significant activity against the epimastigote and amastigote stages of the parasite and showed no cytotoxicity in murine macrophage cells. Key features of programmed cell death (PCD), such as chromatin condensation, mitochondrial membrane potential disruption, and reactive oxygen species accumulation, were observed in T. cruzi treated with these compounds. The potential to induce controlled cell death of these two compounds in T. cruzi suggests they are promising candidates for further research. This study reinforces drug repurposing as a viable approach to discovering novel treatments for neglected tropical diseases like Chagas disease. Full article

Chagas disease is a prevalent health problem in Latin America which has received insufficient attention worldwide. Current treatments for this disease, benznidazole and nifurtimox, have limited efficacy and may cause side effects. A recent study proposed investigating a wide range of nitroindazole and indazolone derivatives as feasible treatments. Therefore, it is proposed that adding a nitro group at the 5-position of the indazole and indazolone structure could enhance trypanocidal activity by inducing oxidative stress through activation of the nitro group by NTRs (nitroreductases). The study results indicate that the nitro group advances free radical production, as confirmed by several analyses. Compound 5a (5-nitro-2-picolyl-indazolin-3-one) shows the most favorable trypanocidal activity (1.1 ± 0.3 µM in epimastigotes and 5.4 ± 1.0 µM in trypomastigotes), with a selectivity index superior to nifurtimox. Analysis of the mechanism of action indicated that the nitro group at the 5-position of the indazole ring induces the generation of reactive oxygen species (ROS), which causes apoptosis in the parasites. Computational docking studies reveal how the compounds interact with critical residues of the NTR and FMNH₂ (flavin mononucleotide reduced) in the binding site, which is also present in active ligands. The lipophilicity of the studied series was shown to influence their activity, and the nitro group was found to play a crucial role in generating free radicals. Further investigations are needed of derivatives with comparable lipophilic characteristics and the location of the nitro group in different positions of the base structure. Full article

Chagas Disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, affecting 6–8 million people, mainly in Latin America. The medical treatment is based on two compounds, benznidazole and nifurtimox, with limited effectiveness and that produce severe side effects; consequently, there is an urgent need to develop new, safe, and effective drugs. Amphotericin B is the most potent antimycotic known to date. A21 is a derivative of this compound with the property of binding to ergosterol present in cell membranes of some organisms. In the search for a new therapeutic drug against T. cruzi, the objective of this work was to study the in vitro and in vivo effects of A21 derivative on T. cruzi. Our results show that the A21 increased the reactive oxygen species and reduced the mitochondrial membrane potential, affecting the morphology, metabolism, and cell membrane permeability of T. cruzi in vitro. Even more important was finding that in an in vivo murine model of infection, A21 in combination with benznidazole was able to reduce blood parasitemia, diminish the immune inflammatory infiltrate in skeletal muscle and rescue all the mice from death due to a virulent T. cruzi strain. Full article

Extracellular vesicles (EVs) are lipid bilayer envelopes that encapsulate cell-specific cargo, rendering them promising biomarkers for diverse diseases. Chagas disease, caused by the parasite Trypanosoma cruzi, poses a significant global health burden, transcending its initial epicenter in Latin America to affect individuals in Europe, Asia, and North America. In this study, we aimed to characterize circulating EVs derived from patients with chronic Chagas disease (CCD) experiencing a reactivation of acute symptoms. Blood samples collected in EDTA were processed to isolate plasma and subsequently subjected to ultracentrifugation for particle isolation and purification. The EVs were characterized using a nanoparticle tracking analysis and enzyme-linked immunosorbent assay (ELISA). Our findings revealed distinctive differences in the size, concentration, and composition of EVs between immunosuppressed patients and those with CCD. Importantly, these EVs play a critical role in the pathophysiology of Chagas disease and demonstrate significant potential as biomarkers in the chronic phase of the disease. Overall, our findings support the potential utility of the CL-ELISA assay as a specific sensitive tool for detecting circulating EVs in chronic Chagasic patients, particularly those with recurrent infection following an immunosuppressive treatment or with concurrent HIV and Chagas disease. Further investigations are warranted to identify and validate the specific antigens or biomarkers responsible for the observed reactivity in these patient groups, which may have implications for diagnosis, the monitoring of treatment, and prognosis. Full article

This study focuses on developing accurate immunoassays for diagnosing Chagas disease (CD), a challenging task due to antigenic similarities between Trypanosoma cruzi and other parasites, leading to cross-reactivity. To address this challenge, chimeric recombinant T. cruzi antigens (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) were synthesized to enhance specificity and reduce cross-reactivity in tests. While these antigens showed minimal cross-reactivity with leishmaniasis, their performance with other trypanosomatid infections was unclear. This study aimed to assess the diagnostic potential of these IBMP antigens for detecting CD in patients with Crithidia sp. LVH-60A, a parasite linked to visceral leishmaniasis-like symptoms in Brazil. This study involved seven Crithidia sp. LVH-60A patients and three Leishmania infantum patients. The results indicated that these IBMP antigens displayed 100% sensitivity, with specificity ranging from 87.5% to 100%, and accuracy values between 90% and 100%. No cross-reactivity was observed with Crithidia sp. LVH-60A, and only one L. infantum-positive sample showed limited cross-reactivity with IBMP-8.1. This study suggests that IBMP antigens offer promising diagnostic performance, with minimal cross-reactivity in regions where T. cruzi and other trypanosomatids are prevalent. However, further research with a larger number of Crithidia sp. LVH-60A-positive samples is needed to comprehensively evaluate antigen cross-reactivity. Full article

For decades, only two nitroheterocyclic drugs have been used as therapeutic agents for Chagas disease. However, these drugs present limited effectiveness during the chronic phase, possess unfavorable pharmacokinetic properties, and induce severe adverse effects, resulting in low treatment adherence. A previous study reported that N-(cyclohexylcarbamothioyl) benzamide (BTU-1), N-(tert-butylcarbamothioyl) benzamide (BTU-2), and (4-bromo-N-(3-nitrophenyl) carbamothioyl benzamide (BTU-3) present selective antiprotozoal activity against all developmental forms of Trypanosoma cruzi Y strain. In this study, we investigated the mechanism of action of these compounds through microscopy and biochemical analyses. Transmission electron microscopy analysis showed nuclear disorganization, changes in the plasma membrane with the appearance of blebs and extracellular arrangements, intense vacuolization, mitochondrial swelling, and formation of myelin-like structures. Biochemical results showed changes in the mitochondrial membrane potential, reactive oxygen species content, lipid peroxidation, and plasma membrane fluidity. In addition, the formation of autophagic vacuoles was observed. These findings indicate that BTU-1, BTU-2, and BTU-3 induced profound morphological, ultrastructural, and biochemical alterations in epimastigote forms, triggering an autophagic-dependent cell death pathway. Full article

Acute phase proteins have been used as tools for the diagnosis, monitoring, and prognosis of several diseases in domestic animals. However, the dynamics of these proteins in infection by Trypanosoma cruzi, the causative agent of Chagas disease in dogs, is still unknown. The aim of this study was to determine concentrations of acute phase proteins (C-reactive protein, haptoglobin, ferritin and paraoxonase-1) in dogs in a coastal town of Ecuador, with natural Trypanosoma cruzi infection with or without seroreactivity of Ehrlichia canis, Ehrlichia ewingii, Anaplasma phagocytophilum, Anaplasma platys, Borrelia burgdorferi and Dirofilaria immitis. For the detection of Trypanosoma cruzi serum antibodies, two different antigen-based enzyme-linked immunosorbent assay tests were implemented. For the detection of seroreactivity of Ehrlichia canis, Ehrlichia ewingii, Anaplasma phagocytophilum, Anaplasma platys, Borrelia burgdorferi and Dirofilaria immitis, an IDEXX SNAP^® 4Dx^® test was used. To determine the concentration of C-reactive protein and ferritin, an immunoturbidimetric assay was used; haptoglobin concentration was measured using a commercial colorimetric method validated in dogs; a spectrophotometric method was used to determine the serum concentration of paraoxonase-1. Results showed a reduction in the serum levels of paraoxonase-1 in Trypanosoma cruzi-seroreactive dogs, either with or without seroreactivity to other vector-borne diseases. A serum ferritin increment was observed in Trypanosoma cruzi-seroreactive dogs with seroreactivity to any other vector-borne diseases. Our findings suggest that paraoxonase-1 levels are reduced in Trypanosoma cruzi-seroreactive dogs without evident clinical signs of Chagas disease, despite their seroreactivity to the other vector-borne diseases studied. These findings could indicate an oxidative stress response in Trypanosoma cruzi-seroreactive dogs with no evident signs of inflammation. Full article

Chagas disease is derived from the infection by the protozoan Trypanosoma cruzi. In many countries, benznidazole is the only drug approved for clinical use despite several side effects and the emergence of resistant parasite strains. In this context, our group has previously pointed out that two novel aminopyridine derivatives complexed with Cu²⁺, namely, cis-aquadichloro(N-[4-(hydroxyphenyl)methyl]-2-pyridinemethamino)copper (3a) and its glycosylated ligand cis-dichloro (N-{[4-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)pheny]lmethyl}-2-pyridinemethamino)copper (3b), are effective against T. cruzi trypomastigote forms. With this result in mind, the present work aimed to investigate the effects of both compounds on trypomastigotes physiology and on the interaction process with host cells. Apart from loss of plasma membrane integrity, an increased generation of reactive oxygen species (ROS) and decreased mitochondrial metabolism were observed. Pretreatment of trypomastigotes with these metallodrugs inhibited the association index with LLC-MK₂ cells in a typical dose-dependent manner. Both compounds showed low toxicity on mammalian cells (CC₅₀ > 100 µM), and the IC₅₀ values calculated for intracellular amastigotes were determined as 14.4 µM for 3a and 27.1 µM for 3b. This set of results demonstrates the potential of these aminopyridines complexed with Cu²⁺ as promising candidates for further antitrypanosomal drug development. Full article

Chagas disease is an endemic tropical disease caused by the protozoan Trypanosoma cruzi, which affects around 7 million people worldwide, mostly in development countries. The treatment relies on only two available drugs, with severe adverse effects and a limited efficacy. Therefore, the search for new therapies is a legitimate need. Within this context, our group reported the anti-Trypanosoma cruzi activity of gibbilimbol B, a natural alkylphenol isolated from the plant Piper malacophyllum. Two synthetic derivatives, LINS03018 (1) and LINS03024 (2), demonstrated a higher antiparasitic potency and were selected for mechanism of action investigations. Our studies revealed no alterations in the plasma membrane potential, but a rapid alkalinization of the acidocalcisomes. Nevertheless, compound 1 exhibit a pronounced effect in the bioenergetics metabolism, with a mitochondrial impairment and consequent decrease in ATP and reactive oxygen species (ROS) levels. Compound 2 only depolarized the mitochondrial membrane potential, with no interferences in the respiratory chain. Additionally, no macrophages response of nitric oxide (NO) was observed in both compounds. Noteworthy, simple structure modifications in these derivatives induced significant differences in their lethal effects. Thus, this work reinforces the importance of the mechanism of action investigations at the early phases of drug discovery and support further developments of the series. Full article