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.

Drug screening and development cascade for Chagas disease: an update of in vitro and in vivo experimental models.

Chagas disease is a tropical neglected disease that affects millions of people worldwide, still demanding a more effective and safer therapy, especially in its chronic phase which lacks a treatment that promotes substantial parasitological cure. The technical note of Romanha and collaborators published in 2010 aimed establish a guideline with the set of minimum criteria and decision gates for the development of new agents against Trypanosoma cruzi with the focus on developing new antichagasic drugs. In this sense, the present review aims to update this technical note, bringing the state of the art and new advances on this topic in recent years.

Anti-Trypanosoma cruzi Activity, Mutagenicity, Hepatocytotoxicity and Nitroreductase Enzyme Evaluation of 3-Nitrotriazole, 2-Nitroimidazole and Triazole Derivatives.

Chagas disease (CD), which is caused by Trypanosoma cruzi and was discovered more than 100 years ago, remains the leading cause of death from parasitic diseases in the Americas. As a curative treatment is only available for the acute phase of CD, the search for new therapeutic options is urgent. In this study, nitroazole and azole compounds were synthesized and underwent molecular modeling, anti-T. cruzi evaluations and nitroreductase enzymatic assays. The compounds were designed as possible inhibitors of ergosterol biosynthesis and/or as substrates of nitroreductase enzymes. The in vitro evaluation against T. cruzi clearly showed that nitrotriazole compounds are significantly more potent than nitroimidazoles and triazoles. When their carbonyls were reduced to hydroxyl groups, the compounds showed a significant increase in activity. In addition, these substances showed potential for action via nitroreductase activation, as the substances were metabolized at higher rates than benznidazole (BZN), a reference drug against CD. Among the compounds, 1-(2,4-difluorophenyl)-2-(3-nitro-1H-1,2,4-triazol-1-yl)ethanol (8) is the most potent and selective of the series, with an IC50 of 0.39 µM and selectivity index of 3077; compared to BZN, 8 is 4-fold more potent and 2-fold more selective. Moreover, this compound was not mutagenic at any of the concentrations evaluated, exhibited a favorable in silico ADMET profile and showed a low potential for hepatotoxicity, as evidenced by the high values of CC50 in HepG2 cells. Furthermore, compared to BZN, derivative 8 showed a higher rate of conversion by nitroreductase and was metabolized three times more quickly when both compounds were tested at a concentration of 50 µM. The results obtained by the enzymatic evaluation and molecular docking studies suggest that, as planned, nitroazole derivatives may utilize the nitroreductase metabolism pathway as their main mechanism of action against Trypanosoma cruzi. In summary, we have successfully identified and characterized new nitrotriazole analogs, demonstrating their potential as promising candidates for the development of Chagas disease drug candidates that function via nitroreductase activation, are considerably selective and show no mutagenic potential.

Trypanocidal Activity of Flavanone Derivatives.

Chagas disease, also known as American trypanosomiasis, is classified as a neglected disease by the World Health Organization. For clinical treatment, only two drugs have been on the market, Benznidazole and Nifurtimox, both of which are recommended for use in the acute phase but present low cure rates in the chronic phase. Furthermore, strong side effects may result in discontinuation of this treatment. Faced with this situation, we report the synthesis and trypanocidal activity of 3-benzoyl-flavanones. Novel 3-benzoyl-flavanone derivatives were prepared in satisfactory yields in the 3-step synthetic procedure. According to recommended guidelines, the whole cell-based screening methodology was utilized that allowed for the simultaneous use of both parasite forms responsible for human infection. The majority of the tested compounds displayed promising anti-Trypanosoma cruzi activity and the most potent flavanone bearing a nitrofuran moiety was more potent than the reference drug, Benznidazole.

In Vitro Trypanocidal and Antibacterial Activities of Essential Oils from Four Species of the Family Annonaceae.

The objective of this study was to evaluate the chemical composition, and the trypanocidal and antibacterial activities of the essential oils from four species of Annonaceae: Bocageopsis multiflora (Mart.) R.E.Fr., Duguetia quitarensis Benth., Fusaea longifolia (Aubl.) Saff., and Guatteria punctata (Aubl.) R.A.Howard. The chemical composition of the essential oils from the aerial parts yielded 23, 20, 21 and 23 constituents, respectively, which were identified by GC/MS. The trypanocidal activity was evaluated against the amastigote and trypomastigote forms of T. cruzi. The antibacterial activity was evaluated by the microdilution method against enterohemorrhagic Escherichia coli, Pseudomonas aeruginosa, Streptococcus mutans, Streptococcus pyogenes, and methicillin-resistant Staphylococcus aureus. The results of trypanocidal activity showed that the essential oils of the four species were active at the tested concentrations, with G. punctata essential oil being the most active, with IC50 =0.029 µg/mL, and selectivity index (SI)=32, being 34 times more active than the reference drug benznidazole. All EOs showed strong antibacterial activity (minimum inhibitory concentrations of 4.68-37.5 µg/mL) against strains of S. mutans.

Synthesis and biological evaluation of potential inhibitors of the cysteine proteases cruzain and rhodesain designed by molecular simplification.

Analogues of 8-chloro-N-(3-morpholinopropyl)-5H-pyrimido[5,4-b]indol-4-amine 1, a known cruzain inhibitor, were synthesized using a molecular simplification strategy. Five series of analogues were obtained: indole, pyrimidine, quinoline, aniline and pyrrole derivatives. The activity of the compounds was evaluated against the enzymes cruzain and rhodesain as well as against Trypanosoma cruzi amastigote and trypomastigote forms. The 4-aminoquinoline derivatives showed promising activity against both enzymes, with IC50 values ranging from 15 to 125µM. These derivatives were selective inhibitors for the parasitic proteases, being unable to inhibit mammalian cathepsins B and S. The most active compound against cruzain (compound 5a; IC50=15µM) is considerably more synthetically accessible than 1, while retaining its ligand efficiency. As observed for the original lead, compound 5a was shown to be a competitive enzyme inhibitor. In addition, it was also active against T. cruzi (IC50=67.7µM). Interestingly, the pyrimidine derivative 4b, although inactive in enzymatic assays, was highly active against T. cruzi (IC50=3.1µM) with remarkable selectivity index (SI=128) compared to uninfected fibroblasts. Both 5a and 4b exhibit drug-like physicochemical properties and are predicted to have a favorable ADME profile, therefore having great potential as candidates for lead optimization in the search for new drugs to treat Chagas disease.

18-Des-hydroxy Cytochalasin: an antiparasitic compound of Diaporthe phaseolorum-92C, an endophytic fungus isolated from Combretum lanceolatum Pohl ex Eichler.

Chemical investigation of the ethyl acetate extract from the endophytic fungus Diaporthe phaseolorum-92C (92C) isolated from the roots of Combretum lanceolatum led to the isolation of 18-des-hydroxy Cytochalasin H (compound 1). The trypanocidal and schistosomicidal activity and cytotoxicity of the extract from 92C were evaluated. The schistosomicidal, leishmanicidal, antimicrobial, and antioxidant actions, as well as the antitumor activity against the breast cancer cells MDA-MB-231 and MCF-7, and the cytotoxicity towards normal human lung fibroblasts GM07492A of compound 1 was tested. The extract from 92C (20 µg/mL) exerted potent trypanocidal activity, reducing 82% of the number of amastigotes and trypomastigotes of Trypanosoma cruzi. Compound 1 at 50 µg/mL killed 50% of Schistosoma mansoni adult worms. Compound 1 reduced the viability of Leishmania amazonenses promastigotes (IC50 = 9.2 µg/mL) and of the cancer cells MDA-MB-231 and MCF-7 (IC50 = 17.5 and 8.88 µg/mL, respectively), presented moderate antioxidant activity, and gave IC50 of 2049.7 ± 39.9 µg/mL for the cytotoxicity towards normal cells GM07492A. This knowledge is highly relevant to the search for new promising compounds for therapeutic purposes.

Synthesis of Xylitan Derivatives and Preliminary Evaluation of in Vitro Trypanocidal Activity.

A series of novel xylitan derivatives derived from xylitol were synthesized using operationally simple procedures. A xylitan acetonide was the key intermediate used to prepare benzoate, arylsulfonate esters and 1,2,3-triazole derivatives of xylitan. These compounds were evaluated for their in vitro anti-Trypanosoma cruzi activity against trypomastigote and amastigote forms of the parasite in T. cruzi-infected cell lineages. Benznidazole was used as positive control against T. cruzi and cytotoxicity was determined in mammalian L929 cells. The arylsulfonate xylitan derivative bearing a nitro group displayed the best activity of all the compounds tested, and was slightly more potent than the reference drug benznidazole. The importance of the isopropylidene ketal moiety was established and the greater lipophilicity of these compounds suggests enhancement in cell penetration.

Synthesis of a sugar-based thiosemicarbazone series and structure-activity relationship versus the parasite cysteine proteases rhodesain, cruzain, and Schistosoma mansoni cathepsin B1.

The pressing need for better drugs against Chagas disease, African sleeping sickness, and schistosomiasis motivates the search for inhibitors of cruzain, rhodesain, and Schistosoma mansoni CB1 (SmCB1), the major cysteine proteases from Trypanosoma cruzi, Trypanosoma brucei, and S. mansoni, respectively. Thiosemicarbazones and heterocyclic analogues have been shown to be both antitrypanocidal and inhibitory against parasite cysteine proteases. A series of compounds was synthesized and evaluated against cruzain, rhodesain, and SmCB1 through biochemical assays to determine their potency and structure-activity relationships (SAR). This approach led to the discovery of 6 rhodesain, 4 cruzain, and 5 SmCB1 inhibitors with 50% inhibitory concentrations (IC50s) of ≤ 10 µM. Among the compounds tested, the thiosemicarbazone derivative of peracetylated galactoside (compound 4i) was discovered to be a potent rhodesain inhibitor (IC50 = 1.2 ± 1.0 µM). The impact of a range of modifications was determined; removal of thiosemicarbazone or its replacement by semicarbazone resulted in virtually inactive compounds, and modifications in the sugar also diminished potency. Compounds were also evaluated in vitro against the parasites T. cruzi, T. brucei, and S. mansoni, revealing active compounds among this series.

In vitro activity of 1,3-bisaryloxypropanamines against Trypanosoma cruzi-infected L929 cultures.

We describe herein the antitrypanosomal activity of 20 novel 1,3-bis(aryloxy)propan-2-amine derivatives. Compounds 2, 4, 6, 12, 15, 16 and 19 were significantly active against amastigote and trypomastigote forms, with half maximal inhibitory concentrationvalues in the range of 6-18 µM. In the cytotoxicity tests against L929 cells, only compound 4 presented selectivity index value above 10, indicating low toxicity.

Bioactive endophytic fungi isolated from Caesalpinia echinata Lam. (Brazilwood) and identification of beauvericin as a trypanocidal metabolite from Fusarium sp.

Aiming to identify new sources of bioactive secondary metabolites, we isolated 82 endophytic fungi from stems and barks of the native Brazilian tree Caesalpinia echinata Lam. (Fabaceae). We tested their ethyl acetate extracts in several in vitro assays. The organic extracts from three isolates showed antibacterial activity against Staphylococcus aureus and Escherichia coli [minimal inhibitory concentration (MIC) 32-64 µg/mL]. One isolate inhibited the growth of Salmonella typhimurium (MIC 64 µg/mL) and two isolates inhibited the growth of Klebsiella oxytoca (MIC 64 µg/mL), Candida albicans and Candida tropicalis (MIC 64-128 µg/mL). Fourteen extracts at a concentration of 20 µg/mL showed antitumour activities against human breast cancer and human renal cancer cells, while two isolates showed anti-tumour activities against human melanoma cancer cells. Six extracts were able to reduce the proliferation of human peripheral blood mononuclear cells, indicating some degree of selective toxicity. Four isolates were able to inhibit Leishmania (Leishmania) amazonensis and one isolate inhibited Trypanosoma cruzi by at least 40% at 20 µg/mL. The trypanocidal extract obtained from Fusarium sp. [KF611679] culture was subjected to bioguided fractionation, which revealed beauvericin as the compound responsible for the observed toxicity of Fusarium sp. to T. cruzi. This depsipeptide showed a half maximal inhibitory concentration of 1.9 µg/mL (2.43 µM) in a T. cruzi cellular culture assay.

The in vitro activity of fatty diamines and amino alcohols against mixed amastigote and trypomastigote Trypanosoma cruzi forms.

Four diamines and three amino alcohols derived from 1-decanol, 1-dodecanol and 1,2-dodecanediol were evaluated in an in vitro assay against a mixture of trypomastigote and intracellular amastigote forms of Trypanosoma cruzi. Two of these compounds (6 and 7) showed better activity against both proliferative stages of T. cruzi than the positive control benznidazole, three were of similar potency (1, 2 and 5) and two were less active (3 and 4).

In vitro cytotoxic, antifungal, trypanocidal and leishmanicidal activities of acetogenins isolated from Annona cornifolia A. St. -Hil. (Annonaceae).

Annona cornifolia A. St. -Hil. is a small annual perennial tree found in the Brazilian savannah; their green fruit is popularly used in the treatment of ulcers. The acetogenins isolated from the seeds of Annona cornifolia previously showed to possess antioxidant activity. In continuation of our investigations on the biological activities of acetogenins, four binary mixtures and ten pure adjacent bis-tetrahydrofuran annonaceous acetogenins were evaluated: the cytotoxic (against three human tumor cell lines), antifungal (against Paracoccidioides brasiliensis), trypanocidal (against Trypanosoma cruzi) and leishmanicidal (against Leishmania amazonensis) activities. Acetogenins presented cytotoxic activity confirming their potential use in anti-cancer therapy. Regarding leishmanicidal and trypanocidal activities, an inhibition of 87% of L. amazonensis amastigotes and 100% of T. cruzi amastigotes and trypomastigotes was observed, when tested at the concentration of 20 µg mL-1. Moreover, six acetogenins showed more activity against all the three tested isolates of P. brasiliensis than trimethoprim-sulfamethoxazole, a drug used for treating paracoccidioidomycosis. Thus, acetogenins may be an alternative in treating a number of diseases that have a huge impact on millions of people worldwide. This paper reports for the first time the antifungal, leishmanicidal and trypanocidal activities for these acetogenins.

New insights into Trypanosoma cruzi genetic diversity, and its influence on parasite biology and clinical outcomes.

Chagas disease, caused by Trypanosoma cruzi, remains a serious public health problem worldwide. The parasite was subdivided into six distinct genetic groups, called "discrete typing units" (DTUs), from TcI to TcVI. Several studies have indicated that the heterogeneity of T. cruzi species directly affects the diversity of clinical manifestations of Chagas disease, control, diagnosis performance, and susceptibility to treatment. Thus, this review aims to describe how T. cruzi genetic diversity influences the biology of the parasite and/or clinical parameters in humans. Regarding the geographic dispersion of T. cruzi, evident differences were observed in the distribution of DTUs in distinct areas. For example, TcII is the main DTU detected in Brazilian patients from the central and southeastern regions, where there are also registers of TcVI as a secondary T. cruzi DTU. An important aspect observed in previous studies is that the genetic variability of T. cruzi can impact parasite infectivity, reproduction, and differentiation in the vectors. It has been proposed that T. cruzi DTU influences the host immune response and affects disease progression. Genetic aspects of the parasite play an important role in determining which host tissues will be infected, thus heavily influencing Chagas disease's pathogenesis. Several teams have investigated the correlation between T. cruzi DTU and the reactivation of Chagas disease. In agreement with these data, it is reasonable to suppose that the immunological condition of the patient, whether or not associated with the reactivation of the T. cruzi infection and the parasite strain, may have an important role in the pathogenesis of Chagas disease. In this context, understanding the genetics of T. cruzi and its biological and clinical implications will provide new knowledge that may contribute to additional strategies in the diagnosis and clinical outcome follow-up of patients with Chagas disease, in addition to the reactivation of immunocompromised patients infected with T. cruzi.

Synthesis of hydrazinyl-thiazole ester derivatives, in vitro trypanocidal and leishmanicidal activities.

Aim: To synthesize novel more potent trypanocidal and leishmanicidal agents. Methods: Hantzsch's synthetic strategy was used to synthesize 1,3-thiazole-4-carboxylates and their N-benzylated derivatives. Results: 28 new thiazole-carboxylates and their N-benzylated derivatives were established to test their trypanocidal and leishmanicidal activities. From both series, compounds 3b, 4f, 4g, 4j and 4n exhibited a better or comparable trypanocidal profile to benznidazole. Among all tested compounds, 4n was found to be the most potent and was better than benznidazole. Conclusion: Further variation of substituents around 1,3-thiazole-4-carboxylates and or hydrazinyl moiety may assist in establishing better and more potent trypanocidal and leishmanicidal agents.

Chagas disease and leishmaniasis are neglected tropical diseases. Herein, 28 1,3-thiazoles have been synthesized from thiosemicarbazones in a rapid, efficient and cost-effective manner. In vitro assays were performed against intracellular amastigotes of Trypanosoma cruzi (T. cruzi) and promastigotes and intracellular amastigote forms of Leishmania infantum (L. infantum) and Leishmania amazonensis (L. amazonensis). Some of the 1,3-thiazole-4-carboxylates inhibited the amastigote form of T. cruzi without affecting macrophage viability, compound 4n being the most potent and better than benznidazole. Our synthesized compounds exhibited promising activity against T. cruzi, thus broadening options for scaffold and lead compound optimization. Concerning the leishmanicidal activity, compound 4g was the best prototype in terms of potency and selectivity. Compounds 4g and 3m showed moderate selectivity and potency against intracellular amastigotes of L. amazonensis and L. infantum, respectively.

Cardiomyocyte dysfunction during the chronic phase of Chagas disease.

Chagas disease, which is caused by the parasite Trypanosoma cruzi, is an important cause of heart failure. We investigated modifications in the cellular electrophysiological and calcium-handling characteristics of an infected mouse heart during the chronic phase of the disease. The patch-clamp technique was used to record action potentials (APs) and L-type Ca2+ and transient outward K+ currents. [Ca2+]i changes were determined using confocal microscopy. Infected ventricular cells showed prolonged APs, reduced transient outward K+ and L-type Ca2+ currents and reduced Ca2+ release from the sarcoplasmic reticulum. Thus, the chronic phase of Chagas disease is characterised by cardiomyocyte dysfunction, which could lead to heart failure.

Novel diamides inspired by protein kinase inhibitors as anti-Trypanosoma cruzi agents: in vitro and in vivo evaluations.

Background: Chagas disease is a life-threatening illness caused by Trypanosoma cruzi. The involvement of serine-/arginine-rich protein kinase in the T. cruzi life cycle is significant. Aims: To synthesize, characterize and evaluate the trypanocidal activity of diamides inspired by kinase inhibitor, SRPIN340. Material & Methods: Synthesis using a three-step process and characterization by infrared, nuclear magnetic resonance and high-resolution mass spectrometry were conducted. The selectivity index was obtained by the ratio of CC50/IC50 in two in vitro models. The most active compound, 3j, was evaluated using in vitro cytokine assays and assessing in vivo trypanocidal activity. Results: 3j activity in the macrophage J774 lineage showed an anti-inflammatory profile, and mice showed significantly reduced parasitemia and morbidity at low compound dosages. Conclusion: Novel diamide is active against T. cruzi in vitro and in vivo.

Structural design, synthesis, and anti-Trypanosomatidae profile of new Pyridyl-thiazolidinones.

The present work reports the synthesis of a novel series of pyridine-thiazolidinones with anti-Trypanosoma cruzi and leishmanicidal activities (compounds 10-27), derived from 2 or 4-pyridine thiosemicarbazones (1-9). The in vitro assays were performed with Trypanosoma cruzi trypomastigotes and amastigotes, as well as with Leishmania amazonensis promastigotes and amastigotes. The cytotoxicity profile was evaluated using the cell line RAW 264.7. From the 18 pyridine-thiazolidinones, 5 were able to inhibit trypomastigotes. Overall, all compounds inhibited amastigotes, highlighting compounds 15 (0.60 µM), 18 (0.64 µM), 17 (0.81 µM), and 27 (0.89 µM). Compounds 15 and 18 were able to induce parasite cell death through necrosis induction. Analysis by scanning electron microscopy showed that T. cruzi trypomastigotes treated with compounds 15 and 18 induced morphological changes such as shortening, retraction and curvature of the parasite body and leakage of internal content. Regarding the antiparasitic evaluation against Leishmania amazonensis, only compound 27 had a higher selectivity compared to Miltefosine against the amastigote form (IC50 = 5.70 µM). Our results showed that compound 27 presented an antiparasitic activity for both Trypanosoma cruzi and Leishmania amazonensis. After in silico evaluation, it was suggested that the new pyridine-thiazolidinones had an appropriate drug-likeness profile. Our results pointed out a new chemical frame with an anti-Trypanosomatidae profile. The pyridine-thiazolidinones presented here for the first time could be used as a starting point for the development of new antiparasitic agents.

Leishmanicidal and antitumoral activities of endophytic fungi associated with the Antarctic angiosperms Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl.

A total of 564 isolates of endophytic fungi were recovered from the plants Deschampsia antarctica and Colobanthus quitensis collected from Antarctica. The isolates were screened against parasites Leishmania amazonensis and Trypanosoma cruzi and against the human tumour cell lines. Of the 313 fungal isolates obtained from D. antarctica and 251 from C. quitensis, 25 displayed biological activity. Nineteen extracts displayed leishmanicidal activity, and six inhibited the growth of at least one tumour cell line. These fungi belong to 19 taxa of the genera Alternaria, Antarctomyces, Cadophora, Davidiella, Helgardia, Herpotrichia, Microdochium, Oculimacula, Phaeosphaeria and one unidentified fungus. Extracts of 12 fungal isolates inhibited the proliferation of L. amazonesis at a low IC(50) of between 0.2 and 12.5 µg ml(-1). The fungus Phaeosphaeria herpotrichoides displayed only leishmanicidal activity with an IC(50) of 0.2 µg ml(-1), which is equivalent to the inhibitory value of amphotericin B. The extract of Microdochium phragmitis displayed specific cytotoxic activity against the UACC-62 cell line with an IC(50) value of 12.5 µg ml(-1). Our results indicate that the unique angiosperms living in Antarctica shelter an interesting bioactive fungal community that is able to produce antiprotozoal and antitumoral molecules. These molecules may be used to develop new leishmanicidal and anticancer drugs.

Impact of IFN-γ Deficiency on the Cardiomyocyte Function in the First Stage of Experimental Chagas Disease.

Chagas disease (CD) is caused by the parasitic protozoan T. cruzi. The progression of CD in ~30% of patients results in Chagasic Cardiomyopathy (CCM). Currently, it is known that the inflammatory system plays a significant role in the CCM. Interferon-gamma (IFN-γ) is the major cytokine involved in parasitemia control but has also been linked to CCM. The L-type calcium current (ICa,L) is crucial in the excitation/contraction coupling in cardiomyocytes. Thus, we compared ICa,L and the mechanical properties of cardiomyocytes isolated from infected wild type (WT) and IFN-γ(-/-) mice in the first stage of T. cruzi infection. Using the patch clamp technique, we demonstrated that the infection attenuated ICa,L in isolated cardiomyocytes from the right and left ventricles of WT mice at 15 days post-infection (dpi), which was not observed in the IFN-γ(-/-) cardiomyocytes. However, ICa,L was attenuated between 26 and 30 dpi in both experimental groups. Interestingly, the same profile was observed in the context of the mechanical properties of isolated cardiomyocytes from both experimental groups. Simultaneously, we tracked the mortality and MCP-1, TNF-α, IL-12, IL-6, and IL-10 serum levels in the infected groups. Importantly, the IFN-γ(-/-) and WT mice presented similar parasitemia and serum inflammatory markers at 10 dpi, indicating that the modifications in the cardiomyocyte functions observed at 15 dpi were directly associated with IFN-γ(-/-) deficiency. Thus, we showed that IFN-γ plays a crucial role in the electromechanical remodeling of cardiomyocytes during experimental T. cruzi infection in mice.