scholarly journals Repurposing Strategy of Atorvastatin against Trypanosoma cruzi: In Vitro Monotherapy and Combined Therapy with Benznidazole Exhibit Synergistic Trypanocidal Activity

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
C. F. Araujo-Lima ◽  
R. B. Peres ◽  
P. B. Silva ◽  
M. M. Batista ◽  
C. A. F. Aiub ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Combined Therapy ◽  
Fixed Ratio ◽  
Drug Repurposing ◽  
Biological Properties ◽  
Cardiac Cells ◽  
Content Type ◽  
Density Reduction ◽  
Different Strains

ABSTRACT Statins are inhibitors of cholesterol synthesis, but other biological properties, such as antimicrobial effects, have also been assigned to them, leading to their designation as pleiotropic agents. Our goal was to investigate the activity and selectivity of atorvastatin (AVA) against Trypanosoma cruzi by using in vitro models, aiming for more effective and safer therapeutic options through drug repurposing proposals for monotherapy and therapy in combination with benznidazole (BZ). Phenotypic screening was performed with different strains (Tulahuen [discrete typing unit {DTU} VI] and Y [DTU II]) and forms (intracellular forms, bloodstream trypomastigotes, and tissue-derived trypomastigotes) of the parasite. On assay of the Tulahuen strain, AVA was more active against intracellular amastigotes (selectivity index [SI] = 3). Also, against a parasite of another DTU (Y strain), this statin was more active (2.1-fold) and selective (2.4-fold) against bloodstream trypomastigotes (SI = 51) than against the intracellular forms (SI = 20). A cytomorphological approach using phalloidin-rhodamine permitted us to verify that AVA did not induced cell density reduction and that cardiac cells (CC) maintained their typical cytoarchitecture. Combinatory approaches using fixed-ratio methods showed that AVA and BZ gave synergistic interactions against both trypomastigotes and intracellular forms (mean sums of fractional inhibitory concentration indexes [∑FICIs] of 0.46 ± 0.12 and 0.48 ± 0.03, respectively). Thus, the repurposing strategy for AVA, especially in combination with BZ, which leads to a synergistic effect, is encouraging for future studies to identify novel therapeutic protocols for Chagas disease treatment.

scholarly journals Phenotypic ScreeningIn Vitroof Novel Aromatic Amidines against Trypanosoma cruzi

2016 ◽  
Vol 60 (8) ◽  
pp. 4701-4707 ◽  
Author(s):  
M. R. Simões-Silva ◽  
A. S. G. Nefertiti ◽  
J. S. De Araújo ◽  
M. M. Batista ◽  
P. B. Da Silva ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Fixed Ratio ◽  
Current Treatment ◽  
Cardiac Cells ◽  
Host Cells ◽  
Mammalian Host ◽  
Standard Drug ◽  
Content Type ◽  
Discrete Typing Unit

ABSTRACTThe current treatment of Chagas disease (CD), based on nifurtimox and benznidazole (Bz), is unsatisfactory. In this context, we performed the phenotypicin vitroscreening of novel mono- and diamidines and drug interaction assays with selected compounds. Ten novel amidines were tested for their activities against bloodstream trypomastigote (BT) and amastigote forms ofTrypanosoma cruzi(Y and Tulahuen strains) and their toxicities for mammalian host cells (L929 cells and cardiac cells). Seven of 10 molecules were more active than Bz against BT, with the most active compound being the diamidine DB2267 (50% effective concentration [EC50] = 0.23 μM; selectivity index = 417), which was 28-fold more active and about 3 times more selective than the standard drug. Five of the six monoamidines were also more active than Bz. The combination of DB2267 and DB2236 in fixed-ratio proportions showed an additive effect (sum of fractional inhibitory concentrations < 4) on BT. Interestingly, when intracellular forms were exposed to DB2267, its activity was dependent on the parasite strain, being effective (EC50= 0.87 ± 0.05 μM) against a discrete typing unit (DTU) II strain (strain Y) but not against a representative DTU VI strain (strain Tulahuen) even when different vehicles (β-cyclodextrin and dimethyl sulfoxide) were used. The intrinsic fluorescence of several diamidines allowed their uptake to be studied. Testing of the uptake of DB2236 (inactive) and DB2267 (active) by amastigotes of the Y strain showed that the two compounds were localized intracellularly in different compartments: DB2236 in the cytoplasm and DB2267 in the nucleus. Our present data encourage further studies regarding the activities of amidines and provide information which will help with the identification of novel agents for the treatment of CD.

scholarly journals Efficacy of Novel Pyrazolone Phosphodiesterase Inhibitors in Experimental Mouse Models of Trypanosoma cruzi

2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Julianna Siciliano de Araújo ◽  
Cristiane França da Silva ◽  
Denise da Gama Jaén Batista ◽  
Aline Nefertiti ◽  
Ludmila Ferreira de Almeida Fiuza ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Phosphodiesterase Inhibitors ◽  
Biological Properties ◽  
Host Cells ◽  
Mammalian Host ◽  
Intracellular Camp ◽  
Additive Interaction ◽  
Content Type

ABSTRACT Pyrazolones are heterocyclic compounds with interesting biological properties. Some derivatives inhibit phosphodiesterases (PDEs) and thereby increase the cellular concentration of cyclic AMP (cAMP), which plays a vital role in the control of metabolism in eukaryotic cells, including the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease (CD), a major neglected tropical disease. In vitro phenotypic screening identified a 4-bromophenyl-dihydropyrazole dimer as an anti-T. cruzi hit and 17 novel pyrazolone analogues with variations on the phenyl ring were investigated in a panel of phenotypic laboratory models. Potent activity against the intracellular forms (Tulahuen and Y strains) was obtained with 50% effective concentration (EC50) values within the 0.17 to 3.3 μM range. Although most were not active against bloodstream trypomastigotes, an altered morphology and loss of infectivity were observed. Pretreatment of the mammalian host cells with pyrazolones did not interfere with infection and proliferation, showing that the drug activity was not the result of changes to host cell metabolism. The pyrazolone NPD-227 increased the intracellular cAMP levels and was able to sterilize T. cruzi-infected cell cultures. Thus, due to its high potency and selectivity in vitro, and its additive interaction with benznidazole (Bz), NPD-227 was next assessed in the acute mouse model. Oral dosing for 5 days of NPD-227 at 10 mg/kg + Bz at 10 mg/kg not only reduced parasitemia (>87%) but also protected against mortality (>83% survival), hence demonstrating superiority to the monotherapy schemes. These data support these pyrazolone molecules as potential novel therapeutic alternatives for Chagas disease.

Drug repurposing strategy against Trypanosoma cruzi infection: In vitro and in vivo assessment of the activity of metronidazole in mono- and combined therapy

2017 ◽  
Vol 145 ◽  
pp. 46-53 ◽  
Author(s):  
M.R. Simões-Silva ◽  
J.S. De Araújo ◽  
G.M. Oliveira ◽  
K.C. Demarque ◽  
R.B. Peres ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Combined Therapy ◽  
Drug Repurposing ◽  
Cruzi Infection ◽  
In Vivo Assessment

scholarly journals Outcome of E1224-Benznidazole Combination Treatment for Infection with a Multidrug-Resistant Trypanosoma cruzi Strain in Mice

2018 ◽  
Vol 62 (6) ◽  
pp. e00401-18 ◽  
Author(s):  
Lívia de Figueiredo Diniz ◽  
Ana Lia Mazzeti ◽  
Ivo Santana Caldas ◽  
Isabela Ribeiro ◽  
Maria Terezinha Bahia
Keyword(s):  
Combination Therapy ◽  
Trypanosoma Cruzi ◽  
Combined Therapy ◽  
Acute Infection ◽  
Combined Treatment ◽  
Multidrug Resistant ◽  
Positive Interaction ◽  
Content Type ◽  
Treatment Onset

ABSTRACT Combination therapy has been proposed as an alternative therapeutic approach for the treatment of Chagas disease. In this study, we evaluated the effect of treatment with benznidazole combined with E1224 (ravuconazole prodrug) in an experimental murine model of acute infection. The first set of experiments assessed the range of E1224 doses required to induce parasitological cure using Trypanosoma cruzi strains with different susceptibilities to benznidazole (Y and Colombian). All E1224 doses were effective in suppressing the parasitemia and preventing death; however, parasitological cure was observed only in mice infected with Y strain. Considering these results, we evaluated the effect of combined treatment against Colombian, a multidrug-resistant T. cruzi strain. After exclusion of antagonistic effects using in vitro assays, infected mice were treated with E1224 and benznidazole in monotherapy or in combination at day 4 or 10 postinoculation. All treatments were well tolerated and effective in suppressing parasitemia; however, parasitological and PCR assays indicated no cure among mice treated with monotherapies. Intriguingly, the outcome of combination therapy was dependent on treatment onset. Early treatment using optimal doses of E1224-benznidazole induced a 100% cure rate, but this association could not eliminate a well-established infection. The beneficial effect of combination therapy was evidenced by further reductions of the patent parasitemia period in the group receiving combined therapy compared with monotherapies. Our results demonstrated a positive interaction between E1224 and benznidazole against murine T. cruzi infection using a multidrug-resistant strain and highlighted the importance of a stringent experimental model in the evaluation of new therapies.

scholarly journals In VitroandIn VivoTrypanosomicidal Action of Novel Arylimidamides against Trypanosoma cruzi

2016 ◽  
Vol 60 (4) ◽  
pp. 2425-2434 ◽  
Author(s):  
F. H. Guedes-da-Silva ◽  
D. G. J. Batista ◽  
M. B. Meuser ◽  
K. C. Demarque ◽  
T. O. Fulco ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Parasite Load ◽  
Host Cells ◽  
Content Type ◽  
Days Of Therapy ◽  
Different Strains ◽  
Dose Dependent

ABSTRACTArylimidamides (AIAs) have been shown to have considerable biological activity against intracellular pathogens, includingTrypanosoma cruzi, which causes Chagas disease. In the present study, the activities of 12 novel bis-AIAs and 2 mono-AIAs against different strains ofT. cruziin vitroandin vivowere analyzed. The most active wasm-terphenyl bis-AIA (35DAP073), which had a 50% effective concentration (EC50) of 0.5 μM for trypomastigotes (Y strain), which made it 26-fold more effective than benznidazole (Bz; 13 μM). It was also active against the Colombiana strain (EC50= 3.8 μM). Analysis of the activity against intracellular forms of the Tulahuen strain showed that this bis-AIA (EC50= 0.04 μM) was about 100-fold more active than Bz (2 μM). The trypanocidal effect was dissociated from the ability to trigger intracellular lipid bodies within host cells, detected by oil red labeling. Both an active compound (35DAP073) and an inactive compound (26SMB060) displayed similar activation profiles. Due to their high selectivity indexes, two AIAs (35DAP073 and 35DAP081) were moved toin vivostudies, but because of the results of acute toxicity assays, 35DAP081 was excluded from the subsequent tests. The findings obtained with 35DAP073 treatment of infections caused by the Y strain revealed that 2 days of therapy induced a dose-dependent action, leading to 96 to 46% reductions in the level of parasitemia. However, the administration of 10 daily doses in animals infected with the Colombiana strain resulted in toxicity, preventing longer periods of treatment. The activity of the combination of 0.5 mg/kg of body weight/day 35DAP073 with 100 mg/kg/day Bz for 10 consecutive days was then assayed. Treatment with the combination resulted in the suppression of parasitemia, the elimination of neurological toxic effects, and survival of 100% of the animals. Quantitative PCR showed a considerable reduction in the parasite load (60%) compared to that achieved with Bz or the amidine alone. Our results support further investigations of this class with the aim of developing novel alternatives for the treatment of Chagas disease.

scholarly journals Neurotrophin Receptor TrkC Is an Entry Receptor for Trypanosoma cruzi in Neural, Glial, and Epithelial Cells

2011 ◽  
Vol 79 (10) ◽  
pp. 4081-4087 ◽  
Author(s):  
Craig Weinkauf ◽  
Ryan Salvador ◽  
Mercio PereiraPerrin
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Mammalian Cells ◽  
Chinese Hamster ◽  
Neuronal Cell ◽  
Host Cells ◽  
Neurotrophin Receptor ◽  
Content Type

ABSTRACTTrypanosoma cruzi, the agent of Chagas' disease, infects a variety of mammalian cells in a process that includes multiple cycles of intracellular division and differentiation starting with host receptor recognition by a parasite ligand(s). Earlier work in our laboratory showed that the neurotrophin-3 (NT-3) receptor TrkC is activated byT. cruzisurfacetrans-sialidase, also known as parasite-derived neurotrophic factor (PDNF). However, it has remained unclear whether TrkC is used byT. cruzito enter host cells. Here, we show that a neuronal cell line (PC12-NNR5) relatively resistant toT. cruzibecame highly susceptible to infection when overexpressing human TrkC but not human TrkB. Furthermore,trkCtransfection conferred an ∼3.0-fold intracellular growth advantage. Sialylation-deficient Chinese hamster ovarian (CHO) epithelial cell lines Lec1 and Lec2 also became much more permissive toT. cruziafter transfection with thetrkCgene. Additionally, NT-3 specifically blockedT. cruziinfection of the TrkC-NNR5 transfectants and of naturally permissive TrkC-bearing Schwann cells and astrocytes, as did recombinant PDNF. Two specific inhibitors of Trk autophosphorylation (K252a and AG879) and inhibitors of Trk-induced MAPK/Erk (U0126) and Akt kinase (LY294002) signaling, but not an inhibitor of insulin-like growth factor 1 receptor, abrogated TrkC-mediated cell invasion. Antibody to TrkC blockedT. cruziinfection of the TrkC-NNR5 transfectants and of cells that naturally express TrkC. The TrkC antibody also significantly and specifically reduced cutaneous infection in a mouse model of acute Chagas' disease. TrkC is ubiquitously expressed in the peripheral and central nervous systems, and in nonneural cells infected byT. cruzi, including cardiac and gastrointestinal muscle cells. Thus, TrkC is implicated as a functional PDNF receptor in cell entry, independently of sialic acid recognition, mediating broadT. cruziinfection bothin vitroandin vivo.

scholarly journals Nitro/Nitrosyl-Ruthenium Complexes Are Potent and Selective Anti-Trypanosoma cruzi Agents Causing Autophagy and Necrotic Parasite Death

2014 ◽  
Vol 58 (10) ◽  
pp. 6044-6055 ◽  
Author(s):  
Tanira M. Bastos ◽  
Marília I. F. Barbosa ◽  
Monize M. da Silva ◽  
José W. da C. Júnior ◽  
Cássio S. Meira ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Inhibitory Concentration ◽  
Content Type ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ruthenium Nitrosyl ◽  
Index Analysis ◽  
Antiparasitic Drug ◽  
Drug Complex

ABSTRACTcis-[RuCl(NO2)(dppb)(5,5′-mebipy)] (complex 1),cis-[Ru(NO2)2(dppb)(5,5′-mebipy)] (complex 2),ct-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2(complex 3), andcc-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2(complex 4), where 5,5′-mebipy is 5,5′-dimethyl-2,2′-bipyridine and dppb is 1,4-bis(diphenylphosphino)butane, were synthesized and characterized. The structure of complex 2 was determined by X-ray crystallography. These complexes exhibited a higher anti-Trypanosoma cruziactivity than benznidazole, the current antiparasitic drug. Complex 3 was the most potent, displaying a 50% effective concentration (EC50) of 2.1 ± 0.6 μM against trypomastigotes and a 50% inhibitory concentration (IC50) of 1.3 ± 0.2 μM against amastigotes, while it displayed a 50% cytotoxic concentration (CC50) of 51.4 ± 0.2 μM in macrophages. It was observed that the nitrosyl complex 3, but not its analog lacking the nitrosyl group, releases nitric oxide into parasite cells. This release has a diminished effect on the trypanosomal protease cruzain but induces substantial parasite autophagy, which is followed by a series of irreversible morphological impairments to the parasites and finally results in cell death by necrosis. In infected mice, orally administered complex 3 (five times at a dose of 75 μmol/kg of body weight) reduced blood parasitemia and increased the survival rate of the mice. Combination index analysis of complex 3 indicated that itsin vitroactivity against trypomastigotes is synergic with benznidazole. In addition, drug combination enhanced efficacy in infected mice, suggesting that ruthenium-nitrosyl complexes are potential constituents for drug combinations.

Activity profile of two 5-nitroindazole derivatives over the moderately drug-resistant Trypanosoma cruzi Y strain (DTU TcII): in vitro and in vivo studies

Parasitology ◽  
2020 ◽  
Vol 147 (11) ◽  
pp. 1216-1228
Author(s):  
Cristina Fonseca-Berzal ◽  
Cristiane França da Silva ◽  
Denise da Gama Jaen Batista ◽  
Gabriel Melo de Oliveira ◽  
José Cumella ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Positive Impact ◽  
Cardiac Cells ◽  
In Vivo Studies ◽  
Drug Resistant ◽  
Activity Profile ◽  
Reference Drug ◽  
Novel Drugs

AbstractIn previous studies, we have identified several families of 5-nitroindazole derivatives as promising antichagasic prototypes. Among them, 1-(2-aminoethyl)-2-benzyl-5-nitro-1,2-dihydro-3H-indazol-3-one, (hydrochloride) and 1-(2-acetoxyethyl)-2-benzyl-5-nitro-1,2-dihydro-3H-indazol-3-one (compounds 16 and 24, respectively) have recently shown outstanding activity in vitro over the drug-sensitive Trypanosoma cruzi CL strain (DTU TcVI). Here, we explored the activity of these derivatives against the moderately drug-resistant Y strain (DTU TcII), in vitro and in vivo. The outcomes confirmed their activity over replicative forms, showing IC50 values of 0.49 (16) and 5.75 μm (24) towards epimastigotes, 0.41 (16) and 1.17 μm (24) against intracellular amastigotes. These results, supported by the lack of toxicity on cardiac cells, led to better selectivities than benznidazole (BZ). Otherwise, they were not as active as BZ in vitro against the non-replicative form of the parasite, i.e. bloodstream trypomastigotes. In vivo, acute toxicity assays revealed the absence of toxic events when administered to mice. Moreover, different therapeutic schemes pointed to their capability for decreasing the parasitaemia of T. cruzi Y acute infected mice, reaching up to 60% of reduction at the peak day as monotherapy (16), 79.24 and 91.11% when 16 and 24 were co-administered with BZ. These combined therapies had also a positive impact over the mortality, yielding survivals of 83.33 and 66.67%, respectively, while untreated animals reached a cumulative mortality of 100%. These findings confirm the 5-nitroindazole scaffold as a putative prototype for developing novel drugs potentially applicable to the treatment of Chagas disease and introduce their suitability to act in combination with the reference drug.

scholarly journals In VitroandIn VivoActivities of Zinc Linolenate, a Selective Antibacterial Agent againstHelicobacter pylori

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Yanqiang Huang ◽  
Xudong Hang ◽  
Xueqing Jiang ◽  
Liping Zeng ◽  
Jia Jia ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Therapeutic Potential ◽  
Combined Therapy ◽  
Peptic Ulcers ◽  
Current Standard ◽  
Gastric Diseases ◽  
Content Type ◽  
H Pylori

ABSTRACTHelicobacter pyloriis a major global pathogen, and its infection represents a key factor in the etiology of various gastric diseases, including gastritis, peptic ulcers, and gastric carcinoma. The efficacy of current standard treatment forH. pyloriinfection including two broad-spectrum antibiotics is compromised by toxicity toward the gut microbiota and the development of drug resistance, which will likely only be resolved through novel and selective antibacterial strategies. Here, we synthesized a small molecule, zinc linolenate (ZnLla), and investigated its therapeutic potential for the treatment ofH. pyloriinfection. ZnLla showed effective antibacterial activity against standard strains and drug-resistant clinical isolates ofH. pyloriin vitrowith no development of resistance during continuous serial passaging. The mechanisms of ZnLla action againstH. pyloriinvolved the disruption of bacterial cell membranes and generation of reactive oxygen species. In mouse models of multidrug-resistantH. pyloriinfection, ZnLla showedin vivokilling efficacy comparable and superior to the triple therapy approach when use as a monotherapy and a combined therapy with omeprazole, respectively. Moreover, ZnLla treatment induces negligible toxicity against normal tissues and causes minimal effects on both the diversity and composition of the murine gut microbiota. Thus, the high degree of selectivity of ZnLla forH. pyloriprovides an attractive candidate for novel targeted anti-H. pyloritreatment.

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