In Vitro and In Vivo Activities of E5700 and ER-119884, Two Novel Orally Active Squalene Synthase Inhibitors, against Trypanosoma cruzi

ABSTRACT Chagas' disease is a serious public health problem in Latin America, and no treatment is available for the prevalent chronic stage. Its causative agent, Trypanosoma cruzi, requires specific endogenous sterols for survival, and we have recently demonstrated that squalene synthase (SQS) is a promising target for antiparasitic chemotherapy. E5700 and ER-119884 are quinuclidine-based inhibitors of mammalian SQS that are currently in development as cholesterol- and triglyceride-lowering agents in humans. These compounds were found to be potent noncompetitive or mixed-type inhibitors of T. cruzi SQS with K i values in the low nanomolar to subnanomolar range in the absence or presence of 20 μM inorganic pyrophosphate. The antiproliferative 50% inhibitory concentrations of the compounds against extracellular epimastigotes and intracellular amastigotes were ca. 10 nM and 0.4 to 1.6 nM, respectively, with no effects on host cells. When treated with these compounds at the MIC, all of the parasite's sterols disappeared from the parasite cells. In vivo studies indicated that E5700 was able to provide full protection against death and completely arrested the development of parasitemia when given at a concentration of 50 mg/kg of body weight/day for 30 days, while ER-119884 provided only partial protection. This is the first report of an orally active SQS inhibitor that is capable of providing complete protection against fulminant, acute Chagas' disease.

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

Infection and Immunity ◽

10.1128/iai.05403-11 ◽

2011 ◽

Vol 79 (10) ◽

pp. 4081-4087 ◽

Cited By ~ 16

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.

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Experimental Chemotherapy for Chagas Disease: A Morphological, Biochemical, and Proteomic Overview of Potential Trypanosoma cruzi Targets of Amidines Derivatives and Naphthoquinones

Molecular Biology International ◽

10.4061/2011/306928 ◽

2011 ◽

Vol 2011 ◽

pp. 1-13 ◽

Cited By ~ 10

Author(s):

Solange L. de Castro ◽

Denise G. J. Batista ◽

Marcos M. Batista ◽

Wanderson Batista ◽

Anissa Daliry ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Chronic Phase ◽

Public Health Problem ◽

Term Therapy ◽

High Morbidity ◽

Synthetic Compounds ◽

Natural And Synthetic

Chagas disease (CD), caused by Trypanosoma cruzi, affects approximately eight million individuals in Latin America and is emerging in nonendemic areas due to the globalisation of immigration and nonvectorial transmission routes. Although CD represents an important public health problem, resulting in high morbidity and considerable mortality rates, few investments have been allocated towards developing novel anti-T. cruzi agents. The available therapy for CD is based on two nitro derivatives (benznidazole (Bz) and nifurtimox (Nf)) developed more than four decades ago. Both are far from ideal due to substantial secondary side effects, limited efficacy against different parasite isolates, long-term therapy, and their well-known poor activity in the late chronic phase. These drawbacks justify the urgent need to identify better drugs to treat chagasic patients. Although several classes of natural and synthetic compounds have been reported to act in vitro and in vivo on T. cruzi, since the introduction of Bz and Nf, only a few drugs, such as allopurinol and a few sterol inhibitors, have moved to clinical trials. This reflects, at least in part, the absence of well-established universal protocols to screen and compare drug activity. In addition, a large number of in vitro studies have been conducted using only epimastigotes and trypomastigotes instead of evaluating compounds' activities against intracellular amastigotes, which are the reproductive forms in the vertebrate host and are thus an important determinant in the selection and identification of effective compounds for further in vivo analysis. In addition, due to pharmacokinetics and absorption, distribution, metabolism, and excretion characteristics, several compounds that were promising in vitro have not been as effective as Nf or Bz in animal models of T. cruzi infection. In the last two decades, our team has collaborated with different medicinal chemistry groups to develop preclinical studies for CD and investigate the in vitro and in vivo efficacy, toxicity, selectivity, and parasite targets of different classes of natural and synthetic compounds. Some of these results will be briefly presented, focusing primarily on diamidines and related compounds and naphthoquinone derivatives that showed the most promising efficacy against T. cruzi.

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In Vitro and In Vivo Studies of the Trypanocidal Activity of a Diarylthiophene Diamidine against Trypanosoma cruzi

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00038-08 ◽

2008 ◽

Vol 52 (9) ◽

pp. 3307-3314 ◽

Cited By ~ 43

Author(s):

Cristiane França da Silva ◽

Marcos Meuser Batista ◽

Denise da Gama Jaen Batista ◽

Elen Mello de Souza ◽

Patrícia Bernardino da Silva ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

In Vivo Studies ◽

Groove Binding ◽

Dna Minor Groove ◽

Drug Concentrations ◽

Mammalian Infection ◽

Related Compounds

ABSTRACT Aromatic diamidines are DNA minor groove-binding ligands that display excellent antimicrobial activity against fungi, bacteria, and protozoa. Due to the currently unsatisfactory chemotherapy for Chagas’ disease and in view of our previous reports regarding the effect of diamidines and analogues against both in vitro and in vivo Trypanosoma cruzi infection, this study evaluated the effects of a diarylthiophene diamidine (DB1362) against both amastigotes and bloodstream trypomastigotes of T. cruzi, the etiological agent of Chagas’ disease. The data show the potent in vitro activity of DB1362 against both parasite forms that are relevant for mammalian infection at doses which do not exhibit cytotoxicity. Ultrastructural analysis and flow cytometry studies show striking alterations in the nuclei and mitochondria of the bloodstream parasites. In vivo studies were performed at two different drug concentrations (25 and 50 mg/kg/day) using a 2-day or a 10-day regimen. The best results were obtained when acutely infected mice were treated with two doses at the lower concentration, resulting in 100% survival, compared to the infected and untreated mice. Although it did not display higher efficacy than benznidazole, DB1362 reduced both cardiac parasitism and inflammation, and in addition, it protected against the cardiac alterations (determined by measurements) common in T. cruzi infection. These results support further investigation of diamidines and related compounds as potential agents against Chagas’ disease.

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In VitroandIn VivoTrypanosomicidal Action of Novel Arylimidamides against Trypanosoma cruzi

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01667-15 ◽

2016 ◽

Vol 60 (4) ◽

pp. 2425-2434 ◽

Cited By ~ 11

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.

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Medicinal Plants and Bioactive Compounds for Diabetes Management: Important Advances for Drug Discovery

Current Pharmaceutical Design ◽

10.2174/1381612826666200928160357 ◽

2020 ◽

Vol 26 ◽

Author(s):

Kondeti Ramudu Shanmugam ◽

Bhasha Shanmugam ◽

Gangigunta Venkatasubbaiah ◽

Sahukari Ravi ◽

Kesireddy Sathyavelu Reddy

Keyword(s):

Herbal Medicine ◽

Medicinal Plants ◽

Bioactive Compounds ◽

Diabetes Management ◽

Therapeutic Potential ◽

Public Health Problem ◽

In Vivo Studies ◽

Major Public Health Problem

Background : Diabetes is a major public health problem in the world. It affects each and every part of the human body and also leads to organ failure. Hence, great progress made in the field of herbal medicine and diabetic research. Objectives: Our review will focus on the effect of bioactive compounds of medicinal plants which are used to treat diabetes in India and other countries. Methods: Information regarding diabetes, oxidative stress, medicinal plants and bioactive compounds were collected from different search engines like Science direct, Springer, Wiley online library, Taylor and francis, Bentham Science, Pubmed and Google scholar. Data was analyzed and summarized in the review. Results and Conclusion: Anti-diabetic drugs that are in use have many side effects on vital organs like heart, liver, kidney and brain. There is an urgent need for alternative medicine to treat diabetes and their disorders. In India and other countries herbal medicine was used to treat diabetes. Many herbal plants have antidiabetic effects. The plants like ginger, phyllanthus, curcumin, aswagandha, aloe, hibiscus and curcuma showed significant anti-hyperglycemic activities in experimental models and humans. The bioactive compounds like Allicin, azadirachtin, cajanin, curcumin, querceitin, gingerol possesses anti-diabetic, antioxidant and other pharmacological properties. This review focuses on the role of bioactive compounds of medicinal plants in prevention and management of diabetes. Conclusion: Moreover, our review suggests that bioactive compounds have the potential therapeutic potential against diabetes. However, further in vitro and in vivo studies are needed to validate these findings.

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Development of new dinuclear Fe(III) coordination compounds with in vitro nanomolar antitrypanosomal activity

Dalton Transactions ◽

10.1039/d1dt01048d ◽

2021 ◽

Author(s):

Felipe Figuerôa Moreira ◽

Juliana de Araujo Portes ◽

Nathalia Florencia Barros Azeredo ◽

Christiane Fernandes ◽

Adolfo Horn ◽

...

Keyword(s):

Public Health ◽

Trypanosoma Cruzi ◽

Chagas Disease ◽

Health Problem ◽

Coordination Compounds ◽

Public Health Problem ◽

Neglected Tropical Disease ◽

Major Public Health Problem ◽

Protozoan Pathogen

Chagas disease is a neglected tropical disease caused by the protozoan pathogen Trypanosoma cruzi. The disease is the major public health problem affecting about 6 to 7 million people worldwide,...

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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 ◽

10.1017/s0031182020000955 ◽

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.

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Lipid biosynthesis pathways as chemotherapeutic targets in kinetoplastid parasites

Parasitology ◽

10.1017/s0031182097001194 ◽

1997 ◽

Vol 114 (7) ◽

pp. 91-99 ◽

Cited By ~ 134

Author(s):

J. A. URBINA

Keyword(s):

Trypanosoma Cruzi ◽

Recent Work ◽

Chagas Disease ◽

Pneumocystis Carinii ◽

Lipid Biosynthesis ◽

Sterol Biosynthesis ◽

Leishmania Braziliensis ◽

Biosynthesis Inhibitors

Inhibitors of sterol and phospholipid biosynthesis in kinetoplastid parasites such as Trypanosoma cruzi, the causative agent of Chagas' disease, and different species of Leishmania have potent and selective activity as chemotherapeutic agents in vitro and in vivo. Recent work with the sterol C14α-demethylase inhibitor D0870, a bis triazole derivative, showed that this compound is capable of inducing radical parasitological cure in murine models of both acute and chronic Chagas' disease. Other inhibitors of this type, such as SCH 56592, have also shown curative, rather than suppressive, activity against T. cruzi in these models. Leishmania species have different susceptibilities to sterol biosynthesis inhibitors, both in vitro and in vivo. Leishmania braziliensis promastigotes, naturally resistant to C14α-demethylase inhibitors such as ketoconazole and D0870, were susceptible to these drugs when used in combination with the squalene epoxidase inhibitor terbinafine. Inhibitors of Δ24(25) sterol methyl transferase have been shown to act as potent antiproliferative agents against Trypanosoma cruzi, both in vitro and in vivo. New inhibitors of this type which show enhanced activity and novel mechanisms of action have been synthesized. Recent work has also demonstrated that this type of enzyme inhibitors can block sterol biosynthesis and cell proliferation in Pneumocystis carinii, a fungal pathogen which had previously been found resistant to other sterol biosynthesis inhibitors. Ajoene, an antiplatelet compound derived from garlic, was shown to have potent antiproliferative activity against epimastigotes and amastigotes of Trypanosoma cruzi in vitro; this activity was associated with a significant alteration of the phospholipid composition of the cells with no significant effects on the sterol content. In addition, alkyllsophospholipids such as ilmofosine, miltefosine and edelfosine have been shown to block the proliferation of T. cruzi and Leishmania and alter both the phospholipid and sterol composition. These results indicate the potential of lipid biosynthesis inhibitors as useful therapeutic agents in the treatment of leishmaniasis and Chagas' disease.

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00414-20 ◽

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.

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