Belo Horizonte, Brazil
Belo Horizonte, Brazil

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PubMed | National University of La Plata, National University of Rosario, Laboratorio Of Biologia Celular, Federal University of Viçosa and Federal University of Minas Gerais
Type: | Journal: Bioorganic & medicinal chemistry | Year: 2017

An efficient method for the synthesis of quinolines using microwave irradiation was developed providing 28 quinolines with good yields. The reaction procedures are environmentally friendly, convenient, mild and of easy work-up. Quinolines were evaluated for their antifungal, anticancer and antioxidant properties and exhibited high activities in all tests performed.


da Gama Jaen Batista D.,Laboratorio Of Biologia Celular | Batista M.M.,Laboratorio Of Biologia Celular | de Oliveira G.M.,Laboratorio Of Biologia Celular | Britto C.C.,Laboratorio Of Biologia Molecular E Doencas Endemicas | And 4 more authors.
PLoS ONE | Year: 2011

Chagas disease caused by Trypanosoma cruzi is an important cause of mortality and morbidity in Latin America but no vaccines or safe chemotherapeutic agents are available. Combined therapy is envisioned as an ideal approach since it may enhance efficacy by acting upon different cellular targets, may reduce toxicity and minimize the risk of drug resistance. Therefore, we investigated the activity of benznidazole (Bz) in combination with the diamidine prodrug DB289 and in combination with the arylimidamide DB766 upon T. cruzi infection in vivo. The oral treatment of T.cruzi-infected mice with DB289 and Benznidazole (Bz) alone reduced the number of circulating parasites compared with untreated mice by about 70% and 90%, respectively. However, the combination of these two compounds decreased the parasitemia by 99% and protected against animal mortality by 100%, but without providing a parasitological cure. When Bz (p.o) was combined with DB766 (via ip route), at least a 99.5% decrease in parasitemia levels was observed. DB766+Bz also provided 100% protection against mice mortality while Bz alone provided about 87% protection. This combined therapy also reduced the tissular lesions induced by T. cruzi infection: Bz alone reduced GPT and CK plasma levels by about 12% and 78% compared to untreated mice group, the combination of Bz with DB766 resulted in a reduction of GPT and CK plasma levels of 56% and 91%. Cure assessment through hemocultive and PCR approaches showed that Bz did not provide a parasitological cure, however, DB766 alone or associated with Bz cured ≥13% of surviving animals.


Melo F.T.V.,Laboratorio Of Biologia Celular | Giese E.G.,Laboratorio Of Biologia Celular | Furtado A.P.,Laboratorio Of Biologia Celular | Soares M.J.,Instituto Carlos Chagas Fiocruz | And 3 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2011

The family Nematotaeniidae, tapeworms commonly found in the small intestines of amphibians and reptiles, includes 27 recognised species distributed among four genera: Bitegmen Jones, Cylindrotaenia Jewell, Distoichometra Dickey and Nematotaenia Lühe. The taxonomy of these cestodes is poorly defined, due in part to the difficulties of observing many anatomical traits. This study presents and describes a new genus and species of nematotaeniid parasite found in cane toads (Rhinella marina) from eastern Brazilian Amazonia. The cestodes were collected during the necropsy of 20 hosts captured in the urban area of Belém, Pará. The specimens were fixed and processed for light microscopy, scanning electron microscopy (SEM) and three-dimensional (3D) reconstruction. Samples were also collected for molecular analyses. The specimens presented a cylindrical body, two testes and paruterine organs. However, they could not be allocated to any of the four existing nematotaeniid genera due to the presence of two each of dorsal compact medullary testes, cirri, cirrus pouches, genital pores, ovaries and vitelline glands per mature segment. Lanfrediella amphicirrus gen. nov. sp. nov. is the first nematotaeniid studied using Historesin analysis, SEM and 3D reconstruction, and it is the Second taxon for which molecular data have been deposited in GenBank.


Ramos-Godinez M.D.P.,Environmental Toxicology Laboratory | Ramos-Godinez M.D.P.,Laboratorio Of Microscopia Electronica | Ramos-Godinez M.D.P.,National Polytechnic Institute of Mexico | Gonzalez-Gomez B.E.,Environmental Toxicology Laboratory | And 5 more authors.
Toxicology in Vitro | Year: 2013

The effects of particulate matter (PM) on endothelial cells have been evaluated in vitro by exposing isolated endothelial cells to different types of PM. Although some of the findings from these experiments have been corroborated by in vivo studies, an in vitro model that assesses the interaction among different cell types is necessary to achieve more realistic assays. We developed an in vitro model that mimics the alveolar-capillary interface, and we challenged the model using TiO2 nanoparticles (TiO2-NPs). Human umbilical endothelial cells (HUVECs) were cultured on the basolateral side of a membrane and pneumocytes (A549) on the apical side. Confluent co-cultures were exposed on the apical side to 10μg/cm2 of TiO2-NPs or 10ng/mL of TNFα for 24h. Unexposed cultures were used as negative controls. We evaluated monocyte adhesion to HUVECs, adhesion molecule expression, nitric oxide concentration and proinflammatory cytokine release. The TiO2-NPs added to the pneumocytes induced a 3- to 4-fold increase in monocyte adhesion to the HUVECs and significant increases in the expression of adhesion molecules (4-fold for P-selectin at 8h, and about 8- and 10-fold for E-selectin, ICAM-1, VCAM-1 and PECAM-1 at 24h). Nitric oxide production also increased significantly (2-fold). These results indicate that exposing pneumocytes to TiO2-NPs causes endothelial cell activation. © 2012 Elsevier Ltd.


PubMed | Laboratorio Of Biologia Celular and Georgia State University
Type: Journal Article | Journal: Parasitology | Year: 2014

The present study aimed to determine the in vitro biological efficacy and selectivity of 7 novel AIAs upon bloodstream trypomastigotes and intracellular amastigotes of Trypanosoma cruzi. The biological activity of these aromatic compounds was assayed for 48 and 24 h against intracellular parasites and bloodstream forms of T. cruzi (Y strain), respectively. Additional assays were also performed to determine their potential use in blood banks by treating the bloodstream parasites with the compounds diluted in mouse blood for 24 h at 4C. Toxicity against mammalian cells was evaluated using primary cultures of cardiac cells incubated for 24 and 48 h with the AIAs and then cellular death rates were determined by MTT colorimetric assays. Our data demonstrated the outstanding trypanocidal effect of AIAs against T. cruzi, especially DB1853, DB1862, DB1867 and DB1868, giving IC50 values ranging between 16 and 70 nanomolar against both parasite forms. All AIAs presented superior efficacy to benznidazole and some, such as DB1868, also demonstrated promising activity as a candidate agent for blood prophylaxis. The excellent anti-trypanosomal efficacy of these novel AIAs against T. cruzi stimulates further in vivo studies and justifies the screening of new analogues with the goal of establishing a useful alternative therapy for Chagas disease.


Ennes-Vidal V.,Instituto Oswaldo Cruz IOC | Menna-Barreto R.F.S.,Laboratorio Of Biologia Celular | Santos A.L.S.,Federal University of Rio de Janeiro | Branquinha M.H.,Federal University of Rio de Janeiro | d'Avila-Levy C.M.,Instituto Oswaldo Cruz IOC
Journal of Antimicrobial Chemotherapy | Year: 2010

Objectives: There is a general lack of effective and non-toxic chemotherapeutic agents for treating Chagas' disease. In the present work, we evaluated the in vitro activity of the calpain inhibitor MDL28170 against Trypanosoma cruzi relevant clinical forms. Methods: The effect of MDL28170 on bloodstream trypomastigotes at different concentrations was assessed by counting the parasites in a Neubauer chamber, which allowed the determination of IC50 values. Sub-sequently, parasite-macrophage interaction was assessed by two approaches: (i) peritoneal mouse macrophages were pre-infected with trypomastigotes for 3 h and then treated daily for 72 h with MDL28170; or (ii) bloodstream trypomastigotes were pre-treated with the calpain inhibitor for 1 h and then subjected to the infection assay. Results: MDL28170 was capable of significantly reducing the viability of bloodstream trypomastigotes, presenting an IC50/24 h value of 20.4 μM. Also, parasites pre-treated with the inhibitor, at subinhibitory drug concentrations, prior to macrophage infection presented a clear dose-dependent inhibition profile, where the inhibition increased from 20% to 50% (in relation to control) as MDL28170 concentration rose from 6.25 to 50 μM. In addition, macrophages experimentally infected with T. cruzi that were treated with the calpain inhibitor presented a significant reduction in the percentage of infection even at the lowest concentrations (6.25 μM). Conclusions: These data may contribute to the study of the calpains in T. cruzi infection and add new in vitro insights into the possibility of exploiting calpains as promising targets to treat Chagas' disease. © The Author 2010.


Ennes-Vidal V.,Instituto Oswaldo Cruz IOC | Menna-Barreto R.F.S.,Laboratorio Of Biologia Celular | Santos A.L.S.,Federal University of Rio de Janeiro | Branquinha M.H.,Federal University of Rio de Janeiro | d'Avila-Levy C.M.,Instituto Oswaldo Cruz IOC
PLoS ONE | Year: 2011

Background: Trypanosoma cruzi is the etiological agent of Chagas' disease. During the parasite life cycle, many molecules are involved in the differentiation process and infectivity. Peptidases are relevant for crucial steps of T. cruzi life cycle; as such, it is conceivable that they may participate in the metacyclogenesis and interaction with the invertebrate host. Methodology/Principal Findings: In this paper, we have investigated the effect of the calpain inhibitor MDL28170 on the attachment of T. cruzi epimastigotes to the luminal midgut surface of Rhodnius prolixus, as well as on the metacyclogenesis process and ultrastructure. MDL28170 treatment was capable of significantly reducing the number of bound epimastigotes to the luminal surface midgut of the insect. Once the cross-reactivity of the anti-Dm-calpain was assessed, it was possible to block calpain molecules by the antibody, leading to a significant reduction in the capacity of adhesion to the insect guts by T. cruzi. However, the antibodies were unable to interfere in metacyclogenesis, which was impaired by the calpain inhibitor presenting a significant reduction in the number of metacyclic trypomastigotes. The calpain inhibitor also promoted a direct effect against bloodstream trypomastigotes. Ultrastructural analysis of epimastigotes treated with the calpain inhibitor revealed disorganization in the reservosomes, Golgi and plasma membrane disruption. Conclusions/Significance: The presence of calpain and calpain-like molecules in a wide range of organisms suggests that these proteins could be necessary for basic cellular functions. Herein, we demonstrated the effects of MDL28170 in crucial steps of the T. cruzi life cycle, such as attachment to the insect midgut and metacyclogenesis, as well as in parasite viability and morphology. Together with our previous findings, these results help to shed some light on the functions of T. cruzi calpains. Considering the potential roles of these molecules on the interaction with both invertebrate and vertebrate hosts, it is interesting to improve knowledge on these molecules in T. cruzi. © 2011 Ennes-Vidal et al.


Salomao K.,Laboratorio Of Biologia Celular | De Souza E.M.,Laboratorio Of Biologia Celular | Carvalho S.A.,Farmanguinhos | Da Silva E.F.,Farmanguinhos | And 3 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2010

From a series of 1,3,4-thiadiazole-2-arylhydrazone derivatives of megazol screened in vitro against Trypanosoma cruzi, eight (S1 to S8) were selected for in vivo screening by single-dose oral administration (200 mg/kg of body weight) to infected mice at 5 days postinfection (dpi). Based on significant decreases in both parasitemia levels and mortality rates, S2 and S3 were selected for further assays. Despite having no in vivo effect, S1 was included since it was 2-fold more potent against trypomastigotes than megazol in vitro. Trypomastigotes treated with S1, S2, or S3 showed alterations of the flagellar structure and of the nuclear envelope. When assayed on intracellular amastigotes, the selectivity index (SI) for macrophages was in the range of >27 to >63 and for cardiac cells was >32 for S1 and >48 for megazol. In noninfected mice, S1 did not alter the levels of glutamic oxalacetic transaminase (GOT), glutamate pyruvate transaminase (GPT), or urea. S2 led to an increase in GOT, S3 to increases in GOT and GPT, and megazol to an increase in GOT. Infected mice were treated with each derivative at 50 and 100 mg/kg from dpi 6 to 15: S1 did not interfere with the course of infection or reduce the number of inflammatory foci in the cardiac tissue, S2 led to a significant decrease of parasitemia, and S3 decreased mortality. There was no direct correlation between the in vitro effect on trypomastigotes and amastigotes and the results of the treatment in experimental models, as S1 showed a high potency in vitro while, in two different schemes of in vivo treatment, no decrease of parasitemia or mortality was observed. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


Gomes S.A.O.,Federal University of Fluminense | Vieira C.S.,Laboratorio Of Transmissores Of Leishmanioses | Almeida D.B.,University of Campinas | Santos-Mallet J.R.,Laboratorio Of Transmissores Of Leishmanioses | And 3 more authors.
Sensors | Year: 2011

Quantum dots (QDs) are colloidal semiconductor nanocrystals of a few nanometers in diameter, being their size and shape controlled during the synthesis. They are synthesized from atoms of group II-VI or III-V of the periodic table, such as cadmium telluride (CdTe) or cadmium selenium (CdSe) forming nanoparticles with fluorescent characteristics superior to current fluorophores. The excellent optical characteristics of quantum dots make them applied widely in the field of life sciences. Cellular uptake of QDs, location and translocation as well as any biological consequence, such as cytotoxicity, stimulated a lot of scientific research in this area. Several studies pointed to the cytotoxic effect against micoorganisms. In this mini-review, we overviewed the synthesis and optical properties of QDs, and its advantages and bioapplications in the studies about microorganisms such as protozoa, bacteria, fungi and virus. © 2011 by the authors; licensee MDPI, Basel, Switzerland.


PubMed | Laboratorio Of Biologia Celular
Type: Journal Article | Journal: Antimicrobial agents and chemotherapy | Year: 2013

In vitro and in vivo activities against Trypanosoma cruzi were evaluated for two sesquiterpene lactones: psilostachyin A and cynaropicrin. Cynaropicrin had previously been shown to potently inhibit African trypanosomes in vivo, and psilostachyin A had been reported to show in vivo effects against T. cruzi, albeit in another test design. In vitro data showed that cynaropicrin was more effective than psilostachyin A. Ultrastructural alterations induced by cynaropicrin included shedding events, detachment of large portions of the plasma membrane, and vesicular bodies and large vacuoles containing membranous structures, suggestive of parasite autophagy. Acute toxicity studies showed that one of two mice died at a cynaropicrin dose of 400 mg/kg of body weight given intraperitoneally (i.p.). Although no major plasma biochemical alterations could be detected, histopathology demonstrated that the liver was the most affected organ in cynaropicrin-treated animals. Although cynaropicrin was as effective as benznidazole against trypomastigotes in vitro, the treatment (once or twice a day) of T. cruzi-infected mice (up to 50 mg/kg/day cynaropicrin) did not suppress parasitemia or protect against mortality induced by the Y and Colombiana strains. Psilostachyin A (0.5 to 50 mg/kg/day given once a day) was not effective in the acute model of T. cruzi infection (Y strain), reaching 100% animal mortality. Our data demonstrate that although it is very promising against African trypanosomes, cynaropicrin does not show efficacy compared to benznidazole in acute mouse models of T. cruzi infection.

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