Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
leishmania metacyclogenesis is promoted in the absence of purines.leishmania parasites, the causative agent of leishmaniasis, are transmitted through the bite of an infected sand fly. leishmania parasites present two basic forms known as promastigote and amastigote which, respectively, parasitizes the vector and the mammalian hosts. infection of the vertebrate host is dependent on the development, in the vector, of metacyclic promastigotes, however, little is known about the factors that trigger metacyclogenesis in leishmania parasites. it has been generally s ...201223050028
immunomodulatory activity of ouabain in leishmania leishmania amazonensis-infected swiss mice.ouabain is a cardiotonic steroid identified as an endogenous substance of human plasma, being produced by the adrenal, pituitary, and hypothalamus. despite the studies demonstrating the ability of ouabain to modulate inflammation and other aspects of the immune response, the effects of this substance in leishmaniasis is unknown. the purpose of this work was to understand the immunomodulatory activity of ouabain in experimental leishmaniasis in swiss mice. it was demonstrated that ouabain reduced ...201323052777
immunopathogenesis of non-healing american cutaneous leishmaniasis and progressive visceral leishmaniasis.the outcomes of leishmania infection are determined by host immune and nutrition status, parasite species, and co-infection with other pathogens. while subclinical infection and self-healing cutaneous leishmaniasis (cl) are common, uncontrolled parasite replication can lead to non-healing local lesions or visceral leishmaniasis (vl). it is known that infection control requires th1-differentiation cytokines (il-12, il-18, and il-27) and th1 cell and macrophage activation. however, there is no gen ...201223053396
cristaxenicin a, an antiprotozoal xenicane diterpenoid from the deep sea gorgonian acanthoprimnoa cristata.a new xenicane diterpenoid, cristaxenicin a (1), has been isolated from the deep sea gorgonian acanthoprimnoa cristata. the structure of 1 was elucidated on the basis of spectral analysis including nmr and ms. the absolute configuration of 1 was determined on the basis of quantum chemical calculation of cd spectra. cristaxenicin a (1) showed antiprotozoal activities against leishmania amazonensis and trypanosoma congolense with ic(50) values of 0.088 and 0.25 μm, respectively.201223057655
the cytotoxic and antileishmanial activity of extracts and fractions of leaves and fruits of azadirachta indica (a juss.).the leishmaniases are severe parasitic diseases that occur worldwide, caused by protozoa of the genus leishmania. studies with medicinal plants can lead to a range of possibilities for treating and improving the patients' quality of life. research on azadirachta indica fractions and extracts has shown that they have excellent anti-leishmanial activity based on bioactivity-guided fractionation of ethanolic extracts of leaves and seeds and in vitro activity against promastigotes. in this research ...201223096354
improved antileishmanial activity of dppz through complexation with antimony(iii) and bismuth(iii): investigation of the role of the metal.two novel trivalent antimony(iii) and bismuth(iii) complexes with the nitrogen-donor heterocyclic ligand dipyrido[3,2-a:2',3'-c]phenazine (dppz) were synthesized and characterized as [sb(dppz)cl₃]∙h₂o∙ch₃oh and [bi(dppz)cl₃]. the crystal structure of sb(iii) complex was determined by x-ray crystallography. these complexes were evaluated for their activity against the promastigote form of sb(iii)-sensitive and -resistant leishmania infantum chagasi and leishmania amazonensis strains. both complex ...201223099618
4-(1h-pyrazol-1-yl) benzenesulfonamide derivatives: identifying new active antileishmanial structures for use against a neglected disease.leishmaniasis is a neglected disease responsible for about 56,000 deaths every year. despite its importance, there are no effective, safe and proper treatments for leishmaniasis due to strain resistance and/or drug side-effects. in this work we report the synthesis, molecular modeling, cytotoxicity and the antileishmanial profile of a series of 4-(1h-pyrazol-1-yl)benzenesulfonamides. our experimental data showed an active profile for some compounds against leishmania infantum and leishmania amaz ...201223117435
synthesis, antitumor, antitrypanosomal and antileishmanial activities of benzo[4,5]canthin-6-ones bearing the n'-(substituted benzylidene)-carbohydrazide and n-alkylcarboxamide groups at c-2.a series of novel benzo[4,5]canthin-6-ones, bearing the n'-(substituted benzylidene)-carbohydrazide (11a-e) and n-alkylcarboxamide (13a-g) moieties at position-2, were synthesized and screened for their in vitro antitumor activity, against seven human cancer cell lines, and for antitrypanosomal and antileishmanial activities against trypanosoma cruzi and leishmania amazonensis. the results indicated that n-methylpiperazyl-6-oxobenzo[4,5]canthine-2-carboxamide (13f) displayed potent antitumor act ...201223124560
17-aag kills intracellular leishmania amazonensis while reducing inflammatory responses in infected macrophages.leishmaniasis is a neglected endemic disease with a broad spectrum of clinical manifestations. pentavalent antimonials have been the treatment of choice for the past 70 years and, due to the emergence of resistant cases, the efficacy of these drugs has come under scrutiny. second-line drugs are less efficacious, cause a range of side effects and can be costly. the formulation of new generations of drugs, especially in developing countries, has become mandatory.201223152914
phosphatidylserine exposure on the surface of leishmania amazonensis amastigotes modulates in vivo infection and dendritic cell function.leishmania amazonensis parasites can cause diverse forms of leishmaniasis in humans and persistent lesions in most inbred strains of mice. in both cases, the infection is characterized by a marked immunosuppression of the host. we previously showed that amastigote forms of the parasite make use of surface-exposed phosphatidylserine (ps) molecules to infect host cells and promote alternative macrophage activation, leading to uncontrolled intracellular proliferation of the parasites. in this study ...201623163958
biochemical and functional characterization of a c-type lectin (bplec) from bothrops pauloensis snake venom.in the present work, we report the isolation and partial biochemical characterization of bplec, a c-type lectin purified from bothrops pauloensis venom by one chromatographic step on an affinity agarose column immobilized with d-galactose. this protein was homogeneous by sds-page under reducing and nonreducing conditions, and was shown to be a 33.6 kda homodimer by maldi tof analysis. bplec presented an isoeletric point of 5.36. its partial sequence of 132 amino acids for each subunit, determine ...201323178369
leishmanicidal, antiproteolytic and antioxidant evaluation of natural biflavonoids isolated from garcinia brasiliensis and their semisynthetic derivatives.the natural biflavonoids morelloflavone-4‴-o-β-d-glycosyl (1), (±)-fukugiside (2) and morelloflavone (3) were isolated from the ethyl acetate extract (eaee) of dried and powdered fruit epicarps of garcinia brasiliensis and derivatives of morelloflavone were semi-synthesised. morelloflavone-7,4',7″,3‴,4‴-penta-o-acetyl (4), morelloflavone-7,4',7″,3‴,4‴-penta-o-methyl (5) and morelloflavone-7,4',7″,3‴,4‴-penta-o-butanoyl (6) were prepared by acylation and alkylation reactions. all compounds showed ...201223178961
in vitro and in vivo leishmanicidal studies of peperomia galioides (piperaceae).petroleum ether and methylene chloride extracts of peperomia galioides and three prenylated diphenols, grifolic acid, grifolin and piperogalin exhibited in vitro antileishmanial activity. during the course of infection of balb/c mice with leishmania amazonensis, the treatments with each of these compounds did not influence the progression of the disease.199623195082
ocular experimental leishmaniasis in c57bl/10 and balb/c mice induced by leishmania amazonensis infection.there are few studies on human ocular leishmaniasis found in the literature. the purpose of this study was to describe experimental ocular leishmaniasis, caused by leishmania amazonensis evaluating two different infection routes: intravitreal and instillation in c57bl/10 and balb/c mice. in this work all animals presented low anti-leishmania igm and igg titers regardless of the infection route or mouse strain. the histopathological eye analysis showed that the mice inoculated by the intravitreal ...201323201219
hybrid furoxanyl n-acylhydrazone derivatives as hits for the development of neglected diseases drug candidates.neglected diseases represent a major health problem. it is estimated that one third of the world population is infected with tuberculosis and additionally leishmaniosis and chagas disease affect approximately 30 million people. n-acylhydrazone moiety is a repeated functional group present in several prototypes and drug candidates for these neglected diseases. on the other hand, furoxan system has been studied as pharmacophore for leishmaniosis and chagas diseases. here we report on the design an ...201323202852
the histopathological and immunological pattern of cba mice infected with leishmania amazonensis after treatment with pyrazole carbohydrazide derivatives.because there is no vaccine in clinical use, control of leishmaniasis relies almost exclusively on chemotherapy and the conventional treatments exhibit high toxicity for patients and emerging drug resistance. recently, we showed that oral treatment with synthetic pyrazole carbohydrazide compounds induced lower parasite load in draining lymph nodes and reduced skin lesion size without causing any toxic effects in an experimental murine infection model with leishmania amazonensis. in this study, c ...201323219949
distinct transcriptional signatures of bone marrow-derived c57bl/6 and dba/2 dendritic leucocytes hosting live leishmania amazonensis amastigotes.the inoculation of a low number (10(4)) of l. amazonensis metacyclic promastigotes into the dermis of c57bl/6 and dba/2 mouse ear pinna results in distinct outcome as assessed by the parasite load values and ear pinna macroscopic features monitored from days 4 to 22-phase 1 and from days 22 to 80/100-phase 2. while in c57bl/6 mice, the amastigote population size was increasing progressively, in dba/2 mice, it was rapidly controlled. this latter rapid control did not prevent intracellular amastig ...201223272268
molecular diagnosis of leishmania amazonensis in a captive spider monkey in bauru, são paulo, brazil.the municipality of bauru, são paulo, brazil, is an area endemic for leishmaniasis. at the zoo, a spider monkey (ateles paniscus) showed nonpathognomonic symptoms, such as weight loss and pale mucous membranes. blood was collected from the jugular vein and investigated for the presence of leishmania spp. dna by polymerase chain reaction and restriction fragment length polymorphism. parasite dna was detected, and the pattern observed was identical to leishmania amazonensis. this study presents mo ...201223272368
sphingolipid degradation in leishmania (leishmania) amazonensis.human leishmaniasis is caused by more than 20 leishmania species and has a wide range of symptoms. our recent studies have demonstrated the essential role of sphingolipid degradation in the virulence of leishmania (leishmania) major, a species responsible for localized cutaneous leishmaniasis in the old world. in this study, we investigated the function of sphingolipid degradation in leishmania (leishmania) amazonensis, an etiological agent of localized and diffuse cutaneous leishmaniasis in sou ...201223285302
lqb-118, an orally active pterocarpanquinone, induces selective oxidative stress and apoptosis in leishmania amazonensis.the pterocarpanquinone lqb-118, previously demonstrated to be effective in vivo via oral delivery, was investigated for its mechanism in selective parasite killing.201323288404
identification of sl addition trans-splicing acceptor sites in the internal transcribed spacer i region of pre-rrna in leishmania (leishmania) amazonensis.trypanosomatidae is a family of early branching eukaryotes harbouring a distinctive repertoire of gene expression strategies. functional mature messenger rna is generated via the trans-splicing and polyadenylation processing of constitutively transcribed polycistronic units. recently, trans-splicing of pre-small subunit ribosomal rna in the 5' external transcribed spacer region and of precursor trnasec have been described. here, we used a previously validated semi-nested reverse transcription-po ...201223295762
the immunomodulatory effect of plant lectins: a review with emphasis on artinm properties.advances in the glycobiology and immunology fields have provided many insights into the role of carbohydrate-protein interactions in the immune system. we aim to present a comprehensive review of the effects that some plant lectins exert as immunomodulatory agents, showing that they are able to positively modify the immune response to certain pathological conditions, such as cancer and infections. the present review comprises four main themes: (1) an overview of plant lectins that exert immunomo ...201323299509
mitochondria superoxide anion production contributes to geranylgeraniol-induced death in leishmania amazonensis.here we demonstrate the activity of geranylgeraniol, the major bioactive constituent from seeds of bixa orellana, against leishmania amazonensis. geranylgeraniol was identified through (1)h and (13)c nuclear magnetic resonance imaging and dept. the compound inhibited the promastigote and intracellular amastigote forms, with ic(50) of 11 ± 1.0 and 17.5 ± 0.7 μg/ml, respectively. this compound was also more toxic to parasites than to macrophages and did not cause lysis in human blood cells. morpho ...201223304195
different secreted phosphatase activities in leishmania amazonensis.leishmania has strong acid phosphatase activity on the external surface of the plasma membrane and secreted into the extracellular milieu. secreted acid phosphatase (sacp), which is the most abundant secreted protein of leishmania, is also a virulence factor that plays a role in vertebrate infection and survival in sand flies. in this study, we characterized the secreted phosphatase activities in leishmania amazonensis. both acidic and alkaline secreted phosphatase activities were observed with ...201323305417
an alternative in vitro drug screening test using leishmania amazonensis transfected with red fluorescent protein.fluorescent and colorimetric reporter genes are valuable tools for drug screening models, since microscopy is labor intensive and subject to observer variation. in this work, we propose a fluorimetric method for drug screening using red fluorescent parasites. fluorescent leishmania amazonensis were developed after transfection with integration plasmids containing either red (rfp) or green fluorescent protein (gfp) genes. after transfection, wild-type (lawt) and transfected (lagfp and larfp) para ...201323312610
antiprotozoal activity of quinonemethide triterpenes from maytenus ilicifolia (celastraceae).the present study describes the leishmanicidal and trypanocidal activities of two quinonemethide triterpenes, maytenin (1) and pristimerin (2), isolated from maytenus ilicifolia root barks (celastraceae). the compounds were effective against the trypanosomatidae leishmania amazonensis and leishmania chagasi and trypanosoma cruzi, etiologic agents of leishmaniasis and chagas' disease, respectively. the quinonemethide triterpenes 1 and 2 exhibited a marked in vitro leishmanicidal activity against ...201323322069
triphenylmethane derivatives have high in vitro and in vivo activity against the main causative agents of cutaneous leishmaniasis.the current standard of care for cutaneous leishmaniasis (cl) is organic antimonial compounds, but the administration of these compounds is complicated by a low therapeutic - toxic index, as well as parenteral administration. thus, there is an urgent need for the development of new and inexpensive therapies for the treatment of cl. in this study, we evaluate the activity of the triphenylmethane (tpm) class of compounds against three species of leishmania which are pathogenic in humans. the tpm h ...201323341885
iron uptake controls the generation of leishmania infective forms through regulation of ros levels.during its life cycle, leishmania undergoes extreme environmental changes, alternating between insect vectors and vertebrate hosts. elevated temperature and decreased ph, conditions encountered after macrophage invasion, can induce axenic differentiation of avirulent promastigotes into virulent amastigotes. here we show that iron uptake is a major trigger for the differentiation of leishmania amazonensis amastigotes, independently of temperature and ph changes. we found that iron depletion from ...201323382545
the natural absence of rpa1n domain did not impair leishmania amazonensis rpa-1 participation in dna damage response and telomere protection.we have previously shown that the subunit 1 of leishmania amazonensis rpa (larpa-1) alone binds the g-rich telomeric strand and is structurally different from other rpa-1. it is analogous to telomere end-binding proteins described in model eukaryotes whose homologues were not identified in the protozoan´s genome. here we show that larpa-1 is involved with damage response and telomere protection although it lacks the rpa1n domain involved with the binding with multiple checkpoint proteins. we ind ...201323388105
cluster randomised trial to evaluate the effectiveness of a vaccine against cutaneous leishmaniasis in the caratinga microregion, south-east brazil.the eco-epidemiological complexity of american cutaneous leishmaniasis (acl) has made it difficult to devise an efficient strategy for management of the disease, and development of an effective vaccine remains the most promising approach. the objective of the study was to determine the reduction in incidence of acl following intramuscular administration of two doses of a killed leishmania (leishmania) amazonensis vaccine.201323423433
antileishmanial activity of diterpene acids in copaiba oil.leishmaniasis is a neglected tropical disease. according to the world health organization, there are approximately 1.5-two million new cases of cutaneous leishmaniasis each year worldwide. chemotherapy against leishmaniasis is based on pentavalent antimonials, which were developed more than a century ago. the goals of this study were to investigate the antileishmanial activity of diterpene acids in copaiba oil, as well as some possible targets of their action against leishmania amazonensis. meth ...201323440116
bnsp-7 toxin, a basic phospholipase a2 from bothrops pauloensis snake venom, interferes with proliferation, ultrastructure and infectivity of leishmania (leishmania) amazonensis.this paper reports the effects of bnsp-7 toxin, a catalytically inactive phospholipase a2 from bothrops pauloensis snake venom, on leishmania (leishmania) amazonensis. bnsp-7 presented activity against promastigote parasite forms both in the mtt assay, with ic50 of 58.7 μg ml(-1) of toxin, and a growth curve, inhibiting parasite proliferation 60-70% at concentrations of 50-200 μg ml(-1) of toxin 96 h after treatment. also, the toxin presented effects on amastigotes, reducing parasite viability b ...201323442579
[antileishmanial activity of six extracts from marine organisms].infections caused by protozoa of the genus leishmania are a global health problem with a high prevalence in underdeveloped countries. there is no vaccine against this disease at present and the treatment used is poor, so the search for more effective and safe medicines is an urgent need.201223444628
leishmanicidal activity of cecropia pachystachya flavonoids: arginase inhibition and altered mitochondrial dna arrangement.the plant cecropia pachystachya trécul is widely used in brazilian ethnomedicine to treat hypertension, asthma, and diabetes. arginase is an enzyme with levels that are elevated in these disorders, and it is central to leishmania polyamine biosynthesis. the aims of this study were to evaluate antileishmanial activity and inhibition of the arginase enzyme by c. pachystachya extracts, and to study changes in cellular organization using electron microscopy. the ethanol extract of c. pachystachya wa ...201323453911
antileishmanial activity of 5-methyl-2,2' : 5',2″-terthiophene isolated from porophyllum ruderale is related to mitochondrial dysfunction in leishmania amazonensis.recently, our group isolated and reported the antiproliferative activity in promastigotes and axenic amastigote forms of leishmania amazonensis treated with 5-methyl-2,2':5',2″-terthiophene (compound a) and 5'-methyl-[5-(4-acetoxy-1-butynyl)]-2,2'-bi-thiophene (compound b) isolated from the aerial parts of porophyllum ruderale. here, we demonstrated that both compounds exhibited activity against intracellular amastigotes showing ic50 values of 37 and 51 µg/ml for compounds a and b, respectively. ...201323457021
divergent profile of emerging cutaneous leishmaniasis in subtropical brazil: new endemic areas in the southern frontier.although known to be highly endemic in the amazon regions of brazil, the presence of cutaneous leishmaniasis (cl) in the subtropical southern part of the country has largely been ignored. this study was conducted to demonstrate cl is emerging in the brazilian state of santa catarina, as well as to characterize the epidemiological profile and leishmania species involved.201323457521
parasite burden in leishmania (leishmania) amazonensis-infected mice: validation of luciferase as a quantitative tool.given the lack of effective and safe alternatives to the drugs already in use, considerable efforts are being applied to the search of new therapeutic options to treat leishmaniasis. a necessary step in the discovery of antileishmanial drugs is the validation of drug candidates in mouse models. the standard methods to quantify the parasite burden in animal models, mainly culture-based, are time consuming and expensive. in recent years, in vivo imaging systems have been proposed as a tool to over ...201323466934
eugenia uniflora l. essential oil as a potential anti-leishmania agent: effects on leishmania amazonensis and possible mechanisms of action.eugenia uniflora l. is a member of the myrtaceae family and is commonly known as brazilian cherry tree. in this study, we evaluated the chemical composition of eugenia uniflora l. essential oil (eueo) by using gas chromatography-mass spectrometry (gc-ms) and assessed its anti-leishmania activity. we also explored the potential mechanisms of action and cytotoxicity of eueo. thirty-two compounds were identified, which constituted 92.65% of the total oil composition. the most abundant components we ...201323533469
potent naphthoquinones against antimony-sensitive and -resistant leishmania parasites: synthesis of novel α- and nor-α-lapachone-based 1,2,3-triazoles by copper-catalyzed azide-alkyne cycloaddition.continuing our screening program for novel anti-parasite compounds, we synthesized seven 1,4-naphthoquinones coupled to 1,2,3-triazoles, five nor-β-lapachone-based 1,2,3-triazoles and ten α-lapachone-based 1,2,3-triazoles. these and other naphthoquinonoid compounds were evaluated for their activity against promastigote forms of antimony-sensitive and -resistant strains of leishmania infantum (syn. leishmania chagasi) and leishmania amazonensis. the toxicity of these compounds to mammalian cells ...201323535320
activity of antimalarial drugs in vitro and in a murine model of cutaneous leishmaniasis.the currently used treatments for leishmaniasis, a neglected parasitic disease, are associated with several side effects, high cost and resistance of the leishmania parasites. here we evaluated in vitro and in vivo the antileishmanial activity of five antimalarial drugs against leishmania amazonensis. mefloquine was effective against promastigotes in axenic cultures and showed an ic50 (concentration giving half-maximal inhibition) value of 8.4±0.7 µm. in addition, mefloquine, chloroquine and hyd ...201323538561
eupomatenoid-5 isolated from leaves of piper regnellii induces apoptosis in leishmania amazonensis.leishmania spp. are protozoa responsible for leishmaniasis, a neglected disease that kills up to 50,000 people every year. current therapies mainly rely on antimonial drugs that are inadequate because of their poor efficacy and safety and increased drug resistance. an urgent need exists to find new and more affordable drugs. our previous study demonstrated the antileishmanial activity of eupomatenoid-5, a neolignan obtained from leaves of piper regnellii var. pallescens. the aim of the present s ...201323573160
in vitro leishmanicidal and cytotoxic activities of the glycoalkaloids from solanum lycocarpum (solanaceae) fruits.leishmaniasis is an infection caused by a protozoan parasite of the genus leishmania and is the second most prevalent parasitic protozoal disease after malaria in the world. we report the in vitro leishmanicidal activity on promastigote forms of leishmania amazonensis and cytotoxicity, using llcmk2 cells, of the glycoalkaloids from the fruits of solanum lycocarpum, determined by colorimetric methods. the alkaloidic extract was obtained by acid-base extraction; solamargine and solasonine were iso ...201323576350
drimanes from drimys brasiliensis with leishmanicidal and antimalarial activity.this paper evaluates chcl3 and ch3oh extracts of the stem bark, branches and leaves of drimys brasiliensis and drimane sesquiterpenes isolated from the stem bark against strains of leishmania amazonensis and leishmania braziliensis promastigotes and plasmodium falciparum trophozoites. all of the extracts and compounds were tested in cell lines in comparison with reference standards and cell viability was determined by the xtt method. the chcl3 and ch3oh extracts from the stem bark and branches y ...201323579790
high content analysis of primary macrophages hosting proliferating leishmania amastigotes: application to anti-leishmanial drug discovery.human leishmaniases are parasitic diseases causing severe morbidity and mortality. no vaccine is available and numerous factors limit the use of current therapies. there is thus an urgent need for innovative initiatives to identify new chemotypes displaying selective activity against intracellular leishmania amastigotes that develop and proliferate inside macrophages, thereby causing the pathology of leishmaniasis.201323593521
new amide derivatives of quinoxaline 1,4-di-n-oxide with leishmanicidal and antiplasmodial activities.malaria and leishmaniasis are two of the world's most important tropical parasitic diseases. continuing with our efforts to identify new compounds active against malaria and leishmaniasis, twelve new 1,4-di-n-oxide quinoxaline derivatives were synthesized and evaluated for their in vitro antimalarial and antileishmanial activity against plasmodium falciparum fcr-3 strain, leishmania infantum and leishmania amazonensis. their toxicity against vero cells (normal monkey kidney cells) was also asses ...201323609622
the role of surface glycoconjugates in leishmania midgut attachment examined by competitive binding assays and experimental development in sand flies.binding of promastigotes to the sand fly midgut epithelium is regarded as an essential part of the leishmania life cycle in the vector. among leishmania surface molecules putatively involved in attachment to the sand fly midgut, two gpi-anchored molecules are the most prominent: lipophosphoglycan (lpg) and promastigote surface protease gp63. in this work, we examined midgut attachment of leishmania lines mutated in gpi-anchored molecules and compared results from 2 different techniques: in vivo ...201323611086
synthesis and biological evaluation against leishmania amazonensis of a series of alkyl-substituted benzophenones.nine o-alkyl and o-prenyl derivatives were synthesized from commercial 2,4-dihydroxybenzophenone, 4,e4,4'-dihydroxybenzophenone and were evaluated for their leishmanicidal activity against promastigote forms of leishmania amazonensis, as well their toxicity in murine macrophages. all derivatives exhibited better biological activity than their hydroxylated benzophenones precursors, and new compound lfqm-123 (3c) was 250-fold more active than its precursor 4,4'-dihydroxybenzophenone (3). moreover, ...201323623672
proteomic analysis reveals differentially expressed proteins in macrophages infected with leishmania amazonensis or leishmania major.cba macrophages effectively control leishmania major infection, yet are permissive to leishmania amazonensis. employing a transcriptomic approach, we previously showed the up-regulation of the genes involved in the classical pathway of macrophage activation in resistant mice. however, microarray analyses do not evaluate changes in gene expression that occur after translation. to circumvent this analytical limitation, we employed a proteomics approach to increase our understanding of the modulati ...201623628411
in vitro antileishmanial, trypanocidal, and mammalian cell activities of diverse n,n' -dihetaryl substituted diamines and related compounds.the leishmaniasis and chagas diseases constitute a serious public health problem worldwide with few and ineffective treatment options. the search for new antiparasitic candidates at the initial steps of drug discovery and development is still necessary. the synthesis of 22 de novo synthetized n,n'-dihetaryl-alkyldiamine derivatives and in vitro antiparasitic activity were evaluated for the first time against intracellular and extracellular forms of leishmania (leishmania) infantum, l. (viannia) ...201223641328
an antigenic domain of the leishmania amazonensis nucleoside triphosphate diphosphohydrolase (ntpdase 1) is associated with disease progression in susceptible infected mice.an antigenic conserved b domain was previously identified within nucleoside triphosphate diphosphohydrolases (ntpdases) of plants and parasites. now, the r-potdomain b, a 6× his-tag polypeptide belonging to the conserved b domain from the potato apyrase, and synthetic peptides lbb1lj and lbb2lj derived from the b domain from leishmania ntpdase 1 were used as molecular tools for studies of the leishmania amazonensis ntpdase 1. widespread subcellular location of the specific ntpdase 1 was detected ...201323681191
in vitro evaluation of 4-phenyl-5-(4'-x-phenyl)-1,3,4-thiadiazolium-2-phenylaminide chlorides and 3[n-4'-x-phenyl]-1,2,3-oxadiazolium-5-olate derivatives on nitric oxide synthase and arginase activities of leishmania amazonensis.leishmaniasis is a spectrum of infectious diseases caused by leishmania protozoan parasites. the purpose of this study was to perform, in vitro, a comparative analysis of the activity amastigotes. results showed excellent efficacy of all compounds against axenic amastigotes, compared to pentamidine isethionate, the reference drug used. the cytotoxic effect of these mesoionic compounds of six mesoionic compounds (three 1,3,4-thiadiazolium-2-aminide and three 1,2,3-oxadiazolium-5-olate class compo ...201323693031
inflammasome-derived il-1β production induces nitric oxide-mediated resistance to leishmania.parasites of the leishmania genus are the causative agents of leishmaniasis in humans, a disease that affects more than 12 million people worldwide. these parasites replicate intracellularly in macrophages, and the primary mechanisms underlying host resistance involve the production of nitric oxide (no). in this study we show that the nlrp3 inflammasome is activated in response to leishmania infection and is important for the restriction of parasite replication both in macrophages and in vivo as ...201323749230
effects of a marine serine protease inhibitor on viability and morphology of trypanosoma cruzi, the agent of chagas disease.it has been reported that serine peptidase activities of trypanosoma cruzi play crucial roles in parasite dissemination and host cell invasion and therefore their inhibition could affect the progress of chagas disease. the present study investigates the interference of the stichodactyla helianthus kunitz-type serine protease inhibitor (shpi-i), a 55-amino acid peptide, in t. cruzi serine peptidase activities, parasite viability, and parasite morphology. the effect of this peptide was also studie ...201323770204
molluscicidal and leishmanicidal activity of the leaf essential oil of syzygium cumini (l.) skeels from brazil.the chemical composition and biological potential of the essential oil extracted from syzygium cumini leaves collected in brazil were examined. gc/ms analyses revealed a high abundance of monoterpenes (87.12%) in the oil. eleven compounds were identified, with the major components being α-pinene (31.85%), (z)-β-ocimene (28.98%), and (e)-β-ocimene (11.71%). to evaluate the molluscicidal effect of the oil, it was tested against biomphalaria glabrata and the lc₅₀ obtained was 90 mg/l. the essential ...201323776029
cytotoxicity and in vitro antileishmanial activity of antimony (v), bismuth (v), and tin (iv) complexes of lapachol.leishmania amazonensis is the etiologic agent of the cutaneous and diffuse leishmaniasis often associated with drug resistance. lapachol [2-hydroxy-3-(3'-methyl-2-butenyl)-1,4-naphthoquinone] displays a wide range of antimicrobial properties against many pathogens. in this study, using the classic microscopic in vitro model, we have analyzed the effects of a series of lapachol and chlorides complexes with antimony (v), bismuth (v), and tin (iv) against l. amazonensis. all seven compounds exhibit ...201323781165
reprogramming neutral lipid metabolism in mouse dendritic leucocytes hosting live leishmania amazonensis amastigotes.after loading with live leishmania (l) amazonensis amastigotes, mouse myeloid dendritic leucocytes/dls are known to undergo reprogramming of their immune functions. in the study reported here, we investigated whether the presence of live l. amazonensis amastigotes in mouse bone marrow-derived dls is able to trigger re-programming of dl lipid, and particularly neutral lipid metabolism.201323785538
synthesis and antiprotozoal activity of dicationic m-terphenyl and 1,3-dipyridylbenzene derivatives.4,4″-diamidino-m-terphenyl (1) and 36 analogues were prepared and assayed in vitro against t rypanosoma brucei rhodesiense , trypanosoma cruzi , plasmodium falciparum , and leishmania amazonensis . twenty-three compounds were highly active against t. b. rhodesiense or p. falciparum. most noteworthy were amidines 1, 10, and 11 with ic50 of 4 nm against t. b. rhodesiense, and dimethyltetrahydropyrimidinyl analogues 4 and 9 with ic50 values of ≤ 3 nm against p. falciparum. bis-pyridylimidamide deri ...201323795673
activation of leishmania spp. leishporin: evidence that dissociation of an inhibitor not only improves its lipid-binding efficiency but also endows it with the ability to form pores.we have previously shown that various species of leishmania produce a lytic activity, which, in leishmania amazonensis, is mediated by a pore-forming cytolysin, called leishporin. it is toxic for macrophages in vitro and optimally active at ph 5.0 to 5.5 and at 37 °c, suggesting that it might be active inside phagolysosomes. leishporin from both l. amazonensis (a-leishporin) and leishmania guyanensis (g-leishporin) can be activated by proteases, suggesting either a limited proteolysis of an inac ...201323812644
activity of recombinant and natural defensins from vigna unguiculata seeds against leishmania amazonensis.antimicrobial peptides (amps), which are differentiated from other antibiotic peptides, such as gramicidins and polymyxins, because they are synthesized by large enzymatic complex and bear modified amino acids including d-amino acids, are short polymers of l-amino acids synthesized by ribosomes upon which all living organisms rely to defend themselves from invaders or competitor microorganisms. amps have received a great deal of attention from the scientific community as potential new drugs for ...201323816644
evaluation of antileishmanial activity of selected brazilian plants and identification of the active principles.this study evaluated extracts, fractions, and isolated compounds from some selected brazilian medicinal plants against strains of promastigotes of leishmania amazonensis and l. brasiliensis in vitro. the cell viability was determined, comparing the results with reference standards. the dichloromethane fractions of the roots, stems, and leaves of allamanda schottii showed ic50 values between 14.0 and 2.0  μ g/ml. plumericin was the main active compound, with ic50 of 0.3 and 0.04  μ g/ml against t ...201323840252
the effects of n-butyl-1-(4-dimethylamino)phenyl-1,2,3,4-tetrahydro- β -carboline-3-carboxamide against leishmania amazonensis are mediated by mitochondrial dysfunction.leishmaniasis is a disease that affects millions of people worldwide. the drugs that are available for the treatment of this infection exhibit high toxicity and various side effects. several studies have focused on the development of new chemotherapeutic agents that are less toxic and more effective against trypanosomatids. we investigated the effects of n-butyl-1-(4-dimethylamino)phenyl-1,2,3,4-tetrahydro-β-carboline-3-carboxamide (c4) and its possible targets against l. amazonensis. the result ...201323843887
a novel alkyl phosphocholine-dinitroaniline hybrid molecule exhibits biological activity in vitro against leishmania amazonensis.parasitic protozoa of the leishmania genus cause leishmaniasis, an important complex of tropical diseases that affect about 12 million people around the world. the drugs used to treat leishmaniasis are pentavalent antimonials, miltefosine, amphotericin b and pentamidine. in the present study, we evaluated the effect of a novel alkyl phosphocholine-dinitroaniline hybrid molecule, tc95, against leishmania amazonensis promastigotes and intracellular amastigotes. antiproliferative assays indicated t ...201323845259
synthesis, antileishmanial activity and structure-activity relationship of 1-n-x-phenyl-3-n'-y-phenyl-benzamidines.two series of n,n'-diphenyl-benzamidines were synthesized as part of a study to search potential new drugs with antileishmanial activity. these compounds were obtained by anilides in pcl5 halogenation reaction with generation in situ of the corresponding benzimidoyl chlorides, and subsequently treatment with adequate anilines. the series i showed expressive results of antileishmanial activity, highlighted the compounds 9a with ic50 = 81.28 μm (log ic50 = 1.91 μm) against leishmania chagasi, 8e w ...201323851118
the genome sequence of leishmania (leishmania) amazonensis: functional annotation and extended analysis of gene models.we present the sequencing and annotation of the leishmania (leishmania) amazonensis genome, an etiological agent of human cutaneous leishmaniasis in the amazon region of brazil. l. (l.) amazonensis shares features with leishmania (l.) mexicana but also exhibits unique characteristics regarding geographical distribution and clinical manifestations of cutaneous lesions (e.g. borderline disseminated cutaneous leishmaniasis). predicted genes were scored for orthologous gene families and conserved do ...201323857904
trans- β -caryophyllene: an effective antileishmanial compound found in commercial copaiba oil (copaifera spp.).this study investigated the leishmanicidal activity against leishmania amazonensis of four commercial oils from copaifera spp. named as c1, c2, c3, and c4, the sesquiterpene and diterpene pools obtained from distilling c4, and isolated β -caryophyllene (car). copaiba oils chemical compositions were analyzed by gas chromatography and correlated with biological activities. diterpenes-rich oils c2 and c3 showed antipromastigote activity. sesquiterpenes-rich c1 and c4, and isolated car presented a d ...201323864897
the eif4e subunits of two distinct trypanosomatid eif4f complexes are subjected to differential post-translational modifications associated to distinct growth phases in culture.the eukaryotic eif4f complex, the cap binding complex, functions during translation initiation through interactions mediated by its three subunits (eif4e, eif4g and eif4a), other initiation factors and the ribosome. in trypanosomatids, various eif4e and eif4g homologues were identified, with two eif4f-like complexes confirmed (eif4e4/eif4g3/eif4ai and eif4e3/eif4g4/eif4ai). here, the expression pattern of these complexes was investigated during leishmania amazonensis and trypanosoma brucei growt ...201323867205
dietary flavonoids fisetin, luteolin and their derived compounds inhibit arginase, a central enzyme in leishmania (leishmania) amazonensis infection.fisetin, quercetin, luteolin and 7,8-hydroxyflavone show high activity in leishmania cultures and present low toxicity to mammalian cells. in this work, the structural aspects of 13 flavonoids were analyzed for their inhibition of the arginase enzyme from leishmania (leishmania) amazonensis. a higher potency of arginase inhibition was observed with fisetin, which was four and ten times greater than that of quercetin and luteolin, respectively. these data show that the hydroxyl group at position ...201323870955
reactive oxygen species production by quercetin causes the death of leishmania amazonensis intracellular amastigotes.the present study reports the mechanism of the antileishmanial activity of quercetin against the intracellular amastigote form of leishmania amazonensis. treatment with 1 reduced the infection index in l. amazonensis-infected macrophages in a dose-dependent manner, with an ic₅₀ value of 3.4 μm and a selectivity index of 16.8, and additionally increased ros generation also in a dose-dependent manner. quercetin has been described as a pro-oxidant that induces the production of reactive oxygen spec ...201323876028
heme uptake mediated by lhr1 is essential for leishmania amazonensis virulence.the protozoan parasite leishmania amazonensis is a heme auxotroph and must acquire this essential factor from the environment. previous studies showed that l. amazonensis incorporates heme through the transmembrane protein lhr1 (leishmania heme response 1). lhr1-null promastigotes were not viable, suggesting that the transporter is essential for survival. here, we compared the growth, differentiation, and infectivity for macrophages and mice of wild-type, lhr1-single-knockout (lhr1/δlhr1), and l ...201323876801
leishmanicidal activity of amphotericin b encapsulated in plga-dmsa nanoparticles to treat cutaneous leishmaniasis in c57bl/6 mice.the major goal of this work was to design a new nanoparticle drug delivery system for desoxycholate amphotericin b (d-amb), based on controlled particle size, looking for the most successful release of the active agents in order to achieve the best site-specific action of the drug at the therapeutically optimal rate and dose regimen. for this, amb nanoencapsulated in poly(lactic-co-glycolic acid) (plga) and dimercaptosuccinic acid (dmsa) nanoparticles (nano-d-amb) has been developed, and its eff ...201323891944
leishmania amazonensis amastigotes trigger neutrophil activation but resist neutrophil microbicidal mechanisms.neutrophils are the first cells to infiltrate to the site of leishmania promastigote infection, and these cells help to reduce parasite burden shortly after infection is initiated. several clinical reports indicate that neutrophil recruitment is sustained over the course of leishmaniasis, and amastigote-laden neutrophils have been isolated from chronically infected patients and experimentally infected animals. the goal of this study was to compare how thioglycolate-elicited murine neutrophils re ...201323918780
liposomal-lupane system as alternative chemotherapy against cutaneous leishmaniasis: macrophage as target cell.leishmania amazonensis causes human diseases that range from self-healing to diffusion cutaneous lesions. the chemotherapy of leishmaniasis requires long-term treatment and has been based on the use of pentavalent antimonials. liposomes have been used as antileishmanial drug carries and have adjuvant activity in vaccines against several microorganisms, representing an important option to the development of new therapeutics for the disease. in this study, we developed a liposomal formulation cont ...201323933281
in vitro antileishmanial activity of essential oil of vanillosmopsis arborea (asteraceae) baker.the search for new immunopharmacological chemical agents to treat various diseases caused by bacteria, fungi, and protozoa, such as leishmaniasis, for example, has led to the exploration of potential products from plant species and their main active ingredients. antimonial drugs are the current treatment for leishmaniasis. these drugs cause major side effects and frequent discontinuation of treatment. in this study, we evaluated the in vitro leishmanicidal activity of essential oil of vanillosmo ...201323935675
in vitro interaction between paromomycin sulphate and four drugs with leishmanicidal activity against three new world leishmania species.to evaluate in vitro interactions between paromomycin sulphate and the antileishmanial drugs meglumine antimoniate, amphotericin b, miltefosine and azithromycin against intracellular leishmania (leishmania) infantum chagasi, leishmania (viannia) braziliensis and leishmania (leishmania) amazonensis amastigotes in peritoneal mouse macrophages.201423970484
cloning, characterization, and inhibition studies of a β-carbonic anhydrase from leishmania donovani chagasi, the protozoan parasite responsible for leishmaniasis.leishmaniasis is an infection provoked by protozoans belonging to the genus leishmania. among the many species and subsepecies of such protozoa, leishmania donovani chagasi causes visceral leishmaniasis. a β-carbonic anhydrase (ca, ec 4.2.1.1) was cloned and characterized from this organism, denominated here ldcca. ldcca possesses effective catalytic activity for the co2 hydration reaction, with kcat of 9.35 × 10(5) s(-1) and kcat/km of 5.9 × 10(7) m(-1) s(-1). a large number of aromatic/heteroc ...201323977960
antileishmanial activity of the essential oil from bixa orellana.leishmaniasis is a neglected tropical disease caused by leishmania protozoa. there is currently no vaccine against leishmaniasis, and chemotherapy remains the only effective control. however, conventional drugs are toxic, expensive, and require long periods of treatment, and resistance to clinical chemotherapeutic agents is emerging. recent research on plants has shown a successful approach to obtain new antileishmanial alternatives. herein, the in vitro and in vivo effects of the essential oil ...201423983115
leishmanicidal, trypanocidal, and cytotoxic activities of endophytic fungi associated with bioactive plants in brazil.one hundred and twenty-one isolates of endophytic fungi were recovered from leaves of the bioactive brazilian plant species ageratum myriadenia , palicourea tetraphylla , piptadenia adiantoides, and trixis vauthieri. all fungal isolates were cultivated in liquid media and crude extracts were obtained with ethyl acetate. the crude extracts were tested in bioassay panels using leishmania amazonensis , trypanosoma cruzi, the enzyme trypanothione reductase (tryr) from trypanosoma cruzi, and three hu ...201024031513
leishmania amazonensis exhibits phosphatidylserine-dependent procoagulant activity, a process that is counteracted by sandfly saliva.leishmania parasites expose phosphatidylserine (ps) on their surface, a process that has been associated with regulation of host's immune responses. in this study we demonstrate that ps exposure by metacyclic promastigotes of leishmania amazonensis favours blood coagulation. l. amazonensis accelerates in vitro coagulation of human plasma. in addition, l. amazonensis supports the assembly of the prothrombinase complex, thus promoting thrombin formation. this process was reversed by annexin v whic ...024037188
assembly of the leishmania amazonensis flagellum during cell differentiation.the flagellar cytoskeleton of leishmania promastigotes contains the canonical 9+2 microtubular axoneme and a filamentous structure, the paraflagellar rod (pfr), which is present alongside the axoneme. in contrast to promastigotes, which contain a long and motile flagellum, the amastigote form of leishmania displays a short flagellum without a pfr that is limited to the flagellar pocket domain. here, we investigated the biogenesis of the leishmania flagellum at 0, 4, 6 and 24h of differentiation. ...201324041804
in vitro cytocidal effects of the essential oil from croton cajucara (red sacaca) and its major constituent 7- hydroxycalamenene against leishmania chagasi.visceral leishmaniasis is the most serious form of leishmaniasis and can be lethal if left untreated. currently available treatments for these parasitic diseases are frequently associated to severe side effects. the leaves of croton cajucara are used as an infusion in popular medicine to combat several diseases. previous studies have demonstrated that the linalool-rich essential oil from c. cajucara (white sacaca) is extremely efficient against the tegumentary specie leishmania amazonensis. in t ...201324088644
fatty acid profiles in leishmania spp. isolates with natural resistance to nitric oxide and trivalent antimony.fatty acids, especially those from phospholipids (plfa), are essential membrane components that are present in relatively constant proportions in biological membranes under natural conditions. however, under harmful growth conditions, such as diseases, environmental changes, and chemical exposure, the fatty acid proportions might vary. if such changes could be identified and revealed to be specific for adverse situations, they could be used as biomarkers. such biomarkers could facilitate the ide ...201424096610
neutrophils have a protective role during early stages of leishmania amazonensis infection in balb/c mice.neutrophils are involved in the early stages of immune responses to pathogens. here, we investigated the role of neutrophils during the establishment of leishmania amazonensis infection in balb/c and c57bl/6 mice. first, we showed an accumulation of neutrophils between 6 and 24 h post-infection, followed by a reduction in neutrophil numbers after 72 h. next, we depleted neutrophils prior to infection using rb6-8c5 or 1a8 mab. neutrophil depletion led to faster lesion development, increased paras ...201424102495
in vitro and in vivo effects of (-)-epigallocatechin 3-o-gallate on leishmania amazonensis.(-)-epigallocatechin 3-o-gallate (1), the most abundant flavanol in green tea, has been reported to have antiproliferative effects on trypanosoma cruzi. the present study reports the effects in vitro and in vivo of 1 on leishmania amazonensis. l. amazonensis-infected macrophages treated with 1 exhibited a significant reduction of the infection index in a dose-dependent manner, with an ic50 value of 1.6 μm. oral administration of 1 on l. amazonensis-infected balb/c mice (30 mg/kg/day) resulted in ...201324106750
effectiveness of novel 5-(5-amino-1-aryl-1h-pyrazol-4-yl)-1h-tetrazole derivatives against promastigotes and amastigotes of leishmania amazonensis.in this research, a series of substituted 5-(5-amino-1-aryl-1h-pyrazol-4-yl)-1h-tetrazoles were synthesized and evaluated for in vitro antileishmanial activity. among the derivatives, examined compounds 3b and 3l exhibited promising activity against promastigotes and amastigotes forms of leishmania amazonensis. the cytotoxicity of these compounds was evaluated on murine cells, giving access to the corresponding selectivity index (si).201424119090
constitutive mosaic aneuploidy is a unique genetic feature widespread in the leishmania genus.using fluorescence in situ hybridization, we determined the ploidy of four species of leishmania: leishmania infantum, leishmania donovani, leishmania tropica and leishmania amazonensis. we found that each cell in a strain possesses a combination of mono-, di- and trisomies for all chromosomes; ploidy patterns were different among all strains/species. these results extend those we previously described in leishmania major, demonstrating that mosaic aneuploidy is a genetic feature widespread to th ...201424120456
synthesis and activity of novel tetrazole compounds and their pyrazole-4-carbonitrile precursors against leishmania spp.a new series of 5-(1-aryl-3-methyl-1h-pyrazol-4-yl)-1h-tetrazole derivatives (4a-m) and their precursor 1-aryl-3-methyl-1h-pyrazole-4-carbonitriles (3a-m) were synthesized and evaluated as antileishmanials against leishmania braziliensis and leishmania amazonensis promastigotes in vitro. in parallel, the cytotoxicity of these compounds was evaluated on the raw 264.7 cell line. the results showed that among the assayed compounds the substituted 3-chlorophenyl (4a) (ic50/24h=15±0.14 μm) and 3,4-di ...201324125880
in vitro and in vivo antileishmanial and trypanocidal studies of new n-benzene- and n-naphthalenesulfonamide derivatives.we report in vivo and in vitro antileishmanial and trypanocidal activities of a new series of n-substituted benzene and naphthalenesulfonamides 1-15. compounds 1-15 were screened in vitro against leishmania infantum , leishmania braziliensis , leishmania guyanensis , leishmania amazonensis , and trypanosoma cruzi . sulfonamides 6e, 10b, and 10d displayed remarkable activity and selectivity toward t. cruzi epimastigotes and amastigotes. 6e showed significant trypanocidal activity on parasitemia i ...201324151871
treatment with triterpenic fraction purified from baccharis uncinella leaves inhibits leishmania (leishmania) amazonensis spreading and improves th1 immune response in infected mice.the current medications used to treat leishmaniasis have many side effects for patients; in addition, some cases of the disease are refractory to treatment. therefore, the search for new leishmanicidal compounds is indispensable. recently, it was demonstrated that oleanolic- and ursolic-containing fraction from baccharis uncinella leaves eliminated the promastigote and amastigote forms of leishmania (leishmania) amazonensis and l. (viannia) braziliensis without causing toxic effects for j774 mac ...201424173812
essential oil from chenopodium ambrosioides and main components: activity against leishmania, their mitochondria and other microorganisms.chenopodium ambrosioides is an aromatic herb used by native people to treat parasitic diseases. the aim of this work is to compare the in vitro anti-leishmanial activity of the essential oil (eo) from c. ambrosioides and its major components (ascaridole, carvacrol and caryophyllene oxide) and study their mechanism of action and activity against a panel of microorganism. antileishmanial activity and cytotoxicity of the eo and major components was study. in addition, experiments to elucidate the m ...201424184772
strychnos pseudoquina and its purified compounds present an effective in vitro antileishmanial activity.the development of new and cost-effective alternative therapeutic strategies to treat leishmaniasis has become a high priority. in the present study, the antileishmanial activity of strychnos pseudoquina st. hil. was investigated and pure compounds that presented this biological effect were isolated. an ethyl acetate extract was prepared, and it proved to be effective against leishmania amazonensis. a bioactivity-guided fractionation was performed, and two flavonoids were identified, quercetin 3 ...201324194781
synthetic oxoisoaporphine alkaloids: in vitro, in vivo and in silico assessment of antileishmanial activities.leishmaniasis is a growing health problem worldwide. as there are certain drawbacks with the drugs currently used to treat human leishmaniasis and resistance to these drugs is emerging, there is a need to develop novel antileishmanial compounds, among which isoquinoline alkaloids are promising candidates. in this study, 18 novel oxoisoaporphine derivatives were synthesized and their possible antileishmanial activity was evaluated. the in vitro activity of these derivatives against leishmania ama ...201324204870
genotoxicity and antileishmanial activity evaluation of physalis angulata concentrated ethanolic extract.antileishmanial in vitro tests, as well as ames and micronucleus assays were performed with a concentrated ethanolic extract of physalis angulata (eepa) results: eepa did not present mutagenic effect in salmonella typhimurium strains at concentration reaching 3000 μg/plate and did not induce mutagenic effects after two oral administrations with a 24h interval at a dose level of 2000 mg/kg. eepa presented antileishmanial activity and presented an ic₅₀ value of 5.35 ± 2.50 μg/ml and 4.50 ± 1.17 μg ...201324231691
inhibition of leishmania (leishmania) amazonensis and rat arginases by green tea egcg, (+)-catechin and (-)-epicatechin: a comparative structural analysis of enzyme-inhibitor interactions.epigallocatechin-3-gallate (egcg), a dietary polyphenol (flavanol) from green tea, possesses leishmanicidal and antitrypanosomal activity. mitochondrial damage was observed in leishmania treated with egcg, and it contributed to the lethal effect. however, the molecular target has not been defined. in this study, egcg, (+)-catechin and (-)-epicatechin were tested against recombinant arginase from leishmania amazonensis (arg-l) and rat liver arginase (arg-1). the compounds inhibit arg-l and arg-1 ...201324260115
brazilian brown propolis elicits antileishmanial effect against promastigote and amastigote forms of leishmania amazonensis.propolis is a complex matrix of chemical constituents extracted from plants and produced by bees which is used in folk medicine due to its several pharmacological properties. its chemical composition varies according to the region where it is produced. this work has studied the antileishmanial activity and cytotoxicity of brown propolis (bp) originating from the semi-arid region of piauí, brazil. the bp showed significant inhibition of the leishmania amazonensis promastigotes growth as well as b ...201424261482
a2 and other visceralizing proteins of leishmania: role in pathogenesis and application for vaccine development.visceral leishmaniasis is a re-emergent disease and a significant cause of morbidity worldwide. amongst the more than 20 leishmania species, leishmania donovani, leishmania infantum and more rarely leishmania amazonensis are associated with visceral leishmaniasis. a major question in leishmaniasis research is how these species migrate to and infect visceral organs whereas other species such as leishmania major and leishmania braziliensis remain in the skin, causing tegumentary leishmaniasis. her ...201424264241
leishmania amazonensis promastigotes present two distinct modes of nucleus and kinetoplast segregation during cell cycle.here, we show the morphological events associated with organelle segregation and their timing in the cell cycle of a reference strain of leishmania (l.) amazonensis promastigotes, the main causative agent of tegumentary leishmaniasis in the americas. we show evidences that during the cell cycle, l. amazonensis promastigotes present two distinct modes of nucleus and kinetoplast segregation, which occur in different temporal order in different proportions of cells. we used dapi-staining and edu-la ...201324278433
in vitro antiparasitic activity and chemical composition of the essential oil obtained from the fruits of piper cubeba.protozoans of the trypanosomatid family cause the neglected tropical diseases leishmaniasis and trypanosomiasis, for which few drugs are available. in this context our group has recently reported that the essential oil obtained by steam distillation of the fruits of piper cubeba is active against schistosoma mansoni. therefore, we have investigated the in vitro effects of the essential oil against the trypomastigote and amastigote forms of trypanosoma cruzi isolated from an llcmk₂ cell line cult ...201324288276
leishmania amazonensis: characterization of an ecto-pyrophosphatase activity.several ecto-enzymatic activities have been described in the plasma membrane of the protozoan leishmania amazonensis, which is the major etiological agent of diffuse cutaneous leishmaniasis in south america. these enzymes, including ecto-phosphatases, contribute to the survival of the parasite by participating in phosphate metabolism. this work identifies and characterizes the extracellular hydrolysis of inorganic pyrophosphate related to an ecto-pyrophosphatase activity of the promastigote form ...201424316462
synthesis and evaluation of the antiparasitic activity of bis-(arylmethylidene) cycloalkanones.a series of bis-(arylmethylidene)-cycloalkanones was synthesized by cross-aldol condensation. the activity of the compounds was evaluated against amastigotes forms of trypanosoma cruzi and promastigotes forms of leishmania amazonensis. the cytotoxicity of the active compounds on uninfected fibroblasts or macrophages was established in vitro to evaluate the selectivity of their antiparasitic effects. six compounds displayed trypanocidal activity against amastigotes intracellular forms of t. cruzi ...201424321832
discovery of the rapanone and suberonone mixture as a motif for leishmanicidal and antifungal applications.leishmaniasis and fungal infections are significant diseases impacting worldwide public health. treatments have developed greatly over time, however, there is a necessity to discover less toxic drugs, which have greater efficacy and are more economically accessible. this work conducted a screening of cerrado species extracts: connarus suberosus planch. (connaraceae), neea theifera oerst. (nyctaginaceae) and myrcia linearifolia cambess. (myrtaceae) against leishmania (leishmania) amazonensis, der ...201424331757
Refresh
firstprev
...1112131415
nextlast
Displaying items 1001 - 1100 of 1455