Complexos imínicos de cobre com atividade antiparasitária frente à doença de chagas / Imine copper complexes with antiparasitic activity against Chagas disease

Neste trabalho foram sintetizados e caracterizados três complexos de cobre com ligantes imínicos, com o objetivo de avaliar sua atividade tripanocida. Esses complexos foram caracterizados por diversas técnicas espectroscópicas, como UV-Vis, Infravermelho e EPR, além de análise elementar e espectrometria de massa. Juntamente com outros complexos similares previamente sintetizados pelo nosso grupo, tiveram suas atividades avaliadas frente à forma tripomastigota do parasita T. cruzi, responsável pela fase aguda da doença de Chagas, por ensaios de viabilidade celular, com determinação do valor de seus IC50, concentração em que observamos a morte de 50% da cultura celular, pela metodologia denominada MTT. Todos os complexos mostraram-se eficientes frente a tripomastigotas, apresentando valores de IC50 abaixo de 10 µM, com quatro deles obtendo índice de seletividade maior que 10, fator importante para definir agentes promissores antichagásicos. Complexos selecionados também tiveram sua atividade verificada frente à forma amastigota do parasita, responsável pela fase crônica da doença, utilizando método de imageamento por microscópio de fluorescência e contagem celular. Estudos de inibição da cruzaína, uma cisteíno-protease importante para o metabolismo do parasita foram conduzidos em colaboração com o laboratório do Prof. Wagner Alves de Souza Júdice, da Universidade de Mogi das Cruzes. Quatro dos compostos testados apresentaram atividade inibitória frente a cruzaína, sendo dois de cobre, um de zinco e um ligante livre. Os estudos também permitiram diferenciar os mecanismos de inibição dos compostos, com os complexos de cobre apresentando um mecanismo de inibição clássico e o composto de zinco e o ligante livre apresentando o mecanismo de inibição competitiva parabólica com cooperatividade

In this work, three copper complexes with iminic ligands were synthesized and characterized, with the objective of evaluating their trypanocidal activity. These complexes were characterized by several spectroscopic techniques, such as UV-Vis, Infrared and EPR, in addition to elementary analysis and mass spectrometry. Together with other similar complexes previously synthesized by our group, their activities were evaluated against the trypomastigote form of the parasite T. cruzi, responsible for the acute phase of Chagas disease, by cell viability tests, with determination of the value of their IC50, concentration in that we observed the death of 50% of the cell culture, by the methodology called MTT, all presenting IC50 values below 10 µM, with four of them obtaining a selectivity index greater than 10, important factor for defining promising antichagasic agents. Selected complexes also had their activity verified against the amastigote form of the parasite, responsible for the chronic phase of the disease, using a fluorescence microscope and cell counting imaging method. Inhibition studies of cruzain, a cysteine protease important for the metabolism of the parasite, were conducted in collaboration with the laboratory of Professor Wagner Alves de Souza Júdice at the University of Mogi das Cruzes. Four of the tested compounds showed inhibitory activity against cruzain, two of copper, one of zinc and a free ligand. The studies also allowed to differentiate the mechanisms of inhibition of the compounds, with the copper complexes presenting a classic inhibition mechanism and the zinc compound and the free ligand presenting the competitive parabolic inhibition mechanism with cooperativity

Evaluation of in vitro anti-Trypanosoma cruzi activity of medications benznidazole, amiodarone hydrochloride, and their combination

Abstract INTRODUCTION: Approximately seven to eight million people worldwide have Chagas disease. In Brazil, benznidazole is the most commonly used active drug against Trypanosoma cruzi; however, its efficacy is limited, and side effects are frequent. Recent studies suggest that amiodarone may be beneficial in the treatment of this disease, by exerting anti-T. cruzi action. This study evaluated changes in T. cruzi cell count in in vitro cultures subjected to different doses of benznidazole, amiodarone, and their combination. METHODS: T. cruzi (Y strain) cultures containing approximately 100,000 cells were treated with either 100mg, 50mg, 25mg, 12.5mg, or 10mg of benznidazole, amiodarone, or their combination. On the 4th day, cell count was compared to the baseline data. RESULTS: On the 4th day, no parasites were observed in any of the treated cultures. CONCLUSIONS: Benznidazole and amiodarone were equally effective in eliminating T. cruzi in culture. The combination of the two drugs was also equally effective, but our data cannot demonstrate synergism, as similar results were obtained when the drugs were tested individually or in combination. It is suggested that this study be repeated with other T. cruzi strains to determine whether similar results can be obtained again.

Behavior of alfa-tomatine and tomatidine against several genera of trypanosomatids from insects and plants and Trypanosoma cruzi / Comportamento de alfa-tomatina e tomatidina contra vários gêneros de tripanossomatídeos de insetos e plantas e Trypanosoma cruzi

Glycoalkaloids are important secondary metabolites accumulated by plants as protection against pathogens. One of them, α-tomatine, is found in high concentrations in green tomato fruits, while in the ripe fruits, its aglycone form, tomatidine, does not present a protective effect, and it is usual to find parasites of tomatoes like Phytomonas serpens in these ripe fruits. To investigate the sensitivity of trypanosomatids to the action of α-tomatine, we used logarithmic growth phase culture of 20 trypanosomatids from insects and plants and Trypanosoma cruzi. The lethal dose 50% (LD50) was determined by mixing 107 cells of the different isolates with α-tomatine at concentrations ranging from 10-3 to 10-8 M for 30 min at room temperature. The same tests performed with the tomatidine as a control showed no detectable toxicity against the same trypanosomatid cultures. The tests involved determination of the percentage (%) survival of the protozoan cultures in a Neubauer chamber using optical microscopy. The LD50 values varied from 10-4 to 10-6 M α-tomatine. Slight differences were detected among the LD50 values of the analyzed samples, and none of them showed evidence of resistance to the action of tomatinase, as shown by some pathogenic fungi.

Os glicoalcaloides são metabólitos secundários importantes produzidos pelas plantas e estão envolvidos em sua proteção contra agentes patogênicos. Um deles, α-tomatina, é encontrado em altas concentrações em frutos de tomate verde, enquanto que, nos frutos maduros, sua forma aglicona, tomatidina, não apresenta um efeito protetor, sendo comum encontrar parasitas de tomates como Phytomonas serpens nesses frutos maduros. Para investigar a sensibilidade dos tripanossomatídeos à ação da α-tomatina, utilizamos formas de cultura em fase logarítmica de 20 tripanossomatídeos de plantas e insetos e Trypanosoma cruzi. A dose letal 50% (DL50) foi determinada, misturando 107 células das formas de cultura com concentrações de 10-3 a 10-8 M de α-tomatina durante trinta minutos a temperatura ambiente. Testes realizados com a tomatidina como controle não mostraram toxicidade detectável contra os mesmos tripanossomatídeos. Os testes foram avaliados pela porcentagem (%) de sobrevivência das formas de cultura dos protozoários observados por microscopia óptica em câmara de Neubauer. Os resultados da determinação de DL50 mostraram que esta variou entre 10-4 a 10-6 M de α-tomatina. Pequenas diferenças foram observadas entre os valores de DL50 das amostras analisadas, e nenhuma delas mostrou evidência de resistência pela ação da tomatinidase, como demonstrado em alguns fungos patogênicos.

Linalool, a Piper aduncum essential oil component, has selective activity against Trypanosoma cruzi trypomastigote forms at 4°C

BACKGROUND Recent studies showed that essential oils from different pepper species (Piper spp.) have promising leishmanicidal and trypanocidal activities. OBJECTIVES In search for natural compounds against Trypanosoma cruzi, different forms of the parasite were incubated for 24 h at 28ºC or 4ºC with Piper aduncum essential oil (PaEO) or its main constituents linalool and nerolidol. METHODS PaEO chemical composition was obtained by GC-MS. Drug activity assays were based on cell counting, MTT data or infection index values. The effect of PaEO on the T. cruzi cell cycle and mitochondrial membrane potential was evaluated by flow cytometry. FINDINGS PaEO was effective against cell-derived (IC50/24 h: 2.8 μg/mL) and metacyclic (IC50/24 h: 12.1 μg/mL) trypomastigotes, as well as intracellular amastigotes (IC50/24 h: 9 μg/mL). At 4ºC - the temperature of red blood cells (RBCs) storage in blood banks - cell-derived trypomastigotes were more sensitive to PaEO (IC50/24 h = 3.8 μg/mL) than to gentian violet (IC50/24 h = 24.7 mg/mL). Cytotoxicity assays using Vero cells (37ºC) and RBCs (4ºC) showed that PaEO has increased selectivity for cell-derived trypomastigotes. Flow cytometry analysis showed that PaEO does not affect the cell cycle of T. cruzi epimastigotes, but decreases their mitochondrial membrane potential. GC-MS data identified nerolidol and linalool as major components of PaEO, and linalool had trypanocidal effect (IC50/24 h: 306 ng/mL) at 4ºC. MAIN CONCLUSION The trypanocidal effect of PaEO is likely due to the presence of linalool, which may represent an interesting candidate for use in the treatment of potentially contaminated RBCs bags at low temperature.

Actividad tripanocida de Piper solmsianum C. DC. sobre formas epimastigota y tripomastigota de Trypanosoma cruzi / Trypanocidal activity of Piper solmsianum C. DC. against epimastigote and trypomastigote forms of Trypanosoma cruzi

Introducción: la infección por Trypanosoma cruzi, conocida como enfermedad de Chagas, es un problema importante de salud pública en países de América Central y Sudamérica.Objetivo: evaluar la actividad de extractos crudos de acetato de etilo de plantas in vitro de 6-8 meses y 10-12 meses de edad, de tallos leñosos y hojas de plantas silvestres maduras y el lignano tetrahidrofurano grandisina, aislados de Piper solmsianum, sobre las formas epimastigota y tripomastigota de T. cruzi in vitro.Métodos: en la evaluación del efecto de diversos extractos crudos de acetato de etilo y grandisina de P. solmsianum, sobre la viabilidad de las formas epimastigota y tripomastigota de T. cruzi, se utilizó el método MTT (3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromuro).Resultados: en la forma epimastigota, el mejor resultado en la inhibición del crecimiento fue obtenido con 50 µg/mL de extracto de tallo y en la forma tripomastigota con 25 y 50 µg/mL de grandisina y plantas in vitro de 6-8 meses de edad, respectivamente. En todos los casos los valores de inhibición oscilaron entre 86 a 96 por ciento. Plantas in vitro de 6-8 meses de edad y grandisina fueron más activas sobre las formas epimastigota y tripomastigota de T. cruzi con valores de CI50 de 0,018 y 0,360 µg/mL, respectivamente.Conclusiones: se demuestra la actividad tripanocida de extractos de plantas silvestres y plantas in vitro de P. solmsianum(AU)

Introduction: the infection by Trypanosoma cruzi, known as Chagas' disease, poses a major public health problem in Central and South America countries.Objective: to evaluate the activity of crude ethyl acetate extracts from in vitro plants of 6-8 and 10-12 months of age, stem barks and mature wild plant leaves and tetrahydrofuran lignin grandisin isolated from Piper solmsianum against the epimastigote and trypomastigote forms of T. cruzi in vitro.Methods: in the evaluation of the effect of various crude ethyl acetate extracts and grandisin from P. solmsianum on the viability of epimastigote and trypomastigote forms of T. cruzi, the MTT method (3-(4,5-dimethylthiazol-2-il)-2,5-diphenyltetrazolium bromide) was used.Results: in the epimastigote form, the best results in growth inhibition was obtained with 50 µg/mL of stem extract, and in the trypomastigote form, with 25 and 50 µg/mL of grandisin and 6-8 months-old in vitro plants, respectively. The inhibition values in all cases ranged from 86 to 96 percent. 6-8 months old in vitro plants and grandisin were found to be active against the epimastigote and trypomastigote forms of T. cruzi with IC50 of 0.018 µg/mL and 0.360 µg/mL, respectively.Conclusions: the trypanocidal activity of extracts from wild plants and in vitro plants of P. solmsianum was proved(AU)

In vitro trypanocidal activity of the Egyptian plant Schinopsis lorentizii against trypomastigote and amastigote forms of Trypanosoma cruzi.

Chagas’ disease is a chronic illness caused by the protozoan Trypanosoma cruzi. According to estimates, approximately 16-18 million people are infected in Latin American. Plant extracts exhibit a wide variety of secondary metabolites and can play an important role in the discovery of new compounds with biological potential. The in vitro trypanocidal activity of the extracts obtained from six plant species collected in Egypt (Parkia africana, Parkia roxburgi, Lagerstromeia speciosa, Schinopsis lorentzii, Lagerstromeia indica, and Sapindus saponaria) was assayed against trypomastigote and amastigote forms of T. cruzi. The cytotoxic activity of the most active extract was also evaluated by conducting MTT assays. S. lorentzii and S. saponaria were the most active extracts against the trypomastigote form;IC50 values were 9.9 and 27.34 g/mL, respectively. The S. lorentzii extract was also evaluated against the amastigote form (IC50 was 111.5 g/mL).The S. lorentzii extract did not exhibit significant cytotoxic activity. The selectivity index value indicated that this extract was highly selective for the parasite. The S. lorentzii and S. saponariaextracts exhibit trypanocidal activity, probably as a result of the presence ofdifferent constituentsand their concentrations in the extracts.

Avaliação das atividades antibacteriana, tripanocida e citotóxica do extrato hidroalcóolico das raízes de Tradescantia sillamontana Matuda (Veludo Branco) (Commelinaceae) / Evaluation of antibacterial, trypanocidal and cytotoxical activities of the hydroalcoholic extract from the roots of Tradescantia sillamontana Matuda (Veludo Branco) (Commelinaceae)

RESUMO O objetivo deste estudo foi avaliar o efeito antibacteriano e tripanocida in vitro do extrato hidroalcóolico das raízes de Tradescantia sillamontana Matuda (Commelinaceae), conhecida popularmente como veludo branco. Foi avaliada a atividade antibacteriana in vitro frente às bactérias Streptococcus mitis (CIM = 100 µg/mL; CMB = 150 µg/mL), Streptococcus mutans (CIM = 200 µg/mL; CMB = 220 µg/mL), Streptococcus sanguinis (CIM = 400 µg/mL; CMB = 425 µg/mL), Streptococcus sobrinus (CIM = 400 µg/mL; CMB = 420 µg/mL) e Bacteroides fragilis (CIM = 400 µg/mL; CMB = 430 µg/mL) pelo método de diluição em caldo. Os protozoários da família tripanossomatídeo causam doenças tropicais que costumam ser negligenciadas que costumam ser como a tripanossomíase, para a qual estão disponíveis poucos medicamentos. Neste contexto, o extrato hidroalcóolico das raízes de T. sillamontana também foi avaliado frente às formas tripomastigotas da cepa Y de Trypanosoma cruzi, com promissora atividade frente a este protozoário (IC50 = 2,4 µg/mL). Quando avaliada a atividade citotóxica frente a fibroblastos da linhagem LLCMK2, o extrato apresentou moderada citotoxicidade (CC50 = 480,37 µg/mL). Os resultados ora apresentados para o extrato hidroalcóolico das raízes de Tradescantia sillamontana Matuda demonstraram promissoras atividades antibacteriana e tripanocida, sendo uma fonte alternativa de produtos naturais com atividades contra T. cruzi e algumas bactérias do gênero Streptococcus e Bacteroides.

ABSTRACT The aim of this study was to investigate the in vitro, antibacterial and trypanocidal effect of the hydroalcoholic extract from the roots of Tradescantia sillamontana Matuda (Commelinaceae), commonly known as Veludo branco. The in vitro antibacterial activity against the standard bacteria Streptococcus mitis (MIC = 100µg/mL; MBC = 150 µg/mL), Streptococcus mutans (MIC = 200µg/mL; MBC = 220 µg/mL), Streptococcus sanguinis (MIC = 400µg/mL; MBC = 425 µg/mL), Streptococcus sobrinus (MIC = 400µg/mL; MBC = 420 µg/mL) andBacteroides fragilis (MIC = 400µg/mL; MBC = 430 µg/mL), using microdilution broth methods. Protozoans from the trypanosomatid family cause neglected tropical diseases such as trypanosomiasis, for which few drugs are available. In this context, the hydroalcoholic extract of the Tradescantia sillamontana roots was also investigated with regards to the in vitro effects against the trypomastigote forms of theY strain of Trypanosoma cruzi, showing strong activity against this parasite (IC50 = 2.4 µg/mL). When performing cytotoxic activity against fibroblasts LLCMK2 line, the extract showed moderate cytotoxicity (CC50 = 480.37 mg/mL). The results presented for the hydroalcoholic extract of the roots of Tradescantia sillamontana Matuda demonstrated effective antibacterial and trypanocidal activities and were shown to be an alternative source of natural products with activity against T. cruzi and some bacteria of the genus Streptococcus and Bacteroides.

Synthesis and trypanocidal activity of salicylhydrazones and p-tosylhydrazones of S-(+)-carvone and arylketones on African trypanosomiasis.

Hydrazones are nowadays considered to be good candidates for various pharmaceutical applications. Here, we have synthesized two series of hydrazones: salicylhydrazones (GS1-4) and p-tosylhydrazones (GT1-4) from S- (+)-carvone and three aryketones with good yields (57-91%). Molecules were characterized by elemental analyses; TLC, NMR 1H, NMR 13C and MS. Submitted, in vitro, to their antiparasitic testing on Trypanosoma brucei brucei, and toxicity on Artemia salina Leach, all compounds except GT2 showed significant antitrypanosomal activity IC50 ranging from 1 to 34 micromolar (μM). Among them, 2-acetynaphthalene salicylhydrazone GS4 (IC50 = 1.97 ± 0.42 μM) and 7-methoxy-1-tetralone p-tosylhydrazone GT3 (IC50 =7.98 ± 1.65 μM) exhibited good trypanocidal activity and the other are moderates on parasite; when the compounds GS1, GT3 and GT4 presented toxic activity on larvae. In agreement to their selectivity index, which is greater than 1 (SI > 1), products turn out quite selective on the parasite: a series of salicylhydrazones revealed more selective (SI ≥ 11), especially GS4 (SI = 157) than the series of p-tosylhydrazones showed 1 ≤ SI ≤ 22. The synthesized compounds clearly displayed significant selective pharmaceutical activities on the parasite tested. Compounds developing could open promising route to news drug-candidates.

Studies of genotoxicity and mutagenicity of nitroimidazoles: demystifying this critical relationship with the nitro group

Nitroimidazoles exhibit high microbicidal activity, but mutagenic, genotoxic and cytotoxic properties have been attributed to the presence of the nitro group. However, we synthesised nitroimidazoles with activity against the trypomastigotes of Trypanosoma cruzi, but that were not genotoxic. Herein, nitroimidazoles (11-19) bearing different substituent groups were investigated for their potential induction of genotoxicity (comet assay) and mutagenicity (Salmonella/Microsome assay) and the correlations of these effects with their trypanocidal effect and with megazol were investigated. The compounds were designed to analyse the role played by the position of the nitro group in the imidazole nucleus (C-4 or C-5) and the presence of oxidisable groups at N-1 as an anion receptor group and the role of a methyl group at C-2. Nitroimidazoles bearing NO2 at C-4 and CH3 at C-2 were not genotoxic compared to those bearing NO 2 at C-5. However, when there was a CH3 at C-2, the position of the NO2 group had no influence on the genotoxic activity. Fluorinated compounds exhibited higher genotoxicity regardless of the presence of CH3 at C-2 or NO2 at C-4 or C-5. However, in compounds 11 (2-CH3; 4-NO2; N-CH2OHCH2Cl) and 12 (2-CH3; 4-NO2; N-CH2OHCH2F), the fluorine atom had no influence on genotoxicity. This study contributes to the future search for new and safer prototypes and provide.

Avaliação da atividade citotóxica e potencial antiparasitário in vitro do a-pineno e carvacrol / Cytotoxic and antiparasitic in vitro activities of a-pinene and carvacrol

A leishmaniose e a doença de Chagas tem sido um grande desafio, no que diz respeito à sua terapêutica. Devido à grande dificuldade de encontrar fármacos que garantam uma ação terapêutica eficiente e menos agressora à espécie humana, diferentes produtos naturais vêm sendo testados. Muitas espécies vegetais foram investigadas quanto à sua ação leishmanicida e tripanocida na expectativa de que seus compostos metabólicos possuam atividade antiparasitária e ausência ou baixa citotoxicidade. Neste estudo sobre bioatividade do a-pineno e carvacrol, avaliaram-se os potenciais leishmanicida e tripanocida. O carvacrol apresentou um percentual de inibição de 38,34% e 74,12% para as formas promastigotas e epimastigotas respectivamente, na concentração de 100µg/mL, apresentando uma citotoxicidade de 21,62%. O a-pineno apresentou 100% e 5,30% de inibição para as formas epimastigota e promastigota na concentração de 100 µg/mL, com citotoxicidade de 87,88%.

Leishmaniasis and Chagas Disease represent a great challenge against the modern therapeutics. Due the high difficult to find new drugs with therapeutic efficacy and low toxicity, several natural products had been screened. Many species of plants were investigated about their leishmanicidal and trypanocidal activities. Some phytocompounds are the a-pinene and carvacrol. In this work, we evaluated the bioactivities of a-pinene and carvacrol against Trypanosoma cruzi and Leishmania braziliensis cell lines. The carvacrol inhibited 38,34% and 74,12% of the promatigote and epimastigote forms, respectively at 100 µg/mL, showing a low cytotoxic activity (21,62%). The O a-pinene inhibited 100% and 5,30% against the epimastigote and promastigote forms respectively, at 100 µg/mL, showing a higher cytotoxic activity (87,88%).

Estudo fitoquímico e avaliação in vitro da atividade anti-Trypanosoma cruzi cepa Y de Pilocarpus spicatus St. Hil. (Rutaceae) / Phytochemical study and in vitro evaluation of the anti-Trypanosoma cruzi Y strain activity of Pilocarpus spicatus A. St. Hil.

A investigação química da espécie Pilocarpus spicatus, popularmente conhecida como jaborandi e usada na medicina tradicional para doenças como estomatite, febre, bronquite e psoríase, teve por objetivo o isolamento e/ou identificação de substâncias ativas e a avaliação da atividade antiparasitária dos extratos frente às formas epimastigotas de Trypanosoma cruzi. O estudo resultou na identificação de nove substâncias, tais como: tridecanona, 2-heptadecanona, espatulenol, aromadendreno, β-cariofileno, ácido 3α-hidroxitirucala-7,24-dien-21-óico, (+)-isoangenomalina, episesamina e sesamina. As estr uturas dos compostos foram elucidadas por análises espectroscópicas e comparação com dados da literatura. Os extratos hexânico e metanólico de folhas e raízes foram testados in vitro contra o Trypanosoma cruzi cepa Y e apresentaram atividade tripanomicida.

The chemical investigation of the species Pilocarpus spicatus - popularly known as jaborandi and used in traditional medicine for diseases, such as stomatitis, fever, bronchitis and psoriasis - aimed to isolate and / or identify the active substances and evaluate the antiparasitic activity of the extracts against the Trypanosoma cruzi epimastigote forms. The study resulted in the identification of nine substances, such as tridecanone, 2-heptadecanone, spathulenol, aromadendrene, β-caryophyllene, 3α-hydroxytirucalla-7,24-dien-21-oic acid, (+)-isoangenomaline, episesamin and sesamin. The structures were elucidated by spectroscopic analysis and comparison with literature data. The hexane and methanol extracts from leaves and roots were tested in vitro against Trypanosoma cruzi Y strain and showed trypanocidal activity.

Citotocixidade e atividade antiparasitária de Lygodium venustum SW / Cytotoxic and antiparasitic activity of Lygodium venustum SW

. Doenças parasitárias infecciosas como leishmaniose e doença de Chagas tem se difundido nas últimas décadas a locais onde antes não se observava sua ocorrência. São consideradas negligenciadas por assolarem países pobres e serem marginalizadas farmacologicamente. O tratamento não apresenta muitas opções de fármacos e estes demonstram relevante toxicidade contribuindo para o aparecimento de diversos efeitos colaterais. A pesquisa com produtos naturais tem se mostrado uma interessante alternativa para a procura por novos fármacos. Lygodium venustum é uma samambaia cosmopolita de hábito lianescente encontrada na encosta na Chapada do Araripe, considerada por algumas populações americanas como planta medicinal para o tratamento de dermatoses, infecções, micoses e tricomoníases. Neste estudo foi avaliada sua atividade anti-parasitária contra Leishmania brasiliensis e Trypanosoma cruzi, bem como sua citotoxicidade através de ensaios n vitro. Foram testadas a fração hexânica e o extrato etanólico obtido das folhas de Lygodium venustum em diferentes concentrações. Para os testes in vitro de T. cruzi, foi utilizado o clone CL-B5 e para Leishmania brasiliensis foram utilizadas formas promastigotas. O ensaio de citotoxicidade foi realizado com linhagens de fbroblastos. L. venustum não apresentou atividade antiparasitária clinicamente relevante na forma de extrato etanólico bruto nem como fração hexânica contra Leishmania. A fração hexânica apresentou uma atividade intermediária contra T. cruzi, porém a concentração de efeito moderado possui citotoxicidade máxima tornando-se inviável para aplicação clínica. Entretanto, a citoxicicidade apresentada poderá ser útil em pesquisas sobre atividade antineoplásica em células tumorais.

Infectious and parasitic diseases like leishmaniasis and Chagas disease have spreading recent decades to places not observed before. They are considered neglected by desolating poor countries and marginalized pharmacologically. There are not many options for the treatment and these drugs have shown signifcant toxicity contributing to the appearance of several side effects. Research on natural products has been shown to be an interesting alternative to the search for new drugs. Lygodium venustum is a cosmopolitan fern with latescence habit found on the Chapada do Araripe, considered by some American popula-tions as a medicinal plant for the treatment of skin diseases, infections, fungal infections and trichomoniasis. This study evaluated its antiparasitic activity against Trypanosoma cruzi and Leishmania brasiliensis, as well as its cytotoxicity through trials in vitro. We tested the ethanolic extract and hexane fraction obtained from the leaves of L. venustum at different concentrations. For in vitro tests of T. cruzi, we used the clone CL-B5 and for L. brasiliensis we used promastigotes. The cytotoxicity assay was performed with strains of fbroblasts. L.venustum showed no antiparasitic activity clinically relevant in the form of crude ethanolic extractor as the hexane fraction against Leishmania. The hexane fraction showed an intermediate activity against T.cruzi, but the concentration of moderate effect has maximum cytotoxicity becoming unfeasible for clinical application. However, the cytotoxicity presented may be useful in research on antineoplastic activity in tumor cells.

Trypanocidal activity of Brazilian plants against epimastigote forms from Y and Bolivia strains of Trypanosoma cruzi

Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fibroblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 µg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93) and Aegiphila lhotzkiana (Am160). Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI) being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.

Avaliação da atividade anti-Trypanosoma e anti-Leishmania de Mentha arvensis e Turnera ulmifolia / Evaluation of the anti-Trypanosoma and anti-Leishmania activity of Mentha arvensis and Turnera ulmifolia

Tripanosomiasis or “Chagas disease”, caused by Trypanosoma cruzi, affect 10 million people in Latin America. Today, the chemotherapy is the only specific treatment against this disease, being the most used drugs the nifurtimox and benznidazole. Leishmaniasis is a disease caused by parasites of the genus Leishmania, mainly founded in regions with forests, as the Amazonia. Recent reports about the Leishmaniasis indicate a deficit of therapeutical drugs available against this disease and reinforce the necessity of the discovering of new drugs. An interesting approach against these diseases is the use of natural products, as the extracts of plants as Mentha arvensis and Turnera ulmifolia. For the in vitro assays against T. cruzi and Leishmania, was used the clone CL-B5 and promastigote forms, respectively. The cytotoxic assay was performed using fibroblasts. Our results indicated that M. arvensis was active against all strains assayed, inhibiting 65 e 47 percent of the assayed strains (IC50 = 192.3 and 531.9 ug/mL respectively), representing an interesting and alternative source of natural products with anti-kinetoplastida activity.

Doença de Chagas, causada por Trypanosoma cruzi, afeta cerca de 10 milhões de pessoas nas Américas. Atualmente, a quimioterapia é o único tratamento específico disponível para esta doença, onde os medicamentos utilizados são nifurtimox e benzonidazol. Leishmaniose tegumentar Americana no Brasil é causada por uma variedade de espécies de Leishmania e uma grande diversidade destes parasitos pode ser encontrada na Região Amazônica. Revisões recentes na quimioterapia de leishmaniose enfatizam as deficiências dos agentes terapêuticos atualmente disponíveis e mostram a necessidade urgente de novos candidatos. Uma alternativa para substituir esses medicamentos são extratos naturais de Mentha arvensis e Turnera ulmifolia. Foram preparados extratos etanólicos das folhas de M. arvensis e T. ulmifolia. Para os testes in vitro de T. cruzi, foi utilizado o clone CL-B5 e para Leishmania brasiliensis foram utilizadas formas promastigotas. O ensaio de citotoxicidade foi realizado com linhagens de fibroblastos. Nossos resultados indicam que M. arvensis foi eficaz contra as cepas de parasitos testadas apresentando 65 e 47 por cento de inibição em uma concentração de 500 ug/mL (respectivamente, CE50 = 192.3 e 531.9 ug/mL), sendo considerada uma fonte alternativa de produtos naturais com atividade contra T. cruzi e L. brasiliensis.

Synthesis, characterization and anti-trypanosomal activity of R-(-)carvone and arylketones-thiosemi carbazones and toxicity against Artemia salina Leach.

This work is focused on the synthesis and characterization of a series of N(4)- substituted thiosemicarbazones and the evaluation of their in-vitro anti-trypanosomal activity and toxicity. A series of thiosemicarbazones (1-4) and N(4)-phenyl-3-thiosemicarbazones (5-8) have been synthesized on R-(-)carvone, acetophenone, 4’-methylacetophenone and benzophenone by condensation reaction with good yields. All compounds were characterized by spectrometrical analysis methods infrared IR, nuclear magnetic resonance NMR (1H &13C) and mass spectrometry MS, confirming their structures respectively, and were evaluated for their invitro parasitic activity against the bloodstream form of the strain 427 of Trypanosoma brucei brucei using the “LILIT, Alamar Blue” method (Baltzet al., 1985; Hirumi et al., 1994; Räz et al.,1997). Their toxicity against brine shrimp larvae (Artemia salina Leach) was studied, according to the method of Michael et al. (1956) resumed byVanhaecke et al. (1981) and bySleet and Brendel (1983). Some of them have exhibited a strong trypanocidal activity, especially compounds 8, 3, 1 and 4 with their half-inhibitory concentrations (IC50) values equal to 8.48, 8.73, 39.71 and 67.17 micro-molar (μM) respectively. Except compounds 1 and 4whose half-lethal concentration (LC50) values were20.58 and 33.72 μM respectively and then toxics, all synthesized compounds showed negligible toxicity against Artemia salinaL. (LC50> 280 μM) and good selectivity (S) (SI “index” ≤1).

Evaluation of the bactericidal and trypanocidal activities of triterpenes isolated from the leaves, stems, and flowers of Lychnophora pinaster

The phytochemical investigation on the aereal parts of Lychnophora pinaster Mart., Asteraceae, was carried to isolation of triterpenes. 3-O-Acetyl-lupeol (1), 3-O-acetyl-pseudotaraxasterol (2), and 3-O-acetyl-α-amyrin (3) were isolated from hexanic extract and 4,4-dimethyl-cholesta-22,24-dien-5-ol (4), α-amyrin (5), and lupeol (6) were isolated from hexanic/dichlorometanic extract of the leaves. Compounds Δ7-bauerenyl acetate (7), friedelin (8), stigmasterol (9), and sitosterol (10) were isolated from the hexanic/dichlorometanic extract of the stems. The steroids 9 and 10 were also isolated from the hexanic/dichlorometanic extract of the flowers. Triterpenes 1, 3, 4, and 7 are described for the first time in the genus Lychnophora. The apolar fractions of the leaf and stem extracts and some isolated triterpenes showed low trypanocidal activity. Moreover, apolar fractions of the leaf and stem extracts and 5 showed antibacterial action against Staphylococcus aureus.

Trypanocidal activity of flavonoids and limonoids isolated from Myrsinaceae and Meliaceae active plant extracts / Atividade tripanocida de flavonoides e limonoides isolados de extratos ativos de plantas de Myrsinaceae e Meliaceae

The activity of crude extracts of three Rapanea species (Myrsinaceae) and Cipadessa fruticosa (Meliaceae) was evaluated in vitro against the trypomastigote forms of Trypanosoma cruzi. Thirty-three extracts from different organs of these species were assayed and eleven of them showed significant activity (lysis percent >50). The fractionation of an active extract from branches of R. lancifolia (99.5 percent) led to the isolation of two flavonoids: quercetin and taxifolin, which have weak trypanocidal activity. Additionally, one active extract from fruits of C. fruticosa (97.7 percent) afforded mexicanolide limonoids: cipadesin, mexicanolide, febrifugin and cipadesin A, that were slightly active on T. cruzi. Moreover, other two flavonoids (flavone and 7-methoxyflavone), previously assayed against T. cruzi, were isolated from the hexane extract from branches of C. fruticosa (100 percent). The results presented here suggest that the plants evaluated could be a source of new active compounds against T. cruzi.

A atividade de extratos brutos de três espécies de Rapanea (Myrsinaceae) e de Cipadessa fruticosa (Meliaceae) foi avaliada in vitro contra formas tripomastigotas de Trypanosoma cruzi. Foram obtidos 33 extratos de diferentes órgãos das espécies estudadas, sendo que onze deles apresentaram atividades significantes ( por cento de lise > 50) nos ensaios realizados. O fracionamento de um extrato ativo dos galhos de R. lancifolia (99,5 por cento) resultou no isolamento de dois flavonoides (quercetina e taxifolina), que apresentaram baixa atividade tripanocida. De um extrato ativo dos frutos de C. fruticosa (97,7 por cento) foram isolados os limonoides mexicanolídeos cipadesina, mexicanolídeo, febrifugina e cipadesina A, que foram moderadamente ativos sobre T. cruzi. Além disso, outros dois flavonoides (flavona e 7-metoxiflavona), previamente ensaiados contra T. cruzi, foram isolados do extrato hexânico dos galhos de C. fruticosa (100 por cento). Os resultados obtidos aqui sugerem que as plantas avaliadas podem constituir fontes de novas substâncias ativas sobre o T. cruzi.

Trypanocidal activity of coumarins and styryl-2-pyrones from Polygala sabulosa A.W. Bennett (Polygalaceae) / Atividade tripanocida de cumarinas e estiril-2-pironas de Polygala sabulosa A.W. Bennett (Polygalaceae)

A bioatividade das frações e compostos obtidos de Polygala sabulosa contra as formas epimastigota, tripomastigota sanguínea e amastigota de Trypanosoma cruzi foram avaliadas in vitro. Frações diclorometano e acetato de etila mostraram potente atividade tripanocida sob as formas epimastigotas (IC50 < 10,4 µg/mL). Análises por cromatografia em camada delgada destas frações confirmaram a presença de compostos previamente descritos (dihidroestiril-2-pironas, estiril-2-pironas e 6-metoxi-7-preniloxicumarina). Após o fracionamento da fração diclorometano por cromatografia em coluna, obteve-se o composto α-espinasterol e da fração acetato de etila obtiveram-se os compostos apigenina, quercetina e uma quercetina-3- O-glicosídeo, todos descritos pela primeira vez para o gênero Polygala. 4-metoxi-6-(11,12-metilenodioxi-14-metoxidihidroestiril)-2-pirona, 4-metoxi-6-(11,12-dimetoxi-14-metoxiestiril)-2-pirona, 6-metoxi-7-preniloxicumarina e quercetina-3- O-glicosídeo mostraram fraca atividade contra a forma tripomastigota sanguínea (IC50 < 1008,6 µg/mL). A cumarina prenilada foi o composto mais ativo contra ambas as formas epimastigota e tripomastigota, com IC50 10,5 e 88,2 µg/mL, respectivamente. A atividade hemolítica e a toxicidade celular de cada composto foram também avaliadas. Além disso, 4-metoxi-6-(11,12-metilenodioxi-14-metoxidihidroestiril)-2-pirona e 6-metoxi-7-preniloxicumarina reduziram em quatro vezes a infecção em ratos por Vero Cells nas concentrações de 100 e 50 µg/mL respectivamente. Esses resultados mostram, pela primeira vez, a atividade de compostos de P. sabulosa contra T. cruzi.

Bioactivity of fractions and compounds obtained from Polygala sabulosa against Trypanosoma cruzi epimastigote, blood trypomastigote and amastigote forms were evaluated in vitro. Dichloromethane and ethyl acetate fractions showed a strong trypanocidal activity on epimastigotes (IC50 < 10.4 µg/mL). Chromatographic analysis by TLC of these fractions confirmed the presence of previously described compounds (dihydrostyryl-2-pyrones, styryl-2-pyrones and 6-methoxy-7-prenyloxycoumarin). The dichloromethane fraction was fractioned by silica gel column chromatography to afford the compound α-spinasterol and the ethyl acetate fraction yielded apigenin, quercetin and a quercetin-3-O-glucoside, being the first description for the Polygala genus. 4-Methoxy-6-(11,12-methylenedioxy-14-methoxydihydrostyryl)-2-pyrone, 4-methoxy-6-(11,12-dimethoxystyryl)-2-pyrone, 6-methoxy-7-prenyloxycoumarin and quercetin-3-O-glucoside showed a weak activity against blood trypomastigotes (IC50 < 1008.6 µg/mL). The prenylated coumarin was the most active compound against both epimastigote and trypomastigote forms, IC50 10.5 and 88.2 µg/mL, respectively. The hemolytic activity and cell toxicity of each active compound was also assessed. Furthermore, 4-methoxy-6-(11,12-methylenedioxy-14-methoxydihydrostyryl)-2-pyrone and 6-methoxy-7-prenyloxycoumarin reduced 4 times the T. cruzi infection rate for Vero cells at 100 and 50 µg/mL, respectively. These results show for the first time active compounds against T. cruzi in P. sabulosa.

Biological activity of the aqueous extract of Lychnophora pinaster Mart.

Lyophilized aqueous extract (LAE) from Lychnophora pinaster Mart (Asteraceae) aerial parts was evaluated in the search of possible biological activities. LAE exhibited trypanocidal activity (113.62 mg/mL), but could not inhibit 5-lipoxygenase in vitro (17 percent of inhibition). LAE chemical characterization by HPLC with UV-Diode Array Detector showed the presence of caffeic acid, isochlorogenic acid, vitexin, isovitexin and quercetin, in comparison with authentic samples.