RESUMO
Trypanosomatidae is a family of unicellular parasites belonging to the phylum Euglenozoa, which are causative agents in high impact human diseases such as Leishmaniasis, Chagas disease and African sleeping sickness. The impact on human health and local economies, together with a lack of satisfactory chemotherapeutic treatments and effective vaccines, justifies stringent research efforts to search for new disease therapies. Here, we present in vitro trypanocidal activity data and mode of action data, repositioning leishmanicidal [1,2,3]Triazolo[1,5-a]pyridinium salts against Trypanosoma cruzi, the aetiological agent of Chagas disease. This disease is one of the most neglected tropical diseases and is a major public health issue in Central and South America. The disease affects approximately 6-7 million people and is widespread due to increased migratory movements. We screened a suite of leishmanicidal [1,2,3]Triazolo[1,5-a]pyridinium salt compounds, of which compounds 13, 20 and 21 were identified as trypanocidal drugs. These compounds caused cell death in a mitochondrion-dependent manner through a bioenergetic collapse. Moreover, compounds 13 and 20 showed a remarkable inhibition of iron superoxide dismutase activity of T. cruzi, a key enzyme in the protection from the damage produced by oxidative stress.
Assuntos
Doença de Chagas/tratamento farmacológico , Compostos de Piridínio/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , Reposicionamento de Medicamentos , Humanos , Leishmaniose/tratamento farmacológico , Membranas Mitocondriais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , América do Sul , Superóxido Dismutase/metabolismo , Tripanossomíase Africana/tratamento farmacológicoRESUMO
Currently, only two drugs (i.e. benznidazole (BZN) and nifurtimox (NFX)) have been approved for the treatment of Trypanosoma cruzi (Tc) infection, the etiological agent causing Chagas disease. Since both drugs exhibit severe side effects, patients frequently abandon therapy, resulting in an inefficient pharmacotherapeutic treatment. In this context, there is an urgent need to develop new, safer and optimised anti-Tc agents. In this report, we present the synthesis and biological activity of 11 novel and 3 already reported N-arylsulfonyl-benzimidazole derivatives (NBSBZD,1-14) currently in development as potential anti-Tc compounds. These compounds were designed as part of a library of synthetic arylsulfonyl heterocycle derivatives constructed from privileged structures exhibiting drug-like properties. Based on bioactivity assays against Tc, (in both the extracellular and intracellular forms), we observed that 10 compounds exhibited bioactivity against the epimastigote form, while six of them exhibited activity against the amastigote counterpart. Also, the compounds showed less cytotoxicity compared to the reference drug BZN as measured in Vero cell culture. In order to elucidate the potential mechanism of action, metabolite excretion profiles studies were performed, and complemented with molecular modeling studies performed over known Tc druggable targets. Consistency was observed between experimental and theoretical findings, with metabolic profiles showing that compounds 1, 2, 9, 12 and 14 interfered with the normal glycolysis cycle of Tc, while molecular modeling studies were able to establish a solid structure-activity relationship towards the inhibition of 6-phospho-1-fructokinase, a key enzyme involved in the parasite glycolytic cascade. Overall, the present study constitutes a multidisciplinary contribution to the development of new anti-Chagas compounds.
Assuntos
Benzimidazóis/farmacologia , Desenho de Fármacos , Tripanossomicidas/síntese química , Trypanosoma cruzi/efeitos dos fármacos , Animais , Benzimidazóis/síntese química , Benzimidazóis/uso terapêutico , Doença de Chagas/tratamento farmacológico , Chlorocebus aethiops , Simulação de Acoplamento Molecular , Tripanossomicidas/farmacologia , Células VeroRESUMO
Abstract: Background: Chagas disease is an endemic illness in the Americas and therefore constitutes a public health problem. An estimated 8 million people are infected and over 20 million live in areas at risk. In Mexico, the problem is under reported and no epidemiological data by the different States indicating true prevalence for this infection is available. During the chronic phase, 30% of infected patients may develop chagasic cardiomyopathy (CCM), characterized by different types of alterations of cardiac function. Objective: To describe cardiac abnormalities in Trypanosoma cruzi seropositive subjects in the endemic areas. Material and methods: This is a descriptive cross-sectional study with non-random sampling. In our project the endemic area was considered for Trypanosoma cruzi using the Epi Info statistical program (Stat Calc) to calculate the number of subjects to study by means of a sample of 1 033 subjects aged 2-90 years. Prior informed consent or parental consent, implementation of a survey, a 5 mL of blood sample free from anticoagulant was taken from the cubital vein to detect anti-Trypanosoma cruzi by ELISA, recombinant ELISA, hemagglutination indirect (HAI), indirect immunofluorescence (IFI) and Western blot (using the enzyme superoxide dismutase iron as antigen). Those subjects who were positive in two or more tests were chosen for electrocardiogram (EKG) and an echocardiogram (ECO) with portable devices. Results: Of the 1 033 participants, 84 between 6 and 88 years tested positive for Trypanosoma cruzi. In the analysis of data with echocardiograms and electrocardiograms, 47 subjects over 26 years (56%), presented right bundle branch block or left bundle block (RBBB/LBBB), changes in the diameters of the right ventricle or left ejection fraction accounting of 70%. In subjects under 26 years there were electrocardiographic changes (RBBB/LBBB). Conclusion: 8.13% were seropositive for Trypanosoma cruzi with ventricular conduction system and morphological alterations.
Resumen: Antecedentes: La enfermedad de Chagas es una patología endémica en las Américas, donde representa un problema de salud pública. Se estima que aproximadamente 8 millones de personas están infectadas y 20 millones viven en áreas de riesgo de infectarse. En México el problema está subestimado y se carece de datos epidemiológicos por estado del país que indiquen una prevalencia real de este padecimiento. Durante la fase crónica, el 30% de los pacientes infectados pueden desarrollar miocardiopatía chagásica (MCC), que se caracteriza por presentar diferentes alteraciones de la función cardiaca. Objetivo: Describir las alteraciones cardiacas en sujetos seropositivos para Trypanosoma cruzi de áreas endémicas. Material y métodos: Es un estudio con diseño transversal descriptivo, con muestra no probabilística. En nuestro proyecto, se consideró una zona endémica a Trypanosoma cruzi, mediante el programa estadístico Epi Info (Stat Calc), para estimar el número de sujetos a estudiar, obteniéndose una muestra de 1 033 sujetos de edades entre 2 a 90 años. Previo consentimiento informado, y aplicación de una encuesta, se puncionó la vena cubital, obteniéndose una muestra sanguínea de 5 mL, sin anticoagulante, para buscar anticuerpos anti-Trypanosoma cruzi mediante, ELISA, ELISA recombinante, hemaglutinación indirecta (HAI), inmunofluorescencia indirecta (IFI) y Western-Blot (usando la enzima superóxido dismutasa de hierro como antígeno). Los sujetos reactivos a dos o más pruebas fueron seleccionados para la realización de un electrocardiograma (EKG) y un ecocardiograma (ECO) con equipos portátiles Resultados: De los 1 033 participantes, 84 entre 6 a 88 años resultaron positivos para Trypanosoma cruzi. En el análisis de los hallazgos ecocardiográficos y electrocardiográficos en los 47 sujetos mayores de 26 años (56%) presentaron bloqueo de rama derecha o izquierda del haz de His (BRDHH/BRIHH). Conclusión: El 8.13% fueron seropositivos para Trypanosoma cruzi con cambios morfológicos ventriculares y del sistema de conducción del haz de His.
RESUMO
BACKGROUND: Chagas disease caused by Trypanosoma cruzi is endemic in Latin America. Human infection is mainly spread by Triatominae insects. Other forms of transmission are congenital, blood transfusion and organ transplantation. METHODS: Anti-T. cruzi antibodies were determined by enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) in 155 serum samples from mothers and their babies. Indirect immunofluorescence (IFA) and a commercial test were used to validate efficacy of a specific ELISA-iron-excreted superoxide dismutase assay. Sera from babies were collected at 6 and 12 months, whereas maternal samples were obtained after delivery. Calostrum and umbilical cord samples were simultaneously obtained. RESULTS: Anti-T. cruzi antibodies were detected in 8 (5.16%) mothers by ELISA-WB, in 7 (4.51%) using IFA and in 1 (0.64%) by a commercial kit. Nine (5.80%) 6-month-old children were positive by ELISA-WB and 7 (4.51%) by IFA; negative results were obtained when the commercial kit was used. At 12 month of age, 15 (9.67%) children were positive by ELISA-WB, 13 (8.38%) by IFA and 1 (0.64%) by the commercial test. Antibodies were detected in 4 mothers whose children were serologically negative. Four other mothers and their children were positive, but only one of them had detected antibodies in umbilical cord up to 12 months, thus assuming vertical transmission. CONCLUSIONS: The use of iron-excreted superoxide dismutase as antigen in serologic tests for detection of T. cruzi yielded promising results as diagnostic procedure.
Assuntos
Doença de Chagas/congênito , Doença de Chagas/diagnóstico , Complicações Infecciosas na Gravidez/parasitologia , Superóxido Dismutase/sangue , Trypanosoma cruzi/imunologia , Adulto , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Western Blotting/métodos , Doença de Chagas/sangue , Doença de Chagas/enzimologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Técnica Indireta de Fluorescência para Anticorpo/métodos , Humanos , Lactente , Transmissão Vertical de Doenças Infecciosas , Mães , Gravidez , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/fisiopatologia , Superóxido Dismutase/imunologia , Trypanosoma cruzi/isolamento & purificação , Adulto JovemRESUMO
Clinical diagnosis of leishmaniasis is highly complex, presenting a wide range of clinical manifestations, sometimes non-specific, and thus the epidemiological study and diagnostic need specific molecular markers for each Leishmania species. Leishmania spp. posses different Fe-SOD isoforms, one of which is excreted into the external milieu and, presenting immunogenic characteristics, is a very reliable molecular marker. Superoxide dismutases (SODs) are antioxidant metal-enzymes responsible for the dismutation of superoxide ion into hydrogen peroxide and molecular oxygen, and it is considered an important virulence factor. In this manuscript we have purified the iron(Fe)-SOD excreted by Leishmania braziliensis using ion-exchange and molecular-sieve chromatography and we have studied it as an antigen in serodiagnostic analyses in ELISA and Western blot techniques, testing 213 human sera from Mexico. Indeed, L. braziliensis Fe-SODe has been purified 123.26 times with a specific activity of about 893.66 U/mg of protein. Applying the purified enzymes in serological tests we found 17.84% sera positive. We have demonstrated that the purified enzyme is more sensitive than the non-purified ones and we also demonstrated, for the first time, the presence of antibodies against L. braziliensis, not the main species in the country, in human population from Hidalgo and Nuevo Leon States.
RESUMO
Trypanosoma cruzi and Leishmania spp. are vector-borne parasitic protozoa, the causative agents of Chagas and Leishmaniasis diseases, respectively. Trypanosoma cruzi and Leishmania spp. have been reported in a wide variety of mammals, including canids, which play an important role in the transmission of these parasites between urban and natural environments. Currently, no studies have been conducted on trypanosomatids in wild canids in Mexico. Using a partially purified fraction of excreted Iron Superoxide dismutase (FeSODe) of T. cruzi, L. mexicana, and L. infantum as antigen for the ELISA and Western blot tests, we detected the presence of antibodies against these parasites in gray foxes (Urocyon cinereoargenteus Schreber, 1775), domestic and feral dogs (Canis lupus familiaris L.) from Queretaro. Our study provides new information regarding the potential of these carnivores as reservoirs of T. cruzi, Leishmania mexicana, and L. infantum for Latin America.
RESUMO
OBJECTIVE: To classify 21 new isolates of Trypanosoma cruzi (T. cruzi) according to the Discrete Typing Unit (DTU) which they belong to, as well as tune up a new pair of primers designed to detect the parasite in biological samples. METHODS: Strains were isolated, DNA extracted, and classified by using three Polymerase Chain Reactions (PCR). Subsequently this DNA was used along with other isolates of various biological samples, for a new PCR using primers designed. Finally, the amplified fragments were sequenced. RESULTS: It was observed the predominance of DTU I in Colombia, as well as the specificity of our primers for detection of T. cruzi, while no band was obtained when other species were used. CONCLUSIONS: This work reveals the genetic variability of 21 new isolates of T. cruzi in Colombia.Our primers confirmed their specificity for detecting the presence of T. cruzi.
RESUMO
Immunological diagnostic methods for Trypanosoma cruzi depend specifically on the presence of antibodies and parasitological methods lack sensitivity during the chronic and "indeterminate" stages of the disease. This study performed a serological survey of 1,033 subjects from 52 rural communities in 12 of the 18 municipalities in the state of Querétaro, Mexico. We detected anti-T. cruzi antibodies using the following tests: indirect haemagglutination assay (IHA), indirect immunofluorescence assay (IFA), ELISA and recombinant ELISA (rELISA). We also performed Western blot (WB) analysis using iron superoxide dismutase (FeSOD), a detoxifying enzyme excreted by the parasite, as the antigen. Positive test results were distributed as follows: ELISA 8%, rELISA 6.2%, IFA and IHA 5.4% in both cases and FeSOD 8%. A comparative study of the five tests was undertaken. Sensitivity levels, specificity, positive and negative predictive values, concordance percentage and kappa index were considered. Living with animals, trips to other communities, gender, age, type of housing and symptomatology at the time of the survey were statistically analysed using SPSS software v.11.5. Detection of the FeSOD enzyme that was secreted by the parasite and used as an antigenic fraction in WBs showed a 100% correlation with traditional ELISA tests.
Assuntos
Anticorpos Antiprotozoários/isolamento & purificação , Doença de Chagas/sangue , Doença de Chagas/diagnóstico , População Rural , Trypanosoma cruzi/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Chagas/epidemiologia , Criança , Pré-Escolar , Habitação , Humanos , Lactente , Estilo de Vida , México/epidemiologia , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Superóxido Dismutase/metabolismo , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/isolamento & purificação , Adulto JovemRESUMO
Immunological diagnostic methods for Trypanosoma cruzi depend specifically on the presence of antibodies and parasitological methods lack sensitivity during the chronic and “indeterminate” stages of the disease. This study performed a serological survey of 1,033 subjects from 52 rural communities in 12 of the 18 municipalities in the state of Querétaro, Mexico. We detected anti-T. cruzi antibodies using the following tests: indirect haemagglutination assay (IHA), indirect immunofluorescence assay (IFA), ELISA and recombinant ELISA (rELISA). We also performed Western blot (WB) analysis using iron superoxide dismutase (FeSOD), a detoxifying enzyme excreted by the parasite, as the antigen. Positive test results were distributed as follows: ELISA 8%, rELISA 6.2%, IFA and IHA 5.4% in both cases and FeSOD 8%. A comparative study of the five tests was undertaken. Sensitivity levels, specificity, positive and negative predictive values, concordance percentage and kappa index were considered. Living with animals, trips to other communities, gender, age, type of housing and symptomatology at the time of the survey were statistically analysed using SPSS software v.11.5. Detection of the FeSOD enzyme that was secreted by the parasite and used as an antigenic fraction in WBs showed a 100% correlation with traditional ELISA tests.
Assuntos
Humanos , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Anticorpos Antiprotozoários/isolamento & purificação , Doença de Chagas/sangue , Doença de Chagas/diagnóstico , População Rural , Trypanosoma cruzi/imunologia , Doença de Chagas/epidemiologia , Habitação , Estilo de Vida , México/epidemiologia , Estudos Soroepidemiológicos , Superóxido Dismutase/metabolismo , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/isolamento & purificaçãoRESUMO
Leishmania sp. survival in the vertebrate host depends on the host macrophage immune response as well as on the parasite's defense against free radicals. Iron-superoxide dismutase (Fe-SOD) is a key antioxidant enzyme that contributes to radical superoxide dismutation, preventing the disease from surging and propagating itself. Leishmania sp. has various Fe-SOD isoforms, one of which (Fe-SODe) is excreted into the medium and, being highly immunogenic, can be considered a very good molecular marker. In this work, we purified the Fe-SOD enzymes excreted by L. peruviana and L. amazonensis and studied them as antigens in serodiagnosis. We used ELISA and Western blot techniques to test 51 human cutaneous leishmaniasis sera from Colombia. All 51 patients presented with dermal injuries caused by unknown Leishmania species. The results observed with the purified proteins were compared with those obtained when total soluble lysate and unpurified Fe-SODe were used as the antigen fraction. Thus, we conclude that the purified enzymes are more sensitive and specific than their unpurified counterparts and that there is no cross-reactivity between them.
Assuntos
Anticorpos , Leishmaniose Cutânea/diagnóstico , Superóxido Dismutase/imunologia , Superóxido Dismutase/isolamento & purificação , Anticorpos/imunologia , Especificidade de Anticorpos , Colômbia , Radicais Livres/metabolismo , Humanos , Leishmania/enzimologia , Leishmania/imunologia , Leishmaniose Cutânea/imunologiaRESUMO
The activity of a family scorpiand-like azamacrocycles against Leishmania infantum and Leishmania braziliensis was studied using promastigotes, axenic and intracellular amastigotes forms. All the compounds are more active and less toxic than meglumine antimoniate (Glucantime). Moreover, the data on infection rates and amastigotes showed that compounds P2Py, PN and P3Py are the most active against both species of Leishmania. On the other hand, studies on the inhibitory effect of these compounds on SOD enzymes showed that while the inhibition of the Fe-SOD enzyme of the promastigote forms of the parasites is remarkable, the inhibition of human CuZn-SOD and Mn-SOD from Escherichia coli is negligible. The ultrastructural alterations observed in treated promastigote forms confirmed that the compounds having the highest activity were those causing the largest cell damage. The modifications observed by (1)H NMR, and the amounts of catabolites excreted by the parasites after treatment with the compounds, suggested that the catabolic mechanism could depend on the structure of the side chains linked to the aza-scorpiand macrocycles.
Assuntos
Antiprotozoários/farmacologia , Compostos Aza/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Compostos Macrocíclicos/farmacologia , Antiprotozoários/síntese química , Antiprotozoários/química , Compostos Aza/síntese química , Compostos Aza/química , Relação Dose-Resposta a Droga , Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/química , Estrutura Molecular , Testes de Sensibilidade Parasitária , Relação Estrutura-AtividadeRESUMO
Human lagochilascariasis (HL) is a parasite produced by Lagochilascaris minor Leiper 1909 that also can be found in cats and dogs. HL is considered an emerging zoonosis in the Americas, spreading from Mexico to Argentina, and the Caribbean Islands. The present paper describes three HL cases from the Peninsula of Yucatan, Mexico, recorded in the last decade. It describes the characteristics of the lesions and discusses the route of transmission in humans and particularly in the observed patients.
La Lagochilascariasis humana (HL) es producida por Lagochilascaris minor Leiper, 1909; el cual es un parásito que puede ser encontrado también en gatos y perros. HL es considerada una zoonosis emergente en América distribuida desde México hasta Argentina y las islas del Caribe. El presente artículo describe tres casos de HL en la Península de Yucatán, México registrados en la última década. Se describen las características de las lesiones y se discute la ruta de transmisión en humanos y particularmente en los pacientes observados.
Assuntos
Adolescente , Idoso , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Ascaridida/diagnóstico , Ascaridídios/isolamento & purificação , Albendazol/uso terapêutico , Antinematódeos/uso terapêutico , Infecções por Ascaridida/tratamento farmacológico , México , Pamoato de Pirantel/uso terapêuticoRESUMO
Human lagochilascariasis (HL) is a parasite produced by Lagochilascaris minor Leiper 1909 that also can be found in cats and dogs. HL is considered an emerging zoonosis in the Americas, spreading from Mexico to Argentina, and the Caribbean Islands. The present paper describes three HL cases from the Peninsula of Yucatan, Mexico, recorded in the last decade. It describes the characteristics of the lesions and discusses the route of transmission in humans and particularly in the observed patients.
Assuntos
Infecções por Ascaridida/diagnóstico , Ascaridídios/isolamento & purificação , Adolescente , Idoso , Albendazol/uso terapêutico , Animais , Antinematódeos/uso terapêutico , Infecções por Ascaridida/tratamento farmacológico , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Pamoato de Pirantel/uso terapêuticoRESUMO
OBJECTIVES: To evaluate the potential of iron-oxide dismutase excreted (SODeCRU) by T. cruzi as the antigen fraction in the serodiagnosis of Chagas disease and compile new epidemiological data on the seroprevalence of this disease in the suburban population of the city of Santiago de Querétaro (Mexico). DESIGN AND METHODS: 258 human sera were analyzed by the techniques of ELISA and Western blot and using the homogenate and the SODeCRU. RESULTS: A total of 31 sera were positive against ELISA/SODeCRU (12.4%), while 30 sera proved positive by WB/SODeCRU (11.6%). The comparison between the technique of ELISA and WB showed a sensitivity of 93%, and a specificity of 99%. The positive predictive value was 93% and the negative predictive value was 99%, with a Kappa (κ) value of 1. CONCLUSIONS: These preliminary data reveal the degree of infection of nonrural areas of Mexico and demonstrated that SODeCRU is an antigen useful to diagnose Chagas disease.
Assuntos
Doença de Chagas/sangue , Doença de Chagas/epidemiologia , Trypanosoma cruzi/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antiprotozoários/sangue , Western Blotting , Doença de Chagas/parasitologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Valor Preditivo dos Testes , Projetos de Pesquisa , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Testes Sorológicos , População Suburbana , TemperaturaRESUMO
Studies on the anti-proliferative activity in vitro of seven ternary nickel (II) complexes with a triazolopyrimidine derivative and different aliphatic or aromatic amines as auxiliary ligands against promastigote and amastigote forms of Leishmania infantum and Leishmania braziliensis have been carried out. These compounds are not toxic for the host cells and two of them are effective at lower concentrations than the reference drug used in the present study (Glucantime). In general, the in vitro growth rate of Leishmania spp. was reduced, its capacity to infect cells was negatively affected and the multiplication of the amastigotes decreased. Ultrastructural analysis and metabolism excretion studies were executed in order to propose a possible mechanism for the action of the assayed compounds. Our results show that the potential mechanism is at the level of organelles membranes, either by direct action on the microtubules or by their disorganization, leading to vacuolization, degradation and ultimately cell death.
Assuntos
Antiprotozoários/farmacologia , Complexos de Coordenação/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Níquel/farmacologia , Organelas/ultraestrutura , Pirimidinas/farmacologia , Animais , Antiprotozoários/síntese química , Antiprotozoários/química , Cátions Bivalentes/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Feminino , Leishmania braziliensis/metabolismo , Leishmania infantum/metabolismo , Ligantes , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Níquel/química , Organelas/efeitos dos fármacos , Testes de Sensibilidade Parasitária , Triazóis/farmacologiaRESUMO
Although human leishmaniasis has been reported in 20 states in Mexico, no case of leishmaniasis has been reported in cats to date. In the Yucatan Peninsula, it has been found that dogs may act as reservoirs for at least three Leishmania species (Leishmania mexicana, Leishmania braziliensis, and Leishmania panamensis). In this study we identified specific antibodies against these three Leishmania spp. and Trypanosoma cruzi in the sera from 95 cats from two States on the Yucatan Peninsula, namely Quintana Roo and Yucatan, by ELISA and Western blot techniques using whole extract and an iron superoxide dismutase excreted by the parasites as antigens. As well as demonstrating the presence of trypanosomatid antibodies in the feline population on the Yucatan Peninsula, we were also able to confirm the high sensitivity and specificity of the iron superoxide dismutase antigen secreted by them, which may prove to be very useful in epidemiological studies.
Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Gato/imunologia , Doença de Chagas/veterinária , Leishmania/imunologia , Leishmaniose/veterinária , Superóxido Dismutase/imunologia , Trypanosoma cruzi/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Western Blotting , Doenças do Gato/epidemiologia , Doenças do Gato/parasitologia , Gatos , Doença de Chagas/epidemiologia , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Ensaio de Imunoadsorção Enzimática , Leishmania/isolamento & purificação , Leishmania/patogenicidade , Leishmaniose/epidemiologia , Leishmaniose/imunologia , Leishmaniose/parasitologia , México/epidemiologia , Carga Parasitária , Prevalência , Sensibilidade e Especificidade , Trypanosoma cruzi/isolamento & purificação , Trypanosoma cruzi/patogenicidadeRESUMO
The activity of five (1-5) abietane phenol derivatives against Leishmania infantum and Leishmania braziliensis was studied using promastigotes and axenic and intracellular amastigotes. Infectivity and cytotoxicity tests were performed with J774.2 macrophage cells using Glucantime as a reference drug. The mechanisms of action were analysed by performing metabolite excretion and transmission electron microscopy ultrastructural studies. Compounds 1-5 were more active and less toxic than Glucantime. The infection rates and mean number of parasites per cell observed in amastigote experiments showed that derivatives 2, 4 and 5 were the most effective against both L. infantum and L. braziliensis. The ultrastructural changes observed in the treated promastigote forms confirmed that the greatest cell damage was caused by the most active compound (4). Only compound 5 caused changes in the nature and amounts of catabolites excreted by the parasites, as measured by ¹H nuclear magnetic resonance spectroscopy. All of the assayed compounds were active against the two Leishmania species in vitro and were less toxic in mammalian cells than the reference drug.
Assuntos
Animais , Feminino , Camundongos , Antiprotozoários/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Macrófagos/parasitologia , Terpenos/farmacologia , Antiprotozoários/química , Leishmania braziliensis/ultraestrutura , Leishmania infantum/ultraestrutura , Espectroscopia de Ressonância Magnética , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Testes de Sensibilidade Parasitária , Terpenos/químicaRESUMO
The activity of five (1-5) abietane phenol derivatives against Leishmania infantum and Leishmania braziliensis was studied using promastigotes and axenic and intracellular amastigotes. Infectivity and cytotoxicity tests were performed with J774.2 macrophage cells using Glucantime as a reference drug. The mechanisms of action were analysed by performing metabolite excretion and transmission electron microscopy ultrastructural studies. Compounds 1-5 were more active and less toxic than Glucantime. The infection rates and mean number of parasites per cell observed in amastigote experiments showed that derivatives 2, 4 and 5 were the most effective against both L. infantum and L. braziliensis. The ultrastructural changes observed in the treated promastigote forms confirmed that the greatest cell damage was caused by the most active compound (4). Only compound 5 caused changes in the nature and amounts of catabolites excreted by the parasites, as measured by ¹H nuclear magnetic resonance spectroscopy. All of the assayed compounds were active against the two Leishmania species in vitro and were less toxic in mammalian cells than the reference drug.
Assuntos
Antiprotozoários/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Macrófagos/parasitologia , Terpenos/farmacologia , Animais , Antiprotozoários/química , Feminino , Concentração Inibidora 50 , Leishmania braziliensis/ultraestrutura , Leishmania infantum/ultraestrutura , Espectroscopia de Ressonância Magnética , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Testes de Sensibilidade Parasitária , Terpenos/químicaRESUMO
Leishmania spp. has been recorded in humans and in dogs, and numerous studies have demonstrated that dogs act as reservoirs for visceral leishmaniasis. The objective of this study was to determine the prevalence of three species of the Leishmania genus and possible associated factors in sera of 218 dogs from two different populations in Mérida, Yucatán (Mexico). The sera were analyzed to detect antibodies against L. mexicana, L. braziliensis, and L. infantum using the superoxide dismutase- enzyme-linked immunosorbent assay (SOD-ELISA) and Western blot as confirmation. The Fe-SOD excreted was used as the antigenic fraction for the three Leishmania species. The prevalence values found were 30.2% (L. mexicana), 8.2% (L. braziliensis), and 11.9% (L. infantum), with L. mexicana seroprevalence being greater than L. braziliensis and L. infantum (p<0.05). Five percent (11/218) of the dogs showed antibodies against L. mexicana/L. braziliensis, 5.5% (12/218) with L. mexicana/L. infantum and 1.8% (4/218) with L. mexicana/L. braziliensis/L. infantum. No relationship (p>0.05) was found between antibodies against L. mexicana and breed, age, physical condition, or cutaneous lesions in dogs. This study provides evidence of antibodies against L. mexicana, L. braziliensis and L. infantum in dog populations from Mérida, Mexico.
Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/epidemiologia , Doenças do Cão/imunologia , Leishmania braziliensis/imunologia , Leishmania infantum/imunologia , Leishmania mexicana/imunologia , Leishmaniose/veterinária , Animais , Western Blotting , Cães , Ensaio de Imunoadsorção Enzimática , Leishmaniose/imunologia , Masculino , México/epidemiologia , PrevalênciaRESUMO
OBJECTIVES: To evaluate the in vitro leishmanicidal activity of imidazole-based (1-4) and pyrazole-based (5-6) benzo[g]phthalazine derivatives against Leishmania infantum and Leishmania braziliensis. METHODS: The in vitro activity of compounds 1-6 was assayed on extracellular promastigote and axenic amastigote forms, and on intracellular amastigote forms of the parasites. Infectivity and cytotoxicity tests were performed on J774.2 macrophage cells using meglumine antimoniate (Glucantime) as the reference drug. The mechanisms of action were analysed by iron superoxide dismutase (Fe-SOD) and copper/zinc superoxide dismutase (CuZn-SOD) inhibition, metabolite excretion and transmission electronic microscopy (TEM). RESULTS: Compounds 1-6 were more active and less toxic than meglumine antimoniate. Data on infection rates and amastigote mean numbers showed that 2, 4 and 6 were more active than 1, 3 and 5 in both L. infantum and L. braziliensis. The inhibitory effect of these compounds on the antioxidant enzyme Fe-SOD of promastigote forms of the parasites was remarkable, whereas inhibition of human CuZn-SOD was negligible. The ultrastructural alterations observed in treated promastigote forms confirmed the greater cell damage caused by the most active compounds 2, 4 and 6. The modifications observed by (1)H-NMR in the nature and amounts of catabolites excreted by the parasites after treatment with 1-6 suggested that the catabolic mechanisms could depend on the structure of the side chains linked to the benzo[g]phthalazine moiety. CONCLUSIONS: All the compounds assayed were active in vitro against the two Leishmania species and were less toxic against mammalian cells than the reference drug, but the monosubstituted compounds were significantly more effective and less toxic than their disubstituted counterparts.