Leismanicidal Activity of Propolis Collected in the Semiarid Region of Brazil.

Objective: The aim of the current study is to investigate the chemical composition, cytotoxic effect, and leishmanicidal activity of propolis collected in the semi-arid region of Bahia, Brazil. Methods: EtOH extract, hexane, EtOAc and MeOH fractions from propolis were analyzed by ultra-performance liquid chromatography coupled with diode array detector and quadrupole time-of-flight mass spectrometry. The identification was based on the exact mass, general fragmentation behaviors and UV absorption of the flavonoids. The in vitro cytotoxic effect and leishmanicidal activity of ethanolic extract, hexane, ethyl acetate, and methanolic fractions of propolis were evaluated. Results: Five triterpenes and twenty-four flavonoids were identified. The propolis did not present toxicity to the host cell up to the maximum concentration tested. In addition, all tested samples showed statistically significant activity against promastigotes of Leishmania chagasi and Leishmania amazonensis. Regarding the activity against amastigote forms of L. amazonensis, the hexane fraction, presented statistically significant activity with IC50 of 1.3 ± 0.1 µg/ml. Conclusion: The results support the idea that propolis can be used for future antileishmania studies.

Detection of Leishmania infantum DNA in the non-parasitized lung of dogs with visceral leishmaniasis.

BACKGROUND: Despite the very low or absent parasitism in the lungs, the interstitial pneumonitis is a common lesion found in humans and dogs with visceral leishmaniasis. The lung is a neglected organ in the study of dogs and humans with visceral leishmaniasis, but interstitial pneumonitis represents an important lesion characterized by thickening of the alveolar septum due to fibrosis and inflammatory exudate, and its pathogenesis is still uncertain. In this study, the polymerase chain reaction (PCR) was used to detect Leishmania infantum in paraffin-embedded lung biopsies from naturally infected dogs from an endemic area in Minas Gerais State, Brazil; PCR was compared to histological and immunohistochemical techniques for detecting Leishmania. RESULTS: Eighteen dogs in which leishmaniasis had been diagnosed by serological tests - indirect immunofluorescence assay (IFAT), enzyme-linked immunosorbent assay (ELISA) and complement fixation tests (CFT) - were classified as asymptomatic, oligosymptomatic or symptomatic. Nine of the 18 dogs studied had a positive PCR (50%) but parasites were not detected by histopathological and immunocytochemistry methods. CONCLUSIONS: These data indicate that PCR on DNA extracted from paraffin-embedded tissue is a valuable method for detecting Leishmania infantum parasites in lungs of naturally infected dogs, despite the apparent absence of parasites from standard HE (hematoxylin and eosin) stained slides and of labeled parasites from immunocytochemical preparations.

Avaliação de IFN-γ e IL-10 em cães naturalmente infectados com Leishmania (Leishmania) chagasi com e sem manifestações clínicas / Evaluation of INF-γ and IL-10 in dogs naturally infected by Leishmania (Leishmania) chagasi with and without clinic events

As leishmanioses têm como agentes etiológicos parasitas intracelulares obrigatórios pertencentes ao gênero Leishmania capazes de infectar diferentes espécies de mamíferos e nestes se reproduzirem dentro do sistema fagocítico mononuclear. Os cães domésticos são os principais responsáveis pela manutenção da cadeia epidemiológica da doença, podendo apresentar uma grande variedade de perfis clínicos, desde aparentemente sadios a severamente acometidos. Avaliou-se a expressão das citocinas de cães naturalmente infectados com Leishmania (Leishmania) chagasi. Foram coletadas 50 amostras, sendo 20 de animais positivos e sintomáticos para Leishmaniose Visceral Canina (LVC), 20 de animais positivos e assintomáticos e 10 de animais sabidamente negativos para a LVC. As amostras foram analisadas pelo teste imunocromatográfico rápido Dual Path Platform (DPP/Biomanguinhos®) e pelo ELISA (EIE/Biomanguinhos®) indireto para detecção de anticorpos anti-Leishmania. Após as confirmações dos testes, foi realizado o ELISA de captura (R & D Systems) para quantificação das citocinas IL-10 e IFN-γ. Houve diferença estatística entre os grupos observando um aumento nos níveis de IFN-γ nos animais assintomáticos e um aumento de IL-10 nos sintomáticos.(AU)

Leishmaniasis has as obligatory intracellular parasitic etiological agents belonging to the genus Leishmania capable of infecting different species of mammals and reproducing them within the mononuclear phagocytic system. Domestic dogs are the main responsible for maintaining the epidemiological chain of the disease, presenting a wide variety of clinical profiles, from apparently healthy to severely affected. The expression of the cytokines from dogs naturally infected with Leishmania (Leishmania) chagasi was evaluated. Blood samples were collected from 50 animals, 20 from positive and symptomatic dogs for Leishmaniasis Canine (CVL), 20 from positive asymptomatic animals and 10 negative. Samples were analyzed by immunochromatographic test Dual Path Platform (DPP/Biomanguinhos®) and by indirect ELISA (EIE/Biomanguinhos®) for detection of anti-Leishmania antibodies. There was statistical difference between the groups observing an increase in IFN-γ levels in asymptomatic animals and an IL-10 increase in symptomatic.(AU)

Avaliação citopatológica da medula óssea e perfil hematológico de cães naturalmente infectados por Leishmania (Leishmania) chagasi / Cytopathologycal evaluation of bone marrow and hematological profile of dogs naturally infected by Leishmania (Leishmania) chagasi

Foram avaliados quarenta e um cães adultos, machos e fêmeas, sem raça definida, provenientes de inquéritos sorológicos para leishmaniose visceral canina realizados pela Secretaria Municipal de Saúde do Rio de Janeiro. O objetivo deste estudo foi descrever as alterações citopatológicas da medula óssea e o perfil hematológico de cães naturalmente infectados por Leishmania (Leishmania) chagasi. A avaliação citológica da medula óssea incluiu a análise qualitativa e quantitativa. O perfil hematológico foi avaliado através de contador automático de células e esfregaços sanguíneos. Adicionalmente, foram realizadas a imunofenotipagem de linfócitos medulares, pesquisa de formas amastigotas na medula óssea e avaliação dos estoques de ferro medular. De acordo com os resultados obtidos, cães naturalmente infectados por L. (L.) chagasi apresentaram hiperplasia das séries mieloide, linfoide e monocítica, onde frequentemente foram observadas formas amastigotas, anemia normocítica normocrômica e aumento dos estoques de ferro medularNão foram observadas diferenças estatisticamente significativas entre as populações de linfócitos T e linfócitos B medulares. Em conclusão, os cães naturalmente infectados por L. (L.) chagasi apresentaram alterações na medula óssea e no perfil hematológico independentemente da manifestação clínica apresentada pelo animal. Hiperplasia das linhagens hematopoiéticas, anemia, eritrofagocitose e aumento dos estoques de ferro medular possibilitaram uma melhor compreensão dos mecanismos fisiopatológicos envolvidos na doença e a pesquisa de formas amastigotas na medula óssea contribuiu como uma importante ferramenta diagnóstica da leishmaniose visceral canina...

Fourty one adult mongrel dogs from the VL serological surveys done by Secretaria Municipalde Saúde of Rio de Janeiro were studied. The purpose of this study was to evaluate theoccurrence of cytopathologycal changes of bone marrow and hematological changes in dogsnaturally infected by Leishmania (Leishmania) chagasi. Evaluation of bone marrow includedthe qualitative and quantitative analysis and complete blood count was performed with anautomated cell counter and blood smears. Additionally, immunophenotyping of lymphocytes,search of amastigotes and iron stores of bone marrow were performed. According to theresults, dogs naturally infected by L. (L.) chagasi showed hiperplasia of myeloid, lymphoideand monocytic series, that often showed amastigotes form, normocytic normochromic anemiaand increase iron stores of bone marrow. No significant difference was observed among the Tlymphocytes and B lymphocytes populations of bone marrow. In conclusion, dogs naturallyinfected by L. (L.) chagasi showed changes in bone marrow and blood profile regardless ofthe clinical manifestations. Hyperplasia of hematopoietic lineages, anemia,erythrophagocytosis and increase iron stores allowed a better understanding of thephysiopathological mechanisms involved in disease and the search of amastigotes in bonemarrow contributed as an important diagnostic tool of canine visceral leishmaniasis...

Dynamics of immunosuppression in hamsters with experimental visceral leishmaniasis

Immunosuppression has been reported to occur during active visceral leishmaniasis and some factors such as the cytokine profile may be involved in this process. In the mouse model of cutaneous leishmaniasis using Leishmania (Leishmania) major, the Th1 response is related to protection while the Th2 response is related to disease progression. However, in hamsters, which are considered to be an excellent model for the study of visceral leishmaniasis, this dichotomy is not observed. Using outbred 45- to 60-day-old (140 to 150 g) male hamsters infected intraperitoneally with 2 x 10(7) L. (L.) chagasi amastigotes, we evaluated the immune response of spleen cells and the production of cytokines. We used 3 to 7 hamsters per group evaluated. We detected a preserved response to concanavalin A measured by index of proliferation during all periods of infection studied, while a proliferative response to Leishmania antigen was detected only at 48 and 72 h post-infection. Messenger RNA from cytokines type 1 (IL-2, TNF-α, IFN-γ) and type 2 (IL-4, IL-10 and TGF-β) detected by reverse transcriptase polymerase chain reaction and produced by spleen cells showed no qualitative difference between control non-infected hamsters and infected hamsters during any period of infection evaluated. Cytokines were measured by the DNA band intensity on agarose gel using the Image Lab 1D L340 software with no differences observed. In conclusion, the present results showed an antigen-dependent immunosuppression in hamsters with active visceral leishmaniasis that was not related to the cytokine profile.

The first case report of Leishmania (leishmania) chagasi in Panthera leo in Brazil.

We reported here the first known case of natural infection of a lion (Panthera leo-Linnaeus, 1758) with Leishmania (Leishmania) chagasi (L. chagasi) in Brazil. The specimen was created by a circus handler in the state of Mato Grosso and was donated to the zoological park of the Federal University of Mato Grosso. Infection by L. chagasi was detected using a PCR-RFLP test. It was known that the domestic felids can act as reservoir of infection of L. chagasi in endemic areas, making it important that studies demonstrate their participation in the epidemiological chain. We demonstrate in this work that wild animals can have an important role in the epidemiological chain and must be considered in order to plan methods of control of this zoonosis.

The first case report of Leishmania (leishmania) chagasi in Panthera leo in Brazil

We reported here the first known case of natural infection of a lion (Panthera leo-Linnaeus, 1758) with Leishmania (Leishmania) chagasi (L. chagasi) in Brazil. The specimen was created by a circus handler in the state of Mato Grosso and was donated to the zoological park of the Federal University of Mato Grosso. Infection by L. chagasi was detected using a PCR-RFLP test. It was known that the domestic felids can act as reservoir of infection of L. chagasi in endemic areas, making it important that studies demonstrate their participation in the epidemiological chain. We demonstrate in this work that wild animals can have an important role in the epidemiological chain and must be considered in order to plan methods of control of this zoonosis.

Ocorrência de leishmaniose visceral canina em assentamento agrícola no Estado de Mato Grosso do Sul, Brasil / Occurrence of canine visceral leishmaniasis in an agricultural settlement in the State of Mato Grosso do Sul, Brazil

During previous research on phlebotomine fauna in a settlement of the Brazilian National Agrarian Reform Institute (INCRA) on the Bodoquena Range, Mato Grosso do Sul State, Brazil, dogs were observed with clinical aspects suggestive of visceral leishmaniasis. A serological survey to leishmaniasis in 97 dogs, by indirect immunofluorescence test, showed 23 (23.7%) serum positive dogs. Samples of the parasites were identified as Leishmania (Leishmania) chagasi.

Durante estudos sobre a fauna flebotomínea em assentamento do Instituto Nacional de Reforma Agrária (INCRA) na Serra da Bodoquena, Estado de Mato Grosso do Sul, Brasil, foram observados cães com manifestações clínicas sugestivas de leishmaniose visceral. Inquérito sorológico para leishmaniose em 97 cães, utilizando reação de imunofluorescência indireta, mostrou 23 (23,7%) soros reagentes. Amostras do parasita foram identificadas como Leishmania (Leishmania) chagasi.