Atividade antimicrobiana dos frutos de Syagrus oleracea e Mauritia vinifera / Antimicrobial activity of Syagrus oleracea and Mauritia vinifera fruits

As espécies pertencentes à família Palmae são muito interessantes do ponto de vista químico e farmacológico. Neste trabalho, foram estudados os frutos de duas espécies da família Palmae, Syagrus oleracea e Mauritia vinifera. Essas palmeiras foram escolhidas por serem espécies brasileiras, abundantes em nosso país, utilizadas popularmente no tratamento de algumas doenças e ainda pouco estudadas. Foram realizados ensaios farmacológicos para avaliação da atividade antimicrobiana dos extratos dos frutos das duas espécies em estudo. Para o teste de atividade antimicrobiana foram utilizadas cepas de bactérias Gram positivas e Gram negativas. A metodologia empregada foi a de Microdiluição em caldo. Foram testados os extratos etanólicos brutos do epicarpo/mesocarpo de S. oleracea e de M. vinifera, o extrato hexânico das amêndoas de S. oleracea, as partições hexânicas e em acetato de etila do epicarpo/mesocarpo de S. oleracea, do epicarpo/mesocarpo e mesocarpo/endocarpo de M. vinifera, na concentração de 100 mg/ml. Os extratos lipofílicos de S. oleracea apresentaram os melhores resultados para essa espécie. Nos testes realizados com M. vinifera, as partições lipofílicas foram as mais inibitórias para a cepa de S. aureus.

Palmae species are very interesting by the chemical and pharmacological points of view. Two species belonging to this family were chosen to initiate the chemical and pharmacological approach of their fruits: Syagrus oleracea (Martius) Beccari and Mauritia vinifera Martius, known in Brazil as Guariroba and Buriti, respectively. Those palm species can be found in several regions of Brazil, especially at the northeast and southeast of the country. They have been used in folk medicine to treat some diseases, however no toxicological and pharmacological studies have been done so far. For the two studied fruits, the antimicrobial activity tests were carried out by broth microdilution methodology. The objective of this work was to contribute for the pharmacological study of palm species, evaluating the antimicrobial activity of the extracts obtained from the fruits of S. oleracea and M. vinifera. The assays evaluated ethanol extracts of the epicarp/mesocarp of S. oleracea and epicarp/mesocarp of M. vinifera; hexane extract of the endosperm of S. oleracea; hexane and ethyl acetate fractions of the epicarp/mesocarp of S. oleracea, epicarp/mesocarp of M. vinifera and mesocarp/endocarp of M. vinifera. The lipophilic extracts of S. oleracea obtained the best results for the species. For M. vinifera, the lipophilic partitions have shown a high inhibitory percentage for S. aureus.

Induction of apoptosis in monocytes by Mycobacterium leprae in vitro: a possible role for tumour necrosis factor-alpha

A diverse range of infectious organisms, including mycobacteria, have been reported to induce cell death in vivo and in vitro. Although morphological features of apoptosis have been identified in leprosy lesions, it has not yet been determined whether Mycobacterium leprae modulates programmed cell death. For that purpose, peripheral blood mononuclear cells obtained from leprosy patients were stimulated with different concentrations of this pathogen. Following analysis by flow cytometry on 7AAD/CD14+ cells, it was observed that M. leprae induced apoptosis of monocyte-derived macrophages in a dose-dependent manner in both leprosy patients and healthy individuals, but still with lower efficiency as compared to M. tuberculosis. Expression of tumour necrosis factor-alpha (TNF-alpha), Bax-alpha, Bak mRNA and TNF-alpha protein was also detected in these cultures; in addition, an enhancement in the rate of apoptotic cells (and of TNF-alpha release) was noted when interferon-gamma was added to the wells. On the other hand, incubation of the cells with pentoxifylline impaired mycobacterium-induced cell death, the secretion of TNF-alpha, and gene expression in vitro. In addition, diminished bacterial entry decreased both TNF-alpha levels and the death of CD14+ cells, albeit to a different extent. When investigating leprosy reactions, an enhanced rate of spontaneous apoptosis was detected as compared to the unreactive lepromatous patients. The results demonstrated that M. leprae can lead to apoptosis of macrophages through a mechanism that could be at least partially related to the expression of pro-apoptotic members of the Bcl-2 protein family and of TNF-alpha. Moreover, while phagocytosis may be necessary, it seems not to be crucial to the induction of cell death by the mycobacteria.

Immunological evaluation of human immunedeficiency virus infected individuals by flow cytometry

Human immunodeficiency virus (HIV) infection heavily compromises the immune system. The decrease of the T cell CD4+ subset along the evolution to acquired immunodeficiency syndrome has been considered as a hallmark of HIV infection. In this paper we review some aspects of the immunopathology of HIV infection and discuss the importance of the flow cytometry for the evaluation of the T lymphocyte subsets in the follow-up of HIV infected children and adults, and for the monitoring of the immune reconstitution upon antiretroviral therapy.