Assessment of Leishmania major and Leishmania braziliensis promastigote viability after photodynamic treatment with aluminum phthalocyanine tetrasulfonate (AlPcS4)

Cutaneous leishmaniasis is an infectious disease caused by protozoans of the genus Leishmania, which is transmitted through the bite of hematophagous insects of the genus Lutzomyia. This study aimed at testing in vitro the phototoxic effect of aluminum phthalocyanine tetrasulfonate (AlPcS4) on the viability of Leishmania major and Leishmania braziliensis. Stationary phase promastigote forms were treated with AlPcS4 at 1.0 µM and 10.0 µM and incubated for one hour. Then 659 nm laser was applied at 5 and 10 J/cm². Parasite viability was determined by differential count using the trypan blue dye exclusion method and by monitoring growth curves for nine days. Trypan blue exclusion assay showed a significant reduction of viable parasites compared to controls, L. major seemed more sensitive to the toxic effects of AlPcS4 in the dark. The most effective photodynamic therapy (PDT) was obtained with AlPcS4 at 10.0 µM and 10 J/cm² whereas L. braziliensis showed the highest mortality rate after treatment.

Immune response to Mycobacterium bovis-AN5 infection in genetically selected mice (selection IV-A)

Mice genetically selected for high (H) and low (L) antibody production (Selection IV-A) were used as murine experimental model. The aim of the present work was to evaluate the macrophagic activity and to characterize the immune response in Mycobacterium bovis-AN5 infected mice (3X107 bacteria). The response profile previously observed in such strains was not similar to that obtained during M. bovis infection; however, it corroborated works carried out using Selection I, which is very similar to Selection IV-A regarding infection by M. tuberculosis and Bacillus Calmette-Guérin (BCG). Considering bacterial recovery, LIV-A mice showed higher control of the infectious process in the lungs than in the spleen, whereas HIV-A mice presented more resistance in the spleen. With respect to macrophagic activity, hydrogen peroxide (H2O2) was probably not involved in the infection control since there was an inhibition in the production of this metabolite. Nitric oxide (NO) and TNF-a production seemed to be important in the control of bacterial replication and varied according to the strain, period and organ. Evaluation of the antibody production indicated that the multi-specific effect commonly observed in these strains was not the same in the response to M. bovis. Antibody concentrations were higher in LIV-A than in HIV-A mice at the beginning of the infection, being similar afterwards. Such data were compared with delayed-type hypersensitivity (DTH), which was more intense in HIV-A than in LIV-A mice, indicating that antibody production is independent of the capability to trigger DTH reactions and that cellular and humoral responses to M. bovis antigens show a polygenic control and an independent quantitative genetic regulation. Differences were observed among organs and metabolites, suggesting that different mechanisms play an important role in this infection in natural heterogeneous populations, indicating that NO, TNF-a and Th1 cytokines are involved in the infection control.(AU)

Efeito de diferentes doses de rutina sobre proteínas totais, enzimas aspartato amino trasferase e alanina amino transferase no soro de coelhos / Effect of different doses of rutin on total proteins, enzimes aspartate amino transferase and alanine amino transferase in serum of rabbits

Modelos com animais são usados para se pesquisar a toxicidade de fármacos, alimentos e novas substâncias com propriedades farmacológicas. Tem sido considerado que o consumo de flavonóides em alimentos é da ordem de 1g proveniente de vegetais, como frutas, leguminosas, etc. Com este objetivo, o presente trabalho avaliou os efeitos da rutina em diferentes doses, através das concentrações de proteínas, enzimas aspartato amino transferase (AST) e alanina amino transferase (ALT) em soro de coelhos. Alterações que ocorreram nos níveis séricos de proteína não foram estatisticamente significativos nos grupos e tempos avaliados para os machos e para as fêmeas. A atividade da AST também não representou diferença estatisticamente significativa. Já para ALT, observou-se variação apenas com 20mg de rutina para os machos nos tempos 0 e 28 dias. Através dos resultados obtidos, pode-se concluir que a rutina não causou patologias hepáticas.