Roles of the endosymbiont and leishmanolysin-like molecules expressed by Crithidia deanei in the interaction with mammalian fibroblasts.

Crithidia deanei is an insect trypanosomatid that harbors a bacterial endosymbiont in its cytoplasm. In this work, we have demonstrated the influence of the endosymbiont on the interaction of C. deanei with mammalian fibroblasts, also implicating the surface leishmanolysin-like molecules of C. deanei in this process. The wild strain of C. deanei expressed a higher amount (2-fold) of leishmanolysin-like molecules in the parasite surface than the aposymbiotic strain. The treatment of parasites with anti-leishmanolysin antibodies or the fibroblasts with purified leishmanolysin-like molecules from C. deanei significantly reduced the association index. The aposymbiotic strain of C. deanei presented interaction rates about 2- and 3-fold lower with fibroblasts than the endosymbiont-bearing counterpart after 1 and 2h, respectively. However, the association indexes were similar after 3 and 4h of interaction. Additionally, we observed a 2-fold increase in the association index after 24-96 h of parasite-fibroblast interaction when compared to the interaction process performed for 4h, irrespective to the presence of the endosymbiont, suggesting that fibroblasts support multiplication and survival of C. deanei. Both parasite strains were able to induce fibroblast lysis. Interestingly, the wild strain led to a 2-fold increase in fibroblasts death in comparison to the aposymbiotic strain after 48-96 h. We also showed that both wild and aposymbiotic biotinylated live parasites recognized the same receptor in the fibroblast cells.

Crude ethanol extract from babassu (Orbignya speciosa): cytotoxicity on tumoral and non-tumoral cell lines.

Plant-derived substances have been considered as important sources of drugs, including antineoplasic agents. Babassu mesocarp is popularly used in Brazil as a food additive, and in popular medicine against several conditions, such as inflammations, menstrual pains and leukaemia. From babassu Orbignya speciosa (Mart.) Barb. Rodr. [Arecaceae (Palmae)] epicarp/mesocarp, an ethanol extract was prepared and named OSEME, which was tested on the viability,morphology and metabolism of several cell lines, such as the leukaemic cell lines, HL-60, K562 and the latter multidrug resistant counterpart K562-Lucena 1, the human breast cancer cell line MCF-7, the mouse fibroblast cell line 3T3-L1 and fresh human lymphocytes. OSEME promoted a dose-dependent decrease on the viability of all cells. This effect was much more pronounced on the tumoral cell lines than on non-tumoral cells, a phenomenon revealed by the dose of OSEME which promotes half of maximal effect (ID50). The decrease on viability was followed by shrinkage of cells, alteration on their morphology, and a markedly nuclear condensation. Curiously, stimulation of 6-phosphofructokinase activity (6.6-times) was observed on HL-60 cells, treated with OSEME, when compared to control treated with ethanol (vehicle). These results support evidences to suggest OSEME as a promising source of novel antineoplasic agents.

Crude ethanol extract from babassu (Orbignya speciosa): cytotoxicity on tumoral and non-tumoral cell lines

Plant-derived substances have been considered as important sources of drugs, including antineoplasic agents. Babassu mesocarp is popularly used in Brazil as a food additive, and in popular medicine against several conditions, such as inflammations, menstrual pains and leukaemia. From babassu Orbignya speciosa (Mart.) Barb. Rodr. [Arecaceae (Palmae)] epicarp/mesocarp, an ethanol extract was prepared and named OSEME, which was tested on the viability,morphology and metabolism of several cell lines, such as the leukaemic cell lines, HL-60, K562 and the latter multidrug resistant counterpart K562-Lucena 1, the human breast cancer cell line MCF-7, the mouse fibroblast cell line 3T3-L1 and fresh human lymphocytes. OSEME promoted a dose-dependent decrease on the viability of all cells. This effect was much more pronounced on the tumoral cell lines than on non-tumoral cells, a phenomenon revealed by the dose of OSEME which promotes half of maximal effect (ID50). The decrease on viability was followed by shrinkage of cells, alteration on their morphology, and a markedly nuclear condensation. Curiously, stimulation of 6-phosphofructokinase activity (6.6-times) was observed on HL-60 cells, treated with OSEME, when compared to control treated with ethanol (vehicle). These results support evidences to suggest OSEME as a promising source of novel antineoplasic agents.

Substâncias derivadas de plantas têm sido usadas como importante fonte de agentes antineoplásicos. O mesocarpo do babaçu é popularmente usado no Brasil como suplemento alimentar e na medicina popular para o tratamento de várias afecções, tais como: inflamações, cólicas menstruais e leucemia. A partir do epicarpo/mesocarpo do babaçu Orbignya speciosa (Mart.) Barb. Rodr. [Arecaceae (Palmae)] foi preparado um extrato etanólico, denominado OSEME, o qual foi incubado com as seguintes linhagens humanas leucêmicas: HL-60, K562 e a sua derivada resistente a múltiplas drogas, K562-Lucena 1; além destas, foram testadas a linhagem humana de câncer de mama, MCF-7; a linhagem de fibroblastos de camundongo, 3T3-L1 e linfócitos humanos de sangue periférico. OSEME promoveu diminuição da viabilidade em todas as linhagens celulares testadas de maneira dose-dependente. Este efeito foi mais pronunciado sobre as linhagens celulares tumorais quando comparado às não tumorais, o que foi revelado pela dose de OSEME capaz de promover metade do efeito máximo (ID50). A diminuição da viabilidade foi acompanhada por danos sobre a morfologia celular com pronunciada condensação citoplasmática e nuclear. Curiosamente, quando a linhagem HL-60 foi tratada com OSEME, foi detectado um aumento de 6,6 vezes da atividade da enzima 6-fosfofrutoquinase, quando comparado ao grupo controle (células tratadas com o veículo etanol). Esses resultados sugerem que OSEME pode ser uma promissora fonte de novos agentes antineoplásicos.