Efeito metabolico in vitro do derivado benzimidazolico (RCB15) em cisticercos de taenia crassiceps

• Autor(a) principal: Picanço, Guaraciara de Andrade
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6293
• topic: Taenia crassiceps; Metabolismo; Derivado benzimidazólico; RCB15; Taenia crassiceps; Metabolism; Benzimidazole derivative; CIENCIAS BIOLOGICAS::PARASITOLOGIA

The high prevalence of intestinal and tissue parasites combined with the breakthrough of parasites resistat to albendazole, encouraged the search for new drugs. Studies on the biochemical response of Taenia crassiceps metacestode to drugs has been shown to be important for the detection of modes of action of drugs within the parasite metabolic pathways. In order to develop new anti-parasitic drugs, the benzimidazole derivative 6-Chloro-5- (2,3-dichlorophenoxy) -2- (trifluoromethyl) -1H-benzimidazole (RCB15) was synthesized. The objective of this study was to determine the in vitro effect of a benzimidazole derivative, RCB15, in the energetic and respiratory metabolism of T. crassiceps cysticerci. For this, 30 larval stage cysticerci were plated in culture plates containing supplemented RPMI and albendazole sulfoxide (ABZSO) (6,5 μM, 13 μM, 26 μM, 52 μM or 104 μM) or RCB15 (6,5 μM, 13 μM, 26 μM, 52 μM or 104 μM) diluted in dimethyl sulfoxide (DMSO). After 24 hours of cultivation, the cysticerci were separated from the culture medium and frozen in liquid nitrogen. Analysis on high-performance liquid chromatography to assess the energetic and respiratory metabolism were performed. There was a decrease in glucose concentrations detected in vesicular fluid in all groups treated with RCB15 and the groups treated with the highest dosages of ABZSO. The non detection of lactate in the culture medium of the groups treated with RCB15 indicates that this acid was used as a precursor of gluconeogenesis. The group treated with RCB15 52 uM performed the aerobic energetic pathways due to the non detection of lactate neither in the vesicular fluid nor in the culture medium. With respect to the tricarboxylic acid (TCA) cycle, low concentrations of α-ketoglutarate or non-detection of this organic acid, indicates that the parasite has preferably used the fumarate reductase pathway. Probably the detected α-ketoglutarate was from the protein catabolism. The alternative routes of energy production, were observed in the groups treated with RCB15 26 uM and 104 uM and ABZSO 13 uM. In those groups acetate was used to produce β-hydroxybutyrate which was completely excreted in other treatments and in the control group acetate was excreted due to excess of acetyl-CoA which was not used in the TCA cycle. It is possible to conclude that the TCB15 treatment influenced glycolysis, diminished the energetic sources as it induced the parasite to use other sources to produce energy such as gluconecogenesis and fatty acid oxidation. Cysticerci that were treated with RCB15 and ABZSO preferred the fumarate reductase pathway. The drugs used in this study did not influence the proteins catabolism. The RCB15 treatment presented greater influence in the glucose uptake and consequently in glycolytic pathway when compared to the ABZSO treatment.