Navegando por Autor "Corrêa, Paulo Roberto Ceridóreo"

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    Antimicrobial activity of synthetic bornyl benzoates against Trypanosoma cruzi.
    (2012) Corrêa, Paulo Roberto Ceridóreo; Miranda, Roqueline Rodrigues Silva de; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Vieira Filho, Sidney Augusto; Okuma, Adriana Akemi; Carazza, Fernando; Díaz, José Andrés Morgado; Pinge Filho, Phileno; Yamauchi, Lucy Megumi; Nakamura, Celso Vataru; Ogatta, Sueli Fumie Yamada
    We report here for the first time the in vitro effects of (1S,2R,4S)-1,7,7-trimethyl-bicyclo[2.2.1]heptan-2-yl- 39,49,59-trimethoxy benzoate (1) and (1S,2R,4S)-1,7,7-trimethyl-bicyclo[2.2.1]heptan-2-yl benzoate (2) on the growth and ultrastructure of Trypanosoma cruzi. These two synthetic compounds exerted an antiproliferative effect on the epimastigote forms of the parasite. The ICs50/72h of two synthetic L-bornyl benzoates, 1 and 2, was 10.1 and 12.8 mg/ml, respectively. Both compounds were more selective against epimastigotes than HEp-2 cells. Ultrastructural analysis revealed intense cytoplasmic vacuolization and the appearance of cytoplasmic materials surrounded by membranes. The treatment of peritoneal macrophages with compounds 1 and 2 caused a significant decrease in the number of T. cruzi-infected cells. L-Bornyl benzoate derivatives may serve as a potential source for the development of more effective and safer chemotherapeutic agents against T. cruzi infections.
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    In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus.
    (2011) Corrêa, Paulo Roberto Ceridóreo; Pinto, Artur da Silveira; Silva, Grácia Divina de Fátima; Vieira Filho, Sidney Augusto; Duarte, Lucienir Pains; Ogatta, Sueli Fumie Yamada
    The effect of 2-pyridinecarboxylic acid (picolinic acid) on trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus was determined in this study. Picolinic acid, at 50 g mL-1, inhibited epimastigote growth by 99% after 12 days incubation. In addition, trypomastigote motility decreased by 50% after 6h and completely after 24h in the presence of 50 g mL-1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was 275 g mL-1 after 4 days incubation. Altogether, these results indicate higher toxicity against trypanosomes. The inhibitory effect of picolinic acid on epimastigote growth can be partially reversed by nicotinic acid and L tryptophan, suggesting a competitive inhibition. Furthermore, two anti-Trypanosoma (Schizotrypanum) cruzi drugs were also evaluated with regard to bat trypanosome growth. Benznidazole, at 50 g mL-1, inhibited epimastigote growth by 90% after 12 days incubation. Nifurtimox, at the same concentration, caused 96% growth inhibition after four days incubation. Corroborating a previous study, bat trypanosomes are a good model for screening new trypanocidal compounds. Moreover, they can be used to study many biological processes common to human pathogenic trypanosomatids.