In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus

Abstract

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 μg 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 μg mL -1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was 275 μg 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 μg 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.

Busca de novos compostos anti->i<Trypanosoma cruzi>/i< e mapeamento da resistência natural a benznidazol em tripanossomatídeos

“…Para T. rangeli não foi investigada a ação de BZ, ao contrário dos relatos que mostram que NFX é eficaz na negativação da parasitemia na infecção murina por esse organismo (MARINKELLE, 1982). Alguns relatos em tripanossomas de morcego do subgênero Schizotrypanum indicam que BZ, em concentrações bastante elevadas, inibem o crescimento de formas epimastigotas (BAKER;SELDEN, 1981;CERIDÓREO CORRÊA et al 2011). Isto também foi verificado para Crithidia fasciculata, que é, em contrapartida, é muito sensível a baixas concentrações de NFX (GUTTERIDGE et al 1982).…”