In this study the effect of eight DNA topoisomerase inhibitors on the growth
Trypanosoma rangeli
epimastigotes in cell culture was investigated. Among the eight compounds tested, idarubicin was the only compound that displayed promising trypanocidal activity with a half-maximal growth inhibition (GI
50) value in the sub-micromolar range. Fluorescence-activated cell sorting analysis showed a reduction in DNA content in
T. rangeli epimastigotes when treated with idarubicin. In contrast to
T. rangeli, against
Trypanosoma cruzi
epimastigotes idarubicin was much less effective exhibiting a GI
50 value in the mid-micromolar range. This result indicates that idarubicin dis- plays differential toxic effects in
T. rangeli and
T. cruzi. Compared with African trypanosomes, it seems that American trypanosomes are generally less susceptible to DNA topoisomerase inhibitors.
