In Vitro and In Vivo High-Throughput Assays for the Testing of Anti-Trypanosoma cruzi Compounds

The treatment of Trypanosoma cruzi infection (the cause of human Chagas disease) remains a significant challenge. Only two drugs, both with substantial toxicity, are available and the efficacy of these dugs is often questioned – in many cases due to the limitations of the methods for assessing efficacy rather than to true lack of efficacy. For these reasons relatively few individuals infected with T. cruzi actually have their infections treated. In this study, we report on innovative methods that will facilitate the discovery of new compounds for the treatment of T. cruzi infection and Chagas disease. Utilizing fluorescent and bioluminescent parasite lines, we have developed in vitro tests that are reproducible and facile and can be scaled for high-throughput screening of large compound libraries. We also validate an in vivo screening test that monitors parasite replication at the site of infection and determines the effectiveness of drug treatment in less than two weeks. More importantly, results in this rapid in vivo test show strong correlations with those obtained in long-term (e.g. 40 day or more) treatment assays. The results of this study remove one of the obstacles for identification of effective and safe compounds to treat Chagas disease

Ultrastructural alterations induced by nifurtimox and another nitro derivative on epimastigotes of Trypanosoma cruzi

We report the ultrastructural alterations induced on epimastigotes by nifurtimox and 5-nitro-2-thienyl-malononitrile (5NO2TM), a novel compound with anti-Trypanosoma cruzi activity. Parasites treated with concentrations of nifurtimox lower than usually employed for this kind of study showed vacuolisation, alterations of the mitochondria, the nucleus and the ribosomes. 5NO2TM caused the same kind of damage, but to a greater degree. This result correlates with the fact that cultures treated with this compound experienced a greater loss of viability.Peer Reviewe