Sensitivity of Trypanosoma equiperdum to the action of tumor-inhibitory antibiotics in vitro

Glutamine Analogues Impair Cell Proliferation, the Intracellular Cycle and Metacyclogenesis in Trypanosoma cruzi

Trypanosoma cruzi is the aetiologic agent of Chagas disease, which affects people in the Americas and worldwide. The parasite has a complex life cycle that alternates among mammalian hosts and insect vectors. During its life cycle, T. cruzi passes through different environments and faces nutrient shortages. It has been established that amino acids, such as proline, histidine, alanine, and glutamate, are crucial to T. cruzi survival. Recently, we described that T. cruzi can biosynthesize glutamine from glutamate and/or obtain it from the extracellular environment, and the role of glutamine in energetic metabolism and metacyclogenesis was demonstrated. In this study, we analysed the effect of glutamine analogues on the parasite life cycle. Here, we show that glutamine analogues impair cell proliferation, the developmental cycle during the infection of mammalian host cells and metacyclogenesis. Taken together, these results show that glutamine is an important metabolite for T. cruzi survival and suggest that glutamine analogues can be used as scaffolds for the development of new trypanocidal drugs. These data also reinforce the supposition that glutamine metabolism is an unexplored possible therapeutic target.

Activity of antitumor drugs against African trypanosomes

Of 49 compounds known to have antitumor properties, 6 were found to have significant activity against Trypanosoma rhodesiense infections in mice. Activity against the African trypanosomes has not been reported previously for any of these six compounds. In order of decreasing activity these compounds were: (i) imidazole-4-carboxamide, 5-(3,3-dimethyl-1,1-triazene), (ii) inosine diglycolaldehyde, (iii) cis-diamminedichloro-platinum, (iv) streptozotocin, (v) coralyne sulfate, and (vi) 5-fluoro-2'-deoxyuridine. The percentage of "hits" (12.2%) from these known antitumor agents was approximately twice as great as when other means are employed for the selection of compounds for this test system.