Life and death of Trypanosoma cruzi in presence of metals

Trypanosoma cruzi has many molecules that need metallic elements to work, allowing cell invasion and the establishment of infection, causing Chagas disease. Nonetheless, knowledge regarding how the parasites address metals and maintain homeostasis is lacking. To study this relationship, zinc, cadmium and mercury were chosen. Epimastigote, trypomastigote and intracellular forms of T. cruzi were incubated with these metals for different times and at different concentrations. In general, epimastigotes were the most sensitive and trypomastigotes the most resistant to metals. ZnCl₂ induced low toxic effects to all parasite forms. Although the parasites were very sensitive to the toxic effects of CdCl₂ and HgCl₂, pretreatment with ZnCl₂ decreased the death rate. The trypomastigotes pretreated with CdCl₂ were unable to infect the host cells, and the treated intracellular forms were damaged after 2 h of incubation, when the toxic effects were poorly reverted. New insights on metal toxicity mechanisms are provided, helping to understand how metallic ions influence the parasite’s biochemical and physiological processes.