CONICET | Buscador de Institutos y Recursos Humanos

Trypanosoma cruzi is the causal agent of Chagas disease. Manyreported drugs take anti- T. cruzi effect by generating ROS and eventhe host cell produces these species in order to protect itself fromthe infection. Therefore, this fact reveals the parasite vulnerabilityto oxidative damage. This work aims to clarify the oxidative damageproduced by vitamin C (vit C) in the presence of heavy metalions traces, present inside the parasite. Employing epimastigotesof T.cruzi treated with vit C (5-30 μM) during 2-8 hs, we evaluatedthe level of free thiols (DTNB reaction), intracellular oxidative stress(using the oxidant-sensitive fluorescent probe H2DCFDA) and superoxidedismutase (SOD) activity (by inhibition of a superoxide-drivenNADH oxidation). The results showed a decrease in the percentageof thiols groups after 5 hs approximately. This decrease is the samefor the three concentrations assayed, acknowledging that the powerof vitamin C pro-oxidant effect is independent of vit C concentration.After 8 hs, the percentage of thiols group increased for the threeconcentrations but, in this case, the major increase was noticed for30 μM of vit C and the minor one for 5 μM of vit C. Thus, vit Canti-oxidant effect is dependent of vit C concentration. When the parasites were treated with Bnz during 2- 9 hours, we noticed thatafter 5 hours a significant decrease in the content of thiols groupappeared only for the higher concentration assayed. After 8 hs, thecontent of thiols decreased for both concentrations (15 μM/30 μM).After 9 hs, the content of thiols was recovered reaching more than80% for both concentrations. Nevertheless, the combined treatment,vit C + Bnz, did not show an additive behavior in accordance withthe results observed on an acute murine model of Chagas disease.The intracellular oxidative stress and SOD activity in epimastigotestreated under the same conditions showed results that support thechange observed in the level of free thiols.