The chemotherapy available for the treatment of Leishmaniosis and Chagas is restricted to a few medicines. Moreover, snake venoms have been studied because they have active substances with therapeutic potential. Thus, the aim of this study was to evaluate the in vitro effects of total venom of Crotalusdurissuscascavella, Crotalusdurissusterrificus and Bothropsjararaca in Leishmania chagasi and Trypanosoma cruzi.RAW264.7 and LLC-MK2 cells, L. chagasi promastigote and trypomastigotes of T. cruzi. In L.chagasi amastigotes of T. cruzi was carried out in situ ELISA test and MTT test. The toxins concentration of 500 μg/mL showed 100% mortality on the cells studied. Since of the 250 μg/mL concentration had obtained less than 50% cytotoxicity. These results presented high toxicity in trypomastigotes and amastigotes of T.cruzi. In promastigotes, the venom of C. d. terrificus caused 71.1% mortality at a concentration of 250 μg/mL and the IC50 of 63.5 to 155.0 mg/mL. In L. chagasi amastigotes, 250 μg/mL the Bothrops jararaca venom caused 96% mortality and a lower IC50 value with the range of 55.6 to 90.9 μg/mL. Therefore, the venoms of C. d. terrificus and B. jararaca in the concentrations tested had anti-Leishmaniosis and anti-Chagas disease activity.
