Fig 1.
Antiparasitic activity of Vit C and Bnz on T. cruzi epimastigote, trypomastigote and amastigote forms.
Vit C concentrations assayed ranged from 1 to 10 μM for epimastigotes, 5 to 100 μM for trypomastigotes and 0.5 to 40 μM for amastigotes. For Bnz, used as reference drug, the concentrations tested ranged from 2.5 to 10 μM for epimastigotes, 0.38 to 380 μM for trypomastigotes and 0.5 to 40 μM for amastigotes. IC50 values were calculated (see Materials and Methods) and shown in the inset table.
Table 1.
Effect of Vit C plus Bnz on T. cruzi trypomastigotes.
Fig 2.
Cytotoxic effect of Vit C and Bnz on Vero cells.
(a). Cells were cultured for 48 h in the presence of different concentrations of Vit C (5 to 5,000 μM) and Bnz (3 to 3000 μM). Cell viability was determined by the MTT assay (see Methods). Effect of Vit C on the cytotoxicity of Bnz (b). In the presence of different concentrations of Vit C (5 to 5000 μM), the cytotoxicity of a fixed concentration of Bnz (100 μM) was evaluated. *Significant differences (p<0.05), when compared to the control, as assessed by the Student’s t-test.
Fig 3.
Reduced thiol content during the short-time treatment with different Vit C concentrations.
Epimastigotes in culture were treated with Vit C (5, 15 or 30 μM) during 2, 5, 8 and 10 h, in the absence (a) or the presence (b) of a fixed concentration of Bnz (15μM). The thiol content was considered 100% for parasite cultures incubated without the addition of Vit C in (a) parasites alone and in (b) parasites treated with Bnz. At different timepoints, parasites were harvested and the thiol content was measured as described in Methods. *Significant differences (p<0.05) when compared to the control, as assessed by the Student’s t-test.
Fig 4.
Effect of the treatment with Vit C and Bnz on a murine model of acute Chagas’ disease.
C3H mice infected with bloodstream trypomastigotes of T. cruzi (5 x 103) were treated during days 7 to 11 and 14 to18 post-infection with either Vit C or Bnz only, or with Vit C + Bnz. The control group corresponds to untreated infected animals. Parasitemia levels (a) were measured and the survival (b) was monitored every day until the end of the treatment. (c) The weight loss of each animal was registered between days 9 and 16 post-infection.