B-NPOx led to a greater reduction in the parasitemia in infected mice than Et-NPOX, Bz or Nx. (A) Parasitemia was evaluated according to the number of bloodstream trypomastigotes in mice infected with the NINOA strain of T. cruzi and subsequently treated with B-NPOx, Et-NPOx, Bz or Nx as indicated in the Methods section. A group of infected/untreated mice was used as a control group. The drugs were administered daily at 100 mg/kg over a period of 50 days. The first dose was given 24 h after the infection. The results have been presented as the mean values ± the standard deviations of the parasitemia from three different experiments. (B) The effects of B-NPOx, Et-NPOx, Bz and Nx towards the parasitemia in mice infected with the Miguz, Compostela, Nayarit and INC-5 strains of T. cruzi were evaluated under the conditions indicated in (A). The percentage of blood trypomastigotes was calculated on the day of maximum parasitemia for all four of the different T. cruzi strains (i.e., 40–45 days after infection with the Miguz and Compostela strains, 15–20 days after infection with the Nayarit and INC-5 strains), and the parasitemia in the control (infected/untreated) group was set to 100% in each case. Data were analyzed with one-way ANOVA followed by Tukey’s multiple comparisons test. ***p ≤ 0.001, **p ≤ 0.01, *p ≤ 0.05, compared with the infected/untreated mice.