Figure 4. BNZ-PSs are more potent than free BNZ against T. cruzi in vivo.

(A) Mice (n = 5 per group) were infected with T. cruzi Y strain trypomastigotes on day 0 and treated with 2 i.v. doses of BNZ-PS and PS after parasitemia had reached approximately 2 × 10⁵/mL on day 7. Standard oral treatment with BNZ was given daily for 14 days (7–21 d.p.i.). Parasitemia was monitored every few days through the end of the experiment on day 25, when mice were sacrificed and organs were collected for further analysis. (B) Effective suppression of parasitemia by BNZ and BNZ-PS. *P ≤ 0.05 for BNZ 100 mg/kg and BNZ-PS 1.5 and 0.15 mg/kg vs. untreated and PS. (C) Cardiac parasitosis was quantitated by quantitative PCR. *P ≤ 0.01 vs. untreated and PS. (D) Cardiac inflammation was quantitated in heart sections 2 ways — by total cellularity (top) and by the percentage of cellular area occupied by nuclei (bottom). *P ≤ 0.05 vs. untreated, PS, and BNZ. (E) Representative cardiac histology from the experiment in C. Scale bar: 100 μM. All error bars reflect mean ± SEM. One-way ANOVA with Tukey’s post hoc test was used for multiple comparisons.