Hydroxymethylnitrofurazone (NFOH) decreases parasitaemia, parasitism and tissue lesion caused by infection with the Bolivia Trypanosoma cruzi type I strain in Swiss and C57BL/6 mice

Abstract The chemical hydroxymethylation of the antimicrobial nitrofurazone leads to the prodrug NFOH, also increases the anti-T. cruzi activities (in vitro and in vivo), as well as showed non-genotoxic (Ames and micronucleus assays). In the present study, we assessed the anti-T. cruzi effect of the NFOH In vivo - in acute Swiss and C57Bl/6 experimental Chagas models. The treatment started at 5 days post-infection during 20 consecutive days (orally, once day, 150mg/kg), and the parasitaemia as well as histopathology analysis were performed. In both experimental murine models, NFOH was able to reduce parasitemia blood avoiding parasitic reactivation, during immunosuppression period (dexamethasone 5mg/kg, 14 days), in 100% of the mice, and decrease tissue parasite nests, demonstrating absence of amastigote forms in all organs (100%) analyzed, data similar to benznidazole (BZN). Therefore, the results shown here pointing to the NFOH as promising compound for further preclinical studies, being a high potential drug to effective and safe chemotherapy to Chagas disease.

Response to different benznidazole doses in animal models of chronic phase Chagas disease: a critical review

Abstract Chagas disease is a protozoan infection that was identified over a century ago. No drugs are available to treat the indeterminate and determinate chronic phases of the disease. Success of a drug design is dependent on correct biological evaluation. Concerning new drug designs for Chagas disease, it is essential to first identify the most effective, existing, experimental chronic protocols that can be used for comparison purposes. Here, we present a literature review regarding experimental models with chronic Chagas disease to evaluate the efficacy of benznidazole (BZN). We searched literature published in PubMed and Web of Science databases, using these keywords: animal model, BZN, Chagas disease, T. cruzi, and chronic phase, with no timeframe limitations. We excluded articles involving acute phase animal models and/or those without BZN treatment. The selected studies were conducted using different BZN concentrations (10mg-100mg) involving several different periods (5-70 days). Concentrations and durations of use are directly related to side effects, but do not prevent chronic tissue lesions. BZN use during the late/chronic phases of Chagas disease is unable to eliminate amastigote forms present in infected tissues. This study suggests the administration of a lower BZN concentration (<100mg/kg/day) during the chronic phase of the animal model, as this had been reported to result in fewer side effects.