RESUMEN
Pythiosis is a rapidly progressing disease that can be lethal to affected individuals due to resistance to available therapeutic protocols. The disease affects mammals, with the largest number of reports in horses and humans. The present study investigated the activity of biogenic silver nanoparticles (bioAgNP) in the treatment of experimental pythiosis. The disease was reproduced in nine female 90-day-old New Zealand rabbits. Animals were divided into three groups: group1 (control, n = 3) daily and topically treated with a nonionized gel-based formulation and 1 ml of sterile distilled water intralesion administered every 48 hours; group 2 (n = 3), daily and topically treated with gel-based formulation containing 1 µg/ml bio-AgNP; group 3 (n = 3), treated with 1 ml bio-AgNP in 1 µg/ml aqueous solution intralesion administered every 48 hours. Animals were treated for 45 days, and the area of subcutaneous lesions was measured every 5 days. Results showed that groups 2 and 3 differed from control group (P < .05) in the lesion area, as well as the amount of hyphae within the lesions. It was observed that lesions of treated animals (groups 2 and 3) did not differ from each other, showing that the application route did not influence the regression of lesions. However, it was observed that one animal from group 2 reached clinical cure at 35 days of treatment. This research is pioneer in the application of nanocomposites for the treatment of experimental pythiosis and showed that bio-AgNP can be powerful allies of integrative medicine and can be included in pythiosis therapeutic protocols.