The current scenario for
cutaneous leishmaniasis treatment includes the use of first and second-choice drugs, both therapeutic strategies presenting several adverse effects and being related to an increment of treatment-refractory parasite strains. These facts encourage the search for new treatment approaches, including repositioning drugs, such as
nystatin. Although in vitro assays show that this polyene
macrolide compound has leishmanicidal activity, no in vivo evidence for a similar activity has been shown so far for the commercial
nystatin cream formulation. This work assessed the effects of
nystatin cream (25,000 IU/g) administered on mice in an amount to completely cover the paw surface of BALB/c mice infected with Leishmania (L.) amazonensis once a day, until a total of up to 20 doses. The data presented herein points to unequivocal evidence that treatment with this formulation causes a statistically significant reduction of swelling/
edema in mice paws when compared to animal groups not submitted to this treatment regimen after the fourth week of
infection: lesion sizes at the sixth (p = 0.0159), seventh (p = 0.0079) and eighth (p = 0.0079) week. Furthermore, swelling/
edema reduction relates to a decrease in parasite load in the footpad (∼48%) and in draining lymph nodes (∼68%) at eight weeks post-
infection. This is the first report of the effectiveness of
nystatin cream used as a topical treatment in BALB/c model for
cutaneous leishmaniasis.