Aqueous ozone therapy improves the standard treatment of leishmaniasis lesions in animals leading to local and systemic alterations.

The current treatment of leishmaniasis presents some problems, such as cell toxicity, parenteral route, and time of treatment. Ozone emerges as an option to accelerate the standard treatment due to the immunomodulatory, antioxidant, and wound healing activity reported in the literature. This work aimed to evaluate the efficacy of aqueous ozone as an adjuvant to the standard treatment of cutaneous lesions caused by Leishmania amazonensis in an experimental model. For in vivo experiments, mice were randomly distributed in 6 groups, which were infected with L. amazonensis and treated in five different schedules using the standard treatment with Glucantime® with or without aqueous ozone. After the last day of treatment, the animals were euthanized and were analyzed: the thickness of lesions; collagen deposition, the parasitic burden of the lesions; blood leukocyte number; NO; and cytokine dosages and arginase activity from peritoneal macrophages. All treated groups showed a decrease in the lesion, but with a significative deposition of collagen in lesions with local ozone treatment. The parasite burden showed that ozone enhanced the leishmanicidal activity of the reference drug. The reduction of NO production and blood leukocyte count and increases in the arginase activity showed an immunomodulatory activity of ozone in the treated animals. Thus, ozone therapy has been shown to work as an adjuvant in the treatment of Leishmania lesions, enhancing leishmanicidal and wound healing activity of standard treatment.