Trypanocidal activity of the essential oils in their conventional and nanoemulsion forms: In vitro tests

Trypanocidal activity of essential oils of andiroba (Carapa guaianensis) and aroeira (Schinus molle) on Trypanosoma evansi, in vitro. •Trypanosoma evansi is the etiologic agent of a disease known as Mal de cadeiras in horse.•The disease has been recorded several cases of resistance to antiprotozoal.•Andiroba and aroeira oils have different properties, as well as action on parasites.•Trypanocidal activity of andiroba and aroeira oils against T. evansi, in vitro.•Nanomolecules essential oils with andiroba and aroeira also had trypanocidal action, in vitro. The aim of this study was to investigate the susceptibility in vitro of Trypanosoma evansi to the essential oils of andiroba (Carapa guaianensis) and aroeira (Schinus molle), in their conventional and nanostructured forms. For that, pure oils at concentrations of 0.5%, 1.0% and 2.0% were used. A negative control (untreated) and a positive control (diminazene aceturate 0.5%) were used as comparative parameters. Later, the same tests were performed, using nanoemulsions oils at concentrations of 0.5% and 1.0%. The tests were carried out in triplicates and the numbers of parasites were quantified on 1, 3 and 6h from onset of the study. A dose-dependent reduction in the number of parasites to the forms of two oils tested was observed after 1h. The concentration of parasites was significantly reduced at low concentrations after 3h, as well as at 6h no alive parasites were observed for the essential oils tested. Ours findings indicate, for the first time, that oils of andiroba and aroeira (in their conventional and nanoemulsion forms) have high activity against T. evansi in vitro, leading to the suggestion that these oils may be applied as an alternative treatment for this disease.