Development of Nanoemulsions to Enhance the Antileishmanial Activity of<i>Copaifera paupera</i>Oleoresins

Abstract

Based on the ethnopharmacological evidences about the antileishmanial activity of <i>Copaifera</i> spp. oleoresins, the effects of crude extracts and fractions of oleoresin of two specimens from <i>Copaifera paupera</i> were evaluated on <i>Leishmania amazonensis</i> and <i>Leishmania infantum</i> strains. The oleoresin rich in <i>α</i>-copaene (38.8%) exhibited the best activity against <i>L. amazonensis</i> (IC₅₀ = 62.5 <i>μ</i>g/mL) and against <i>L. infantum</i> (IC₅₀ = 65.9 <i>μ</i>g/mL). The sesquiterpene <i>α</i>-copaene isolated was tested alone and exhibited high antileishmanial activity <i>in vitro</i> with IC₅₀ values for <i>L. amazonensis</i> and <i>L. infantum</i> of 17.2 and 11.4 <i>μ</i>g/mL, respectively. In order to increase antileishmanial activity, nanoemulsions containing copaiba oleoresin and <i>α</i>-copaene were developed and assayed against <i>L. amazonensis</i> and <i>L. infantum</i> promastigotes. The nanoemulsion containing <i>α</i>-copaene (NANOCOPAEN) showed the best activity against both species, with IC₅₀ of 2.5 and 2.2 <i>μ</i>g/mL, respectively. This is the first report about the antileishmanial activity of <i>α</i>-copaene.