Chemical composition and potential antileishmanial and cytotoxic activity of Duguetia stelechantha (Diels) R.E.Fr. essential oil

Duguetia stelechantha (Diels) R.E.Fr., popularly known as “ata brava” in Brazil, belongs to the Annonaceae family. Biologically active monoterpenes and sesquiterpenes identified in this genus and family, comprising a source of new drugs against several conditions, including leishmaniasis. In this context, the aim of the present study was to extract and chemically characterize the essential oil (EO-DU) obtained from D. stelechantha for the first time. The potential antileishmanial activity and in vitro cytotoxicity of an EO microemulsion (EO-ME) formulated with Tween 80 and Transcutol P surfactants were also evaluated. Duguetia stelechantha leaves were submitted to a hydrodistillation process and their chemical composition was determined by GC/MS. The major identified EO components were β-pinene (46.17 %), α-pinene (20.2 %), and spathulenol (6.68 %). A headspace characterization indicated major EO-DU compounds present in the prepared ME, confirming incorporation. The extracted EO was moderately active against Leishmania (L.) amazonensis promastigotes (IC50 =138.3 µg/mL), while the EO-ME was determined as active, inhibiting these parasites at a lower concentration (IC50 =4.47 µg/mL) compared to the EO-DU, indicating high selectivity against L. (L) amazonensis promastigotes. The major compound α-pinene was also tested, and presented IC50 = 64.78 µg/mL, considering it active against the tested parasites. Considering that D. stelechantha is an abundant species in the Brazilian Legal Amazon and that the antileishmanial potential of the extracted EO was enhanced by EM incorporation, this assessment provides relevant perspectives for future studies focused on the bioeconomy.