Easy Obtainment and Biological Applicability of Pinocarvyl Acetate by Encapsulating of the Microlicia graveolens Essential Oil in Oil-in-Water Nanoemulsions

<b>Background/Objectives:</b> The study of biological activity of plants and their metabolites is an important approach for the discovery of new active material. However, little is known of the properties of the <i>Microlicia</i> genus. In addition to natural products, nanotechnology demonstrates considerable potential in pharmacotherapy. The utilization of nanoemulsions holds considerable promise in enhancing the efficacy of drugs, reducing dose, and therefore, lowering of toxic effects. <b>Methods:</b> In this context, antimicrobial and trypanocidal activities were evaluated to the free and encapsulated essential oil from <i>M. graveolens</i> in oil-in-water (o/w) nanoemulsion. <b>Results:</b> This oil is composed mainly of <i>cis</i>-pinocarvyl acetate (~80.0%). The nanoemulsions were prepared by phase inversion method and showed mean particle size of 58 nm, polydispercity index of 0.09, pH 7.8, zeta potential of -21.9 mV, electrical conductivity of 0.38 mS/cm, and good stability. The essential oil was active against all five Gram-positive bacteria tested, and the formulation enhanced this ability. The cytotoxicity effect on L929 cells was also reduced after encapsulation of this oil in o/w nanoemulsion. In addition, the oil and the nanoemulsion were able to inhibit the growth of <i>Trypanosoma cruzi</i>. <b>Conclusions:</b> Thus, the development of a nanoemulsion loaded with <i>M. graveolens</i> essential oil is an easy and low-cost way to obtain and deliver the <i>cis</i>-pinocarvyl acetate compound as well as allow its use in the treatment of diseases caused mainly by the genus <i>Listeria</i> and <i>Staphylococcus</i>.