Antimicrobial Nanoformulations Based on Schinus areira Essential Oil

The goal of this research was to create an antibacterial formulation from Scinus areira essential oil (EO) that could spread in water. To achieve this, we developed liposomal formulations of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) or DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) that encapsulated the EO. In addition, we utilized the EO as a reducing and stabilizing agent to synthesize silver nanoparticles (AgNPs). The nanoformulations were characterized by determining their size and zeta potential. In the case of liposomal formulations, chemical composition, and encapsulation efficiency were also determined. Furthermore, antimicrobial activity studies against Gram-positive and Gram-negative model bacteria were carried out for both kinds of formulations. The results obtained showed the successful encapsulation of the S. areira EO in multilamellar liposomes of phosphatidylcholine with high efficiency. DPPC liposomes have proven to be a better encapsulation system, retaining more monoterpenes from the EO and therefore presenting antimicrobial activity against S. aureus with an minimal inhibitory concentration (MIC) value of 3 mg/mL of EO. On the other hand, it was also possible to obtain AgNPs by using S. areira EO, which showed antimicrobial activity against S. aureus and E. coli at low concentrations of EO, with MIC values of 6.68 µg/mL and 3.4 µg/mL of silver, respectively. The data obtained will contribute to enhancing the biotechnological value of natural products derived from native plant species in Argentina. This will be achieved through the generation of novel formulations with antibacterial activity and potential bioavailability.