Liposomes loaded with Salvia triloba and Rosmarinus officinalis essential oils: in vitro assessment of antioxidant, antiinflammatory and antibacterial activities.

Essential oils (EOs) have been widely used for their antimicrobial properties but their instability to light and high volatility can limit the clinical practice, therefore a useful strategy to improve their biopharmaceutical properties is represented by vesicular systems. This paper focuses on the development of Salvia triloba and Rosmarinus officinalis EOs-loaded nanovesicles and their evaluation for antioxidant, antiinflammatory and antibacterial activities. GC-MS analyses revealed that Salvia triloba and Rosmarinus officinalis EOs main constituents were eucalyptol (ca. 47 and 49% respectively) and camphor (ca. 11 and 12% respectively). Liposomes loaded with 100 μL/mL of EO, were optimised for their size, polydispersity index, ζ-potential, recovery, encapsulation efficiency (EE%), release properties and morphology. They both exhibited average sizes of about 200 nm with a ζ- potential between −20 mV and −35 mV, and PdI was about 0.25. EE% were ca. 57% for S. triloba and ca. 65% for R. officinalis. Liposomes were stable over one month period if stored at 4 °C and possessed significant antioxidant, antiinflammatory and antibacterial activities. In particular they were active against Klebsiella pneumoniae and more effective than the unformulated EOs. The findings suggest that these formulations can decrease the volatility of EOs, optimise their biological properties and defeat antimicrobial infections.