Evaluation of physical properties of nanoliposome Barije (Ferula gummosa Boiss.) essential oil and its antimicrobial effect on Escherichia coli O157:H7

Abstract

Introduction Escherichia coli is an important bacterial pathogen transmitted through contaminated water and food. The aim of this study was to evaluate the physical characteristics of nanoliposome essential oil (EO) and its antibacterial effect on E. coli. Materials and Methods Nanoliposomes were prepared by thin-film hydration and sonication. Particle size, polydispersity index, and encapsulation efficiency were assessed. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of free EO and nanoliposome barije EO were determined by broth macrodilution against E. coli. Also, effect of different concentrations of the MIC of EO was evaluated before and after encapsulation against the growth of bacteria over 24 h. Results The average particle sizes of the empty and EO loaded nanoliposome were 138.76 and 81.47 nm, respectively. Also, EO loaded nanoliposome had lower polydispersity. Moreover, the encapsulation efficiency of nanoliposomes was determined about 73.26%. MIC and MBC levels for EO loaded nanoliposomes decreased in comparison with free EO. Using 75% MIC of free EO in comparison with control, the bacterial count decreased by 3.528 and 1.12 log (CFU/mL) after 12 and 24 h, respectively. This reduction in the EO loaded nanoliposomes was 3.40 and 2.33 (CFU/mL) log (p <0.05). Conclusion Nanoliposomes encapsulated barije EO were prepared successfully using the thin-film hydration and sonication method and showed enhancing antimicrobial activity against E. coli O157:H7 in comparison with the non-encapsulated one.

Keywords

• barije essential oil
• nanoliposomes
• antimicrobial
• e. coli o157:h7