Study of antimicrobial efficacy of garlic oil loaded ethosome against clinical microbial isolates of diverse origin

Introduction: Garlic oil (GO), a steam-distilled product of Garlic (Allium sativum) has been successfully used as an antiseptic, antimicrobial, antioxidant and anti-inflammatory agent for decades. However, the contact irritation and volatility are practical limitations in their use. This study aimed to evaluate the in-vitro antimicrobial efficacy of garlic oil (GO) encapsulated ethosome against the microbial isolates of diverse origins as well as the effect of the storage temperature on antimicrobial efficacy.Methods: The GO ethosomes were prepared by cold method and characterised for particle size distribution, morphology by Scanning Electron Microscopy (SEM) and molecular fingerprinting by Fourier-transform infrared spectroscopy (FT-IR) and release kinetics. Results: The GO ethosomes at a concentration of 25 mu g/ml was found effective against all tested isolates, whereas at a concentration of 12.5 mu g/ml and 6.25 mu g/ml it was found effective against 146/147 and 139/147 isolates respectively. The average zone of inhibition (ZI) was 33.5 mm (25 mu g/ml), 30.1 mm (12.5 mu g/ml) and 24.0 mm (6.25 mu g/ml). The minimum inhibitory concentration (MIC) values remain relatively constant against reference strain S. aureus (ATCC 29312 and ATCC 43300) and E. coli (NDM) at 0 days to 265 days. The minimum bactericidal concentration (MBC) values against the majority of isolates were in the range of 125-250 mu g/ml. The invitro release data showed zero order kinetics, and best-fit release model was Korsmeyer-peppas and Weibull.Conclusion: The study demonstrated that the encapsulation of GO preserves the antimicrobial efficacy and storage for 265 days at room temperature did not alter the efficacy, suggesting wider applications in therapeutics to food preservation.