Comparative study of antibacterial inhibitory effect of silver nanoparticles and garlic oil nanoemulsion with their combination

Silver can inhibit bacterial activity. Previous studies showed that high concentration of silver nanoparticles (AgNPs) in compared to its lower concentrations is toxic for human health. However, by decreasing concentration of AgNPs, antibacterial activity also decreases. In this study, we investigated synergistic inhibitory activity of the combination of AgNPs and garlic oil nanoemulsion (GONE) for increase antibacterial activity of AgNPs at lower concentrations. AgNPs and GONE with sizes of 30.7 and 19.3 nm were synthesized and prepared by chemical reduction and low energy method, respectively. Physicochemical properties of AgNPs and GONE were investigated. The minimum inhibitory concentration (MIC) of samples was assessed using the standard microdilution method against pseudomonas aeruginosa and staphylococcus aureus. P. aeruginosa was suspected to AgNPs and GONE at all concentration, but in the case of S. aureus, antibacterial activity was revealed at ≥29.1% (v/v) and ≥ 36.4 ppb concentration of GONE and AgNPs, respectively. In addition, at low concentration, S. aureus was unsuspected to AgNPs and GONE. Combination of AgNPs and GONE (CAG) demonstrated synergistic inhibitory effects at low concentration (≥29.1% (v/v) and ≥ 36.4 ppb concentration). Also, CAG revealed antibacterial activity against S. aureus at low concentration. These results indicate that combination of GONE and AgNPs has potential as a green antiseptic agent.