Physical, antimicrobial and antibiofilm properties of Zataria multiflora Boiss essential oil nanoemulsion

Abstract

Summary It was evaluated physical, antibacterial and antibiofilm properties of Zataria multiflora Boiss essential oil (ZEO) and its nanoemulsion. Long‐term stability of nanoemulsion prepared by emulsion phase inversion was satisfying based on low narrow size distribution (polydispersity index ˜0.2) and low droplet size (200 nm) over 21 days of storage. Nanoemulsion showed lower minimum inhibitory concentration (MIC) on Listeria monocytogenes (2500 µg mL−1) than Salmonella Typhimurium (5000 µg mL−1). Killing kinetics study revealed that nanoemulsion was more effective in inhibiting the growth of bacteria in milk than culture media. Both bacteriostatic and bactericidal effects were observed depending on the type of bacteria, nanoemulsion concentration and the time of exposure. Nanoemulsion at 4×MIC concentration reduced 64% and 75% of one‐day‐old biofilm of L. monocytogenes and S. Typhimurium, respectively. In conclusion, nanoemulsion revealed antimicrobial activity, but converting the ZEO to nanoemulsion did not improve its antibacterial activity; however, antibiofilm properties were enhanced.

Production of clove oil nanoemulsion with rapid and enhanced antimicrobial activity against gram‐positive and gram‐negative bacteria

“…As reported previously in the literature the nanometric droplets are able to fuse with the lipid envelope of the microorganisms, releasing the bioactive compound and causing disturbances with subsequent leakage of intracellular constituents (Ghosh et al, ; Hashtjin & Abbasi, ; Sugumar, Ghosh, Nirmala, Mukherjee, & Chandrasekaran, ). Although some studies are available in literature (Donsì, Annunziata, Sessa, & Ferrari, ; Donsì, Annunziata, Vincensi, & Ferrari, ; Franklyne, Mukherjee, & Chandrasekaran, ; Kheawfu, Pikulkaew, Rades, Müllertz, & Okonogi, ; Majeed et al, ; Majeed, Antoniou, Shoemaker, & Fang, ; Salvia‐Trujillo, Rojas‐Graü, Soliva‐Fortuny, & Martín‐Belloso, ; Shahabi, Tajik, Moradi, Forough, & Ezati, ; Spigno et al, ; Tian, Lei, Zhang, & Li, ), it is still needed some investigation around the reduction of the emulsion droplet diameter considering the relation between the nanometric range and the improvement of the bioavailability and biological activity of the active compounds present in these essential oils.…”

“…Although some studies are available in literature (Donsì, Annunziata, Sessa, & Ferrari, 2011;Donsì, Annunziata, Vincensi, & Ferrari, 2012;Franklyne, Mukherjee, & Chandrasekaran, 2016;Kheawfu, Pikulkaew, Rades, Müllertz, & Okonogi, 2018;Majeed et al, 2016;Majeed, Antoniou, Shoemaker, & Fang, 2014;Salvia-Trujillo, Rojas-Graü, Soliva-Fortuny, & Martín-Belloso, 2015;Shahabi, Tajik, Moradi, Forough, & Ezati, 2017;Spigno et al, 2013;Tian, Lei, Zhang, & Li, 2016), it is still needed some investigation around the reduction of the emulsion droplet diameter considering the relation between the nanometric range and the improvement of the bioavailability and biological activity of the active compounds present in these essential oils.…”

Antimicrobia activity of garlic (Allium sativum L.) and holy basil (Ocimum sanctum L.) essential oils applied by liquid vs. vapour phases

“…They contain nonphytotoxic compounds and bioactive agents which enhance microbial control capability (Prakash et al, 2015;Hu et al, 2016). A new strategy has emerged using essential oils with other technologies such as antibiofilm (Alejo-Armijo et al, 2017), edible film coatings (Guerreiro et al, 2017;Yang et al, 2017;Yu et al, 2017), nanoemulsions (Lou et al, 2017;Shahabi et al, 2017), microencapsulation (Abedi et al, 2016;Chitprasert & Ngamekaue, 2017;Piletti et al, 2017) and modified atmosphere packaging (Cosmai et al, 2017).…”

“…Almost all screenings of EO antimicrobial activity have used nutrient media (Shahabi et al, 2017). The disc diffusion method is often applied (Tajkarimi et al, 2010) for qualitative antibacterial analysis of liquid oil (Viuda-Martos et al, 2008;Al-Reza et al, 2009;Boukhatem et al, 2013;Wang et al, 2015;Dannenberg et al, 2016;Alejo-Armijo et al, 2017).…”

“…The disc diffusion method, however, may present a problem, as EOs are hydrophobic, and volatile components have low water solubility in media (Nedorostova et al, 2009;Tajkarimi et al, 2010). In contrast, the volatilisation method is considered suitable (Nedorostova et al, 2009;Ali et al, 2015;Perumal et al, 2016;Shahabi et al, 2017) for determining antimicrobial activity and obtaining minimal inhibitory concentration (MIC) or minimum bactericidal concentration (MBC), which represents the lowest concentration of EO required to inhibit target microorganisms (Dannenberg et al, 2016;Lu et al, 2016;Alejo-Armijo et al, 2017). The screening method is not standardised for comparing liquid and vapour phases of EO (Tyagi & Malik, 2011;Boukhatem et al, 2013).…”