Chemical Composition and Antioxidant Properties and Antimicrobial Effects of Satureja bachtiarica Bunge and Echinophora platyloba DC. Essential Oils Against Listeria monocytogenes

Satureja bachtiarica Bunge and Echinophora platyloba DC. are two important indigenous medicinal plants of Iran with high antimicrobial and antioxidant effects. The existing examination was done to assess the chemical composition and antioxidant and antibacterial properties of S. bachtiarica and E. platyloba essential oils against Listeria monocytogenes. Aerial parts of plants were collected and their essential oil were extracted using the water distillation method (Clevenger apparatus). Chemical components were analyzed using the GC-MS. Total phenolic and flavonoid components and DPPH radical scavenging effects of essential oils were analyzed. Antibacterial effects were assessed using the disk diffusion and MIC and MBC values were assessed by the micro broth dilution. Carvacrol (31.25%), thymol (23.50%) and o-cymene (13.87%) were the most frequently identified chemical components in S. bachtiarica. Ocimene (44.15%), α-phellandrene (16.80%) and γ-terpinene (8.52%) were the most frequently identified chemical components in the E. platyloba. DPPH radical scavenging effects of S. bachtiarica and E. platyloba were 76.72 ± 2.52% and 64.21 ± 2.11%, respectively. TPC of S. bachtiarica and E. platyloba were 88.33 ± 1.69and 30.05 ± 1.14 (mg GAE per 100 g dw), respectively. TFC of S. bachtiarica and E. platyloba were 20.63 ± 1.24 and 17.28 ± 1.07 (mg quercetin per 100 g dw), respectively. Antibacterial effects of S. bachtiarica and E. platyloba essential oils were dose-dependent (P<0.05). S. bachtiarica (40 mg/mL) had the highest diameter of the growth inhibition zone (23.64 ± 0.35 mm). MICs and MBCs of S. bachtiarica and E. platyloba essential oils were 5 and 20 and 10 and 40 mg/mL, respectively. Both plants are suitable candidate as food preservatives.