The In Vitro Activity of Essential Oils against Growth and Urease Activity.

The anti- properties of 26 different commercial essential oils were examined in vitro by MIC (minimal inhibitory concentration) determination for the reference strain ATCC 43504. We selected 9 essential oils with different anti- activities and established their phytochemical composition and urease inhibition activities. Phytochemical analysis of the selected essential oils by GC-MS method and antioxidant activity were performed. The phenol red method was used to screen the effect of essential oils on urease activity expressed as IC (the half of maximal inhibitory concentration). The most active essential oils, with MIC = 15.6 mg/L, were thyme, lemongrass, cedarwood and lemon balm oils; MIC = 31.3 mg/L-oregano oil; MIC = 62.5 mg/L-tea tree oil; MIC = 125 mg/L-pine needle, lemon and silver fir oils with bactericidal effect. Urease activity was inhibited by these oils with IC ranged from 5.3 to > 1049.9 mg/L. The most active was cedarwood oil (IC = 5.3 mg/L), inhibiting urease at sub-MIC concentrations (MIC = 15.6 mg/L). The statistical principal component analysis allowed for the division of the oils into three phytochemical groups differing in their anti- activity. To summarize, the activity in vitro of the five essential oils silver fir, pine needle, tea tree, lemongrass, and cedarwood oils against was found in this paper for the first time. The most active against clinical strains of were cedar wood and oregano oils. Moreover, cedarwood oil inhibited the urease activity at subinhibitory concentrations. This essential oil can be regarded as a useful component of the plant preparations supporting the eradication therapy.