The In Vitro Activity of Essential Oils against Helicobacter Pylori Growth and Urease Activity

Abstract

The anti-<i>H. pylori</i> properties of 26 different commercial essential oils were examined in vitro by MIC (minimal inhibitory concentration) determination for the reference strain <i>H. pylori</i> ATCC 43504. We selected 9 essential oils with different anti-<i>Helicobacter</i> 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 IC₅₀ (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 IC₅₀ ranged from 5.3 to > 1049.9 mg/L. The most active was cedarwood oil (IC₅₀ = 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-<i>H. pylori</i> activity. To summarize, the activity in vitro of the five essential oils silver fir, pine needle, tea tree, lemongrass, and cedarwood oils against <i>H. pylori</i> was found in this paper for the first time. The most active against clinical strains of <i>H. pylori</i> 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 <i>H. pylori</i> therapy.