A Review of the Phytochemistry and Antimicrobial Properties of <i>Origanum vulgare</i> L. and Subspecies.

Abstract

<i>Origanum</i> <i>vulgare</i> L. (<i>O. vulgare</i>) is an important medicinal herb of the family Lamiaceae. In the current study, we explained the critical evaluation of traditional uses, the phytochemistry and the antimicrobial properties of <i>O. vulgare</i> and its subspecies, with a focus on the mechanisms of actions of the most important phytochemicals from <i>O. vulgare</i> subspecies. The most important phytochemicals of <i>O. vulgare</i> are volatile (essential oil) and non-volatile phenolic compounds (phenolic acids & flavonoids). The constituents of the <i>O. vulgare</i> essential oil (EO) include high percentages of thymol and carvacrol with excellent antimicrobial activity alone or in combination with other antibiotics. Interesting results have been reported the remarkable antimicrobial activities of infusion or tea products of <i>O. vulgare</i> with a high amount of EO against multidrug-resistant bacterial and fungal microorganism (such as <i>Escherichia coli, Staphylococcus aureus, Candida albicans</i> and <i>Pseudomonas aeruginosa</i>). The most important antibacterial mechanisms of <i>O. vulgare</i> are enzyme inhibition, efflux pump inhibition, ATP depletion, biofilm formation inhibition and cytoplasmic membrane damage. The antimicrobial activity of the <i>hirtum</i> subspecies has been confirmed in different <i>in-vitro</i> and <i>in-vivo</i> studies. The present review confirms the clinical and preclinical research showing the <i>O. vulgare</i> and its subspecies antimicrobial effects.