Properties and limits of some essential oils: chemical characterisation, antimicrobial activity, interaction with antibiotics and cytotoxicity

<p>Because of the emergence of multi-drug resistance bacteria and fungi, alternatives to conventional antimicrobial therapy are needed. This study aims to evaluate <i>in vitro</i> the antimicrobial activity of: <i>Mirtus communis</i>, <i>Coriandrum sativum</i>, <i>Pelargonium capitatum</i>, <i>Cuminum cyminum</i>, <i>Ocimum basilicum</i>, <i>Citrus aurantium amara</i>, <i>Cymbopogon. winterianus</i>, <i>Cymbopogon martini</i>, <i>Salvia sclarea</i>, <i>Melaleuca alternifolia</i> and <i>Mentha suaveolens</i> essential oils on bacteria and fungi, in relation to their chemical composition. The potential interaction of <i>M. alternifolia</i> (TTO), <i>C. sativum</i> (CDO) and <i>M. suaveolens</i> (EOMS) essential oils when used in combination with gentamicin and fluconazole has been evaluated. The results obtained showed a synergic effect on some bacteria and fungi, with FICI values ≤5. The cytotoxicity of TTO, CDO and EOMS was investigated towards HeLa cells. Only EOMS did not result cytotoxic at the active concentrations on micro-organisms. Further studies are necessary to obtain optimal ratios and dosing regimens for higher therapeutic efficacy and to decrease toxicological profiles.</p>