02132nas a2200133   4500008004100000245011300041210006900154260014100223520155900364100002101923700001501944700001801959856002101977       2009                        eng d00aThe antimicrobial activity of four commercial essential oils in combination with conventional antimicrobials0 aantimicrobial activity of four commercial essential oils in comb  aDepartment of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, Parktown, South Africa.c2009/02//3 aAbstract Aims: Due to the emergence of multi-drug resistance, alternatives to conventional antimicrobial therapy are needed. This study aims to investigate the in vitro pharmacological interactions between essential oils (considered valuable as natural therapeutic treatments) and conventional antimicrobials (ciprofloxacin/amphotericin B) when used in combination. Methods and Results: Interactions of the essential oils (Melaleuca alternifolia, Thymus vulgaris, Mentha piperita and Rosmarinus officinalis) when combined with ciprofloxacin against Staphylococcus aureus indicate mainly antagonistic profiles. When tested against Klebsiella pneumoniae the isobolograms show antagonistic, synergistic and additive interactions depending on the combined ratio. The R. officinalis/ciprofloxacin combination against K. pneumoniae displayed the most favourable synergistic pattern. The interactions of M. alternifolia (tea tree), T. vulgaris (thyme), M. piperita (peppermint) and R. officinalis (rosemary) essential oils with amphotericin B indicate mainly antagonistic profiles when tested against Candida albicans. Conclusion: While a number of interactions show complete antagonism, others show varied (synergistic, additive and/or antagonistic) interactions, thus the efficacy is dependent on the ratio in which the two components co-exist. Significance and Impact of the Study: The predominant antagonistic interactions noted here, suggests that some natural therapies containing essential oils should be used with caution when combined with antibiotics.1 avan Vuuren, S, F1 aSuliman, S1 aViljoen, A, M  uwww.refworks.com02667nas a2200205   4500008004100000245009600041210006900137260026900206300001400475490000700489520158900496100001802085700002402103700001502127700001402142700001502156700001502171700001502186856026002201       1999                        eng d00aIn-vitro antimicrobial activity and chemical composition of Sardinian Thymus essential oils0 aInvitro antimicrobial activity and chemical composition of Sardi  aAffiliation: Department of Experimental Biology, University of Cagliari, Sardinia, Italy; Affiliation: Department of Toxicology, University of Cagliari, Sardinia, Italy; Affiliation: University of Cagliari, Department of Experimental Biology, S.S. 554 Km.c1999///  a130 - 1350 v293 aEssential oils and their components are becoming increasingly popular as naturally occurring antimicrobial agents. In this work the chemical composition and the antimicrobial properties of Thymus essential oils and of their main components were determined. Three essential oils obtained from different species of Thymus growing wild in Sardinia and a commercial sample of Thymus capitatus oil were analysed. The essential oil components were identified by GC/MS analysis. The antimicrobial activity of the oils and components was determined against a panel of standard reference strains and multiple strains of food-derived spoilage and pathogenic bacteria, using a broth microdilution method. The GC/MS analysis showed that the major constituents of the oils were monoterpene hydrocarbons and phenolic monoterpenes, but the concentration of these compounds varied greatly among the oils examined. The results of the antimicrobial assay showed that essential oils extracted from Sardinian Thymus species have an antimicrobial activity comparable to the one observed in other thyme oils. It seems also confirmed that the antimicrobial properties of thyme essential oils are mainly related to their high phenolic content. Among the single compounds tested carvacrol and thymol turned out to be the most efficient against both reference strains and food-derived bacteria. The results of this study confirmed the possibility of using thyme essential oils or some of their components in food systems to prevent the growth of foodborne bacteria and extend the shelf-life of processed foods.1 aCosentino, S.1 aTuberoso, C., I. G.1 aPisano, B.1 aSatta, M.1 aMascia, V.1 aArzedi, E.1 aPalmas, F.  uhttp://www.scopus.com/scopus/inward/record.url?eid=2-s2.0-0032856392&partnerID=40&rel=R6.5.0http://muse.lib.auth.gr:9797/com/blackwell-synergy/?MuseHost=www.blackwell-synergy.com&MuseFirst=1&prevSearch=allfield:(thymus+AND+(labiatae+OR+lamiaceae))&StartMu