Evaluation of in vitro antimicrobial activity of Thai basil oils and their micro-emulsion formulas against Propionibacterium acnes

摘要

The aim of this study was to evaluate the efficacy of Thai basil oils and their micro-emulsions,on in vitro activity against Propionibacterium acnes.An agar disc diffusion method was employed for screening antimicrobial activity of the essential oils of Ocimum basilicum L.(sweet basil),Ocimum sanctum L.(holy basil) and Ocimum americanum L.(hoary basil) against P.acnes.Minimum inhibitory concentration (MIC) values of the basil oils were determined using an agar dilution assay.The obtained results indicated that the MIC values of sweet basil and holy basil oils were 2.0% and 3.0% v/v,respectively,whereas hoary basil oil did not show activity against P.acnes at the highest concentration tested (5.0% v/v).Gas chromatogra-phy-mass spectrometry analysis revealed that methyl chavicol (93.0%) was the major compound in sweet basil oil,and eugenol (41.5%),y-caryo-phyllene (23.7%) and methyl eugenol (11.8%) were major compounds in holy basil oil.