The clove essential oil and its combination with galangal oil exhibit antibacterial activity, potential as antiseptic agent

Abstract

Essential oils are known and have been tested for their antimicrobial properties. Previous studies have tested the antimicrobial activity of clove and galangal essential oils alone. Thus, the purpose of this study was to determine the antimicrobial activity of clove and galangal essential oils alone as well as their combinations. The screening of antimicrobial activity was performed by disc diffusion assay against Gram-positive bacteria and Gram-negative bacteria. Both essential oils showed antimicrobial activity against Escherichia coli at 10% (v/v) concentration. Furthermore, five combinations of clove and galangal essential oils were made and tested at 1:1, 7:3, 9:1, 3:7, and 1:9 ratio. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of three combinations with the highest activity were performed against Escherichia coli. The MIC and MBC of clove oil is at 2.5% (v/v) and 5% (v/v) while the MIC and MBC of Galangal oil is at 5% (v/v) and 10% (v/v). All three combinations showed MIC and MBC value is at 5% (v/v) and 10% (v/v) respectively. In addition, based on SNI EN 1276:2019 assay, the clove and galangal essential oil as well as their combinations meet the requirement as antiseptic agent against E. coli.