Inhibition of Bacteria and Yeast by Oil of Fennel and Paraben: Development of Synergistic Antimicrobial Combinations

Abstract

This study describes inhibitory properties of combinations of oil of fennel and paraben (methyl, ethyl or propyl) against C. albicans, E. coli and S. aureus. Bacteria or yeast were cultured in broth at 25°C and viable counts were measured over a period of 24 h. E. coli was particularly sensitive to inhibition by each combination where there was C. albicans and S. aureus were less susceptible to inhibition by the combination of oil of fennel and methyl paraben but very susceptible to inhibition by oil of fennel in combination with propyl paraben where after 4 h there was <10 cf units/mL. Synergistic inhibition by one or more combinations was evident against each microbe.