Combination Effects of the Antimicrobial Agents and Cinnamon Oil

摘要

The use of antimicrobial combination may be interesting because it can decrease doses and side effects of antimicrobial agents. The cinnamon essential oil was examined with respect to antimicrobial modifying activity. The combination effect of antimicrobial agents (doxycycline hyclate, ciprofloxacin HCl and metronidazole) and cinnamon oil was evaluated by checkerboard method to obtain a fractional inhibitory concentration (FIC) index. The effect of metronidazole+doxycycline hyclate and metronidazole+ciprofloxacin hydrochloride combinations were additive against Staphylococcus aureus. The indifference FIC index was observed only with the doxycycline hyclate+ciprofloxacin HCl combination. Combinations of cinnamon oil and all antimicrobial agents showed the additive effects against S. aureus. These results indicated that the antimicrobial activity of cinnamon oil was generally additive to all test antimicrobial agents.