The combination effects of the essential oils from Perilla frutescens var. acuta with antibiotics against antibiotic-resistant and susceptible Vibrio and Salmonella species

Salmonella and Vibrio species comprise many of the common pathogens causing food-borne diseases. There has been an increased emergence of antibiotic resistant strains in recent. This is thought to have largely resulted from the consumption of processed food and agricultural products that have been in contact with antibiotics. P. frutescens Britton var. acuta Kudo is an annual herb cultivated in Korea, mainly in the southern district. It has been used in traditional medicine to disperse cold causing fever, chills, headache, nasal congestion, or cough. It is also has effects to treat nausea, vomiting and other gastrointestinal symptoms. In this study, the essential oil fraction obtained from the fresh and dried leaves of P. frutescence var. acuta by steam distillation and analyzed by GC-MS. Its main components were isolated by column chromatography. The inhibiting activities of the essential oil fraction and isolated compounds were evaluated against antibiotic-susceptible and -resistant strains of Vibrio and Salmonella species. In addition the potential of synergistic effects were accessed by combing the oils with ampicillin or trimethoprim-sulfamethoxazole (T/S). The essential oil fraction of P. frutescence var. acuta and its main component, apiol showed significant inhibitory activity against most of the tested strains of antibiotic-susceptible and -resistant bacteria. The FICs and FICI of its main component combined with ampicillin or T/S depicted on the basis of results of checkerboard microtiter test indicated synergism or additive effects.

Acknowledgement: This work was supported by National Research Foundation of Korea Grant funded by the Korean Government (NRF-531–2008–1-E00106).

References: Shin S (2005) Arch Pharm Res 28: 765–769.