In vitro antibacterial and synergistic effect of phlorotannins isolated from edible brown seaweed Eisenia bicyclis against acne-related bacteria

Abstract

-1 . Furthermore, FF clearly re- versed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromy- cin against P. acnes were dramatically reduced from 2,048 to 1.0 μg mL -1 in combination with MIC of FF (64 μg mL -1 ). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in com- bination with 32 or 64 μg mL -1 of FF against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes. The results of this study suggest that the compounds derived from E. bicyclis can be a potential source of natural antibacterial agents and a pharmaceutical component against acne- related bacteria.