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

doi:2014.29.1.47

Algae > Volume 29(1); 2014 > Article

Algae 2014;29(1): 47-55. doi: https://doi.org/10.4490/algae.2014.29.1.047

Jeong-Ha Lee¹, Sung-Hwan Eom², Eun-Hye Lee², Yeoun-Joong Jung², Hyo-Jung Kim², Mi-Ra Jo³, Kwang-Tae Son³, Hee-Jung Lee³, Ji Hoe Kim³, Myung-Suk Lee¹ and Young-Mog Kim^2,*

¹Department of Microbiology, Pukyong National University, Busan 608-737, Korea
²Department of Food Science and Technology, Pukyong National University, Busan 608-737, Korea
³Food Safety Research Division, National Fisheries Research & Development Institute, Busan 619-705, Korea

*Corresponding Author

Email: ymkim@pknu.ac.kr

ABSTRACT

To develop effective and safe acne vulgaris therapies with a continuing demand for new solutions, we investigated unique efficacy of an antibacterial agent from marine brown alga Eisenia bicyclis in treating acne vulgaris. The methanolic extract of E. bicyclis exhibited potential antibacterial activity against acne-related bacteria. The ethyl acetate fraction showed the strongest antibacterial activity against the bacteria among solvent fractions. Six compounds (1-6), previously isolated from the ethyl acetate fraction of E. bicyclis, were evaluated for antibacterial activity against acne-related bacteria. Among them, compound 2 (fucofuroeckol-A [FF]) exhibited the highest antibacterial activity against acne-related bacteria with a minimum inhibitory concentration (MIC) ranging from 32 to 128 μg mL-1. Furthermore, FF clearly reversed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromycin 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 combination 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 acnerelated bacteria.

Key words: acne-related bacteria; antimicrobial activity; Eisenia bicyclis; phlorotannins; synergistic effect