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

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 INTRODUCTIONAcne vulgaris is a common skin disease affecting children and adolescents. The pathogenesis of acne is multifactorial and complex. There are four important factors that cause acne in humans, such as an increase in sebum secretion, keratinization of the follicle, bacteria, and inflammation (Farrar and Ingham 2004). Pro pionibacterium acnes, Staphylococcus epidermidis, S. aureus, and Pseudomonas aeruginosa are often involved in the development of abnormal follicular keratinization and inflammation (Yamaguchi et al. 2009 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 48 MATERIALS AND METHODS Raw materials and extractionIn late September 2010, E. bicyclis was purchased from Ulleung Trading Co. (Ulleung-gun, Korea). A voucher specimen has been deposited in the author's laboratory. Dried E. bicyclis was finely ground and powdered with a food mixer (HMF-1000A; Hanil Electronics, Seoul, Korea). The dried powder was vacuum-packed and kept at -20°C until use. The dried E. bicyclis powder (1.0 kg) was extracted with methanol (MeOH; 10 L × 3) at 70°C for 3 h (3 times) and the solvent was evaporated ...

Synergistic Antibacterial Activity of Ecklonia cava (Phaeophyceae: Laminariales) against Listeria monocytogenes (Bacillales: Listeriaceae)

“…The median ∑FIC against L. monocytogenes strains ranged from 0.172 to 0.344. As described by Lee et al (2014), the synergistic ranges of FIC <1 were observed for all combinations of streptomycin and the EtOAc fraction against L. monocytogenes strains. Indeed, the median ∑FIC of the streptomycin-EtOAc fraction ranged from 0.172 to 0.344, suggesting marked synergy (Table 4).…”

“…It has been demonstrated that one of the more effective strategies in developing new drugs or alternative therapies is the restoration of antibiotic activity, in combination with antibacterial materials derived from natural products and traditional medicines, against drug-resistant bacteria (Eom et al 2014;Lee et al, 2014). In this study, the interaction between the EtOAc fraction of E. cava and the commercial antibiotic streptomycin against L. monocytogenes strains was evaluated by FIC assay.…”

“…The antibacterial efficacy of marine algae extracts was evaluated by disk diffu sion assay followed by the CLSI (2009), as described in our previous reports (Lee et al, 2014;Eom et al, 2011). In brief, bacterial strains were cultured in BHI at 37°C until an OD at 600 nm of 0.5.…”

“…Dried E. cava powder (1.0 kg) was extracted and fractionated using organic solvents as described in Lee et al (2014). The methanolic extract of E. cava (101.3 g) was partitioned in turn with n-hexane (Hexane; 1.0 L × 3), dichloromethane (DCM; 1.0 L × 3), ethyl acetate (EtOAc; 1.0 L × 3), and n-butanol (nBuOH; 1.0 L × 4).…”

Anti-inflammatory Effects of Chitosan-phytochemical Conjugates against Propionibacterium acnes-induced Inflammation

“…, P. acnes , , 2 (Eom et al, 2016;Kim et al, 2016;Nam et al, 2003;Tan, 2003). , (Eom et al, 2016;Lee et al, 2014a , (Kim et al, 2009;Lee et al, 2014b;Poquet et al, 2008).…”