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 ...

From 2009 to 2013, 80 oyster and 16 seawater samples were collected from the southern coast of Korea, including designated shellfish growing areas for export. The concentrations and bioaccumulation of heavy metals were determined, and a potential risk assessment was conducted to evaluate their hazards towards human consumption. The cadmium (Cd) concentration in oysters was the highest of three hazardous metals, including Cd, lead (Pb), and mercury (Hg), however, below the standards set by various countries. The metal bioaccumulation ratio in oysters was relatively high for zinc and Cd but low for Hg, Pb, arsenic, and chromium. The estimated dietary intakes of all heavy metals for oysters accounted for 0.02%-17.75% of provisional tolerable daily intake. The hazard index for all samples was far <1.0, which indicates that the oysters do not pose an appreciable hazard to humans for the metal pollutants of study.

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An investigation was conducted into the clinical symptoms and causative agent associated with a whelk poisoning incident that occurred in March 2005 in Korea. The whelk consumed in the poisoning incident was identified as Neptunea intersculpta. All of the 17 patients suffered from eyeball pain, headache, dizziness, abdominal pain, and nausea but no diarrhea. The causative agent was identified as tetramine, based on results from liquid chromatography-tandem mass spectrometry. Based on the tetramine concentration in the leftover whelk meat and the amount of meat consumed, the amount of tetramine ingested by the patients was estimated to be > or = 10 mg. This is the first report of the identification of tetramine as the causative agent in whelk poisoning in Korea. The anatomical distribution of tetramine in fresh and boiled N. intersculpta was examined. The toxin concentration in the meat was higher in specimens boiled in the shell than in fresh specimens collected on the same date. In meat boiled separately after removing the shell, the salivary gland, and the midgut gland, the tetramine concentration was much lower than that in fresh specimens or those boiled in the shell. This result suggests that boiling the meat after removing the salivary gland is a suitable way to prevent tetramine poisoning.

Six phlorotannins, isolated from Eisenia bicyclis, were evaluated for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MIC) of the compounds were in the range 32 to 64 µg/mL. Phlorofucofuroeckol-A (PFF) exhibited the highest anti-MRSA activity, with an MIC of 32 µg/mL. An investigation of the interaction between these compounds and the β-lactam antibiotics ampicillin, penicillin, and oxacillin revealed synergistic action against MRSA in combination with compound PFF. To our knowledge, this is the first report on the anti-MRSA activity of phlorotannins from E. bicyclis. The results obtained in this study suggest that the compounds derived from E. bicyclis can be a good source of natural antibacterial agents against MRSA.