Ecklonia cava is a common edible brown algae that is plentiful in Jeju Island of Republic of Korea. Polyphenols from E. cava have strong anti-inflammatory activity. However, a large number of the by-products from E. cava processing are discarded. In the present study, to utilize these by-products, we assessed the anti-inflammatory activity of the polyphenol-rich fraction (PRF) from E. cava processing by-product (EPB) in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells. Four compounds, namely eckol, eckstolonol, dieckol, and phlorofucofuroeckol-A, were isolated and identified from PRF. We found that PRF suppressed the production of nitric oxide (NO), inducible nitric oxide synthase, and cyclooxygenase-2 in the LPS-induced cells. Furthermore, the protective effect of PRF was investigated in vivo in LPS-stimulated inflammation zebrafish model. PRF had a protective effect against LPS-stimulated toxicity in zebrafish embryos. In addition, PRF inhibited LPS-stimulated reactive oxygen species and NO generation. According to the results, PRF isolated from EPB could be used as a beneficial anti-inflammatory agent, instead of discard.Key Words: anti-inflammation; by-product; Ecklonia cava; polyphenol; seaweeds
INTRODUCTIONSeaweeds are rich in vitamins, minerals, proteins, polyphenols, and polysaccharides. Therefore, several species of seaweeds are used in cosmetics, food, and pharmaceuticals. Many studies have shown that seaweeds have diverse bioactivities such as antioxidant, anticoagulant, anti-inflammation, antibacterial, and anticancer activities (Heo et al. 2003, Shin et al. 2006, Kim et al. 2007, Erbert et al. 2012, Ko et al. 2012. In particular, Ecklonia cava is a common edible brown algae that is plentiful in Jeju Island of Republic of Korea. E. cava has been identified to contain various natural substances such as carotenoids, fucoidans, and phlorotannins, which have beneficial biological activities including antioxidant, anti-inflammation, anticoagulant, antiviral, and antidiabetic effects (Kang et al. 2010, 2012b, 2013a. Dried forms of E. cava are consumed, but steam heated E. cava products sometimes are manufactured. When steaming the alga, a large amount of by-product is produced and discarded without utilization. Some studies have suggested that fermenting Received April 25, 2014, Accepted June 3, 2014 *Corresponding Author E-mail: youjinj@jejunu.ac.kr Tel: 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.
Preparation of PRF from EPBEPB was kindly provided by Taerim Co., Ltd. (Jeju, Korea) and then was freeze-dried. The dried EPB powder (5 g) was suspended in 500 mL of 80% ethanol and mechanically stirred for 24 h at room temperature. The solution was filtered and the filtrate was concentrated under reduced pressure to give the oily extract. Aft...
