Eckol fromEisenia bicyclisInhibits Inflammation Through the Akt/NF-κB Signaling inPropionibacterium acnes-Induced Human Keratinocyte Hacat Cells

To investigate whether eckol, a phlorotannin compound from edible brown seaweed Eisenia bicyclis, could be responsible for the suppression of inflammatory processes, we examined the anti-inflammatory effects of eckol on Propionibacterium acnes-induced human skin keratinocytes (HaCaT) cells. P. acnes–treated HaCaT cells increased the expression of pro-inflammatory cytokines and chomokines. We also examined in vitro regulatory function of eckol on production of nitric oxide (NO), matrix metalloproteinase (MMP)−2 and MMP-9 as well as expression of inducible NO synthase, cyclooxygenase-2, and tumor necrosis factor-α. Eckol inhibited the expression or formation production of these proinflammatory mediators and cytokines in HaCaT cells. Additionally, treatment of HaCaT cells with P. acnes significantly increased protein kinase B (Akt) and nuclear factor kappa B (NF-κB) activation. Eckol inhibited P. acnes-mediated phosphorylation of Akt and activation of NF-κB in a dose-dependent manner. These results suggest that eckol could be a potential therapeutic agent to effectively treat the inflammatory skin disease induced by P. acnes. Practical Applications Eisenia bicyclis is a common perennial phaeophyceae (brown alga) and generally inhabits the region of Ulleung Island in the East sea of Korea. This edible seaweed is widely consumed in various ways such as appetizers, casseroles, muffins, pilafs, and soups. E. bicyclis also has various physiological properties such as antioxidant and anti-inflammatory activities because of their substantial quantities of phenolic compounds, constituted mainly by marine-derived polyphenols (phlorotannins). Eckol, one of phlorotannins from E. bicyclis, shows therapeutic effectiveness against viable P. acnes-induced inflammation in HaCaT cells. Thus, we suggest that eckol from E. bicyclis is a potential treatment for anti-inflammatory therapy for acne vulgaris.