Anti-Inflammatory Effect of Ishige okamurae Ethanolic Extract via Inhibition of NF-κB Transcription Factor in RAW 264.7 Cells

Nowadays, much attention has been paid to the development of anti-inflammatory agents from marine natural resources. As a result of screening anti-inflammatory agents from marine algae using immunoassay, we found for the first time that ethanolic extract of Ishige okamurae (IO) classified into brown algae was effective in inhibiting the production of inflammatory mediators, such as tumor necrosis factor-alpha, interleukin-1 beta interleukin-6 and prostaglandin E-2, in RAW264.7 cells stimulated by lipopolysaccharide, compared with dexamethasone and aspirin used as positive control in this study. Moreover, transcriptional activation of NF-kappa B transcription factor that regulates the expression of these inflammatory mediators was also examined using reporter gene assay and western blot analysis. It was observed that IO extract exerted anti-inflammatory effect via inactivation of NF-kappa B transcription factor in macrophages. In addition, the expression and activity of matrix metalloproteinase-2 and 9 that play an important role in chronic inflammation were decreased in dose-dependent manner in the presence of IO extract in HT1080 cells. The above results suggest that IO extract can inhibit inflammation through inactivation of NF-kappa B transcription factor in macrophage. Copyright (C) 2008 John Wiley & Sons, Ltd.