Inhibition of Lipopolysaccharide (LPS)-Induced Inflammatory Responses by Sargassum hemiphyllum Sulfated Polysaccharide Extract in RAW 264.7 Macrophage Cells

Sargassum hemiphylium, a kind of brown seaweed generally found along coastlines in East Asia, has long served as a traditional Chinese medicine. S. hemiphyllum has shown an anti-inflammatory effect; however, its mechanism has not been elucidated dearly. This study explored S. herniphyllum for its biomedical effects. S. hemiphyllum sulfated polysaccharide extract (SHSP) was first prepared; the mouse macrophage cell line (RAW 264.7) activated by lipopolysaccharide (LPS) was used as a model system. The secretion profiles of pro-inflammatory cytokines, including IL-1 beta, IL-6, TNF-alpha, and NO, were found significantly to be reduced in 1-5 mg/mL dose ranges of SHSP treatments. RT-PCR analysis suggested SHSP inhibits the LPS-induced mRNA expressions of IL-beta, NOS, and COX-2 in a dose-dependent manner. At protein levels, Western blot analysis demonstrated a similar result for NF-kappa B (p65) in cytosol/nuclear. Taken together, the anti-inflammatory properties of SHSP may be attributed to the down-regulation of NF-kappa B in nucleus.