title: Characterization of Macrophage-Activating Polysaccharide Isolated from Fermented Brown Rice.
abstract: Brown rice has nutritional benefits due to its abundant nutrients and high dietary fiber content. However, it is often consumed in a fermented form for improved chewy texture and digestibility. In this study, a polysaccharide, FBR-4a, was isolated from fermented brown rice and its chemical composition was analyzed. In addition, its immune-stimulating activity was determined using RAW264.7 cells. FBR-4a is a carbohydrate and consists of nine types of monosaccharides, including galactose, arabinose, rhamnose, mannose, fucose, xylose, glucose, galacturonic acid, and glucuronic acid. FBR-4a increased the gene expression of iNOS and IL-6 and enhanced the production of immune-stimulatory molecules (nitric oxide [NO], IL-6, and TNF-α) in RAW264.7 cells. Western blot analysis showed that FBR-4a phosphorylated the mitogen-activated protein kinases, NF-κB and c-Jun (major component of AP-1 transcription factor) in RAW264.7 cells, in a concentration-dependent manner. FBR-4a-induced IL-6 and NO production was completely suppressed by IκBα and JNK inhibition, but not by ERK and p38 inhibition. Furthermore, the phosphorylation of c-Jun was also suppressed by IκBα and JNK inhibition. These findings suggest that FBR-4a isolated from fermented brown rice has immune potentiation activity on macrophages through IκBα and JNK signaling pathways, which play a central role in IL-6 and NO production.
authors.affiliation: 1 Department of Food Science and Biotechnology, Kyonggi University , Gyeonggi-do, Korea.
authors.forename: Dae-Young
authors.initials: DY
authors.lastname: Lee
authors.affiliation: 1 Department of Food Science and Biotechnology, Kyonggi University , Gyeonggi-do, Korea.|2 Natural Constituents Research Center, Korea Institute of Science and Technology (KIST) , Gangneung, Gangwon, Korea.
authors.forename: Myoung-Sook
authors.initials: MS
authors.lastname: Shin
authors.affiliation: 1 Department of Food Science and Biotechnology, Kyonggi University , Gyeonggi-do, Korea.
authors.forename: Kwang-Soon
authors.initials: KS
authors.lastname: Shin
mesh_terms: D000818:Animals; D005285:Fermentation; D007109:Immunity / Q000187:drug effects; D015850:Interleukin-6 / Q000096:biosynthesis; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D051379:Mice; D009005:Monosaccharides / Q000032:analysis; D000072000:NF-KappaB Inhibitor alpha / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D012275:Oryza / Q000737:chemistry*; D010766:Phosphorylation / Q000187:drug effects; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D000067996:RAW 264.7 Cells; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D015850:Interleukin-6; D009005:Monosaccharides; D011134:Polysaccharides; D000072000:NF-KappaB Inhibitor alpha; D009569:Nitric Oxide
keywords: FBR-4a; JNK signaling pathway; NF-κB signaling pathway; brown rice; immunomodulatory agent