title: Dewaxed Brown Rice Contains a Significant Amount of Lipopolysaccharide Pointing to Macrophage Activation via TLRs.
abstract: OBJECTIVE
  Oral ingestion of lipopolysaccharide (LPS) has been shown to be effective in diseases' prevention. Brown rice contains large amounts of LPS not actively consumed because of bad taste. Recently, a new type of brown rice with its wax layer removed has been produced. In this report, we measured the LPS content of this dewaxed rice and evaluated the function of innate immune activation on macrophages.
  
  
  METHODS
  Dewaxed brown rice and polished rice were prepared using the Saika-style rice polishing process. LPS content extracted using hot water from this sample was evaluated by the Limulus reaction and the activation of macrophage RAW246.7 cells was evaluated by nitric oxide (NO) production. In addition, toll-like receptors (TLRs) 2-, 4- and 9-induced human embryonic kidney (HEK) 293 cells were used for the confirmation of the activated pathway.
  
  
  RESULTS
  Mean LPS content in the 15 types of dewaxed brown rice was found to be 6.4±2.6 μg/g, while that of brown rice was 10.9±4.3 μg/g. The extract of dewaxed brown rice induced significant amounts of NO by RAW246.7 cells, while production was reduced to 1/6 by adding polymyxin B. The macrophage activating effect of dewaxed brown rice was 79- and 51-times higher than that of polished rice in TLR4- and 2-induced HEK 293 cells.
  
  
  CONCLUSIONS
  LPS content in dewaxed brown rice was found to be able to activate macrophages. This rice activated macrophages mainly via the TLR4 and, to a lesser extent, TLR2 pathways. It is suggested that dewaxed brown rice can be considered effective in allergy and cancer prevention.
authors.affiliation: Control of Innate Immunity, Technology Research Association, Kagawa, Japan Faculty of Medicine, Kagawa University, Kagawa, Japan Macrophi Inc., Kagawa, Japan Research Institute for Healthy Living, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan PXS07205@nifty.ne.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Inagawa
authors.affiliation: Toyo Rice Corp., Wakayama, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Saika
authors.affiliation: Macrophi Inc., Kagawa, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nisizawa
authors.affiliation: Control of Innate Immunity, Technology Research Association, Kagawa, Japan Faculty of Medicine, Kagawa University, Kagawa, Japan Macrophi Inc., Kagawa, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Kohchi
authors.affiliation: Nagoya Keizai University, Aichi, Japan.
authors.forename: Maya
authors.initials: M
authors.lastname: Uenobe
authors.affiliation: Control of Innate Immunity, Technology Research Association, Kagawa, Japan Faculty of Medicine, Kagawa University, Kagawa, Japan Macrophi Inc., Kagawa, Japan Research Institute for Healthy Living, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan.
authors.forename: Gen-Ichiro
authors.initials: G
authors.lastname: Soma
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000971:Antineoplastic Combined Chemotherapy Protocols; D002945:Cisplatin; D007069:Ifosfamide; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects*; D051379:Mice; D016685:Mitomycin; D009569:Nitric Oxide / Q000378:metabolism; D012275:Oryza / Q000737:chemistry*; D000067996:RAW 264.7 Cells; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D014885:Waxes / Q000737:chemistry
chemical_list: D016588:Anticarcinogenic Agents; D008070:Lipopolysaccharides; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014885:Waxes; D009569:Nitric Oxide; D016685:Mitomycin; D002945:Cisplatin; D007069:Ifosfamide
keywords: Brown rice; innate immunity; lipopolysaccharide; macrophages