Hiroyuki Inagawa1, Toshiyuki Saika2, Takashi Nisizawa3, Chie Kohchi4, Maya Uenobe5, Gen-Ichiro Soma6. 1. 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. 2. Toyo Rice Corp., Wakayama, Japan. 3. Macrophi Inc., Kagawa, Japan. 4. Control of Innate Immunity, Technology Research Association, Kagawa, Japan Faculty of Medicine, Kagawa University, Kagawa, Japan Macrophi Inc., Kagawa, Japan. 5. Nagoya Keizai University, Aichi, Japan. 6. 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.
Abstract
BACKGROUND/AIM: 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. MATERIALS AND 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. CONCLUSION: 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. Copyright
BACKGROUND/AIM: 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. MATERIALS AND 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 humanembryonic 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. CONCLUSION: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. Copyright