Suppressive effect of an isoflavone fraction on tumor necrosis factor-alpha-induced interleukin-8 production in human intestinal epithelial Caco-2 cells.
This study demonstrates the effect of soybean components on the tumor necrosis factor-alpha (TNF-alpha)-induced production of interleukin-8 (IL-8), one of the major inflammatory chemokines, in intestinal epithelial-like Caco-2 cells. Among the soybean components, an isoflavone fraction (IFF) suppressed the TNF-alpha-induced IL-8 secretion by Caco-2 cells in a dose-dependent manner, whereas a soyasaponin fraction and soypeptide fraction had no significant effect on TNF-alpha-induced IL-8 secretion. The IL-8 secretion induced by hydrogen peroxide and by IL-1beta was not suppressed by IFF, suggesting that the inhibitory effect of isoflavone was specific for the TNF-alpha-induced regulation of IL-8. The increased expression of IL-8 mRNA by TNF-alpha was almost completely suppressed by IFF. Furthermore, the transcriptional activity of the human IL-8 promoter was increased by the TNF-alpha treatment, and IFF significantly suppressed the IL-8 promoter activity. These results indicate that IFF suppressed TNF-alpha-induced IL-8 production at the transcriptional level in human intestinal Caco-2 cells, suggesting IFF of soybean as a promising food component for preventing intestinal inflammation such as inflammatory bowel disease.
Satsu
Hideo
H
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan. asatsu@mail.ecc.u-tokyo.ac.jp
Hyun
Ja Shil
JS
Shin
Hee Soon
HS
Shimizu
Makoto
M
D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D018938:Caco-2 Cells; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide; D053583:Interleukin-1beta; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects; D007529:Isoflavones / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D012503:Saponins / Q000494:pharmacology; D030262:Soybean Proteins / Q000494:pharmacology; D013025:Glycine max / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
D000893:Anti-Inflammatory Agents; D053583:Interleukin-1beta; D016209:Interleukin-8; D007529:Isoflavones; D010936:Plant Extracts; D012333:RNA, Messenger; D012503:Saponins; D030262:Soybean Proteins; D014409:Tumor Necrosis Factor-alpha; D006861:Hydrogen Peroxide