Affiliations: Department of Applied Biological Chemistry, Graduate
School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi,
Bunkyo-ku, Tokyo 113-8657, Japan | Kaneka Co. Ltd., 1-8 Miyamae-machi, Takasago-cho,
Takasago, Hyogo 676-8688, Japan
Abstract: It is well known that various cytokines such as interleukin-8 (IL-8)
and tumor necrosis factor-α (TNF-α are expressed and secreted from
intestinal epithelial cells and that these cytokines affect the immune cells
beneath the intestinal epithelial monolayers. As the secretion of these
cytokines is likely to be regulated by food-derived substances, we focused on
those food substances which regulate the secretion of IL-8 in human intestinal
epithelial Caco-2 cells. 72 food samples extracted with 40% ethanol were
tested, and the extracts of peppermint and dokudami significantly increased the
IL-8 secretion. Among the compounds known to be contained in peppermint and
dokudami, α-humulene substantially increased the IL-8
secretion.α-Humulene had no significant effect on the secretion of such
other soluble factors as TNF-α, IL-1β, IL-6, or NGF, suggesting that
the effect of α-humulene was specific for IL-8 secretion. The expression
level of IL-8 mRNA was significantly increased by treating with
α-humulene. These results suggest that the secretion of IL-8 by
α-humulene is regulated at the transcriptional level.
