2011 Volume 64 Issue 4 Pages 207-214
Intestinal epithelial cells (IECs) have various functions, including absorption of food substances, immune functions such as cytokine secretion, and barrier function against xenobiotics involving drug metabolizing enzymes. In this study, we examined the absorption mechanism of food factors in IECs and also the effect of food factors on the function of IECs mainly at the cellular level. We found that various food factors permeate across the IEC monolayer via transporters, the paracellular route, and transcellular passive diffusion, respectively. On the other hand, intestinal transporter activity was regulated by other food factors. We developed an in vitro model of inflammatory bowel disease using intestinal epithelial Caco-2 cells and macrophage-like THP-1 cells, and applied it for screening and analysis of anti-inflammatory food factors. It was also revealed that the secretion of interleukin-8 from IECs was suppressed by food factors that prevented intestinal inflammation in vivo. Furthermore, several phytochemicals were shown to induce the expression and activity of drug metabolizing enzymes in IECs via activation of nuclear receptors such as the pregnane X receptor. These findings related to the interaction between IECs and food factors at the cellular and molecular levels are important for understanding the molecular mechanism of absorption and the physiological function of food factors.
