title: Nuclear translocation of NF-κB in intact human gut tissue upon stimulation with coffee and roasting products.
abstract: In the healthy gut, NF-κB is a critical factor of the intestinal immune system, whereas inflammatory bowel diseases are associated with chronic activation of NF-κB. Previous studies indicated that coffee induces nuclear translocation of NF-κB in macrophages, an effect attributed to roasting products. In the present work, coffee extract or roasting products induced nuclear translocation of NF-κB in macrophages, Caco-2 cells, and primary human intestinal microvascular endothelial cells (up to fivefold, p<0.001). Since the effect clearly depended on the cell type, ex vivo experiments were performed with intact human gut tissue from biopsies. The uniformity of the specimens and tissue viability during ex vivo incubation for up to 2 h were verified. Roasting products led to a concentration dependent significant increase of nuclear translocation of NF-κB in human gut tissue (up to 2.85 fold increase, p=0.0321), whereas coffee extract induced a trend towards higher nuclear NF-κB concentration. NF-κB activation in macrophages and Caco-2 cells by roasting products was significantly blocked by co-incubation with catalase (p=0.011 and p=0.024) indicating involvement of H(2)O(2)-signaling. Monitoring of extracellular H(2)O(2) indicated that roasting products in coffee constantly generate H(2)O(2) by spontaneous oxygen reduction, which is only partially detoxified by cellular antioxidative systems. Thus, it can be concluded that ex vivo stimulation of intact human gut tissue is a valuable model to study nutritional effects on complex tissue systems. Furthermore, the consumption of coffee and roasting products may be able to induce nuclear NF-κB translocation in the human gut.
authors: Department of Chemistry and Pharmacy, Food Chemistry, Emil Fischer Center, Friedrich-Alexander University, Schuhstr. 19, 91052 Erlangen, Germany.
authors: Tanja
authors: T
authors: Sauer
authors: Martin
authors: M
authors: Raithel
authors: Jürgen
authors: J
authors: Kressel
authors: Sonja
authors: S
authors: Muscat
authors: Gerald
authors: G
authors: Münch
authors: Monika
authors: M
authors: Pischetsrieder
mesh_terms: D018938:Caco-2 Cells; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D040503:Coffea / Q000737:chemistry; D003069:Coffee / Q000737:chemistry*; D016207:Cytokines / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007422:Intestines / Q000187:drug effects* / Q000648:ultrastructure*; D008264:Macrophages / Q000187:drug effects / Q000648:ultrastructure; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects; D012639:Seeds / Q000737:chemistry
chemical_list: D003069:Coffee; D016207:Cytokines; D016328:NF-kappa B; D010936:Plant Extracts; D011108:Polymers; C011908:melanoidin polymers; D006861:Hydrogen Peroxide