Quercetin and kaempferol suppress immunoglobulin E-mediated allergic inflammation in RBL-2H3 and Caco-2 cells.

Objective: We investigated the inhibitory effects of quercetin and kaempferol treatment on the suppression of immunoglobulin E (IgE)-mediated allergic responses in relation to intestinal epithelium barrier function in RBL-2H3 and Caco-2 cells.

Methods: RBL-2H3 cells as a model of intestinal mucosa mast cells were treated with flavonols followed by IgE-anti-dinitrophenyl sensitization. The extent of degranulation and the release of pro-inflammatory cytokines were measured. Caco-2 cells were stimulated with interleukin (IL)-4 or IgE-allergen with or without flavonol pretreatment and changes in the expression of CD23 mRNA and mitogen-activated protein kinase (MAPK), and chemokine release were determined.

Results: Flavonols inhibited the secretion of allergic mediators in RBL-2H3 cells and suppressed the CD23 mRNA expression and p38 MAPK activation in IL-4 stimulated Caco-2 cells. Flavonols also suppressed IgE-OVA induced extra signal-regulated protein kinase (ERK) activation and chemokine release.

Conclusions: Quercetin and kaempferol effectively suppressed the development of IgE-mediated allergic inflammation of intestinal cell models.