Conditioned medium from LS 174T goblet cells treated with oxyresveratrol strengthens tight junctions in Caco-2 cells

•Oxyresveratrol (OXY) increased TFF3 expression in LS 174T goblet cells.•Conditioned medium was prepared from goblet cells treated with OXY (GCO-CM).•GCO-CM increased the expression levels of claudin-1, occludin, and ZO-1.•GCO-CM significantly increased tight junction integrity and reduced permeability.•OXY strengthened tight junctions by stimulating TFF3 production in goblet cells.

BackgroundStrengthening of intestinal tight junctions provides an effective barrier from the external environment. Goblet cell-derived trefoil factor 3 (TFF3) increases transepithelial resistance by upregulating the expression of tight junction proteins. Oxyresveratrol (OXY) is a hydroxyl-substituted stilbene found in the roots, leaves, stems, and fruit of many plants and known to have various biological activities. In this study, we investigated the strengthening effect of OXY on intestinal tight junctions through stimulation of TFF production in goblet cells.MethodsWe prepared conditioned medium from LS 174T goblet cells treated with OXY (GCO-CM) and investigated the effect of GCO-CM on strengthening tight junctions of Caco-2 cells. The mRNA and protein expression levels of major tight junction components (claudin-1, occludin, and ZO-1) were measured by quantitative real-time PCR and western blotting, respectively. Transepithelial electric resistance (TEER) was measured using an ohm/V meter. Monolayer permeability was evaluated by paracellular transport of fluorescein isothiocyanate-dextran.ResultsOXY showed a strong antioxidant activity. It significantly increased the expression level of TFF3 in LS 174T goblet cells. GCO-CM prepared by treatment with 2.5, 5, and 10 μg/ml OXY did not show cytotoxicity in Caco-2 cells. GCO-CM increased the mRNA and protein expression levels of claudin-1, occludin, and ZO-1. It also significantly increased tight junction integrity and reduced permeability in a dose-dependent manner.ConclusionOXY stimulates the expression of TFF3 in goblet cells, which might increase the integrity of the intestinal tight junction barrier.