Fucoidan enhances intestinal barrier function by upregulating the expression of claudin-1

Figure 2 Fucoidan prevented H₂O₂-induced destruction of intestinal epithelial barrier function in a dose-dependent manner. Polarized Caco-2 cell monolayers were injured by H₂O₂ (500 μmol/L) on the apical side of Caco-2 cell monolayers. Fucoidan was added into the basolateral side 30 min prior to H₂O₂ stimulation and cultured for 6 h. Changes in intestinal epithelial barrier function were monitored by measuring the trans-epithelial resistance (TER). The data are expressed as the means ± SEM of 5 independent experiments. ^aP < 0.05, ^bP < 0.01 compared with cells exposed to H₂O₂ alone at respective time point (Tukey’s multiple comparison test).