In present study, we investigated if inflammatory mediators secreted by the inflamed colonic mucosa from patients with Crohn's disease and ulcerative colitis had the ability to up-regulate the expression of two adhesion molecules, E-selectin and intercellular adhesion molecule-1. Organ culture techniques and enzyme-linked immunoassays were used to quantify these up-regulations in human umbilical vein endothelial cells. Our results show that, in Crohn's disease patients, the expression of E-selectin was up-regulated 5.5-fold over control values and intercellular adhesion molecule-1 expression was increased 2.4-fold. In ulcerative colitis patients, E-selectin expression was up-regulated twofold over controls with only a 1.5-fold increase in intercellular adhesion molecule-1 expression. Histologically, there was no difference in the degree of inflammation between the two disease groups. Sulfasalazine, in a dose-dependent manner, inhibited E-selectin expression up to 58% and intercellular adhesion molecule-1 up to 62% when stimulated by lipopolysaccharide. The up-regulation of E-selectin and intercellular adhesion molecule-1 may play an important role in mediating the inflammatory process in inflammatory bowel disease. The observed difference between Crohn's disease and ulcerative colitis may reflect differences in inflammatory cell infiltrates or the histopathological differences between the two diseases.