Objective: To investigate the influence of traditional Chinese medicine Qingjieling on leukocyte adhesion to vascular endothelial cells and the possible mechanisms.Methods: Firstly

We successfully established in vitro culture of human umbilical vein endothelial cells (HUVEC) monolayer. Then we constructed a leukocyte-endothelial cell adhesion model and imitated the inflammation state by using endothelial cells stimulated with recombinant tumor necrosis factor a (TNFα) or interleukin-1 (IL-1) respectively. The drug-induced change of leukocyte adhesion function was observed after we directly administered traditional Chinese medicine Qingjieling on the leukocytes. Finally

we inquired into the molecular mechanism of the effect of Qingjieling by monoclonal antibody blocking assay.Results: HUVEC as a representative large vessel endothelial cell could perfectly construct an adhesion model with leukocytes. Under the stimulation of cytokines (TNFα or IL-1)

endothelial cells demonstrated drastically improved adhesion with leukocytes

certain dose of Qingjieling (1mg/g body weight) might augment the leukocyte adhesion capacity with a 2-hour co-incubation. At least part of the reason of Qingjieling’s improving adhesion effect is due to the increased lymphocyte functional associated antigen-1 (LFA-1) expression of the white blood cells.Conclusion: Qingjieling could increase LFA-1-dependent leukocytes adhesion to endothelial cells.