Pristimerin is known to have anti-cancer and anti-inflammatory activities; however, its therapeutic mechanism has not been described. In this study, to investigate the therapeutic mechanism of pristimerin, we examined the effect of pristimerin on TNF-α-induced endothelial inflammatory response both in vitro and in vivo. Leukocyte-endothelium Adhesion Assay was use to evaluate the endothelial cell-monocyte interaction. Western blotting was used to confirm protein expression. NF-κB p65 nuclear translocation in endothelial cells was detected using immunofluorescent microscopy. In vivo leukocyte infiltration was evaluated using acute lung inflammation model. Pristimerin profoundly inhibited TNF-α-induced adhesion of monocytes to human endothelial cells and the leukocyte transmigration. Pristimerin dramatically inhibited the expression of TNF-α-induced endothelial adhesion molecules (intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1)) and the pro-inflammatory cytokine (IL-6, IL-8 and monocyte chemoattractant protein-1 (MCP-1)). Pristimerin suppressed the penetration of the leukocyte in the acute lung injury mice model. Furthermore, pristimerin also suppressed the TNF-α-activated Nuclear factor kappa B (NF-κB) activation. Pristimerin has the anti-inflammatory properties in endothelial cells, at least in part, through the suppression of NF-κB activation, which may have a potential therapeutic effects for inflammatory vascular diseases. Copyright © 2020. Published by Elsevier B.V.