Objective: To observe the changes of coagulation and fibrinolysis function in human umbilical cord vein endothelial cells (HUVEC) induced by recombinant human tumor necrosis factor-α (rhTNF-α) and the effect of Naotaifang extract (NTE) on it.Methods: Cultured HUVEC is randomly divided into six groups: Control group

NTE control group (only 2 g/L NTE)

rhTNF-α group (100 μg/ L rhTNF-α)

and low-dosage

middle-dosage and high-dosage NTE group (100 μg/L rhTNF-α and 0. 67 g/L

2 g/L

6 g/L NTE). The coagulation activity of frozen-dissolved HUVEC

von Willebrand factor (vWF) content in the conditioned medium and tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor (PAD activity were to be detected after 24 hrs.Results: Compared with the control group

PAI activity were enhanced

vWF release markedly increased in conditioned medium of TNF-α group (P < 0.01) and the frozen-dissolved HUVEC markedly shortens the rabbit plasma prothrombin time

and the above changes could be significantly inhibited by the 3 dosages of NTE (P < 0.05

P < 0. 01).Conclusion: NTE is effective in inhibiting the coagulation activity of the HUVEC non-stimulated or stimulated by rhTNF-α to enhance the vWF release

and to adjust fibrinolytic function

and mainly to inhibit the PAI activity.