Influence of tetramethylpyrazine on the tissue factor expression induced by TNFα in endothelial cells

Objective Tetramethylpyrazine (TMP) is a Chinese plant-derived compound used as antithrombotic drug. The purpose of this study was to observe the effect of TMP on the expression of tissue factor (TF) induced by tumor necrosis factor (TNF)α in human umbilical vein endothelium derived cell line ECV304. Methods ECV304 was cultured in RPMI-1640. TF activity was determined with one-stage clotting assay measuring total cellular pro-coagulant activity. TF antigen was assayed by ELISA. TF mRNA was examined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Results The preincubation of TMP inhibited TF activity induced by different hours or different concentrations of TNFα. Increasing concentrations of TMP (1~1000 μg/mL) reduced the TF activity,TF antigen induced in ECV304 by TNFα (1000 u/mL) (P 0.01),in a dose-dependent fashion. TF activity induced by TNFα decreased to approximately 30% after treating with 1000 μg/mL of TMP. TMP also reduced the expression of TF mRNA induced by TNFα. Conclusion The present data suggests that TNFα induced the TF expression of vascular endothelial cells in a dose and time-dependent fashion,and TMP could inhibit this effect at mRNA level.