Mechanism of ligustrazini against thrombosis.
OBJECTIVE
To investigate the mechanism of Chinese medicine ligustrazini against thrombosis, and the effects of ligustrazini on plasminogen activator inhibitor (PAI-1) expression in normal endothelial cells and lipopolysaccharide (LPS) stimulated endothelial cells.


METHODS
Human umbilical vein endothelial cells (HUVECs) were cultured by trypsin digestion method. PAI-1 protein in HUVEC conditioned medium was measured by Sandwich enzyme-linked immunosorbent assay (ELISA), and PAI-1 mRNA expression was determined by Northern blot analysis. Using electrophoretic mobility shift assay (EMSA), we observed HUVEC nuclear factor-kappa B (NF-kappa B) nuclear translocation.


RESULTS
LPS treatment of cultured HUVECs resulted in a significant increase in PAI-1 protein and mRNA expression by these cells. However, when HUVECs were incubated with LPS plus ligustrazini, the upregulation of PAI-1 by LPS was abated. Moreover, ligustrazini could decrease the basal level of PAI-1 protein and mRNA in HUVECs as compared with control. Nuclear extracts prepared from HUVECs stimulated by LPS demonstrated that binding to the NF-kB oligo nucleotide increased as compared with the unstimulated cells, but ligustrazini did not change those binding in the absence or presence of LPS.


CONCLUSIONS
Ligustrazini inhibited both basal and LPS-induced PAI-1 protein and mRNA expression in endothelial cells, and the modulation of PAI-1 in HUVECs by ligustrazini might have other mechanisms rather than NF-kB pathway.
Song
J
J
Department of Infectious Disease, Tongji Hospital, Tongji Medical University, Wuhan 430030, China.
Ruan
Q
Q
D001667:Binding, Competitive; D015152:Blotting, Northern; D002478:Cells, Cultured; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D024202:Electrophoretic Mobility Shift Assay; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D006801:Humans; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000378:metabolism; D011719:Pyrazines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D013927:Thrombosis / Q000188:drug therapy*
D004365:Drugs, Chinese Herbal; D005343:Fibrinolytic Agents; D016328:NF-kappa B; D017395:Plasminogen Activator Inhibitor 1; D011719:Pyrazines; D012333:RNA, Messenger; C017953:tetramethylpyrazine