Background & objective: It has been showed that triptolide (T10) has antitumor activities. This study was to observe the inhibitory effects of T10 on proliferation of vascular endothelial cells and expression of urokinase-type plasminogen activator (u-PA), and to elucidate the antiangiogenic mechanism of T10.
Methods: Human umbilical vein endothelial cells were cultured in vitro for 3 generations, and treated with T10 (0, 5, 10, 20, and 30 microg/L), or dexamethasone (300 mg/L) as control. Cell count and 3H-TDR incorporation were used to observe cell proliferation. The chick embryo chorioallantoic membrane (CAM) test was carried out to observe the effect of T10 on angiogenesis. Immunohistochemistry and real-time quantitive reverse transcription-polymerase chain reaction (RT-PCR) were used to detect protein and mRNA levels of u-PA.
Results: T10 inhibited the proliferation of umbilical vein endothelial cells in a dose-dependent manner; inhibitory rate of endothelial cells was 28.93% after treatment of 5 microg/L of T10. T10 significantly reduced angiogenesis in CAM, even at the concentration of 5 microg/L (P<0.05). T10 decreased protein and mRNA levels of u-PA in endothelial cells in a dose-dependent manner; the protein level of u-PA was reduced by 41.05% after treatment of 5 microg/L of T10.
Conclusion: T10 could inhibit the proliferation of human umbilical vein endothelial cells and expression of u-PA, which may contribute to its antiangiogenic activity.