Effect Of Extract From Tripterygium Hypoglaucum (Levl.) Hutch On Human Endothelial Cells And Vascular Smooth Muscle Cells

Objective:Percutaneous coronary intervention (PCI) has already become an important means of coronary heart disease's treatment, but a high incidence of30%-45%in postoperative6months has influenced PCI to get clinical curative effect seriously. Some studies found that PCI caused damage of the vascular endothelium which promote vasoconstriction and proliferation of vascular smooth muscle cell (VSMC), then cause intimai hyperplasia, chronic remodeling and take place RS finally. To prevent the restenosis, key point is to inhibit proliferation of VSMC in addition to restore activity of endothelial cell (EC) as soon as possible. Tripterygium hypoglaucum (Levl) Hutch (THH) is a traditional Chinese herb belonging to the genus Celastraceae. In addition to the excellent immunosuppressive ability, it has also been reported that THH shows other activities such as anti-inflammation, anti-tumor and anti-fertility, et al. TH-1, a diterpene triepoxide, is a purified compound from THH that has been identified as one of the major components responsible for the immunosuppressive and anti-infammatory effects of this herb. The present study was designed to determine the effects of TH-1on proliferation of human umbilical vein endothelial cell (HUVEC) and VSMC in vitro in order to provide a scientific and experimental basis for preventing and treating RS.Methods:HUVEC and VSMC were cultured by sterile techniques and selected the4th and10th well grown generations for our study. HUVEC survival rate was examined using Trypan blue staining exclusion experiment. The effects of TH-1on proliferation of HUVEC and VSMC were measured by modified MTT assay. Cell cycle analysis was performed by flow cytometry. The apoptosis of VSMC induced by TH-1was examined using TUNEL/PI double labeled assay. Results:TH-1(5-200μg/ml) lower the VSMC absorbance values using MTT assay in a concentration-dependent manner. Analysis of cell cycle phase showed TH-1at low concentration (25μg/ml) mainly lead to the blockage of G0/G1phase, high concentration (100μg/ml) mainly lead to blockage of G0/G1and G2/M phase.TH-1(1-200μg/ml) reduced the HUVEC survival rate by trypan blue staining exclusion experiment, lower the HUVEC absorbance values using MTT assay in a concentration-dependent manner. TH-1increase the cell numbers in G0/G1phase measured by fluorospectrophotometry. We find TH-1can induce VSMC's apoptosis by using TUNEL/P1double labeled assay.Conclusion:TH-1mainly through induce apoptosis inhibit VSMC hyperplasia, so it has potential clinical using value for intimal hyperplasia in inhibiting support from plant into. TH-1also has non-alternative inhibitory activity on endothelial cells of blood vessel, and the mechanism may be associated with the effect of TH-1inhibition of cell cycle transiting from G1/G0phase to S phase.