Effects Of Tripterygium Hypoglaucum (Levl.) Hutch On Proliferation Of Vascular Smooth Muscle Cells Induced By EGF And C-jun MRNA Expression

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 one of important mechanisms of restenosis is that vascular smooth muscle cells (VSMC) proliferation and migration. To prevent the restenosis, the key point is to inhibit proliferation of VSMC. 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. This study aims to establish VSMC proliferation model induced by epidermal growth factor (EGF) in vitro which was designed to determine the effects of Tripterygium Hypoglaucum (Levl.) Hutch on proliferation of VSMC induced by EGF and c-jun mRNA expression.In order to study the mechnisum of VSMC proliferation which was inhibited by THH.Methods:VSMC were cultured by sterile techniques and selected the4th and10th well grown generations for our study. MTT chromatometry was applied to observe the effects of EGF and THH on the proliferation of VSMC. RT-PCR was used to observe effects of THH on the expression of c-jun mRNA in proliferative VSMC induced by EGF.Results:THH (0.05-1.6ug/ml) lower the VSMC absorbance values using MTT assay in a concentration-dependent manner. The result detected on VSMC growth inhibition by MTT is consistent with cell counting method. RT-PCR results show that the difference is no statistically significant between the group of concentration of0.025μg/ml and the other group of concentration of0.05μg/ml. While the model group compared with other concentrations, the difference was highly statistically significant. The experimental results suggest that THH significantly inhibited the VSMC proto-oncongene c-jun mRNA expression. With increasing drug concentration, VSMC proto-oncongene c-jun mRNA expression decreased in a dose-dependent manner.Conclusions:THH inhibits the proliferation of VSMC induced by EGF, so it has potential clinical using value for prevention of RS after stenting. And the mechanism may be associated with inhibition of VSMC proto-oncongene c-jun mRNA of expression.