昆明山海棠提取物对血管平滑肌细胞增殖及凋亡的影响

目的探讨昆明山海棠提取物(THW-4)对离体血管平滑肌细胞(VSMC)增殖及凋亡的影响。方法培养家兔主动脉平滑肌细胞，加入不同浓度的THW-4进行处理，用MTT法测定细胞生长曲线，以Annexin V-FITC／PI双标记、透射电镜、原位末端标记法检测细胞凋亡。结果THW-4可以明显抑制VSMC增殖，呈剂量和时间依赖性，作用48h的半有效抑制浓度(IC50)为15．6μg／L；VSMC在含10～100μg／L THW-4的培养液中孵育56h，可检测到细胞早期凋亡，且凋亡率随THW-4浓度增加而升高；延长孵育时间至72h，透射电镜下可观察到典型的凋亡细胞形态学改变，原位末端标记法显示DNA片段化增多，有核碎裂、固缩等改变；细胞周期时相分布显示THW-4主要阻滞VSMC于G2/M期。结论THW-4能有效抑制体外培养的VSMC增殖及诱导其凋亡，提示THW-4可能会作为防治血管成形术后再狭窄的候选药物。

Effect of Extract from Tripterygium Hypoglaucum on Proliferation and Apoptosis of Vascular Smooth Muscle Cells

OBJECTIVE: To study the effect of THW-4, an extract from Trypterygium hypoglaucum on proliferation and apoptosis of vascular smooth muscle cells (VSMC). METHODS: VSMC derived from rabbit aorta were cultured in vitro and different concentrations of THW-4 were added in experimental groups. Cell proliferation was evaluated by MTT and apoptosis by transmission electron microscopy (TEM), TUNEL assay and Annexin V-FITC/PI double labelled assay. RESULTS: The inhibitory effects of THW-4 on proliferation of VSMC displayed dose-time dependently, with the IC50 value of 15.6 microg/L at 48 hrs. Incubated with THW-4 (10-100 microg/L) for 56 hrs, VSMC mainly appeared early stage apoptosis and the percentage of apoptosis was found to raise along with the increase of the THW-4 concentration. Typical images of apoptosis could be observed under TEM and TUNEL assay showed increase of DNA segments with karyorrhexis and pyknosis after THW-4 treatment for 72 hrs. Analysis of cell cycle indicated the THW-4 mainly lead to the blockage of VSMC in G2/M stage. CONCLUSION: THW-4 could inhibit the proliferation and induce the apoptosis of VSMC in vitro, suggesting that THW-4 is a potential agent for prevention of restenosis following angioplasty.