Proliferation Inhibition and Apoptosis Induction of HMEC Cells by 23 -HBA

Objective 　To study the proliferation-inhibitng and apoptosis-inducing effect s of 23-hydroxy betulinic acid ( 23-HBA ) on human microcapillary endothelial cells ( HMEC) . Methods 　The effect of 23-HBA on in vitro proliferation of HMEC was examined by SRB assay. The effect of 23-HBA on the cell cycle and apoptosis were analyzed by flow cytometry. Results 　The proliferation of HMEC was inhibited significantly by 23-HBA with IC50 being 40. 44μg/ ml. Apoptosis peak was also shown by flow cytometry. The percentage of cell apoptosis increased with the increase of the drug concent ration, and the increase rate was significantly higher than that of the control cell group. The content of cells increased in Sphase and decreased in G₂ / M phase. Conclusion 　23-HBA can inhibit HMEC proliferation and induce apoptosis, could be developed as an antiangiogenic drug.