Abstract: AIM: To study the effects of portulaca total flavone (PTF) on proliferation induced by PDGF-BB of rabbit aortic smooth muscle cells(VSMCs)and explore its mechanisms. METHODS: The VSMCs of cultured organization-adherence was induced to proliferate by PDGF-BB, and effects of PTF on VSMCs was tested by cell counting method and 3H-thymidine (3H-TdR) incorporation test; The effect of PTF on cell proliferative cycle of VSMC was observed by flow cytomytry technique;The intra-cellular calcium concentration was investigated by fluorimetry.RESULTS: PTF inhibited the proliferation of VSMCs induced by PDGF-BB in a dose dependent manner,and DNA symthesis,the cells numbers of G₁/G₀ phase were increased and that of G₂/S phase were decreased markedly(P<0.01).CONCLUSION: Proliferation of VSMCs induced by PDGF-BB can be inhibited by PTF.The mechanisms may be related with diminished VSMCs [Ca²⁺]_i.

Key words: Portulaca total flavone, Vascular smooth muscle cslls, Cell proliferation, PDGF-BB, 3H-TdR, Cell cycle, [ Ca²⁺] _i