Abstract: Objective: To investigate potential mechanisms of aspirin in inhibition of Human umbilical artery smooth cells (HUASMCs) proliferation through TGF-β1 signaling. Methods: HUASMCs were isolated and cultured in vitro incubated with or without specific anti–TGF-β1 neutralizing antibody. Cell proliferation and cell cycles were measured by MTT and flow cytometry after treated with different levels of aspirin. Results: The proliferation of HUASMCs were inhibited by aspirin（2.0、5.0 mmol/L）in vitro (P <0.05), independent of cytotoxicity. The anti-proliferation effects can be reversed by specific anti-TGF-β1 neutralizing antibody(P<0.05). Aspirin（2.0 mmol/L）restrained cells in G0 phase (P<0.05)，which can be reversed by specific anti-TGF-β1 neutralizing antibody(P <0.05). Conclusion: Aspirin, independent of its cytotoxicity, can inhibit the proliferation of HUASMCs in vitro, in which TGF-β1 signaling might be involved.

Key words: Vascular Smooth Muscle Cells, Cell Proliferation, Cell Cycle, Transforming Growth Factor-β1, Aspirin