['To investigate the proliferation of vascular smooth muscle cells (VSMC) affected by ginsenoside Rg1 and further explore the molecular mechanism of ginsenoside Rg1 using proteomics.', 'The proliferation of VSMC was measured by MTS assay kit and flow cytometry. Proteomic alterations were analyzed using two-dimensional electrophoresis and peptide mass fingerprinting. Differential proteins found in proteomics were confirmed by RT-PCR.', 'The proliferation of VSMC was enhanced significantly after tumor necrosis factor-alpha (TNF-alpha) treatment, and ginsenoside Rg1 treatment inhibited proliferation in a dose-dependent manner. Proteomic analysis showed 24 protein spots were changed, including 17 spots that were increased and 7 spots that were decreased. Ginsenoside Rg1 could restore the expression levels of these proteins, at least partly, to basic levels of untreated cells. The expression of G-protein coupled receptor kinase, protein kinase C (PKC)-zeta, N-ras protein were decreased, while cycle related protein p21 was increased by ginsenoside Rg1 in TNF-alpha treated VSMC.'] Does ginsenoside Rg1 inhibit proliferation of vascular smooth muscle cells stimulated by tumor necrosis factor-alpha?