The matrix metalloproteinases (MMP-9 and MMP-2) in aortic smooth muscle cells (SMC) play key roles in the pathogenesis atherosclerosis. The SMC migration into the vascular wall via the bloodstream is directly linked with MMP-9 expression. Deoxypodophyllotoxin (DPT), a naturally occurring flavolignan with anti-inflammatory activity, was isolated from Anthriscus sylvestris Hoffm. and has been known inhibit the expression of MMP-9 in tumor necrosis factor-alpha (TNF-alpha) stimulated human aortic smooth muscle cells (HASMC). In this study, DPT was purified and demonstrated to inhibit the MMP-9/2 activities in TNF-alpha-induced HASMC. In addition, MMP-9 expression and migration was strongly inhibited by DPT in TNF-alpha-induced HASMC. To examine whether TNF-alpha-induced MMP-9 expressions are involved with migrations of HASMC, reverse transcription-polymerase chain reaction (RT-PCR) and luciferase-tagged promoter analysis were applied. These experiments revealed that DPT inhibited the mRNA transcription of MMP-9 gene expression. Furthermore, Western blot analysis indicated that the TNF-alpha-induced phosphorylation of extracellular signal regulated kinase 1 and 2 (ERK1/2), p38 and c-Jun N-terminal kinase (JNK) were strongly inhibited by DPT. From these results, it is concluded that DPT has an inhibitory activities on migration and MMP-2/9 activities, and MMP-9 transcription in HASMC.