3,4,5-trihydroxybenzaldehyde from Geum japonicum has dual inhibitory effect on matrix metalloproteinase 9; inhibition of gelatinoytic activity as well as MMP-9 expression in TNF-alpha induced HASMC.

The matrix metalloproteinases (MMP-9 and MMP-2) production and smooth muscle cell (SMC) migration may play key roles in the pathogenesis of atherosclerotic lesions. In particular, the cancer cell invasion and SMC migration through vascular wall were shown to be directly associated with inducible MMP-9 expression. Previously, 3,4,5-trihydoroxybenzaldehyde (THBA) was purified from Geum japonicum and we demonstrated a direct inhibition effect of THBA on MMP-9 and MMP-2 activity in the supernatants of TNF-alpha-induced HASMCs. In addition, MMP-9 expression and migration was suppressed by THBA in the TNF-alpha-induced HASMCs. In this study, we also investigated whether TNF-alpha-induced MMP-9 expressions are involved with migrations of HASMCs by using cell signal inhibitors and MMP-9 inhibitors. An RT-PCR and luciferase-tagged promoter analysis revealed that THBA inhibits the transcription of MMP-9 mRNA. Moreover, an electrophoretic mobility shift assay (EMSA) exhibited that THBA also suppressed DNA binding of nuclear factor (NF)-kappaB and activator protein (AP)-1 transcription factors. Furthermore, Western blot analysis indicated TNF-alpha-induced phosphorylation of extracellular signal regulated kinase 1 and 2 (ERK1/2), p38 and c-Jun N-terminal kinase (JNK) were inhibited by THBA. Taken together, we suggest that THBA has inhibition effect to the migrations as well as MMP-2 and MMP-9 activities in HASMCs. Especially gelatinolytic activity was controlled by enzymatic inhibition of MMP-2 and MMP-9, and also down-regulated MMP-9 transcription via mitogen-activated protein kinase (MAPK) pathways in THBA treated HASMCs.