Biol. Pharm. Bull. 28(5) 925—928 (2005)

of Korea. In traditional medicine, the herb has been used as an expectorant, a diuretic, and an antiinflammatory for bronchitis, rheumatism, skin eruptions, and eczema. Previous phytochemical studies on Viola species have revealed them to be a rich source of cyclotides and several flavone glycosides. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endoproteinases that play pivotal roles in the dynamic remodeling of extracellular matrix. Based on substrate preference and structural homology, MMPs are sub-classified into functional groups: collagenases, gelatinases, stromelysins, matrilysins, membrane type-MMPs (MT-MMPs) and other non-classified MMPs. MMPs are frequently overexpressed by the various extracellular stimuli including growth factors, cytokines, tumor promoters, and ultraviolet (UV), and this increase in MMP-related activities may be involved in the pathogenesis of diseases such as cancer and inflammation as well as in physiologic processes. It has been also reported that up-regulation of some MMPs is responsible for the enhanced degradation of dermal collagen during chronological and UV-induced skin aging. Therefore, the regulation of MMP activity might be a potential strategy for prevention and/or treatment of UV-induced skin damage. Recently, Kim et al. reported the isolation of the styraxjaponoside B from the stem bark of Styrax japonica to regulate MMP-1 expression. In this study, we investigated the effect of 2 ,4 ,7-trihydroxyisoflavone, Isoflavonoid from Viola hondoensis, on the expression of UV-induced MMP-1 and MMP-2 mRNA and protein in human skin fibroblasts.