Quercus glauca extract and rutin inhibit the UVB-induced expression of matrix metalloproteinase-1 in human dermal fibroblasts

Matrix metalloproteinases (MMPs) are known to be up-regulated by a reactive oxygen species (ROS)-dependent mechanism in skin after exposure to ultraviolet radiation (UV) and to participate in tissue remodeling, leading to wrinkles and other phenotypes of photo-aging. Thus, it has been assumed that the progress of photo-aging may be decelerated by suppressing the UVinduced expression of MMPs. In this regard, plant extracts enriched with polyphenolic antioxidants are attractive materials, because they may suppress the expression of MMPs by lowering ROS levels. To examine this possibility, the extracts of twelve plants were tested for their ability to alter the UVB-induced MMP-1 expression in cultured human dermal fibroblasts. Among the tested extracts, an extract of Quercus glauca Thunberg (QG) inhibited MMP-1 expression most effectively without any noticeable cytotoxicity. In addition, its water fraction was more active than 1-buthanol and methylene chloride fractions, implicating the active constituents may be watersoluble. Rutin, one of the major water-soluble polyphenolic constituents of QG, showed an inhibitory effect against UVB-induced MMP-1 expression. Both QG extract and rutin lowered ROS levels in UVB-exposed cells, suggesting that their inhibitory effects on MMP-1 expression may be associated with the antioxidant effects of lowering intracellular ROS levels. The watersoluble constituents of QG may provide a protective effect against the UVB-induced photo-aging of human skin.