Effects on Photoaging and Wound Healing of Flavonoids

Abstract

Exposure of strong and repeated UV on the skin leads to skin aging, characterized with wrinkling, sagging, dyspigmentation, and laxity. Numerous studies revealed that Matrix metalloproteinases are related to skin aging and functions as degrading enzyme of various types of collagen. Here, we attempted to evaluate the effectiveness of glycitin (4'-hydroxy-6-methoxyisoflavone-7-D-glucoside) on skin aging and mechanisms of action in UV-irradiated human dermal fibroblasts. Especially we focused on the expression of Matrix metalloproteinase-1 (MMP-1), which degrades procollagen type-I in dermis, by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, and reverse transcription polymerase chain reaction in cell lysates or media. Our results showed that glycitin increased the viability of human dermal fibroblast and alleviated MMP-1 expression caused by UV irradiation. In addition, synthesis of type-I collagen was increased and elastase inhibition activity was increased. UV-induced phosphorylation of ERK/JNK/p38 was decreased in dose-dependent manners. Taken together, we demonstrated that treatment with glycitin have a protective effect on skin aging by inhibiting of MMP-1 and increasing of collagen through ERK/JNK/P38 down-regulation, which may be mediated by the inhibition of ERK, JNK, and p38 mitogen-activated protein kinases. We suggest that glycitin is a potential agent for the treatment of skin ageing.