Inhibition effect of Gynura procumbens extract on UV-B-induced matrix-metalloproteinase expression in human dermal fibroblasts

Ethnopharmacological relevance: Gynura procumbens Merr. (Asteraceae) has been used as a traditional remedy for various skin diseases in certain areas of Southeast Asia. Aim of the study: In order to evaluate the protective activity of Gynura procumbens extract on skin photoaging and elucidate its mode of action. Materials and methods: Matrix-metalloproteinase (MMP)-1 and -9 expressions were induced by UV-B irradiation in human primary dermal fibroblasts. MMP-1 expression level was measured by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Zymography was employed for evaluating the enzymatic activity of MMP-9. Anti-inflammatory activity and anti-oxidative capacity of the extract were evaluated by ELISA and dichlorodihydrofluorescein diacetate (DCF-DA) assay. Results: The ethanolic extract of Gynura procumbens inhibited MMP-1 expression up to 70% compare to negative control group. The enzymatic activity of MMP-9 was inhibited around 73% by the treatment of 20 mu g/mL of the extract. The extract markedly reduced the production of reactive oxygen species (ROS). Gynura procumbens extract showed an inhibitory effect on releasing pro-inflammatory cytokines (IL-6 and IL-8) in human HaCat keratinocyte. Conclusion: The ethanolic extract of Gynura procumbens inhibited MMP-1 and MMP-9 expressions induced by UV-B irradiation via inhibition of pro-inflammatory cytokine mediator release and ROS production. (C) 2011 Elsevier Ireland Ltd. All rights reserved.