Dietary Foeniculum vulgare Mill extract attenuated UVB irradiation-induced skin photoaging by activating of Nrf2 and inhibiting MAPK pathways

Background: Foeniculum vulgare Mill (FV) has long been prescribed in traditional medicine due to its antioxidant anti-inflammatory properties. However, little research has been done on the use of FV to alleviate changes in UVB-induced photoaging Purpose: This study was to investigate the photoprotective effects and mechanism of FV in vitro and in vivo. Methods: The anti-photoaging effect of FV was assessed in normal human dermal fibroblasts (NHDFs) in vitro. The secretion of reactive oxygen species (ROS), lactate dehydrogenase (LDH), GSH, matrix metalloproteinases (MMPs), procollagen type I, IL-6 and transforming growth factor-beta 1 (TGF-beta 1) were measured by kits. Additionally, the level of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), p-ERK and p38 were evaluated by western blotting. In vivo, H&E and Masson's trichrome staining were employed. The expression of MMP-1, procollagen type I, TGF-beta 1 and elastin were measured by western blot. Results: FV significantly increased the production of collagen, elastin and TGF-beta 1 levels, while blocked matrix metalloproteinases (MMPs) production in UVB irradiation induced hairless mice, which were consistent with the result in NHDFs. Furthermore, FV dose-dependently decreased the production of ROS and LDH by promoting the nuclear amount of Nrf2 and enhancing the expression of cytoprotective antioxidants such as GSH. FV also significantly quenched UVB-induced phosphorylation of ERK and p38 in NHDFs. Conclusion: Our results indicate that FV is a potential botanical agent for the treatment of skin damage induced by UV irradiation. (C) 2016 Elsevier GmbH. All rights reserved.