title: Pretreatment of Ferulic Acid Protects Human Dermal Fibroblasts against Ultraviolet A Irradiation.
abstract: BACKGROUND
  Approximately 90%~99% of ultraviolet A (UVA) ray reaches the Earth's surface. The deeply penetrating UVA rays induce the formation of reactive oxygen species (ROS), which results in oxidative stress such as photoproducts, senescence, and cell death. Thus, UVA is considered a primary factor that promotes skin aging.
  
  
  OBJECTIVE
  Researchers investigated whether pretreatment with ferulic acid protects human dermal fibroblasts (HDFs) against UVA-induced cell damages.
  
  
  METHODS
  HDF proliferation was analyzed using the water-soluble tetrazolium salt assay. Cell cycle distribution and intracellular ROS levels were assessed by flow cytometric analysis. Senescence was evaluated using a senescence-associated β-galactosidase assay, whileGadd45α promoter activity was analyzed through a luciferase assay. The expression levels of superoxide dismutase 1 (SOD1), catalase (CAT), xeroderma pigmentosum complementation group A and C, matrix metalloproteinase 1 and 3, as well as p21 and p16 were measured using quantitative real-time polymerase chain reaction.
  
  
  RESULTS
  Inhibition of proliferation and cell cycle arrest were detected in cells that were irradiated with UVA only. Pretreatment with ferulic acid significantly increased the proliferation and cell cycle progression in HDFs. Moreover, ferulic acid pretreatment produced antioxidant effects such as reduced DCF intensity, and affected SOD1 and CAT mRNA expression. These effects were also demonstrated in the analysis of cell senescence, promoter activity, expression of senescent markers, and DNA repair.
  
  
  CONCLUSIONS
  These results demonstrate that ferulic acid exerts protective effects on UVA-induced cell damages via anti-oxidant and stress-inducible cellular mechanisms in HDFs.
authors.affiliation: Department of Dermatology, Konyang University College of Medicine, Daejeon, Korea.
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Hahn
authors.affiliation: Department of Biological Engineering, Graduate School of Engineering, Konkuk University, Seoul, Korea.
authors.forename: Ki Bbeum
authors.initials: KB
authors.lastname: Kim
authors.affiliation: Department of Biological Engineering, Graduate School of Engineering, Konkuk University, Seoul, Korea.
authors.forename: Seunghee
authors.initials: S
authors.lastname: Bae
authors.affiliation: Department of Dermatology, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Byung Gon
authors.initials: BG
authors.lastname: Choi
authors.affiliation: Department of Biological Engineering, Graduate School of Engineering, Konkuk University, Seoul, Korea.
authors.forename: Sungkwan
authors.initials: S
authors.lastname: An
authors.affiliation: Department of Dermatology, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Kyu Joong
authors.initials: KJ
authors.lastname: Ahn
authors.affiliation: Department of Biological Engineering, Graduate School of Engineering, Konkuk University, Seoul, Korea.
authors.forename: Su Young
authors.initials: SY
authors.lastname: Kim
keywords: Cell aging; DNA repair; Ferulic acid; Reactive oxygen species; Ultraviolet rays