title: 18beta-glycyrrhetinic acid and glabridin prevent oxidative DNA fragmentation in UVB-irradiated human keratinocyte cultures.
abstract: BACKGROUND
  UVB radiation is the major etiological factor in the pathogenesis of skin aging and cancer development. New approaches to prevent and reverse UVB damage are needed to reduce sunlight-induced skin cancer. This study aimed to investigate a possible protective activity of liquorice root extracts glycyrrhizin (GL), 18β-glycyrrhetinic acid (18β-GA) and glabridin (GLB) against UVB radiation damage in human keratinocyte cultures.
  
  
  METHODS
  The MTT test was performed to assess cell viability. DNA damage was evaluated by comet assay, whereas generation of intracellular reactive oxygen species (ROS) was measured by fluorescent 2'7'-dichlorodihydrofluorescein diacetate assay. In addition, the activation of p53, regulation of BCL-2 and PARP cleavage were analyzed by Western blot analysis.
  
  
  RESULTS
  The treatment of human keratinocytes with 18β-GA and GLB prevented direct and indirect DNA damage avoiding apoptosis activation.
  
  
  CONCLUSIONS
  18β-glycyrrhetinic acid and glabridin are potent antioxidants that prevent oxidative DNA fragmentation and the activation of apoptosis-associated proteins in human keratinocytes.
authors: Department of Dermatology, Via del Pozzo 71, University of Modena and Reggio Emilia, Modena, Italy.
authors: Eugenia
authors: E
authors: Veratti
authors: Tiziana
authors: T
authors: Rossi
authors: Stefania
authors: S
authors: Giudice
authors: Luisa
authors: L
authors: Benassi
authors: Giorgia
authors: G
authors: Bertazzoni
authors: Daria
authors: D
authors: Morini
authors: Paola
authors: P
authors: Azzoni
authors: Elisa
authors: E
authors: Bruni
authors: Alberto
authors: A
authors: Giannetti
authors: Cristina
authors: C
authors: Magnoni
mesh_terms: D002478:Cells, Cultured; D004247:DNA / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D004249:DNA Damage; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D007529:Isoflavones / Q000494:pharmacology*; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects*; D009381:Neoplasms, Radiation-Induced / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control; D018384:Oxidative Stress; D010636:Phenols / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012878:Skin Neoplasms / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control; D014466:Ultraviolet Rays
chemical_list: D007529:Isoflavones; D010636:Phenols; D017382:Reactive Oxygen Species; C119129:18alpha-glycyrrhetinic acid; D004247:DNA; C107601:glabridin; D006034:Glycyrrhetinic Acid