title: Predominant effects of Polypodium leucotomos on membrane integrity, lipid peroxidation, and expression of elastin and matrixmetalloproteinase-1 in ultraviolet radiation exposed fibroblasts, and keratinocytes.
abstract: BACKGROUND
  Polypodium leucotomos has been reported to have antioxidant, anti-inflammatory and photoprotective properties. Exposure of skin to ultraviolet (UV) radiation can lead to deposition of excessive elastotic material, reduction in collagen, and increased expression of matrix metalloproteinases (MMPs).
  
  
  OBJECTIVE
  The goal of this research was to determine the effects of P. leucotomos in the absence or presence of UVA or UVB radiation on membrane damage, lipid peroxidation, and expression of elastin and MMP-1 in fibroblasts and keratinocytes, respectively.
  
  
  METHODS
  Fibroblasts and keratinocytes, respectively, were irradiated by a single exposure to UVA (0.6, 1.8 or 3.6 J) or UVB radiation (0.75, 2.5 or 7.5 mJ), and then incubated with, or without, P. leucotomos (0.01, 0.1 and 1%) and examined for membrane damage, lipid peroxidation, expression of elastin (protein levels) and MMP-1 (protein levels or MMP-1 promoter activity).
  
  
  RESULTS
  UV radiation did not significantly alter membrane integrity, lipid peroxidation or MMP-1 expression, but increased elastin expression. P. leucotomos significantly improved membrane integrity, inhibited lipid peroxidation, increased elastin expression, and inhibited MMP-1 expression in both fibroblasts, and keratinocytes. The effects of P. leucotomos predominated in the presence of UVA or UVB in both fibroblasts and keratinocytes, respectively, with the exception of inhibition of MMP-1 protein levels in fibroblasts only in combination with UV radiation.
  
  
  CONCLUSIONS
  Lower concentration of P. leucotomos (lower than 0.1%), may be beneficial in preventing photoaging by improving membrane integrity and inhibiting MMP-1, without increasing elastin expression. Higher concentration (greater than 0.1%) of P. leucotomos may reverse the loss of normal elastic fibers associated with intrinsic aging.
authors.affiliation: Departments of Biology and Chemistry/Biochemistry, Georgian Court College, Lakewood, NJ, USA. philips@georgian.edu
authors.forename: Neena
authors.initials: N
authors.lastname: Philips
authors.forename: Joan
authors.initials: J
authors.lastname: Smith
authors.forename: Thomas
authors.initials: T
authors.lastname: Keller
authors.forename: Salvador
authors.initials: S
authors.lastname: Gonzalez
mesh_terms: D002478:Cells, Cultured; D004549:Elastin / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism* / Q000528:radiation effects; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism* / Q000528:radiation effects; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D015227:Lipid Peroxidation; D061965:Matrix Metalloproteinase Inhibitors; D008566:Membranes / Q000201:enzymology / Q000378:metabolism; D032494:Polypodium / Q000502:physiology*; D014466:Ultraviolet Rays
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D004549:Elastin; D007770:L-Lactate Dehydrogenase