title: Oral Polypodium leucotomos extract decreases ultraviolet-induced damage of human skin.
abstract: BACKGROUND
  UV radiation induces damage to human skin. Protection of skin by an oral photoprotective agent would have substantial benefits. Objective We investigated the photoprotective effect of oral administration of an extract of the natural antioxidant Polypodium leucotomos (PL).
  
  
  METHODS
  A total of 9 healthy participants of skin types II to III were exposed to varying doses of artificial UV radiation without and after oral administration of PL (7.5 mg/kg). At 24 hours after exposure the erythema reaction was assessed and paired biopsy specimens were obtained from PL-treated and untreated skin.
  
  
  RESULTS
  A significant decrease in erythema was found in PL-treated skin (P < .01). Histologically, PL-treated biopsy specimens showed less sunburn cells (P < .05), cyclobutane pyrimidine dimers (P < .001), proliferating epidermal cells (P < .001), and dermal mast cell infiltration (P < .05). A trend toward Langerhans cell preservation was seen.
  
  
  CONCLUSIONS
  Oral administration of PL is an effective systemic chemophotoprotective agent leading to significant protection of skin against UV radiation.
authors.affiliation: Wellman Laboratories of Photomedicine, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Maritza A
authors.initials: MA
authors.lastname: Middelkamp-Hup
authors.forename: Madhu A
authors.initials: MA
authors.lastname: Pathak
authors.forename: Concepcion
authors.initials: C
authors.lastname: Parrado
authors.forename: David
authors.initials: D
authors.lastname: Goukassian
authors.forename: Francisca
authors.initials: F
authors.lastname: Rius-Díaz
authors.forename: Martín C
authors.initials: MC
authors.lastname: Mihm
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Fitzpatrick
authors.forename: Salvador
authors.initials: S
authors.lastname: González
mesh_terms: D000284:Administration, Oral; D000328:Adult; D004890:Erythema / Q000473:pathology / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000187:drug effects; D008875:Middle Aged; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use*; D032494:Polypodium; D012867:Skin / Q000276:immunology / Q000473:pathology*; D013471:Sunburn / Q000473:pathology / Q000517:prevention & control*; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D010936:Plant Extracts