title: Effects of various flavonoids isolated from Scutellaria baicalensis roots on skin damage in acute UVB-irradiated hairless mice.
abstract: OBJECTIVE
  Solar ultraviolet (UV) radiation causes skin damage including increasing skin thickness, edema and flush. Scutellaria baicalensis roots have been traditionally used as a remedy for allergic inflammatory diseases in China and Japan. In this study, we examined the effects of four flavonoids isolated from these roots, namely 2',5, 5',7-tetrahydroxy-6',8-dimethoxyflavone (1), skullcapflavone II (2), 2(S)-2',5,6',7-tetrahydroxyflavanone (3) and 2(R), 3(R)-2',3,5,6',7-pentahydroxyflavanone (4), on acute UVB irradiation-induced skin damage in hairless mice.
  
  
  METHODS
  The four flavonoids were orally administered twice daily, at doses of 10 and 50 mg/kg, for 14 consecutive days. The UVB irradiation was performed at a dose of 200 mJ cm(-2) on days 7 and 8 after beginning oral administration of the four flavonoids.
  
  
  RESULTS
  Compounds 1 and 4 prevented increases in skin thickness, levels of matrix metalloproteinases (MMP)-2 and MMP-9, and vascular endothelial growth factor (VEGF) induced by UVB irradiation. The other two flavonoids 2 and 3 had no effect.
  
  
  CONCLUSIONS
  Compounds 1 and 4 isolated from Scutellaria baicalensis roots may be useful for preventing skin inflammation induced by acute UVB irradiation.
authors: Division of Biochemical Pharmacology, Department of Basic Medical Research, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, Japan. yokim@m.ehime-u.ac.jp
authors: Yoshiyuki
authors: Y
authors: Kimura
authors: Maho
authors: M
authors: Sumiyoshi
mesh_terms: D000284:Administration, Oral; D000818:Animals; D020405:Dermis / Q000187:drug effects / Q000528:radiation effects; D004431:Ear, External / Q000473:pathology; D005419:Flavonoids / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D051379:Mice; D008812:Mice, Hairless; D018517:Plant Roots / Q000737:chemistry; D012039:Regional Blood Flow / Q000187:drug effects; D031364:Scutellaria baicalensis / Q000737:chemistry*; D012867:Skin / Q000098:blood supply / Q000473:pathology* / Q000528:radiation effects*; D015595:Skin Aging / Q000473:pathology*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D005419:Flavonoids; D042461:Vascular Endothelial Growth Factor A; D020782:Matrix Metalloproteinases