Effects of various flavonoids isolated from Scutellaria baicalensis roots on skin damage in acute UVB-irradiated hairless mice

J Pharm Pharmacol. 2011 Dec;63(12):1613-23. doi: 10.1111/j.2042-7158.2011.01365.x. Epub 2011 Oct 27.


Objectives: 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.

Key findings: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Dermis / drug effects
  • Dermis / radiation effects
  • Ear, External / pathology
  • Flavonoids / administration & dosage
  • Flavonoids / chemistry
  • Flavonoids / pharmacology*
  • Magnetic Resonance Spectroscopy
  • Male
  • Matrix Metalloproteinases / metabolism
  • Mice
  • Mice, Hairless
  • Plant Roots / chemistry
  • Regional Blood Flow / drug effects
  • Scutellaria baicalensis / chemistry*
  • Skin / blood supply
  • Skin / pathology*
  • Skin / radiation effects*
  • Skin Aging / pathology*
  • Spectrophotometry, Infrared
  • Spectrophotometry, Ultraviolet
  • Ultraviolet Rays
  • Vascular Endothelial Growth Factor A / metabolism


  • Flavonoids
  • Vascular Endothelial Growth Factor A
  • Matrix Metalloproteinases