title: Effects of baicalein and wogonin isolated from Scutellaria baicalensis roots on skin damage in acute UVB-irradiated hairless mice.
abstract: Solar ultraviolet (UV) radiation causes skin damage including increases in skin thickness, edema, and flush. In this study, we examined the effects of two main flavonoids (wogonin and baicalein) isolated from the roots of Scutellaria baicalensis, a traditional remedy for allergic inflammatory diseases long used in China and Japan, on acute UVB irradiation-induced skin damage in hairless mice. Baicalein and wogonin (10 or 50 mg/kg) were administered orally twice daily for 14 consecutive days. The UVB irradiation was performed at a dose of 200 mJ/cm(2) on days 7 and 8 of the treatment with the two main flavonoids. Baicalein, and wogonin prevented the increases in skin thickness and the levels of matrix metalloproteinase (MMP)-9, and vascular endothelial growth factor (VEGF) induced by the irradiation. Wogonin reduced the levels of cyclooxygenase (COX)-2 and hypoxia inducible factor (HIF)-1α in UVB-treated HaCaT cells. These findings suggest that wogonin inhibits irradiation-induced skin damage by suppressing increases in the levels of MMP-9, and VEGF through the inhibition of COX-2 and HIF-1α expression. Baicalein inhibited COX-2 and NF-κB/p65 expression, but stimulated HIF-1α expression. Therefore, its inhibitory action is likely due to the expression of MMP-9 and VEGF through the suppression of COX-2 and NF-κB/p65 expression. Furthermore, the inhibitory effects of baicalein on UVB-irradiated hyperplasia of skin epidermis may be due to the stimulation of HIF-1α expression.
authors.affiliation: Division of Biochemical Pharmacology, Department of Basic Medical Research, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Japan. yokim@m.ehime-u.ac.jp
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kimura
authors.forename: Maho
authors.initials: M
authors.lastname: Sumiyoshi
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000187:drug effects / Q000473:pathology; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004423:Ear / Q000473:pathology; D004817:Epidermis / Q000187:drug effects / Q000473:pathology; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D044950:Flavanones / Q000302:isolation & purification / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008812:Mice, Hairless; D018517:Plant Roots / Q000737:chemistry*; D031364:Scutellaria baicalensis / Q000737:chemistry*; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D051996:Transcription Factor RelA / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D044950:Flavanones; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C498144:Rela protein, mouse; D051996:Transcription Factor RelA; D042461:Vascular Endothelial Growth Factor A; C006680:baicalein; D051546:Cyclooxygenase 2; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; C085514:wogonin