title: Orange peel extract, containing high levels of polymethoxyflavonoid, suppressed UVB-induced COX-2 expression and PGE2 production in HaCaT cells through PPAR-γ activation.
abstract: Ultraviolet light (UV) induces an inflammatory response in the skin by cyclooxygenase (COX)-2 expression and prostaglandin (PG) E2 production. Citrus peel has been used as a natural medicine. It contains polymethoxyflavonoids (PMFs) as a major ingredient, which have anti-inflammatory activity. We obtained orange peel extract containing high levels of PMFs. The extract suppressed UVB-induced COX-2 expression and PGE2 production in HaCaT cells. Furthermore, it was found that this extract acted as a peroxisome proliferator-activated receptor (PPAR)-γ agonist. The suppression of UVB-induced COX-2 expression by this extract was inhibited by GW 9662 and T0070907, which are both PPAR-γ antagonists. It is therefore suggested that orange peel extract, containing high levels of PMFs, suppresses UVB-induced COX-2 expression and PGE2 production through PPAR-γ. Hence, these extracts could provide useful protection against or alleviation of UV damage.
authors.affiliation: Advanced Technology Research Laboratory, NOF Corporation, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Yoshizaki
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujii
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Masaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okubo
authors.forename: Kunio
authors.initials: K
authors.lastname: Shimada
authors.forename: Ron
authors.initials: R
authors.lastname: Hashizume
mesh_terms: D000813:Anilides / Q000494:pharmacology; D001549:Benzamides / Q000494:pharmacology; D002460:Cell Line; D032084:Citrus sinensis / Q000737:chemistry; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D047495:PPAR gamma / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D011837:Radiation-Protective Agents / Q000737:chemistry / Q000494:pharmacology; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: C457499:2-chloro-5-nitrobenzanilide; D000813:Anilides; D001549:Benzamides; D005419:Flavonoids; D047495:PPAR gamma; D010936:Plant Extracts; D011725:Pyridines; D011837:Radiation-Protective Agents; C458508:T 0070907; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D015232:Dinoprostone
keywords: cyclooxygenase-2; orange peel; polymethoxyflavonoid; proliferator-activated receptor-γ; ultraviolet light