title: In vivo photoprotective and anti-inflammatory effect of hyperforin is associated with high antioxidant activity in vitro and ex vivo.
abstract: Hyperforin, a major constituent of St. John's Wort (Hypericum perforatum, HP), provides anti-inflammatory, anti-tumor, and anti-bacterial properties. Previous studies have shown anti-oxidative properties of St. John's Wort extracts; however, its free radical scavenging activity in skin cells or skin has not been assessed in detail so far. Therefore, the free radical scavenging activity of hyperforin was tested in the H(2)DCFDA-assay in vitro in HaCaT keratinocytes irradiated with solar simulated radiation. Hyperforin (EC(50) 0.7 μM corresponding to 0.42 μg/ml) was much more effective compared to Trolox (EC(50) 12 μg/ml) and N-acetylcysteine (EC(50) 847 μg/ml) without showing phototoxicity. The radical protection factor of a cream containing 1.5%w/w of a hyperforin-rich HP extract was determined to be 200 × 10(14) radicals/mg, indicating a high radical scavenging activity. The cream was further applied ex vivo on porcine ear skin and significantly reduced radical formation after infrared irradiation. Finally, the UV-protective effect of the HP cream was tested on 20 volunteers in a randomized, double-blind, vehicle-controlled study. HP cream significantly reduced UVB-induced erythema as opposed to the vehicle. Occlusive application of HP cream on non-irradiated test sites did not cause any skin irritation. Taken together, these results demonstrate that hyperforin is a powerful free radical scavenger.
authors.affiliation: Department of Dermatology, Venerology and Allergology, Charité - Universitätsmedizin Berlin, Berlin, Germany. martina.meinke@charite.de
authors.forename: Martina C
authors.initials: MC
authors.lastname: Meinke
authors.forename: Sabine
authors.initials: S
authors.lastname: Schanzer
authors.forename: Stefan F
authors.initials: SF
authors.lastname: Haag
authors.forename: Federica
authors.initials: F
authors.lastname: Casetti
authors.forename: Marcel L
authors.initials: ML
authors.lastname: Müller
authors.forename: Ute
authors.initials: U
authors.lastname: Wölfle
authors.forename: Anke
authors.initials: A
authors.lastname: Kleemann
authors.forename: Juergen
authors.initials: J
authors.lastname: Lademann
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Schempp
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D004311:Double-Blind Method; D004890:Erythema / Q000517:prevention & control*; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D020902:Hypericum / Q000737:chemistry; D007249:Inflammation / Q000188:drug therapy; D015603:Keratinocytes / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D010696:Phloroglucinol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology; D012867:Skin / Q000187:drug effects / Q000528:radiation effects; D013552:Swine; D013729:Terpenes / Q000008:administration & dosage / Q000494:pharmacology*; D014466:Ultraviolet Rays / Q000009:adverse effects; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D013729:Terpenes; D010696:Phloroglucinol; C001654:hyperforin