title: Daytime serum levels of melatonin after topical application onto the human skin.
abstract: The hormone melatonin is produced in the pineal gland and secreted into the blood in a circadian rhythm. Due to its antioxidative and immunomodulatory effects it might play a role as a topical drug in dermatology. In this study we investigated the penetration kinetics of melatonin applied to the skin of 6 healthy volunteers aged 26-34 years (M/F = 2/4). First the individual physiologic daytime melatonin serum levels were determined by radioimmunoassay. Then 3 of the participants were treated once topically on their scalp with 20 mg melatonin dissolved in 70% ethanol, while the other 3 individuals received 100 mg. The application was performed at 9.00 a.m., and blood samples were collected repeatedly for a total of 8 h. Physiologic daytime melatonin levels in the 6 individuals were 16.8 +/- 10.0 pg/ml. The 3 individuals treated with 20 mg melatonin displayed peak serum levels of 762, 918 and 3,440 pg/ml, respectively, those treated with 100 mg melatonin showed peak levels of 1,136, 3,360 and 4,230 pg/ml lasting throughout the entire observation period of 8 h. These findings indicate that melatonin might accumulate in the stratum corneum with prolonged release into the blood system from this depot.
authors.affiliation: Department of Dermatology, University of Zurich, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Bangha
authors.forename: D
authors.initials: D
authors.lastname: Lauth
authors.forename: G S
authors.initials: GS
authors.lastname: Kistler
authors.forename: P
authors.initials: P
authors.lastname: Elsner
mesh_terms: D000287:Administration, Topical; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D000431:Ethanol / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000008:administration & dosage* / Q000097:blood* / Q000493:pharmacokinetics; D011863:Radioimmunoassay; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption; D012996:Solutions
chemical_list: D012996:Solutions; D000431:Ethanol; D008550:Melatonin