title: Photoprotective effect of calcipotriol upon skin photoreaction to UVA and UVB.
abstract: It has been shown that 1,25-dihydroxyvitamin D3 has a photoprotective effect against UVB injury in mouse skin and cultured rat keratinocytes by induction of metallothionein (MT). Calcipotriol is a synthetic analogue of 1,25-dihydroxyvitamin D3 with equipotent cell regulating properties, but with a lower risk of calcium-related side effects. The aim of the present study was to see whether calcipotriol has a photoprotective property both in vitro and in vivo. We examined the effect of calcipotriol on UV-induced damage of cultured human keratinocytes through a cell viability assay, and measurement of DNA synthesis by cultured keratinocytes, on UV-induced damage of mouse skin and on minimal erythema dose (MED). We found that calcipotriol was protective against UVB-induced reduction in DNA synthetic activity of cultured keratinocytes in relatively low doses (20 and 40 mJ/cm2) of UVB. With phototesting following application of calcipotriol, five subjects among 10 healthy volunteers and three among six psoriasis patients showed an increase in MED compared with the vehicle-treated site. These findings imply that calcipotriol may be photoprotective and that more extensive studies with various doses of UV irradiation and modes of calcipotriol delivery are required.
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Korea.
authors.forename: J I
authors.initials: JI
authors.lastname: Youn
authors.forename: B S
authors.initials: BS
authors.lastname: Park
authors.forename: J H
authors.initials: JH
authors.lastname: Chung
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000818:Animals; D002117:Calcitriol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects / Q000528:radiation effects; D003879:Dermatologic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004890:Erythema / Q000209:etiology; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000528:radiation effects; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D014677:Pharmaceutical Vehicles; D011565:Psoriasis / Q000503:physiopathology; D011829:Radiation Dosage; D011837:Radiation-Protective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D012867:Skin / Q000187:drug effects / Q000528:radiation effects*; D012882:Skin Tests / Q000379:methods; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D003879:Dermatologic Agents; D014677:Pharmaceutical Vehicles; D011837:Radiation-Protective Agents; C055085:calcipotriene; D004247:DNA; D002117:Calcitriol