title: Protective effect of alpha-tocopherol-6-O-phosphate against ultraviolet B-induced damage in cultured mouse skin.
abstract: The ability of the novel water-soluble provitamin E, alpha-tocopherol-6-O-phosphate, to protect against ultraviolet B-induced damage in cultured mouse skin was investigated and compared with the protectiveness of alpha-tocopherol acetate in cultured mouse skin. Pretreatment of skin with 0.5% (9.4 mM) alpha-tocopherol-6-O-phosphate in medium for 3 h significantly prevented such photodamage as sunburn cell formation, DNA degradation, and lipid peroxidation, which were induced in control cultured skin by a single dose of ultraviolet B irradiation at 0 to 40 kJ per m2 (290-380 nm, maximum 312 nm). This protection was greater than that seen with alpha-tocopherol acetate, the most common provitamin E that is used in commercial human skin care products. The concentration of alpha-tocopherol in cultured skin pretreated with 0.5% alpha-tocopherol-6-O-phosphate rose to approximately two to three times that found in the control skin and the reduction in cutaneous alpha-tocopherol that was induced by ultraviolet irradiation was significantly inhibited. In the group pretreated with 0.5% alpha-tocopherol acetate, however, conversion of alpha-tocopherol acetate to alpha-tocopherol was not observed, although the level of provitamin incorporated into the cultured skin was the same as that for alpha-tocopherol-6-O-phosphate. These findings indicated that the enhanced ability of alpha-tocopherol-6-O-phosphate to protect against ultraviolet B-induced skin damage compared with alpha-tocopherol acetate may have been due to alpha-tocopherol-6-O-phosphate's conversion to alpha-tocopherol. Moreover, following pretreatment with a 0.5% alpha-tocopherol-6-O-phosphate, alpha-tocopherol-6-O-phosphate was incorporated into the human skin in a three-dimensional model and 5% of the incorporated alpha-tocopherol-6-O-phosphate was converted to alpha-tocopherol. These results suggest that treatment with the novel provitamin E, alpha-tocopherol-6-O-phosphate may be useful in preventing ultraviolet-induced human skin damage.
authors.affiliation: Kyoritsu College of Pharmacy, Tokyo 105-8512, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Nakayama
authors.forename: Eiko M
authors.initials: EM
authors.lastname: Katoh
authors.forename: Toshi
authors.initials: T
authors.lastname: Tsuzuki
authors.forename: Shizuko
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D046508:Culture Techniques; D005260:Female; D006801:Humans; D006868:Hydrolysis; D051379:Mice; D008812:Mice, Hairless; D008954:Models, Biological; D009994:Osmolar Concentration; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D024505:Tocopherols; D014466:Ultraviolet Rays / Q000009:adverse effects*; D024502:alpha-Tocopherol / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D011837:Radiation-Protective Agents; C012552:alpha-tocopherol phosphate; D010744:Phosphoric Monoester Hydrolases; D024502:alpha-Tocopherol; D024505:Tocopherols