title: Ascorbic acid 2-O-alpha-glucoside, a stable form of ascorbic acid, rescues human keratinocyte cell line, SCC, from cytotoxicity of ultraviolet light B.
abstract: Environmental exposure to ultraviolet light B (UVB, wave lengths 290-320 nm) of the solar spectrum causes major damage, including an inflammatory response, in skin. In the present study, we estimated the ability of a stable derivative of ascorbic acid, ascorbic acid 2-O-alpha-glucoside (AA-2G), to reduce UVB damage, using the human keratinocyte cell line, SCC, established from squamous cell carcinoma. By pre- (9 h) and post-cultivation with AA-2G, a significant preventive effect on the decrease in the absolute number of surviving cells by exposure to UVB (typical dose, 20 mJ/cm2) was measurable by a neutral red-uptake assay. The release of lactate dehydrogenase from the cell membrane damaged by UVB was inhibited by AA-2G. In agarose gel electrophoresis, relatively high molecular weight DNA fragments were detected in irradiated cells after 6 h post-irradiation, suggesting that the mechanism of cell death was necrosis. Quantitative analysis of DNA content by flow cytometry indicated that AA-2G suppressed both an increase in debris with degraded nuclei and a decrease in cells in G1 and S phases, but not in the G2/M phase, by UVB exposure. These data suggest that AA-2G shows a photoprotective effect against UVB-induced damage in human epithelial cells.
authors.affiliation: Department of Immunochemistry, Faculty of Pharmaceutical Sciences, Okayama University, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Miyai
authors.forename: M
authors.initials: M
authors.lastname: Yanagida
authors.forename: J
authors.initials: J
authors.lastname: Akiyama
authors.forename: I
authors.initials: I
authors.lastname: Yamamoto
mesh_terms: D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D002294:Carcinoma, Squamous Cell; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects / Q000528:radiation effects; D005434:Flow Cytometry; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000528:radiation effects*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D012878:Skin Neoplasms; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays
chemical_list: D011837:Radiation-Protective Agents; C065378:ascorbic acid 2-O-glucoside; D004247:DNA; D007770:L-Lactate Dehydrogenase; D001205:Ascorbic Acid