Premium
Exacerbating Effect of Vitamin E Supplementation on DNA Damage Induced in Cultured Human Normal Fibroblasts by UVA Radiation ¶
Author(s) -
Nocentini Silvano,
Guggiari Michèle,
Rouillard Danielle,
Surgis Sophie
Publication year - 2001
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2001)0730370eeoves2.0.co2
Subject(s) - dna damage , trolox , comet assay , chemistry , hydrogen peroxide , microbiology and biotechnology , superoxide , vitamin e , dna , biochemistry , reactive oxygen species , flow cytometry , antioxidant , biology , enzyme , dpph
The effects of vitamin E supplementation were evaluated in cultured human normal fibroblasts exposed to ultraviolet A radiation (320–380 nm) (UVA). Cells were incubated in medium containing α‐tocopherol, α‐tocopherol acetate or the synthetic analog Trolox for 24 h prior to UVA exposure. DNA damage in the form of frank breaks and alkali‐labile sites, collectively termed single‐strand breaks (SSB), was assayed by the technique of single cell gel electrophoresis (comet assay), immediately following irradiation or after different repair periods. The generation of hydrogen peroxide (H 2 O 2 ) and superoxide ion (O 2 ·− ) was measured by flow cytometry through the oxidation of indicators into fluorescent dyes. It was observed that pretreatment of cells with any form of vitamin E resulted in an increased susceptibility to the photoinduction of DNA SSB and in a longer persistence of damage, whereas no significant change was observed in the production of H 2 O 2 and O 2 ·− reactive oxygen species, compared to untreated controls. These findings indicate that in human normal fibroblasts, exogenously added vitamin E exerts a promoting activity on DNA damage upon UVA irradiation and might lead to increased cytotoxic and mutagenic risks.