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Ruby Laser Irradiation (694 nm) of Human Skin Biopsies: Assessment by Electron Spin Resonance Spectroscopy of Free Radical Production and Oxidative Stress during Laser Depilation
Author(s) -
Haywood Rachel M.,
Wardman Peter,
Gault David T.,
Linge Claire
Publication year - 1999
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 - 10.1111/j.1751-1097.1999.tb08147.x
Subject(s) - chemistry , radical , photochemistry , electron paramagnetic resonance , spin trapping , irradiation , oxidative stress , adduct , human skin , nuclear magnetic resonance , biochemistry , organic chemistry , physics , biology , nuclear physics , genetics
Human skin biopsies (hair‐bearing scalp skin and non‐hair‐bearing breast skin) were treated with t‐butylhydro‐peroxide, irradiated with UV light (UVR) or irradiated with 694 nm ruby laser red light. Free‐radical production and oxidative stress were assessed with electron spin resonance spectroscopy (ESR) using the ascorbate radical as a marker. In comparison with both UVR and t‐butyl‐hydroperoxide (which readily induce the ascorbate radical in hair‐bearing and hairless skin), 694 nm red light does not result in the formation of the ascorbate radical in detectable concentrations. Spin‐trapping experiments with the spin trap 5,5‐dimethyl‐l‐pyrroline N‐oxide (DMPO) showed that while free radicals could be detected after treatment of skin with t‐butylhydroperoxide, radicals could not be trapped after laser treatment. Treatment of lasered skin (containing DMPO) with t‐bu‐tylhydroperoxide produced radical adducts as well as the ascorbate radical, demonstrating that the laser neither depletes endogenous ascorbate nor the preadministered spin trap. It is concluded that 694 nm red light does not induce oxidative stress in human skin in levels comparable either to t‐butyl hydroperoxide or UV light.