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

Abstract

Human skin biopsies (hair-bearing scalp skin and non-hair-bearing breast skin) were treated with t-butylhydroperoxide, 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-1-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-butylhydroperoxide 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.

Measuring reactive species and oxidative damagein vivoand in cell culture: how should you do it and what do the results mean?

“…However, traps can be used on body fluids and tissue samples. For example, DMPO was used to measure free radicals in human skin biopsies ( Haywood et al ., 1999 ). A hydroxylamine probe has been used to measure free radicals in liver biopsies ( Valgimigli et al ., 2002 ).…”

“…Ascorbic acid (vitamin C) reacts with a wide range of free radicals and other RS ( Buettner, 1993 ; Halliwell, 1999c ) and one of its oxidation products, semidehydroascorbate radical, can easily be detected by ESR ( Buettner & Jurkiewicz, 1993 ). Measurement of semidehydroascorbate has been used as an indication of free radical production in organs, blood plasma and skin ( Buettner & Jurkiewicz, 1993 ; Sharma & Buettner, 1993 ; Sharma et al ., 1994 ; Jurkiewicz & Buettner, 1996 ; Haywood et al ., 1999 ). It is only semiquantitative, since ascorbate radicals quickly react with each other to generate ESR‐silent species (ascorbate and dehydroascorbate) ( Bielski et al ., 1975 ; Kobayashi et al ., 1991 ).…”

Electron paramagnetic resonance as a unique tool for skin and hair research

“…Nevertheless, using the specially shaped surface‐coil‐type resonator (39), the real in vivo EPR experiment is possible, regardless of whether it was performed on normal or pathological skin. Nevertheless, specifically dermatological EPR studies have been performed on all levels of skin organization using skin specimens (40,41), perfused skin flaps (42), biopsies (43,44), homogenates (45,46) and skin cells cultured in vitro (47,48). Finally EPR studies on model liposomes (49) and biological membranes (50), although in fact expanding beyond the strictly understood field of interest, are often intuitively associated with dermatology and cosmetology.…”

“…In dermatology, EPR spectroscopy of free radicals as serving to estimate the general redox state in vivo (81) may be used to identify the mechanisms of their production (42–45,64) and utilization (46), to test effective, natural or artificial (79,82,83) antioxidants , to identify potential pro‐oxidants (76,84) and to explore them in therapy , e.g. photodynamic therapy of various skin diseases (85) including tumors (76).…”

Use of Electron Paramagnetic Resonance Spectroscopy to Evaluate the Redox StateIn Vivo

“…Once this is established and the spin traps have been demonstrated to be safe for use in human subjects, this method will have very attractive potential clinical applications. Nonetheless, spin traps have been successfully used on body fluids and tissue samples (27,106). We believe that the future of in vivo spin trapping lies in the hands of chemists who can synthesize spin traps that can result in more persistent radical adducts with greater spectral resolution between different radical adducts, are less toxic, and can accumulate in relevant sites and cell compartments.…”