Electron Spin Resonance Detection of UVA-Induced Free Radicals

Herrling, T.; Zastrow, L.; Fuchs, Jürgen; Groth, Norbert

doi:10.1159/000064545

Cited by 25 publications

(14 citation statements)

References 2 publications

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“…Electron spin resonance (ESR) studies have shown that lipid alkyl and alkoxyl radicals can be generated in skin biopsies following UVA exposure (Jurkiewicz and Buettner, 1996;Herrling et al, 2002). From a different aspect, Packer and coworkers have shown that the cutaneous antioxidant defense system can be impaired by UVA irradiation (Fuchs et al, 1989;Thiele et al, 1999).…”

Section: Discussionmentioning

confidence: 99%

A Chemiluminescence Study of UVA-Induced Oxidative Stress in Human Skin In Vivo

Ouyang

Stamatas

Saliou

et al. 2004

Journal of Investigative Dermatology

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Oxidative stress is defined as an imbalance between pro-oxidants and antioxidants in favor of pro-oxidants. Photon emission (also called chemiluminescence) has been widely used to study oxidative stress in biological systems in vitro. In vivo chemiluminescence has been proposed as a non-invasive method to assess oxidative stress in the skin. UVA (320-400 nm part of the ultraviolet radiation) exposure is generally accepted as a source of oxidative stress in the skin. In this study, UVA-induced oxidative stress was studied by using an in vivo chemiluminescence detection method. First, the dose response and the fluence rate response of the UVA-induced oxidative stress in human skin were investigated by examining the decay kinetics of the chemiluminescence signal following UVA exposure. A kinetic model was proposed to help differentiate these two responses. We found that the initial burst of the chemiluminescence signal depended on the UVA fluence rate, whereas the decay of the signal following exposure can be related to the UVA dose involved. Second, a significant reduction of UVA-induced chemiluminescence signal was observed after tape-stripping, indicating that stratum corneum is a major source of UVA-induced oxidative stress in the skin. Furthermore, the oxygen dependence of UVA-induced chemiluminescence signal was also confirmed by application of a pressure cuff, implying that some of the oxidative stress occurs in the deeper layers of the skin. Finally, topical application of vitamin C before exposure significantly reduced the UVA-induced chemiluminescence signal. We thus conclude that chemiluminescence is an effective method to assess the oxidative stress induced by UVA in human skin in vivo.

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Section: Discussionmentioning

confidence: 99%

A Chemiluminescence Study of UVA-Induced Oxidative Stress in Human Skin In Vivo

Ouyang

Stamatas

Saliou

et al. 2004

Journal of Investigative Dermatology

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“…Radical formation was investigated using UV irradiation, which is known to induce free radicals in the skin [29,30] . EPR measurements were performed before and after 3, 6 and 9 min of UV irradiation of the skin.…”

Section: Radical Formation Induced By Uv Irradiationmentioning

confidence: 99%

Comparative Study of Carotenoids, Catalase and Radical Formation in Human and Animal Skin

Haag

Bechtel²,

Darvin³

et al. 2010

Skin Pharmacol Physiol

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Animal skin is widely used in dermatological free radical research. Porcine ear skin is a well-studied substitute for human skin. The use of bovine udder skin is rare but its high carotenoid content makes it particularly appropriate for studying the redox state of the skin. Yet, information on the suitability of animal skin for the study of external hazard effects on the redox state of human skin has been lacking. In this study, we investigated the activity of the antioxidant enzyme catalase and the carotenoid content defining the redox status as well as UV-induced radical formation of human, porcine ear and bovine udder skin ex vivo. In human skin only low levels of radical formation were detected following UV irradiation, whereas bovine skin contains the highest amount of carotenoids but the lowest amount of catalase. Porcine ear skin does not exhibit a carotenoid signal but its catalase activity is close to human skin. Therefore, radical formation can neither be correlated to the amount of catalase nor to the amount of carotenoids in the skin. All skin types can be used for electron paramagnetic resonance-based detection of radicals, but porcine skin was found to be the most suitable type.

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“…Electron paramagnetic resonance (EPR) spectroscopy can be used to measure radical formation in the skin ex vivo as well as in vivo . So far, most of the investigations applying irradiation have been performed ex vivo . Only very few measurements could be found on single volunteers in vivo , because the major problem is to conduct reproducible measurements before and after irradiation when an external irradiation source is used.…”

Section: Introductionmentioning

confidence: 99%

Radical protection in the visible and infrared by a hyperforin‐rich cream – in vivo versus ex vivo methods

Arndt

Haag

Kleemann

et al. 2013

Experimental Dermatology

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The formation of radicals plays an important role in the development of atopic eczema or barrier-disrupted skin. We evaluated the radical scavenging effect of a cream containing a Hypericum perforatum extract rich in hyperforin in a double-blind placebo-controlled study on 11 healthy volunteers. Electron paramagnetic resonance spectroscopy was applied to determine radical formation during VIS/NIR irradiation of the inner forearm. The results were compared to ex vivo investigations on excised porcine ear skin after a single application of the creams. The non-treated skin was measured as control. The absolute values and the kinetics are not comparable for ex vivo and in vivo radical formation. Whereas in vivo, the radical production decreases with time, it remains stable ex vivo over the investigated timescale. Nevertheless, ex vivo methods could be developed to estimate the protection efficiency of creams. In vivo as well as ex vivo, the radical formation could be reduced by almost 80% when applying the hyperforin-rich cream onto the skin, whereas placebo resulted in about 60%. In vivo, a daylong protection effect could be validated after a 4-week application time of the cream indicating that a regular application is necessary to obtain the full effect.

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Electron Spin Resonance Detection of UVA-Induced Free Radicals

Abstract: Free radicals generated during UV irradiation of human skin biopsies were measured with electron spin resonance spectroscopy by using spin traps. The generation of hydroxyl and lipid radicals in skin is mainly caused by the UVA part of the solar spectrum.

Cited by 25 publications

References 2 publications

A Chemiluminescence Study of UVA-Induced Oxidative Stress in Human Skin In Vivo

A Chemiluminescence Study of UVA-Induced Oxidative Stress in Human Skin In Vivo

Comparative Study of Carotenoids, Catalase and Radical Formation in Human and Animal Skin

Radical protection in the visible and infrared by a hyperforin‐rich cream – in vivo versus ex vivo methods

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