UV-induced free radicals in the skin detected by ESR spectroscopy and imaging using nitroxides

Herrling, T.; Fuchs, Jürgen; Rehberg, Joachim; Groth, Norbert

doi:10.1016/s0891-5849(03)00241-7

Cited by 151 publications

(94 citation statements)

References 42 publications

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“…The antioxidants react with the spin probe and reduce it to the corresponding EPR silent hydroxylamine. The antioxidant defense system of the skin depletes the radical molecules [36,37]. The decay of the EPR signal intensity can be expressed as a simple exponential function I = I exp(−kt), where k is the rate constant.…”

Section: Technical Aspects Of the Performance Of In Vivo Epr-measuremmentioning

confidence: 99%

“…Often, in vivo experiments display some problems; the reproducibility is often insufficient, most test products are denied official approval and the experiments are difficult to handle, especially when exposure to radiation is involved. Up to now, most irradiation experiments have been performed ex vivo, only a few studies have been conducted on volunteers in vivo [37,72,73]. Taking into consideration the risk of erythema development, the formation of free radicals in the radiation-exposed skin can only be investigated for a limited time, in vivo.…”

Section: Comparison Of In Vivo and Ex Vivo Investigationsmentioning

confidence: 99%

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Determination of the Antioxidant Status of the Skin by In Vivo-Electron Paramagnetic Resonance (EPR) Spectroscopy

et al. 2015

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Organisms produce free radicals which are essential for various metabolic processes (enzymatic oxidation, cellular respiration, signaling). Antioxidants are important chemical compounds that specifically prevent the oxidation of substances by scavenging radicals, especially reactive oxygen species (ROS). Made up of one or two unpaired electrons, ROS are free radicals that are highly reactive and can attack other metabolites. By using electron paramagnetic resonance (EPR) spectroscopy, it is possible to measure paramagnetic substances such as free radicals. Therefore the dermal antioxidant activity can be determined by applying semi-stable radicals onto the skin and measuring the antioxidant-induced radical scavenging activity in the skin. In recent years, EPR has been OPEN ACCESS Cosmetics 2015, 2 287 developed as a spectroscopic method for determining the antioxidant status in vivo. Several studies have shown that an additional uptake of dietary supplements, such as carotenoids or vitamin C in physiological concentrations, provide a protective effect against free radicals. Using the EPR technique it could be demonstrated that the radical production in stress situations, such as irradiation with infrared and visible light, was reduced with time. However, not only the oral uptake of antioxidants, but also the topical application of antioxidants, e.g., a hyperforin-rich cream, is very useful against the development of oxidative stress. Regular application of a hyperforin-rich cream reduced radical formation. The skin lipids, which are very important for the barrier function of the skin, were also stabilized.

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Section: Technical Aspects Of the Performance Of In Vivo Epr-measuremmentioning

confidence: 99%

Section: Comparison Of In Vivo and Ex Vivo Investigationsmentioning

confidence: 99%

Determination of the Antioxidant Status of the Skin by In Vivo-Electron Paramagnetic Resonance (EPR) Spectroscopy

et al. 2015

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“…In this study we explored the use of per-deuterated nitroxide 3-carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCA) 22 as a probe of regional blood flow, to distinguish ischemic and non-ischemic brain tissue after cerebral ischemia in a mouse. The pharmacokinetic information of nitroxide free radical in mouse brain after i.v.…”

Section: Epr Imaging (Epri)mentioning

confidence: 99%

Application of in vivo EPR in brain research: monitoring tissue oxygenation, blood flow, and oxidative stress

et al. 2004

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Although oxygen levels are critical to tissue survival, monitoring tissue oxygen levels in vivo, in real time, remains a technical challenge. This is especially so for repetitive measurements in non-superficial tissue. There currently exist several techniques that can be utilized for tissue oxygen measurement, but technical difficulties have limited their usefulness and general application. Here we describe a relatively new method, electron paramagnetic resonance (EPR) oximetry, for in vivo measurement of brain tissue oxygen, as well as information on blood flow and oxidative stress. In this paper we report experiments designed to assess and illustrate the effectiveness of this new method. Using the unique capability of this approach, we have measured both absolute values and temporal changes of pO 2 in ischemic penumbra and core during cerebral ischemia and reperfusion in a rat model. EPR oximetry with particulate probe sensitively reflected differential changes in oxygenation in the core and penumbra during ischemia, reperfusion and also hyperoxic conditions. Simultaneous two-site detection with particulate probes was also obtained with good spatial resolution. Additionally, EPR measurement of oxidative stress, EPR imaging of brain with nitroxide and triarylmethyl soluble probes are also described. These results demonstrate that EPR oximetry with particulate probe can provide accurate and reproducible measurements of localized pO 2 in the brain, and it is a versatile and useful method in the measurement of tissue pO 2 under a variety of physiological and pathophysiological conditions.

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“…Herrling et al used nitroxides and found them suitable to detect UV generated radicals in human skin biopsies [34]. Our work uses the nitroxides' relatively simple chemistry and almost non-toxic nature to observe quantitatively UV light induced changes in human skin.…”

Section: Influence Of Uv Lightmentioning

confidence: 98%

Electron paramagnetic resonance and mass spectrometry: Useful tools to detect ultraviolet light induced skin lesions on a molecular basis – A short review

Hochkirch¹,

Herrmann²,

Stößer³

et al. 2006

Journal of Spectroscopy

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Abstract. Ultraviolet radiation is considered responsible for sunburning, premature skin aging, and cancerogenesis through the production of free radical species. Therefore, the favoured possibility for direct detection of unpaired electrons -electron paramagnetic resonance spectroscopy -is predestinated for detection and structural and dynamic analysis of this kind of molecules. However, many of UV induced radicals in skin have a short lifetime at ambient conditions and possibilities for stabilisation or transformation into definite para-or diamagnetic products have to be found. On the other hand, diamagnetic products, potentially also originated by reporter molecules, which are not detectable by EPR, are target molecules for mass spectrometric analysis. In this review, potentials and limitations of both spectroscopic methods are reviewed, and the effect of ultraviolet radiation on human skin is discussed in particular. Suitable combinations of both techniques result in detailed information about photoproducts and processes taking place within skin during and after irradiation. The literature is viewed from a recent perspective; historical aspects were not in the scope of this paper.

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UV-induced free radicals in the skin detected by ESR spectroscopy and imaging using nitroxides

Cited by 151 publications

References 42 publications

Determination of the Antioxidant Status of the Skin by In Vivo-Electron Paramagnetic Resonance (EPR) Spectroscopy

Determination of the Antioxidant Status of the Skin by In Vivo-Electron Paramagnetic Resonance (EPR) Spectroscopy

Application of in vivo EPR in brain research: monitoring tissue oxygenation, blood flow, and oxidative stress

Electron paramagnetic resonance and mass spectrometry: Useful tools to detect ultraviolet light induced skin lesions on a molecular basis – A short review

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