Electron Spin Resonance of Eumelanin From Hair: Photoinduced Radicals in Solid Matrix

Bibang, René; Arnaud, René; Lemaire, Jácques; Deflandre, André; Lang, Gérard

doi:10.1111/j.1600-0749.1989.tb00226.x

Cited by 4 publications

(3 citation statements)

References 25 publications

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“…There are two types of melanin in hair: eumelanin, which gives a brown or black hue, and pheomelanin, which gives a yellow, orange‐red hue. Melanin in hair serves to protect the body against ultraviolet (UV) and visible radiation by absorbing [1–3] them. It is known that melanin contains stable semiquinone‐like free radicals with g = 2.0037 иΔH = 0.5 mTl.…”

Section: Introductionmentioning

confidence: 99%

ESR study of photoinduced free radicals by visible light in hair and the effects of ascorbic acid (vitamin C)

Chikvaidze

Khachatryan

2011

Intern J of Cosmetic Sci

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The ESR spectra of melanin's free radicals in natural black and red hair have been investigated. It is shown that the ESR spectrum of black hair is slightly asymmetric singlet with g=2.0037 and ΔH=0.5 mTl. The ESR spectrum of red hair with g=2.0053 differs from the spectrum of black hair. Using the method of saturation was shown that ESR spectrum of red hair represents a superposition of two signals: a singlet, relating to the black hair, and a triplet from red hair's pheomelanin. Under the influence of visible light (blue with λ(max) =450 nm, green with λ(max) =510 nm and red with λ(max) =650 nm) in both types of hair (black and red), the photoinduced free radicals appear, which indicates an increase in the intensity of already existing ESR spectrum of hair. It should be noted that the ESR spectra of red hair from various donors are different. The antioxidant ascorbic acid (vitamin C) has the different effect on the photoinduced free radicals. In particular, in the case of black hair, the concentration of photoinduced free radicals is slightly reduced, whereas in red hair, the disappearance of the triplet in the spectrum is observed, and at the same time, the spectrum becomes a singlet, the intensity of which increases sharply. It is assumed that the antioxidants, effective for black hair, may be ineffective for red hair and vice versa. Therefore, in each, specific case is necessary to investigate the effectiveness of an antioxidant separately.

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Section: Introductionmentioning

confidence: 99%

ESR study of photoinduced free radicals by visible light in hair and the effects of ascorbic acid (vitamin C)

Chikvaidze

Khachatryan

2011

Intern J of Cosmetic Sci

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“…In the previous article of this series, (Bibang et al, 1989) the following attributions have been proposed:…”

Section: Introductionmentioning

confidence: 99%

Electron Spin Resonance Study of Photoinduced Radicals in Various Eumelanins in Solid Matrix

Bibang

Arnaud

Lemaire

et al. 1989

Pigment Cell Research

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“…4b) pieces of tumor tissue ex vivo , and even on paraffin‐embedded sections of tumor taken from microscopic slides (155), up to EPRI employing melanin as the contrast agent (54,156). EPR is here a priceless tool to investigate the induction of skin melanoma by UV, starting with UV dosimetry (157), through mechanisms of melanoma induction by melanin radicals (158), mechanisms of induction and dynamics of melanoma pigmentation (6,51,52) and the role of melanin in melanoma therapy (159), up to study on preventive activity of some UV screens in melanoma induction (160).…”

Section: Key Problems In Skin Research As Targets Of Epr Techniquesmentioning

confidence: 99%

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

Płonka

2009

Experimental Dermatology

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Electron paramagnetic resonance (EPR) spectroscopy and imaging (EPRI) are deeply rooted in the basic and quantum physics, but the spectrum of their applications in modern experimental and clinical dermatology and cosmetology is surprisingly wide. The main aim of this review was to show the physical foundation, technical limitations and versatility of this method in skin studies. Free radical and metal ion detection, EPR dosimetry, melanin study, spin trapping, spin labelling, oximetry and NO-metry, EPR imaging, new generation methods of EPR and EPR ⁄ NMR hybrid technology used under ex vivo and in vivo regime are portrayed in the context of clinical and experimental skin research to study problems such as oxidative and nitrosative stress generated by UV or inflammation, skin oxygenation, hydration of corneal layer of epidermis, transport and metabolism of drugs and cosmeceutics, skin carcinogenesis, skin tumors and many others. A part of the paper is devoted to hair and nail research. The review of dermatological applications of EPR is supplemented with a handful of advice concerning practical aspects of EPR experimentation and usage of EPR reagents.

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Electron Spin Resonance of Eumelanin From Hair: Photoinduced Radicals in Solid Matrix

Cited by 4 publications

References 25 publications

ESR study of photoinduced free radicals by visible light in hair and the effects of ascorbic acid (vitamin C)

ESR study of photoinduced free radicals by visible light in hair and the effects of ascorbic acid (vitamin C)

Electron Spin Resonance Study of Photoinduced Radicals in Various Eumelanins in Solid Matrix

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

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