Research on free radicals by the method of Electronic Paramagnetic Resonance (EPR) and skin protection from ultraviolet radiation

Author: ia begiashvili
Keywords: pheomelanin, eumelanin, method of EPR.
Annotation:

It is of great importance in dermatology and cosmetology to determine the amount of pheomelanin in human skin and hair for the prevention and cure of such severe diseases as various kinds of eczema, vitiligo, melanoma and etc. which are caused by ultraviolet radiation. The purpose of the research is to find the antioxidant which is capable of neutralizing the harmful free radical of pheomelanin. Therefore we studied the influence of the antioxidant ascorbic acid on both black and auburn hair (so called ginger/red hair). The goal of our experiment is to study the existing free radicals in natural auburn hair of humans. The use of EPR method defined the existence of two types of EPR range which represents the triple spectra superposition of eumelanin, singlet and pheomelanin. By saturating auburn hair EPR spectrum with microwave power we detected the triplet of pheomelanin EPR spectrum and measured its options: g=2,005, ∆H=0,372mtl The EPR spectrum of eumelanin free radical is singlet g=2,0035. As well as this, the EPR spectrum g exsp factor of auburn hair of various donors differs, which is caused by the different ratio of amount of pheomelanin to eumelanin in their hair.g exsp is defined: g_x = (g_(3*) g_4)/(g_4+[g_3 〖-g〗_4 ] ) By the impact of daylight with different wave length, additional free radicals generate in hair whose EPR spectrum attaches to the EPR spectrum of already existing radicals (eumelanin and pheomelanin) in it. The kinetics of radicals in both black and auburn hair is measured with light (blue, green and red).The influence of the antioxidant ascorbic acid (vitamin C) on both black and auburn hair EPR spectrum is already investigated. In the case of Black Hair, vitamin C reveals antioxidant features, while in auburn hair .the characteristic of pheomelanin EPR spectrum completely disappears and oxidized ascorbic acid EPR spectrum is formed, it attaches to the spectrum of eumelanin, which causes the growth of EPR spectrum intensity. So ascorbic acid with its powerful reconstructive quality neutralizes the free radical of pheomelanin and the EPR spectrum of the free radical that is formed by oxidizing ascorbic acid attaches to the spectrum of eumelanin, which causes the expansion of general spectrum intensity.

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