Effect of UV-irradiated fatty acids on the spectral properties of myoglobin

Abstract

The efficiency of free radical oxidation of higher fatty acids (palmitic, oleic, linoleic, linolenic acids, complex of unsaturated fatty acids of omega-3 and omega-6 plant origin) under the influence of UV irradiation (λ = 180-400 nm) as a possible marker of lipid peroxidation is studied. Micelles of fatty acids (FA) in ethyl alcohol were used as a model of the lipid phase. The effect of UV irradiation on fatty acids was determined from the spectral changes of myoglobin in the region of the Soret band. The level of peroxide oxidation of the lipid phase at the same time was estimated from the accumulation of malonic dialdehyde as a well-known product of irradiation of phospholipids. The direct proportional dependence of the intensity of the difference spectrum of Mb (ΔD) on the number of double bonds in the molecule of oxidized fatty acids, as well as on the time of their UV irradiation and the accumulation of secondary LPO products is obtained. This shows that the spectral changes of Mb under the action of the pool of oxidized forms of fatty acids correlate well with the level of lipid phase peroxidation and can characterize the antioxidant potential of the blood when combined with the known antioxidant Trolox as a calibrator-inhibitor. Communicated by Corresponding Member Sergei A. Usanov