ИСТИНА

Lipid peroxidation (LPO) is causative for pathogenesis of many diseases, including neurodegenerative and inflammatory processes. To suppress LPO, it has recently been proposed to use polyunsaturated fatty acids (PUFAs) containing deuterium atoms instead of protons at bis-allylic positions (D-PUFAs). The presence of less than 20% D-PUFA in the total amount of PUFA was shown to completely stop LPO in yeast cells under oxidative stress. Here, we report results of studying the impact of phospholipids containing D-PUFAs on LPO in model bilayer lipid membranes by using two approaches: 1) monitoring diene conjugates in liposomal membranes and 2) measuring permeabilization of liposomes. The latter was estimated with the fluorescence correlation spectroscopy method from changes in the amplitude of the autocorrelation function of liposomes loaded with the fluorescent dye sulforhodamine B. Both approaches revealed a strong protective action of small amounts of deuterated PUFA against LPO in bilayer membranes. The extent of protection depended on the nature of D-PUFAs, being determined predominantly by the total level of deuterated bis-allylic (CD2) groups. For each D-PUFA, there was found a threshold percentage (about 20-25% for 1-acyl-2-(11,11-D2-linoleyl)-sn-glycero-3-phosphatidylcholine and much less for 1-acyl-2-(6,6,9,9,12,12,15,15,18,18-D10-docosahexaenoyl)-sn-glycero-3-phosphatidylcholine) in the H-PUFA matrix that inhibited LPO, which could be attributed to an ability of D-PUFA-derived radicals to interrupt LPO chain reactions in a lipid bilayer. The protecting effect of D-PUFAs was compared to the action of various free-radical scavengers, e.g. trolox. This work was supported by the Russian Science Foundation grant 19-74-00015.