Effects of the Divalent Metal Ions on Lecithin Liposomes

The mechanism of participation of MnCl₂, ZnCl₂, CdCl₂ and PbCl₂ salts in different stages of lipid peroxidation (LP) processes in liposomes formed from natural lipids (lecithin of soybeans) in distilled water was studied, using mathematical processing of UV-spectra of liposomes and their mixtures of metal ions by the Gauss method in combination with the study of the effect of metal ions on spontaneous aggregation of liposomes (dynamic light scattering method) and the intensity of bacterial bioluminescence. While all metal ions at the studied concentration of 10^–4 mol/L are considered as damaging substances for biological systems, the degree of toxicity of both pollutants (Pb²⁺ and Cd²⁺) and biogenic manganese and zinc ions is due to differences in their participation in the regulation of LP processes. Thus, the biological effectiveness of Cd²⁺ is mainly related to its ability to initiate LP. The Pb²⁺ affects its inhibitory effect on LP by forming complexes with the polar groups of phospholipids, the diene conjugates, and the ketodiene fatty acids found within liposomes. Mn²⁺ inhibits LP by forming complexes with ketodiene fatty acids and phosphate groups of phospholipids, while Zn²⁺ affects the structural state of liposomes by forming complexes with phosphate groups of phospholipids and diene conjugates.