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Regarding free genistein small delivery to the central nervous system, physico-chemical parameters of dimiristoylphosphatidylcholine liposome-loaded genistein were investigated, as well as its in vitro activity against the DPPH radical and glioma cells. Data obtained by UV-vis spectroscopy, Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance, Differential Scanning Calorimetry and Dynamic Light Scattering were used to characterize the liposomal system with respect to motion restriction, hydration degree, trans-gauche isomerization and phase state. In vitro antitumoral effects were monitored through conting and viability assays. Genistein hydroxyl group and lipid hydrogen bonds may have important role in dimiristoylphosphatidylcholine phosphate and choline motion restriction. Genistein-induced choline restriction may be also related to a decrease in the group rotation rate. Genistein: dimiristoylphosphatidylcholine system showed higher molecular package at the acyl chains region compaired to empty liposomes, and it may be related to a decrease in gauche bonds quantity and system size. Lipid acyl chain length seems to influence different genistein effects on membranes, due to the presence of gauche conformers. Genistein: dimiristoylphosphatidylcholine liposome was more efficient as DPPH reducting system than the free-Gen. Liposomal system, at genistein 100 μM, was so efficient as the correspondent free-form genistein, probably showing higher stability to cross the blood-brain barrier. Genistein and the lipid did not show an additive activity against glioma cells. Antioxidant and anti-glioma genistein-loaded liposome potential may be related to the isoflavone location and its restriction effect in the lipid molecular motion. Anti-glioma activity may also be related to a decrease of system size and trans-gauche isomerization., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this study, the interaction between soy isoflavone genistein and asolectin liposomes was investigated by monitoring the effects of isoflavone on lipidic hydration, mobility, location and order. These properties were analyzed by the following techniques: horizontal attenuated total reflection Fourier transform infrared spectroscopy (HATR-FTIR), low-field (1)H nuclear magnetic resonance (NMR), high-field (31)P NMR, zeta potential, differential scanning calorimetry (DSC) and UV-vis spectroscopy. The antioxidant and antitumoral activities of the genistein liposomal system were also studied. The genistein saturation concentration in ASO liposomes corresponded to 484 μM. HATR-FTIR results indicated that genistein influences the dynamics of the lipidic phosphate, choline, carbonyl and acyl chain methylenes groups. At the lipid polar head, HATR-FTIR and (31)P NMR results showed that the isoflavone reduces the hydration degree of the phosphate group, as well as its mobility. Genistein ordered the lipid interfacial carbonyl group, as evidenced by the HATR-FTIR bandwidth analysis. This ordering effect was also observed in the lipidic hydrophobic region, by HATR-FTIR, NMR, DSC and turbidity responses. At the saturation concentration, liposome-loaded genistein inhibits the lipid peroxidation induced by hydroxyl radical in 90.9%. ASO liposome-loaded genistein at 100 μM decreased C6 glioma cell viability by 57% after 72 h of treatment. Results showed an increase of the genistein in vitro activities after its incorporation in liposomes. The data described in this work will contribute to a better understanding of the interaction between genistein and a natural-source membrane and of its influence on isoflavone biological activities. Furthermore, the antitumoral results showed that genistein-based liposomes, which contain natural-sourced lipids, may be promising as a drug delivery system to be used in the glioma therapy., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)