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.