Quantitative evaluation of oxidative stability of biomembrane lipids in the presence of vitamin E.

In this report, the oxidation of biomembrane lipids, phospholipid and cholesterol (ChH), was examined experimentally in the presence of vitamin E (VEH) by using a liposome system, which is widely used as a biomembrane model. A kinetic model was constructed by taking into account mechanisms of antioxidation and pro-oxidation by VEH and the co-oxidation mechanisms of biomembrane lipids reported previously. The model quantitatively described oxidation behavior in the liposome system under various VEH addition conditions. The model also predicted oxidation behavior in vivo under various oral ingestion conditions of VEH. The results suggest that ChH oxidation, which causes various diseases, can be suppressed effectively by taking a certain amount of VEH once a day to avoid a reduction in the VEH concentration present in the biomembrane. The proposed kinetic approach should be a useful tool for quantitatively characterizing complicated reaction systems, such as biomembrane oxidation.