P18: Influence of vitamin C on alcohol binding to phospholipid monolayers

The mechanism of toxic effect of chronic ethanol uptake has been studied intensively. The simple model of the biological membrane is provided by well-controlled lipid monolayers at the air–water interface. The Maxwell displacement current technique (MDC) provides a novel approach to confirm studies of the membrane models. Aim of this study is the observation of changes in structural, electrical and mechanical properties of dipalmitoyl-phosphatidylcholine (DPPC) monolayer on the subphase of methanol–water and ethanol–water mixtures after addition of an antioxidant agent, vitamin C. Surface pressure–area isotherms show similar behavior of the DPPC monolayer on alcohol–water mixtures independently from the presence of vitamin C. Binding/adsorption process induces change of electron density distribution across monolayer and thus the molecular dipole moment. We observe small or negligible binding of methanol molecules on oxygen bonds of DPPC. From these results, different protective effects of vitamin C as antioxidant can be drawn.