DIPALMITOYLPHOSPHATIDYLCHOLINE LINOLEIC ACID MIXED UNILAMELLAR VESICLES AS MODEL MEMBRANES FOR STUDIES ON NOVEL FREE-RADICAL SCAVENGERS/

Large unilamellar vesicles (LUVs) are generally accepted to be a suita ble model for peroxidation studies. In the present report, dipalmitoyl phosphatidylcholine (DPPC)/linoleic acid-mixed LUVs were employed as m odel membranes to verify the inhibitory effect of tocopherol (an effic ient representative antioxidant) against ,2'-azobis(2-amidinopropane)- hydrochloride-induced peroxidation (evaluated by monitoring conjugated diene accumulation). In this model, the appropriate experimental cond itions (particularly, liposome composition and peroxidation temperatur e) were selected following characterization of bilayer physical state, and not only by evaluation of peroxidation rate. Thus, the experiment s described provide a routine screening procedure that would be approp riate for assessing the activity profile of novel free-radical scaveng ers. (C) 1997 Elsevier Science Inc.