Evaluation of antioxidant capacity of Allium ursinum L. volatile oil and its effect on membrane fluidity

A total of 20 components were identified in Allium ursinum volatile oil (AUVO) by GC-MS, and 10 of them are found for the first time in this plant species. The antioxidant capacity of AUVO was examined by beta-carotene-linoleic acid bleaching, lipid peroxidation by Fenton reaction, EPR spin-probing assay using stable nitroxide radicals, DPPH., and ABTS(.+) scavenging assays. Reaction mechanism of the volatile oil components with nitroxide radicals, based on IR spectra analysis, is proposed. AUVO demonstrated poor scavenging ability against DPPH, and ABTS(.+) comparing to synthetic antioxidants BHT and trolox, while in beta-carotene-linoleic acid system AUVO showed an effect comparable to those for BHT. AUVO was also capable to scavenge stable nitroxide radicals such as water-soluble Tempone, and 7-DS and 12-DS, incorporated into the liposome membrane. Finally, AUVO increased membrane fluidity, which could be an important feature for further in vivo investigation of some disorders, such as hypertension and atherosclerosis. (C) 2007 Elsevier Ltd. All rights reserved.