title: Nutritional aspects of β-carotene and resveratrol antioxidant synergism in giant unilamellar vesicles.
abstract: Giant unilamellar vesicles of soy phosphatidylcholine are found to undergo budding when sensitized with chlorophyll a ([phosphatidylcholine] : [chlorophyll a] = 1500 : 1) under light irradiation (400-440 nm, 16 mW mm(-2)). 'Entropy' as a dimensionless image heterogeneity measurement is found to increase linearly with time during an initial budding process. For β-carotene addition ([phosphatidylcholine] : [β-carotene] = 500 : 1), a lag phase of 23 s is observed, followed by a budding process at an initial rate lowered by a factor of 3.8, whereas resveratrol ([phosphatidylcholine] : [resveratrol] = 500 : 1) has little if any protective effect against budding. However, resveratrol, when combined with β-carotene, is found to further reduce the initial budding rate by a total factor of 4.7, exhibiting synergistic antioxidation effects. It is also interesting that β-carotene alone determines the lag phase for the initiation of budding, while resveratrol supports β-carotene in reducing the rate of the budding process following the lag phase; however, it alone has no observable effect on the lag phase. Resveratrol is suggested to regenerate β-carotene following its sacrificial protection of unsaturated lipids from oxidative stress, modeling the synergistic effects in cell membranes by combinations of dietary antioxidants.
authors.affiliation: Department of Chemistry, Renmin University of China, Beijing 100872, China. rliang06@ruc.edu.cn jpzhang@chem.ruc.edu.cn.
authors.forename: Hui-Jing
authors.initials: HJ
authors.lastname: Wang
authors.forename: Ran
authors.initials: R
authors.lastname: Liang
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Fu
authors.forename: Rui-Min
authors.initials: RM
authors.lastname: Han
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Zhang
authors.forename: Leif H
authors.initials: LH
authors.lastname: Skibsted
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D007091:Image Processing, Computer-Assisted; D008856:Microscopy, Fluorescence; D018384:Oxidative Stress; D010713:Phosphatidylcholines / Q000737:chemistry; D000077185:Resveratrol; D013025:Glycine max / Q000737:chemistry; D013267:Stilbenes / Q000737:chemistry*; D053835:Unilamellar Liposomes / Q000737:chemistry*; D019207:beta Carotene / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010713:Phosphatidylcholines; D013267:Stilbenes; D053835:Unilamellar Liposomes; D019207:beta Carotene; D000077185:Resveratrol