Damage to liposomal lipids: protection by antioxidants and cholesterol-mediated dehydration
Damage to liposomal lipids: protection by antioxidants and cholesterol-mediated dehydration
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DOI：
10.1016/s0009-3084(99)00136-x
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发表时间：
2000-04-01
影响因子：
3.4
通讯作者：
Barenholz, Y
中科院分区：
文献类型：
--
作者：
Samuni, AM;Lipman, A;Barenholz, Y
研究了卵磷脂酰胆碱(EPC)(13.4%的酰基链为多不饱和脂肪酸(PUFA))和EPC/胆固醇(10：1摩尔/摩尔)组成的脂质体在长期(16个月)储存过程中影响脂类氧化损伤和水解性的因素。研究的因素包括：(1)脂/水界面水合程度，与脂双层中胆固醇的存在有关；(2)膜相关抗氧化剂维生素E；(3)水溶性抗氧化剂Tempoll；以及(4)暴露在光下。脂质体分散体在室温下储存，暴露在日光下或避免日光照射，为期16个月。在几个时间点监测化学和物理变化，以评估脂质体的氧化和水解性降解。本研究的结论是：(1)多不饱和脂肪酸是脂质体双层中对氧化降解损伤最敏感的成分；(2)EPC脂质体在储存过程中比EPC/胆固醇脂质体更容易降解，胆固醇的存在对脂双层具有保护作用，可能是由于其减少了脂双层的水化；(3)氧化降解是长期储存过程中的主要过程，发生的时间早于水解降解；(4)坦普尔对EPC脂质体PUFA的长期储存具有明显优于维生素E的保护作用。讨论了胆固醇作为干燥剂存在于含有多不饱和脂肪酸的膜中与生物膜对氧化损伤的抵抗力的相关性。(C)2000爱思唯尔爱尔兰科学有限公司。保留所有权利。
Liposomes composed of egg phosphatidylcholine (EPC) (13.4% of the acyl chains being polyunsaturated fatty acids (PUFA)) and EPC/cholesterol (10:1 mol/mol) were studied for factors that affect liposomal lipid oxidative damage and hydrolysis upon long-term (16 months) storage. Factors studied include: (1) levels of lipid/water interface hydration, related to the presence of cholesterol in the lipid bilayer; (2) the membrane-associated antioxidant vitamin E; (3) the water-soluble antioxidant Tempol; and (4) exposure to light. Liposomal dispersions were stored at room temperature, either exposed to or protected from daylight, for a period of 16 months. Chemical and physical changes were monitored at several time points to assess oxidative and hydrolytic degradation of liposomal lipids. The conclusions of the study are: (1) PUFA are the most sensitive component of the liposome bilayer to oxidative degradation damage during long-term storage; (2) EPC liposomes are more sensitive to degradation during storage than EPC/cholesterol liposomes, the presence of cholesterol in the lipid bilayer having a protective effect, probably due to its effect in decreasing the lipid-bilayer hydration; (3) oxidative degradation is the major process during long-term storage, having an earlier onset than the hydrolytic degradation; and (4) Tempol provided significantly better protection than vitamin E to EPC liposomal PUFA against oxidative damage during long-term storage. The relevance of cholesterol's presence, as a 'drying agent', in membranes containing PUFA to resistance of biological membranes to oxidative damage is discussed. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.