Zhang Jingli, Stanley Roger A, Melton Laurence D
The Horticulture and Food Research Institute of New Zealand Ltd., Private Bag 92169, Auckland, New Zealand.
Mol Nutr Food Res. 2006 Aug;50(8):714-24. doi: 10.1002/mnfr.200600018.
An in vitro antioxidant assay has been developed to better reflect the in vivo conditions of antioxidants interacting with membrane and lipid surfaces. The lipid peroxidation inhibition capacity (LPIC) method measures the ability of both lipophilic and hydrophilic antioxidants to protect a lipophilic fluorescent probe 4, 4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undecanoic acid, incorporated in the membrane, from 2,2'-azobis(2-amidinopropane)hydrochloride generated radicals in the surrounding aqueous solution. Antioxidant activities of test compounds were measured either after they were mixed with preformed liposomes (LPIC(Mixed)) or after they were incorporated into liposomes (LPIC(Inco)) as they were made. The results were analysed to determine how the method of mixing and the structures of the antioxidants influenced their protection of the membrane from free radical attack. The LPIC(Mixed) values were larger than the LPIC(Inco) values for a range of 12 structurally diverse antioxidant compounds. However, there was no linear correlation between the lipophilicities, as measured by their partition coefficient, log P and either LPIC(Inco) or LPIC(Mixed) values. A strong correlation was found between LPIC(Inco) and LPIC(Mixed) values.
已开发出一种体外抗氧化剂测定方法，以更好地反映抗氧化剂与膜和脂质表面相互作用的体内条件。脂质过氧化抑制能力（LPIC）方法测量亲脂性和亲水性抗氧化剂保护掺入膜中的亲脂性荧光探针4,4-二氟-5-（4-苯基-1,3-丁二烯基）-4-硼-3a,4a-二氮杂-s-茚满-3-十一烷酸免受周围水溶液中2,2'-偶氮二（2-脒基丙烷）盐酸盐产生的自由基影响的能力。测试化合物的抗氧化活性在它们与预先形成的脂质体混合后（LPIC（混合））或在它们形成时掺入脂质体后（LPIC（掺入））进行测量。分析结果以确定混合方法和抗氧化剂的结构如何影响它们对膜免受自由基攻击的保护作用。对于一系列12种结构不同的抗氧化化合物，LPIC（混合）值大于LPIC（掺入）值。然而，通过它们的分配系数log P测量的亲脂性与LPIC（掺入）或LPIC（混合）值之间没有线性相关性。在LPIC（掺入）和LPIC（混合）值之间发现了很强的相关性。
