Aldini G, Piccoli A, Beretta G, Morazzoni P, Riva A, Marinello C, Maffei Facino R
Istituto Chimico Farmaceutico Tossicologico, Facoltà di Farmacia, Università degli Studi di Milano, Abruzzi, Italy.
Fitoterapia. 2006 Feb;77(2):121-8. doi: 10.1016/j.fitote.2005.11.010. Epub 2006 Jan 6.
The antioxidant profile of extracts from solid olive residue (SOR) of c.v. Coratina, a cultivar widely diffused in the south of Italy, using both cell-free and cell-based experimental models, was investigated. A total hydroalcoholic extract (polyphenols content 19.7%) and a purified extract (Oleaselecttrade mark) (polyphenols content 35.1%) were tested for their ability to quench the stable free radical DPPH, the peroxyl radicals (ORAC assay), by monitoring the loss in fluorescence of R-phycoerythrin induced by the peroxyl radical generator AAPH and their ability to inhibit the cumene hydroperoxide-induced lysis of rat red blood cells (RBC). The total hydroalcoholic extract showed IC(50) 26.96+/-1.53 microg/ml in the DPPH assay, that 10 microg/ml were equivalent to 2.11+/-0.12 microg/ml Trolox (ORAC assay) and IC(50) 1.7+/-0.20 microg/ml in the RBC hemolysis. The Oleaselect extract was 4 to 5 folds more active than the hydroalcoholic extract in all the experimental models, with IC(50) values of 7.36+/-0.38 microg/ml in the DPPH test and of 0.38+/-0.03 microg/ml in RBC; the antioxidant activity in the ORAC assay was slightly greater than that of Trolox (10 microg/ml equivalent to 11.45+/-0.40 microg/ml). The scavenging effect of the extract in the ORAC assay was compared to that of verbascoside (the main polyphenol component) and of caffeic acid (the basic constituent of verbascoside): the results indicate that caffeic acid (10 microg/ml equivalent to 35.70+/-2.95 microg/ml Trolox) is more potent than verbascoside (10 microg/ml equivalent to 15.42+/-1.21 microg/ml Trolox) in entrapping peroxyl radicals. Finally the antioxidant activity of the Oleaselect extract was confirmed in human umbilical endothelial cells (EC) exposed to the site-specific peroxyl radical inducer AAPH, where a massive lipid peroxidation process (marker the fluorescence probe BODIPY) takes place, paralleled by a marked loss of cell viability (calcein assay). The purified extract (1-20 microg/ml) pre-incubated with EC for 1 h dose-dependently inhibited both the lipid-peroxidation damage and cell death. Taking into account the total polyphenol content, these results clearly indicate a greater antioxidant activity for the purified extract, due to a cooperative antioxidant interaction among its polyphenol constituents.
使用无细胞和基于细胞的实验模型，对意大利南部广泛种植的科拉蒂纳（Coratina）品种固体橄榄渣（SOR）提取物的抗氧化特性进行了研究。测试了一种总水醇提取物（多酚含量19.7%）和一种纯化提取物（Oleaselect商标）（多酚含量35.1%）淬灭稳定自由基DPPH、过氧自由基（ORAC测定）的能力，通过监测过氧自由基引发剂AAPH诱导的藻红蛋白荧光损失以及它们抑制氢过氧化异丙苯诱导的大鼠红细胞（RBC）裂解的能力。总水醇提取物在DPPH测定中的IC(50)为26.96±1.53微克/毫升，在ORAC测定中10微克/毫升相当于2.11±0.12微克/毫升Trolox，在RBC溶血试验中的IC(50)为1.7±0.20微克/毫升。在所有实验模型中，Oleaselect提取物的活性比水醇提取物高4至5倍，在DPPH试验中的IC(50)值为7.36±0.38微克/毫升，在RBC试验中为0.38±0.03微克/毫升；在ORAC测定中的抗氧化活性略高于Trolox（10微克/毫升相当于11.45±0.40微克/毫升）。将提取物在ORAC测定中的清除效果与毛蕊花糖苷（主要多酚成分）和咖啡酸（毛蕊花糖苷的基本成分）的清除效果进行了比较：结果表明，咖啡酸（10微克/毫升相当于35.70±2.95微克/毫升Trolox）在捕获过氧自由基方面比毛蕊花糖苷（10微克/毫升相当于15.42±1.21微克/毫升Trolox）更有效。最后，在暴露于位点特异性过氧自由基诱导剂AAPH 的人脐静脉内皮细胞（EC）中证实了Oleaselect提取物的抗氧化活性，在该细胞中发生了大量脂质过氧化过程（荧光探针BODIPY为标志物），同时细胞活力显著丧失（钙黄绿素测定）。与EC预孵育1小时的纯化提取物（1 - 20微克/毫升）剂量依赖性地抑制了脂质过氧化损伤和细胞死亡。考虑到总多酚含量，这些结果清楚地表明纯化提取物具有更高的抗氧化活性，这归因于其多酚成分之间的协同抗氧化相互作用。
