怀疑自由基和氧反应物质的过量产生与广泛的代谢反应有关,这些代谢反应可能对各种人类疾病的发展产生有害影响。植物提取物是对抗自由基和氧反应性物质的抗氧化剂的来源。植物提取中使用的加工条件可能会影响抗氧化剂组合物;因此,来自同一植物的不同提取物可能具有不同的抗氧化特性。为了说明这个事实,我们使用三种商业迷迭香(迷迭香)叶提取物进行了研究。这三种提取物被标准化以包含,分别,20%鼠尾草酸,40%熊果酸,或20%迷迭香酸.评估了它们对氧自由基吸收能力(ORAC)的总(亲水亲脂)抗氧化作用,它们的铁还原/抗氧化能力(FRAP),以及它们体外抑制Cu(2)诱导的低密度脂蛋白(LDL)氧化的能力。熊果酸提取物在所有模型中显示出最低的抗氧化能力。迷迭香酸提取物在ORAC上的抗氧化能力比鼠尾草酸提取物高1.5倍,在FRAP上的抗氧化能力高4倍。然而,鼠尾草酸提取物在体外抑制LDL氧化方面优于迷迭香酸提取物。这些结果鼓励进行进一步的研究以在体内评估鼠尾草酸和迷迭香酸提取物。我们的研究提供了提取程序重要性的一个例子,取决于抗氧化剂组合物的性质,并强调了进行体外/离体测定选择以评估植物提取物的抗氧化特性的兴趣。
The overproduction of free radicals and oxygen reactive species is suspected to be implicated in a wide range of metabolic reactions that can have pernicious consequences in the development of a variety of human diseases. Botanical extracts are sources of antioxidants that counteract both free radicals and oxygen reactive species. The processing conditions used in the botanical extraction may influence the antioxidant composition; therefore, different extracts from the same plant may have different antioxidant properties. To illustrate this fact, we conducted a study using three commercial rosemary (
Rosmarinus officinalis L.) leaf extracts. The three extracts were standardized to contain, respectively, 20% carnosic acid, 40% ursolic acid, or 20% rosmarinic acid. They were evaluated for their total (hydrophilic + lipophilic) antioxidant effects on oxygen radical absorbance capacity (ORAC), their ferric reducing/antioxidant power (FRAP), and their capacity to inhibit Cu(2+)-induced low-density lipoprotein (LDL) oxidation ex vivo. The ursolic acid extract showed the lowest antioxidant capacity on all models. The rosmarinic acid extract had an antioxidant capacity 1.5 times higher on ORAC and four times higher on FRAP than the carnosic acid extract. However, the carnosic acid extract was better than the rosmarinic acid extract in inhibiting the oxidation of LDL ex vivo. These results encourage conducting further studies to evaluate the carnosic acid and rosmarinic acid extracts in vivo. Our study offers an example of the importance of the extraction procedures, on which depends the nature of the antioxidant composition, and highlights interest to proceed with in vitro/ex vivo assay selection for the evaluation of the antioxidant properties of botanical extracts.