Kolodziejczyk-Czepas Joanna, Nowak Pawel, Moniuszko-Szajwaj Barbara, Kowalska Iwona, Stochmal Anna
Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz , Lodz , Poland and.
Pharm Biol. 2015;53(9):1277-84. doi: 10.3109/13880209.2014.974064. Epub 2015 Apr 9.
Three clover [Trifolium L. (Leguminosae)] species were selected on the basis of data from traditional medicine, phytochemical profiles, and agricultural significance.
The in vitro evaluations of free radical scavenging properties, ferric reducing abilities, and antioxidant effects of extracts from T. pratense L. (crude extract and phenolic fraction), T. pallidum L., and T. scabrum L. (phenolic fractions) were performed.
Activities of the Trifolium extracts were determined at their final concentrations of 1.5-50 µg/ml. Free radical scavenging properties of methanol extract solutions were estimated by the reduction of DPPH(•) and ABTS(•) radicals. Measurements of the total antioxidant capacity (TAC) were carried out to assess the antioxidant activities of the extracts in human blood plasma under conditions of oxidative stress, induced by 200 μM peroxynitrite.
The phenolic fraction of T. pratense displayed the strongest ABTS(•) and DPPH(•) radical scavenging effects (EC50 value of 21.69 and 12.27 µg/ml, respectively). The EC50 value for T. pallidum extract attained 29.77 and 30.06 µg/ml. The two remaining extracts were less potent scavengers (EC50 value higher than 50 µg/ml). Similar differences were obtained during evaluation of the ferric reducing abilities. Analysis of antioxidant properties of the extracts in blood plasma did not provide such evident differences in their actions, however, it indicated that the T. pratense phenolic fraction displayed the strongest effect.
The examined Trifolium extracts partly protected blood plasma and enhanced its non-enzymatic antioxidant defense against harmful action of peroxynitrite in vitro.
根据传统医学数据、植物化学特征和农业重要性，选择了三种三叶草[车轴草属（豆科）]物种。
对草地车轴草（粗提物和酚类组分）、苍白车轴草和粗糙车轴草（酚类组分）提取物的自由基清除特性、铁还原能力和抗氧化作用进行体外评估。
车轴草提取物在终浓度为1.5 - 50μg/ml时测定活性。通过DPPH(•)和ABTS(•)自由基的还原作用评估甲醇提取物溶液的自由基清除特性。在由200μM过氧亚硝酸盐诱导的氧化应激条件下，测量总抗氧化能力（TAC）以评估提取物在人血浆中的抗氧化活性。
草地车轴草的酚类组分表现出最强的ABTS(•)和DPPH(•)自由基清除作用（EC50值分别为21.69和12.27μg/ml）。苍白车轴草提取物的EC50值达到29.77和30.06μg/ml。其余两种提取物的清除能力较弱（EC50值高于50μg/ml）。在评估铁还原能力时也获得了类似的差异。然而，对血浆中提取物抗氧化特性的分析并未显示出它们作用上的明显差异，但表明草地车轴草酚类组分的作用最强。
所检测的车轴草提取物在体外部分保护了血浆，并增强了其对过氧亚硝酸盐有害作用的非酶抗氧化防御能力。
