蓝莓叶不同溶剂提取物抗氧化活性研究

Antioxidant activities of different solvent extracts from Vaccinium blueberry leaves

研究蓝莓叶不同溶剂提取物中总酚和黄酮的含量以及抗氧化活性。分别用水、甲醇、乙醇、乙酸乙酯、氯仿、石油醚等不同极性溶剂提取蓝莓叶中的活性物质,采用Folin-Cioeaile法、三氯化铝显色法分别测定不同提取物中总酚和黄酮的含量;应用1,1-二苯基-2-三硝基苯肼(DPPH)自由基和2,2-联氮基双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基清除体系及β-胡萝卜素-亚油酸体系评价其抗氧化活性,考察活性物质含量与抗氧化活性的关系。结果表明,蓝莓叶提取物的抗氧化活性随提取溶剂极性的减小而减小。水提取物具有较强的抗氧化活性,其清除DPPH·和ABTS+·的EC50分别为(12.78±0.10)、(6.35±0.03)μg/mL,抑制β-胡萝卜素淬灭IC50值为(25.33±0.02)μg/mL。含量测定显示水提物中总酚含量最高,为(264.67±0.29)mg/g,而甲醇提取物中黄酮含量最高,为(68.94±0.08)mg/g,相关性分析表明,不同溶剂提取物抗氧化能力差别较大,总酚和黄酮含量与抗氧化能力具有相关性,提示水可作为蓝莓叶抗氧化活性物质提取的优选溶剂,而总酚和黄酮含量可作为蓝莓叶抗氧化提取物的质量评价指标。

The objective of this study was to explore the in vitro antioxidant activities and the active compounds contents of different solvent extracts from Vaccinium blueberry leaves. The Vaccinium blueberry leaves were extracted with distilled water ,methanol ,ethanol ,ethyl acetate,chloroform and petroleum ether,respectively. The contents of total phenolics and flavonoids in different extracts were detected by the Folin-Ciocalie method and the aluminium trichloride colorimetry method. Meanwhile,the antioxidant activity and the anti-lipid peroxidation activity of extracts from blueberry leaves were investigated by 1,1-diphenyl-2- picrylhydrazyl（DPPH） free radical scavenging assay, 2,2＇-Azino-bis （3-ethylbenzethiazoline-6-sulfonic acid） diammonium salt （ABTS） free radical scavenging assay and β-carotene/linoleic acid system. Furthermore,the correlation between the contents of the active compounds and antioxidant properties was analyzed. The data showed that the antioxidant activity of extracts from blueberry leaves decreased with the reducing of polarity of extracted solvents. The water extract showed remarkable scavenging activity on DPPH- EC50（12.78±0.10）,ABTS＋. EC＋ （6.35±0.03）μg/mL,and prominent 15-carotene bleaching effect IC50 （25.33±0.02）μg/mL. The water extract had the highest total phenolics content （264.67±0.29）mg/g and methanol extract had the highest flavonoids content （68.94±0.08）mg/g among different solvent extracts. Analyses indicated that different solvent extracts from blueberry leaves showed a significant difference in their antioxidant activities,and a correlation between their contents of the active compounds and antioxidant properties. It was revealed that water could be one of the best solvents used for extract antioxidant ingredients from blueberry leaves,and the contents of total phenolics and flavonoids could be the quality evaluation index of antioxidant extracts from blueberry leaves.