15种中草药提取物抗氧化活性的研究

Studies on the Antioxidant Activity of Extracts of 15 Chinese Medicinal Herbs

用石油醚、乙酸乙酯、甲醇和水对所选定的15种中草药进行浸泡提取,采用Folin-Ciocalteu方法测定各提取物中的总酚含量;用DPPH和FRAP分析法评估了同溶剂提取物的抗氧化活性,并与2种参照抗氧化剂(抗坏血酸和BHT)进行比较。结果表明:不同中草药显示出不同的抗氧化活性,在15种中草药中以大花紫薇叶(LagerstroemiaSpeciosa)的抗氧化活性最高,其甲醇提取物中酚类物质的含量最高;同一种中草药的不同溶剂提取物显示出不同的抗氧化活性,通常甲醇提取物比石油醚、乙酸乙酯和水提取物有更强的抗氧化活性和更高的总酚含量。与参照抗氧化剂比较,大花紫薇叶甲醇提取物对DPPH自由基的清除能力强于抗坏血酸。

15 Chinese medicinal herbs were extracted with petroleum ether, ethyl acetate, methanol and water in turn. The total phenolics content of the extracts was measured by Folin-Ciocaheu method. The antioxidant activities of different polar solvent extracts were evaluated by the DPPH assay and the FRAP assay and results were compared to two ＇reference＇ antioxidants, ascorbic acid and butylated hydroxytoluene （BHT） . The results showed that among 15 Chinese medicinal herbs, leaves of Lagerstroemia Speciosa had the highest antioxidant activities and the methanol extract of it had the highest total phenolics content. The different solvent extracts of same Chinese medicinal herb had different antioxidant activities. Methanol extracts generally demonstrated stronger antioxidant power and higher total phenolics content than the petroleum ether, ethyl acetate, or water extracts. As compared with the reference antioxidants, the methanol extract of leaves of Lagerstroemia Speciosa demonstrated stronger antioxidant power than ascorbic acid. Results provided preliminary information on these selected herbs.