苦丁茶冬青乙醇提取物体外抗氧化特性测定

In vitro anti-oxidative properties of Kuding tea extract in ethanol

以没食子酸为标准品,采用Folin-Ciocalteu比色法测定苦丁茶多酚含量,研究其乙醇提取物的总还原力、清除ABTS+自由基和清除DPPH自由基的能力,分别以绿茶、乌龙茶、芦丁以及Vc作对照。实验结果显示,苦丁茶的多酚含量为23.97%,显著低于绿茶(43.43%)和乌龙茶(31.98%)(P<0.05);然而其乙醇提取物的总还原力显著高于芦丁(P<0.05);乙醇提取物清除ABTS+自由基的能力为:苦丁茶>乌龙茶>绿茶;苦丁茶乙醇提取物清除DPPH自由基的能力(IC50=47.48μg/m L)高于Vc(IC50=62.71μg/m L)。苦丁茶乙醇提取物有较强的抗氧化能力,且在一定范围与浓度呈量效关系,可作为天然抗氧化剂的原料。

Folin-Ciocalteu colorimetry was used to determine the polyphenol content of Kuding tea with gallic acid as standard. Total reducing ability, ABTS＋ radical and DPPH radical scavenging abilities of Kuding tea extract in ethanol were studied with green tea, oolong tea, rutin and Vc as controls, respectively. The results showed that the polyphenol content of Kuding tea was 23.97%, lower than that of green tea （43.43%） and oolong tea （31.98%） significantly （P〈0.05）; however, its total reducing power was significantly higher than that of rutin （P〈0.05）; the ABTS＋ radical scavenging ability were： Kuding tea ethanol extract〉oolong tea ethanol〉extract green tea ethanol extract; the DPPH radical scavenging ability of Kuding tea ethanol extract （IC50=47.48 μg/mL） was higher than that of Vc （ICso=62.71 μg/mL）. Therefore, Kuding tea ethanol extract has a strong antioxidant capacity, shows a dose-effect in a certain range of concentration, which can be used as a natural anti-oxidant ingredient.