云南种植的三种颜色玛咖体外抗氧化活性分析?

采用铁离子还原能力(FRAP)、Fenton 反应体系、DPPH 法及邻苯三酚自氧化体系评价种植于云南的玛咖乙醇提取物体外抗氧化能力。结果表明：在云南种植的3 种颜色玛咖乙醇提取物均表现出抗氧化活性，且呈现一定的量效关系，但在4 种抗氧化体系中的结果有所不同；紫色玛咖的总还原能力最强，黄色次之，白色最弱，3200m 海拔地区种植的玛咖高于其他相对低海拔地区的玛咖；紫色和黄色玛咖的清除DPPH 自由基能力高于白色，3200m 海拔地区种植的玛咖高于其他相对低海拔地区的玛咖；3 种颜色玛咖对羟自由基的清除能力明显，各样品的清除率在加入量为200μL 时均达到90% 以上，3000m 海拔地区种植的黄色玛咖最强；3 种颜色玛咖对超氧阴离子自由基的清除能力在实验范围内均较弱。

in vitro Antioxidant Activity of Ethanol Extract of Maca (Lepidium meyenii Walpers) Cultivated in Yunnan

The total antioxidant activity (TAC) of ethanol extracts of different color types (white, yellow and purple) of maca (Lepidium meyenii Walpers) cultivated at different altitude areas (2000, 2500, 3000 m and 3200 m) in Yunnan was measured by ferric reducing antioxidant power (FRAP) assay. Also, their scavenging activities against hydroxyl free radicals generated from Fenton reaction, DPPH free radicals and superoxide anion free radicals by a pyrogallol autooxidation system were evaluated. The results indicated that ethanol extracts of 3 color types of maca cultivated in Yunnan all had dose-dependent total antioxidant and free radical scavenging effects. Purple maca presented the highest TAC, followed by yellow and white macas. The DPPH free radical scavenging activity of white maca was lower than those of other two color types of maca. A higher TAC and a higher DPPH free radical scavenging activity were both observed in maca cultivated at 3200 m-altitude area than that from lower altitude areas. Three color types of maca were all able to remarkably scavenge hydroxyl radicals, with a scavenging ratio of more than 90% at a dose of 200 μL and yellow maca cultivated at 3000 m-altitude area had the best hydroxyl free radical scavenging activity. Three color types of maca all had only weak scavenging effect on superoxide anion free radicals.