α-乳白蛋白酶解物体外抗氧化及活性氧清除作用

摘要

以α-乳白蛋白为原料,研究其酶解产物的体外抗氧化活性及对HepG2肝细胞(人肝肿瘤细胞株)氧化损伤的保护作用.以ABTS(2,2'-azino-bis(3-ethylbenzyhiazoline-6-sulfpnic acid))自由基清除率、Fe2+螯合能力和羟自由基清除能力为指标,分析了水解产物的抗氧化活性;以DCFH-DA(dichlorofluorescin diacetate)荧光探针所产生的荧光强度为指标,探究了水解产物对HepG2肝细胞内活性氧(reactive oxygen species,ROS)的清除作用.结果表明,与α-乳白蛋白相比,α-乳白蛋白酶解物表现出较强的ABTS自由基清除能力、Fe2+螯合能力和羟自由基清除能力;利用质量浓度0.25～2.0 g/Lα-乳白蛋白酶解物孵育细胞12h,对H2O2诱导的HepG2肝细胞内ROS水平上升的抑制率达到78.61％.%The in vitro antioxidant capacity and the protective effect against oxidative stress injury in H2O2-treated HepG2 cells of bovine α-lactalbumin hydrolysates were investigated in this study.Hydrolysates were prepared by enzymatic hydrolysis using alkaline protease.ABTS radical scavenging activity,ferrous ion (Fe2+) chelating ability and hydroxyl radical scavenging capacity were determined to analyze the reactive oxygen species (ROS) scavenging activity of the hydrolysates.Fluorescence intensity of DCFH-DA fluorescent probe was used to evaluate the ROS scavenging activity.Results showed that α-lactalbumin hydrolysates exhibited higher ABTS radical scavenging activity,ferrous ion chelating ability and hydroxyl radical scavenging capacity comparing to α-lactalbumin.Using 0.25-2.0 mg/mL α-lactalbumin hydrolysates to incubate HepG2 cells for 12 h,the inhibition rate ofROS increase in HepG2 cells reached 78.61％.