蛋清蛋白肽体外抗氧化作用模式的研究

Study on antioxidantive action mode of egg white-derived peptides in vitro

目的研究蛋清蛋白肽抗氧化作用模式。方法利用超滤技术分离蛋清蛋白木瓜蛋白酶酶解产物;采用Fenton体系、邻苯三酚自氧化体系和亚油酸自氧化体系分别测定超滤各组分清除羟自由基、超氧阴离子及抑制脂质过氧化的能力,同时测定各组分对二苯代苦味肼基自由基清除能力(DPPH自由基)、还原能力及对猪胎儿成纤维细胞(porcine embryonic fibroblast,PEF)过氧化损伤的保护作用。结果超滤各组分中分子量小于3kDa组分(蛋清蛋白酶解产物-Ⅲ,egg white protein hydrolysate,EWPH-Ⅲ)占蛋清蛋白酶解产物(EWPHs)总量的50.06%。EWPH的抗氧化活性随分子量的降低而增强(P<0.05),其中EWPH-Ⅲ在浓度为5mg/mL时,对羟自由基、超氧阴离子、DPPH自由基的清除率分别为52.86%、35.05%和78.74%,对亚油酸氧化的抑制率为74.57%。在浓度为2.5mg/mL时,PEF细胞存活率达到70.06%。结论蛋清蛋白肽具有较强的抗氧化活性且分子量越小,抗氧化活性越强,可以作为氢供体、自由基稳定剂和金属离子螯合剂来抑制过氧化作用。

Objective To investigate antioxidantive action mode of egg white-derived peptides in vitro. Methods The egg white-derived peptides were separated by ultrafiltration from egg white protein hydroly-sates (EWPHs) produced by papain into three fractions. The hydroxyl radical, superoxide anion scavenging ac-tivities and lipid peroxidation inhibition of three fractions were detected by the methods related to Fenton sys-tem, pyrogallol autoxidation, and linoleic acid emulsion system. The reducing power, DPPH radical scavenging activities and alleviation of H2O2-induced oxidative stress on porcine embryonic fibroblast (PEF) cell were also determined. Results EWPH-Ⅲ (MW<3 kDa) accounted for 50.06% of the total amount of EWPHs. The values of hydroxyl radical, superoxide anion and DPPH radical scavenging activities were 52.86%, 35.05%and 78.74% at the concentration of 5 mg/mL, respectively. The percentage of inhibition of lipid peroxidation was 74.57% at the same concentration. The cell survival rate reached 70.06% at the concentration of 2.5mg/mL. EWPH exhibited significant increase (P<0.05) in antioxidant activity with a decrease in molecular weight of fraction values. Conclusion EWPH could act as a metal ion chelator, a hydrogen donor, as well as a radical stabilizer to inhibit lipid oxidation because of its antioxidant activity.