多肽体外抗氧化活性测定方法的比较

为确定适用于多肽体外抗氧化活性的测定方法,以丁基羟基茴香醚(butyl hydroxylanisole,BHA)、VC和生育酚(vitamin E,VE)为对照,测定大豆肽的还原能力、螯合Fe2+能力、清除2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)二胺盐(2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt,ABTS)自由基和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基及抑制脂质体氧化的活性。结果显示:在质量浓度为0~30 mg/m L时,大豆肽还原能力随质量浓度的增加而增强,与BHA、VE、VC类似,大豆肽最大还原能力仅为0.487。大豆肽抑制脂质体氧化的活性弱于BHA和VE,但具有较稳定的增加趋势,最大抑制率达到20.6%;在质量浓度为0~15 mg/m L时,大豆肽螯合Fe2+能力随质量浓度的增加而增强,最大螯合率为38.7%。然而,未检测出BHA、VE、VC具有螯合Fe2+的能力;在质量浓度为0~3.0 mg/m L时,大豆肽清除ABTS+·活性与VC基本相同,大于BHA和VE,ABTS+·清除率最大为61.2%。大豆肽DPPH自由基清除率最大仅为2.1%,清除DPPH自由基活性远低于VC(45.0%)、BHA(10.1%)和VE(10.7%),表明螯合Fe2+能力、清除ABTS+·及抑制脂质体氧化活性的测定方法适合用于评价大豆肽体外抗氧化活性。

Comparison of Various Methods for Measuring Antioxidant Activities of Polypeptide in Vitro

Various methods including reducing power, Fe2+-chelating, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic
acid) diammonium salt (ABTS) radical scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and liposome
oxidation inhibition capacity assays were used for evaluating the antioxidant activities of soybean peptide employing butyl
hydroxylanisole (BHA), VC and VE as controls, aiming to investigate the applicability of these assays for measuring the
antioxidant activities of polypeptide in vitro. The results showed that the reducing power of soybean peptide increased with
its concentration in the range of 0–30 mg/mL, attaining a maximum value of only 0.487, and BHA, VC, and VE similarly
exhibited reducing power in a concentration-dependent manner. The inhibitory activity of soybean peptide against liposome
oxidation was lower than that of BHA and VE, and this antioxidant activity exhibited a stable upward trend with increasing
concentration of soybean peptide, reaching maximum percentage inhibition of 20.6%. Fe2+-chelating capacity of soybean
peptide increased up to 38.7% with its concentration in the range of 0–15 mg/mL, whereas BHA, VE and VC had no such
activity. Soybean peptide in the concentration range of 0–3.0 mg/mL possessed ABTS radical scavenging activity very
similar to that of VC and higher than that of BHA and VE, and the maximum scavenging percentage was 61.2%. However,
the maximum DPPH radical scavenging percentage of soybean peptide was only 2.1%, which was much lower than that of
VC (45.0%), BHA (10.1%), and VE (10.7%). Therefore, Fe2+-chelating capacity, ABTS radical scavenging, and liposome
oxidation inhibition capacity assays can be used to investigate the antioxidant activity of soybean peptide in vitro.