摘要
目的研究酪蛋白经过加热氧化和脂质过氧化物MDA氧化后,对小鼠体内氧化还原状态及小鼠血液中肽组成的影响。方法酪蛋白经100℃加热(0、30、60、90 min)和丙二醛(MDA)氧化(MDA终浓度0、0.2、20、200 mmol/L)处理,测定其羰基、巯基含量及表面疏水性的变化。小鼠分为四组,分别灌胃生理盐水、正常酪蛋白、加热90 min、MDA氧化酪蛋白,测定0、30、60、90、120、160min血液中自由基水平,并采用HPLC-MS分析灌胃后120 min小鼠血浆肽组分的变化,测定小鼠的肝脏、空肠、十二指肠组织抗氧化能力指标(总抗氧化能力T-AOC、丙二醛MDA、还原型谷胱甘肽GSH)。结果酪蛋白经过两种氧化处理,羰基含量均随氧化程度呈显著上升,巯基含量呈下降趋势。加热氧化后酪蛋白表面疏水性比正常酪蛋白低,而MDA氧化导致疏水性上升。小鼠血液中自由基最高峰出现在灌胃后160min。灌胃两种方式处理的酪蛋白,血液中自由基的含量均显著高于灌胃正常酪蛋白组(P<0.05),肝脏、空肠、十二指肠还原型谷胱甘肽(GSH)含量和总抗氧化能力(T-AOC)均低于正常酪蛋白组,丙二醛(MDA)含量显著提高(P<0.05)。HPLC-MS分析显示,灌胃MDA氧化酪蛋白组血液中肽组成与对照组不同,出现C_7H_(15)N_4O含羰基类的物质。结论氧化会导致酪蛋白理化性质的改变,摄入氧化酪蛋白引起机体的氧化应激,降低组织抗氧化能力。
Objective To investigate the effects of casein modified by the heating and lipid peroxidation product MDA on the redox state and the peptide composition of plasma in mice. Methods Casein was heated at 100℃for different time(0,30,60,90 rain) ,oxidized by different doses of MDA( 0,0.2,20.0,200.0 mmol/L). The variation on carbonyl content, free thiol groups, surface hydrophobicity of casein were measured in vitro. The mice were divided into four groups : ig normal saline, normal casein, heating oxidated casein and MDA oxidated casein. The production of free radical (FR) in mice blood were detected respectively at 0,30,60,90,120,160 min after administration. The plasma peptides were detected by HPLC-MS. The redox-related indicators( T-AOC, MDA, GSH)in liver, Jejunum, Duodenum were determined. Results The carbonyl content of casein increased while free thiol groups content decreased with casine modified by MDA concentration or heating. The surface hydrophobicity was lower in heated casein than that of normal casein, but higher in MDA oxidized casein. The FR peak of blood appeared at 160 min. The blood FR was significantly higher in mice administered oxidized casein than that of normal casein. The T- AOC,GSH content of liver, jejunum and duodenum decreased while MDA increased in mice ig with oxidized casein. HPLC-MS analysis showed that composition of plasma peptides were different in the plasma of mice ig MDA oxidized casein group with nomal casein, new C7H15 N4O substances containing carbonyl appeared in plasma. Conclusion The oxidation will lead to changes in physical and chemical properties of casein. The intake of the oxidated casein can cause a high oxidative stress in mice and fragments of oxidized protein hydrolyzote appeared in blood.
出处
《世界科技研究与发展》
CSCD
2011年第3期489-493,共5页
World Sci-Tech R&D
基金
国家自然科学基金(30571347)
食品科学与技术国家重点实验室资助项目(SKLF-MB-200803)