桑椹花色苷对晚期糖基化末端产物抑制作用及其机制分析

Inhibitory Effect of Mulberry Fruit Anthocyanins on Advanced Glycation End-product Formation

摘要:

晚期糖基化末端产物（Advanced Glycation End Products，AGEs）是蛋白质游离氨基与还原糖羰基反应形成的一类复杂物质的总称，是诱发糖尿病等多种慢性病的重要因素之一，而多酚类化合物能够抑制AGEs的形成。为了探讨桑椹花色苷对AGEs的抑制机制，建立牛血清蛋白（BSA）/葡萄糖（Glucose）生成AGEs模拟反应体系，以0.5%酸性乙醇提取、AB-8型大孔树脂纯化的桑椹花色苷为抑制剂，测定反应体系中蛋白质羰基、巯基含量变化、羟基自由基（?OH）对AGEs形成的影响，利用SDS-PAGE凝胶电泳技术分析BSA的分子量变化。研究结果表明，随着桑椹花色苷浓度的增加，反应体系中的AGEs含量显著降低（P<0.05）。桑椹花色苷可显著抑制?OH诱导的AGEs的形成（P<0.05）。桑椹花色苷通过保护巯基和抑制蛋白质形成羰基而抑制AGEs生成；SDS-PAGE图谱显示，桑椹花色苷可阻断糖基化反应导致的蛋白质交联物的形成。

Abstract:

Advanced glycation end product (AGE) is a complex group of compound that formed through Maillard reaction, a nonenzymatic reaction between free amino groups of protein and the carbonyl group of reducing sugar, which is one of the important factors that induce diabetes and other chronic diseases. In this paper, Mulberry anthocyanins were extracted with 0.5% acidic ethanol and purified by AB-8 macroporous resin. To investigate inhibitory effect of Mulberry anthocyanins on the formation of AGEs, BSA/Glucose model systems were carried out. Meanwhile, the effects of protein carbonyl and thiol groups content, hydroxyl radicals (?OH) on AGEs formation were observed to study the inhibition mechanism of mulberry anthocyanins, and the molecular weight change in natvie and glycated-BSA was analyzed by SDS-PAGE gel electrophoresis. The results indicated that AGEs decreased significantly (P < 0.05) with the increase of mulberry anthocyanins concentration. Mulberry anthocyanins had a significant (P < 0.05) inhibitory effect on the formation of AGEs induced by hydroxyl radicals (?OH), and it could inhibit the generation of AGEs by protecting thiol and capturing reactive carbonyl intermediates. The SDS-PAGE electrophoretogram showed that mulberry anthocyanins could inhibit the formation of protein crosslinking caused by glycosylation reaction.