槲皮素等中药成分对蛋白非酶糖化的体外抑制研究

Study on Inhibitory Effect of Quercetin on Nonenzymatic Giycosylation of Protein in vitro

目的:从部分中药成分中筛选新的非酶糖化(NEG)抑制荆,探讨其可能的作用机制。方法:通过建立体外牛血清白蛋白 NEG 系统以模拟糖尿病的体内环境,测定16种中药成分在不同浓度梯度(1×10^(-1)～1×10^(-7)mg/ml)下对糖化终末产物(AGEs 的荧光抑制率及半效抑制浓度(IC_(50)),并与公认的 NEG 抑制剂——氨基胍(AG)作比较。结果:槲皮素、芦丁、羟乙基芦丁、黄芩甙元、黄芩甙、水飞蓟素等具有明显的 NEG 抑制作用,其 IC_(50)分别为0.86mg/L、1.16mg/L、1.64mg/L、2.36mg/L、4.71mg/L 与1.75mg/L,相应的 AG 为0.38mg/L;部分补中益气类中药,其皂甙也有一定的 NEG 抑制作用,但较 AG 弱。结论:槲皮素等6种黄酮类中药在抑制体外蛋白 NEG 作用方面与 AG 相近,但机制可能与 AG 不同。某些抗衰老药物的作用机制可能与抑制蛋白 AGEs 形成有关。

Objective:To lind some ingredients of Chinese Herbal medicine which have effect of nonenzymatic glycosylation (NEG) of protein and explore its mechanism.Methods:A bovine serum albumin glycosylation system in vitro was estab- lished to simulate the internal environment of diabetes.This system was used to estimate the fluorescence inhibition rate and median inhibitory concentration (IC_(50)) on advanced glycosylation endprc^uct (AGE) of 16 ingredients of Chinese herbal medicine in different concentration (from 10^(-1) mg/ml to 10^(-7) mg/ml),with aminoguanidine (AG) as referential standard.Results:Quercetin,rutin,troxerutin,baicalein,baicalin and silybin etc.had obvious inhibitory action on NEG,the IC_(50) of them were 0.86 mg/L,1.16 mg/L,1.64 mg/L,2.36 mg/L,4.71 mg/L and 1.75 mg/L respec- tively,while that of AG was 0.38 mg/L.Some Saponin of tonic Chinese herbs also showed inhibitory effect on NEG in a certain degree weaker than the effect of AG.Conclusion:Six flavonoids of Chinese herbal medicine such as quercetin,has inhibitory effect on NEG of protein similar to that of AG,but the mechnisrns might be different.The mechanism of some anti-aging drugs might be related with inhibiting from AGE formation.