植物性食品对尿激酶活性抑制的测定实验

Test for urokinase-type plasminogen activator inhibitor of edible plants in vitro

目的 了解水果、蔬菜和茶叶等植物性食物对于促进细胞恶性转化的尿激酶活性抑制效果。方法 利用谷氨酸 甘氨酸 精氨酸肽为底物的尿激酶活性测定原理 ,分别用 2 5种水果、37种蔬菜的榨汁和 5 1种茶叶的水浸提液与尿激酶反应 ,再加入光活性尿激酶反应底物反应后用酶标仪测定剩余酶活性。结果 2 5种水果、37种蔬菜的测试样中有近一半的尿激酶活性抑制率为 2 0 %以上 ,其中 ,柠檬、猕猴桃、豌豆、菠菜、南瓜等的抑制率超过 80 % ,大蒜、萝卜、蜂斗菜、旱芹、李子、菠萝、葡萄等的抑制率为 5 0 %～ 79% ;5 1个茶叶样的平均抑制率为 83 2 % ,其中 2 8个茶叶样的抑制率 >90 % ,10个茶叶样为 80 %～ 89% ,10个茶样本为 70 %～ 79% ,绿茶类的平均抑制率比红茶类的抑制率高出10 %～ 15 % ;蔬菜的加工方式对抑制效果有影响 ,有刺激味的蔬菜以有机溶剂浸提效果好于水浸提效果 ,无刺激味的则以水浸提的效果为好 ;多数新鲜蔬菜经冷藏和热处理后的效果为减弱。结论 日常生活中的植物性食物有抑制尿激酶活性的作用。

Objective To study the effect of anti-progression activity of edible plants using urokinase as the biomarker. Methods Based on the assay of urokinase activity with peptide of Glu-Gly-Arg as the reaction substrate,extract of 25 fruits and 37 vegetables and water extract of tea were reacted against urokinase activity after Spectrozyme UK [carbobenzl-1-γ-Glu(α- t -BuO)-Gly-Arg-ρ-nitroanilide.2C 2H 5OH] was added and the residual urokinase activity was measured by the microplate photometer. Results About half of the fruit and vegetable samples showed urokinase inhibitory activity (UIA) at 20% or more and among them lemon,kiwi-fruit,peas,spinach and pumpkin showed effects over 80%,while garlic,radish,Japanese butterbur,garland chrysanthemum,celery,plum,pineapple and grape ranged between 50% and 79%. Average UIA of 51 kinds of tea was 83.2% and among them 28 kinds showed UIA over 90% and other 20 kinds of tea ranged from 70% to 89%. Green tea showed inhibitory effects on urokinase activity more powerful than black tea and Oolong tea. On the other hand,vegetable showed various UIA with different ways of processing. Comparing the effects of various solvents,garlic extracted with methanol,spinach with ethyl acetate,and pumpkin and radish with water showed highest UIA. Conclusion Popular fruits,vegetables and tea in daily life could inhibit urokinase activity and may be helpful in the prevention of malignant tumor formation.