Scavenging Potency of Tea Extracts to Active Oxygen and Regulation of Aging via MAILLARD Reaction in vivo

(1)用1，1-二苯基-2-苦皮酰肼法和5，5-二甲基吡咯啉-N-氧化物电子自旋共振法检测了几种茶叶提取物(绿茶、波雷茶、罗伊伯茶)对自由基的清除能力。茶提取物对超氧阴离子的清除作用由强到弱依次为绿茶、波雷茶、罗伊布茶。(2)给链脲佐菌素治疗的糖尿病小鼠灌胃茶提取物后，用抗糖基化终末产物(AGE)抗体用ELISA法测定糖基化终产物(AGE)含量的时程变化。绿茶和波雷茶对血浆AGE含量有明显的抑制作用。从亲和-高效液相色谱法和酶联免疫吸附试验数据来看，糖尿病患者血浆中AGE含量明显高于正常人。AGE含量与HbA、1C、GT有一定的相关性。

(1) The radical scavenging potency of several tea extracts (green tea, Polei tea, Rooibos tea) was examined by 1,1-diphenyl-2-picrylhydrazil method and electron spin resonance method using 5,5-dimethylpyrroline-N-oxide. All tea extract showed high scavenging effects on superoxide anion and the activity was in order of green tea, Polei tea and Rooibos tea.(2) After administration of tea extract to streptozotocin treated diabetic mice, time course of advanced glycation endproducts (AGE) content was determined by ELISA method using anti-AGE antibody. Green tea and Polei tea showed clear inhibitory effects on AGE content in plasma. Catechins from green tea and flavonoids from Polei tea were identified as inhibitors.(3) From the data of affinity-HPLC and ELISA,AGE contents in plasma of diabetic patients were significantly higher than those of normal subjects. A certain correlation was observed between AGE content and HbA_<1C>.