地瓜藤提取物对酪氨酸酶的激活作用

目的：探讨地瓜藤提取物对酪氨酸酶活性的影响。方法：以采集自四川周边地区的地瓜藤药用植物为材料，用70％乙醇提取有效成分，并对其浓缩物用极性由小到大的溶剂再进行萃取。利用多巴速率氧化法体外测定酪氨酸酶活性，衡量地瓜藤乙醇提取物及各萃取物对酪氨酸酶的激活作用，并用动力学分析激活机理。结果：5个浓度的地瓜藤提取物对酪氨酸酶均有激活作用，其中，浓度为1mg·mL^-1的地瓜藤提取物对酪氨酸酶的激活调控最为显著，达64．58％，较相同浓度补骨脂阳性对照组激活率高；4种萃取物对酪氨酸酶均有激活作用，其中乙酸乙酯萃取物对酪氨酸酶的激活率最高，达84．30％；酶动力学测定结果显示，地瓜藤萃取物中含有的活性物对酪氨酸酶具非竞争性激活和混合型激活多重激活作用。结论：地瓜藤提取物对酪氨酸酶活性在体外有显著激活作用，为色素减退或色素脱失性皮肤病的治疗提供了实验证据。

Effects on the Activity of Tyrosinase by Ficus tikoua Extract

Objective ： To study the effects on the activity of tyrosinase by Ficus tikoua extract. Methods： Used 75% ethanol extracted Ficus tikoua Collected from Sichuan province. Then the bio-active extract compound of Ficus tikoua divided into four parts by different polarity. Measuring the rate of oxidation of L-dopa detected the activity of tyrasinase. Enzyme kinetics curve analyze the mechanism. Results： Ficus tikoua ethanol extract can activate tyrosinase. When the concentration of the ethanol extract was 1 mg· mL^-1, the enzyme activity of the extract raised 64.58%. Its enzyme activity was stronger than that of Fructus Psoralea positive control group. Especially the ethyl acetate extract raised 84. 30%, which is the strongest enzyme activity among the 4 extracts of polar solvents. The results of enzyme kinetics showed that the bio-active compound of Ficus tikoua extract possessed non-competitive activating effects and mutiple activating effects. Conclusion： Ficus tikoua extract has a significant effect on activating the activity of tyrosinase in vitro. The project results showed an experimental evidence for clinical administration of the drugs in treating hypomelanosis.