当归提取物对酪氨酸酶的抑制作用

以乙醇为提取剂,用高压均质技术提取当归,采用酶动力学方法研究了当归提取物对酪氨酸酶活力的抑制效应。结果表明,当归提取物对酪氨酸酶单酚酶和二酚酶活性均有抑制作用,相对抑制率达到50%的当归提取物质量浓度(IC50)分别约为0.32 g/L和0.58 g/L,比熊果苷抑制二酚酶活性的IC50值1.44 g/L有效得多。Lineweaver-Burk图显示当归提取物对二酚酶的抑制作用表现为竞争性抑制,对酪氨酸酶的抑制常数(KI)为0.24 g/L。

Tyrosinase inhibition by extract of Radix Angelica Sinensis

Radix Angelica Sinensis was extracted in a high pressure homogenizer with ethanol as solvent.The inhibitory effects of Radix Angelica Sinensis extract on the activity of tyrosinase was studied using enzymological kinetic method.Results showed that the activity of both phenolase and catecholase containing in the tyrosinase are inhibited by the extract of Radix Angelica Sinensis.The concentration of Radix Angelica Sinensis extract leading to 50% inhibition (IC50) is 0.32 g/L for phenolase activity and 0.58 g/L for catecholase activity respectively,which is more effective than that of arbutin (IC50 =1.44 g/L for catecholase activity).The inhibition kinetics analysis based on Lineweaver-Burk plots showed that the inhibition action of Radix Angelica Sinensis extract belongs to competitive inhibition for catecholase containing in the tyrosinase.The equilibrium constant for inhibition on tyrosinase (KI) is 0.24 g/L.