中文摘要：

叶下珠为传统民间草药,具有平肝清热、利水解毒之功效.以叶下珠为研究对象,经乙醇提取,溶剂极性递增分离法制备获得叶下珠植物成分,测定了叶下珠植物对酪氨酸酶的抑制作用,以及运用1,1-二苯基-2-苦苯肼（DPPH）自由基法检测其清除自由基的能力.结果表明：叶下珠乙酸乙酯提取物和正丁醇提取物对酪氨酸酶二酚酶有较强抑制作用,IC50值分别达到0.26和0.49mg/mL,动力学研究表明：叶下珠乙酸乙酯提取物和正丁醇提取物对酪氨酸酶抑制作用均是可逆的,其抑制类型为混合型抑制作用;叶下珠乙酸乙酯提取物和正丁醇提取物对DPPH自由基具有一定的清除作用,在较低的浓度下有较高的清除效果,IC50值分别为0.012和0.008mg/mL,说明叶下珠植物具有开发成天然酪氨酸酶抑制剂和抗氧化剂的潜力.

英文摘要：

As a kind of Chinese traditional medicine herb,Phyllanthus urinaria L.has the abilities of reducing pathogenic fire and detoxification.The abilities of anti-tyrosinase and anti-oxidation in the extract of Phyllanthus urinaria were measured in our study.This paper took Phyllanthus urinaria as research object and used the method of ethanol extraction and increasing solvent polarity separation to obtain the component of Phyllanthus urinaria,measured its inhibition of tyrosinase and 1,1-diphenyl-2-picrylhydrazyl（DPPH） free radical scavenging ability.The result shows that ethyl acetate-soluble extraction and butanol-soluble extraction of Phyllanthus urinaria has strong inhibition to tyrosinase,the values of IC50 reach 0.26 and 0.49 mg/mL respectively.The kinesis study shows that their inhibition to tyrosinase are both reversible and inhibition types are both mixed.The ethyl acetate-soluble extraction and butanol-soluble extraction of Phyllanthus urinaria has strong scavenging effect of DPPH radical in low concentrate and the values of IC50 are 0.012 and 0.008 mg/mL respectively.This result shows that Phyllanthus urinaria has great development potential of natural tyrosinase inhibitors and anti-oxidants.