中药白及抑制酪氨酸酶及清除DPPH自由基的有效部位筛选及其制备工艺考察

Screening of Effective Parts of Bletilla striata Inhibiting Tyrosinase and Scavenging DPPH Free Radical and Its Preparation Technology

目的:对白及不同提取物的抗氧化活性和对酪氨酸酶的抑制作用进行考察,筛选具有抗氧化及美白作用的功效部位,为白及的综合利用开发提供依据。方法:采用水、70%乙醇、70%乙醇提取后水提等提取方式分别对白及进行回流提取,酪氨酸酶抑制法及DPPH自由基清除试验对各提取部位进行相关活性比较。以酪氨酸酶抑制率及DPPH自由基的清除率为指标,对醇提浓度及具体制备工艺进行考察。结果:白及水提物具有促进酪氨酸酶活性作用(-96.78%),其作用随反应时间延长而减弱,白及醇提物对酪氨酸酶具有良好的抑制率(68.36%),而醇提后水提物对酪氨酸酶呈现出先抑制后促进的作用,而后促进作用减弱;白及醇提物与水提物具有一定的清除DPPH自由基能力,其中醇提物抗氧化能力较高,为37.13%,而醇提水提物有增强自由基活性作用(为-43.73%)。综上结果得出,白及醇提物对酪氨酸酶具有良好的抑制作用,对DPPH自由基具有一定的清除作用。因此对醇提部位进行提取浓度、用量及提取时间、次数的考察,结果以95%乙醇,用量为100倍,提取时间为2 h,共提取1次,所得提取物的酪氨酸酶抑制率及DPPH自由基清除率较高。结论:白及具有一定的抗氧化及美白功效,其中具体活性成分尚需进一步研究。

Objective： To investigate the antioxidant activity and tyrosinase inhibitory activity of different extracts from Rhizoma Bletillae, and to screen the effective parts with antioxidant and whitening effects, so as to provide the basis for the comprehensive utilization of Rhizoma bletillae. Methods： Using water extraction, 70% ethanol extraction and water extraction after 70% ethanol extraction, the inhibition rate of tyrosinase and DPPH radical scavenging rate from each extraction site were compared. The tyrosinase inhibition rate and DPPH free radical scavenging rate were used as indicators to investigate the alcohol concentration and the specific preparation process. Results： The alcohol extracts and water extracts has a certain inhibition of tyrosinase activity, and alcohol extract the highest rate of 68. 36%. While the the water after alcohol extracts has enhanced free radical activity （ -43.73% ） . With 100 times 95% ethanol as solvent, 2h was extracted and extracted for 1 times, the inhibition rate of tyrosinase and DPPH radical scavenging rate were higher. Conclusion： Rhizoma Bletillae has a certain antioxidant and whitening effects, which specific active ingredients still need further study.