泻白散及其主药体外抗氧化活性研究

目的 建立泻白散和方中3味主药甘草、地骨皮、桑白皮的体外抗氧化活性测定方法，并对31批药材和10批泻白散煎液的抗氧化活性进行测定。方法 采用紫外可见分光光度法检测一定浓度的药材提取液引起DPPH溶液吸光度（A）值降低，考察波长为517 nm，分别探索3味药材抗氧化活性成分的提取条件；并进行不同溶剂的吸收考察、专属性考察、DPPH线性考察、药材提取液线性考察、精密度试验、重复性试验、耐用性考察等方法学验证；以清除DPPH自由基的半抑制浓度（IC₅₀）作为评价指标，对泻白散和方中3味药材的体外抗氧化活性进行考察。结果 地骨皮、甘草、桑白皮和泻白散提取液的IC₅₀均值为0.31、1.24、1.49和0.91 g/L，泻白散提取工艺对方中药物抗氧化活性的保留均值为56%。结论 建立的抗氧化活性测定方法可用于泻白散及方中主药的抗氧化活性测定，为多维度评价中药和中药材质量提供新思路。

Study on antioxidant activity of famous classical formula Xiebai San and main compositions in vitro

Objective To establish a method for the determination of antioxidant activity of Xiebai San and three main compositions of it in vitro, determine the antioxidant activity of 31 batch samples of CMM and 10 batch samples of Xiebai San. Methods To explore the extraction conditions of antioxidative components from 3 CMM, the decrease of DPPH solution absorption value caused by a certain concentration CMM solution was taken as the evaluation index (change of absorption value/concentration of CMM); the blank absorption, specificity, DPPH linearity, herbal extract linearity, precision test, repeatability test and durability test were used to verify the methodology. The IC₅₀ of cleared DPPH free radicals was used as the index to evaluate the antioxidant activity in vitro of Xiebai San and three CMM. Results The mean IC₅₀ of Lycii Cortex, Glycyrrhizae Radix et Rhizoma, Mori Cortex and Xiebai San were 0.31, 1.24, 1.49 and 0.91 g/L; The mean value of the antioxidant activity of the extract from Xiebai San was 56%. Conclusion The method was applicable to determine the antioxidant activity of Xiebai San and the main compositions of it in vitro. And it provides new idea for multi-dimensional evaluation the quality of traditional Chinese medicine and CMM.