目的采用DNA条形码分子鉴定技术鉴别市售柴胡药材及其混伪品,以确保柴胡药材质量及临床用药安全。方法共收集85份柴胡药材,对其ITS2序列进行PCR扩增并双向测序,所得序列经CodonCode Aligner校对拼接后,利用MEGA 6.0对序列进行分析比对,计算种内、种间遗传距离,利用邻接法(NJ)构建系统聚类树,并应用ITS2数据库网站预测其ITS2二级结构。结果柴胡种内遗传距离明显小于柴胡与其近缘物种种间遗传距离,基于ITS2建立的NJ树和网站预测的ITS2二级结构,均能将柴胡药材及其混伪品区分开。85份样品中,55份符合《中国药典》2015年版规定的柴胡正品来源,正品率为64.7%。结论基于ITS2序列可以准确可靠地鉴别柴胡药材及其混伪品,为确保临床用药安全提供新的技术手段。
Objective DNA barcoding technology, a molecular identification method, is applied to distinguishing Bupleuri Radix from its adulterants in order to ensure the quality and clinical curative effect. Methods In this study, the internal transcribed spacer 2(ITS2) regions of 85 samples were amplified by PCR and sequenced bi-directionally. Obtained sequences were assembled using Codon Code Aligner. The genetic distances were computed by MEGA 6.0 in accordance with the kimura 2-parameter(K2P) model and the phylogenetic tree was constructed by Neighbor-joining(NJ) method. Moreover, the secondary structure of ITS2 was predicted using ITS2 database websites. Results The intra-specific genetic distances were smaller than inter-specific ones in ITS2 regions of Bupleuri Radix. NJ tree and secondary structure results could distinctly differentiate quality product and adulterants. Only 64.7% of the 85 samples were in accordance with the requirements of Chinese Pharmacopoeia. Conclusion ITS2 sequence can accurately and reliably identify the authenticity of Bupleuri Radixand could provide a new technique to ensure clinical safety of this traditional Chinese medicine.