From Electrophoresis Detection to Visual Judgment: New Application of SYBR Green I in the Authentication of the Traditional Medicine Rhizoma Paridis

Paris polyphylla Smith var. chinensis (Franck) Hara (PPC) has been used as a traditional Chinese medicine for a long period and is recorded in the Chinese Pharmacopoeia as the certified original plant component of Rhizoma Paridis. However, we discovered that eight other Paris species and subspecies are often present act as adulterants of PPC owing to the decrease in wild resources, according to a survey of resources and research into the herb market. In order to prevent fraudulent substitution and ensure clinical safety, this study aimed to devise a specific authentication method for the differentiation of PPC from its adulterants in the form of eight Paris species and subspecies. For this purpose, we devised a visual molecular authentication method for the differentiation of PPC from its adulterants, which is based on the diversity of the internal transcribed spacer (ITS) sequence of nuclear ribosomal DNA (nrDNA) and employs the double-stranded DNA-specific dye SYBR Green I. This method consists of three main procedures, namely, analysis of the ITS sequence of nrDNA, a species-specific polymerase chain reaction and a fluorescence reaction. We successfully devised a visual molecular identification method whereby PPC can be accurately differentiated from its adulterants. This study provides a good example of how to reliably, sensitively, and immediately differentiate an authentic medicinal plant from its closely related adulterants using a molecular approach. (C) 2019 Friends Science Publishers