Molecular authentication of the medicinal plant Paris polyphylla Smith var. yunnanensis (Melanthiaceae) and its related species by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP)

Abstract

Paris polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz. (Melanthiaceae) is a traditional herb widely used by Chinese people, especially in southwestern provinces. Its dried rhizome (medicinal Paris) is a traditional Chinese medicine. In the trade and raw drug market, the medicinal Paris is available in the mixture form with other Paris species, thus making it difficult to distinguish medicinal Paris from its related species. Recent studies have shown that the Paris spp. possess different chemical constituents, pharmacological activities, and efficiency in clinical application, which may cause a series of inconsistent therapeutic effects and quality control problems in the herbal medicine industry. In this study, the differential identification of P. polyphylla var. yunnanensis and its 11 congeners were investigated through DNA sequence analysis of nuclear internal transcribed spacer (ITS) regions. Based on sequence alignments, we concluded that the ITS sequence can distinguish P. polyphylla var.yunnanensis from other Paris species. Polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) was applied successfully through the digestion of ITS product by the restriction enzyme EaeI. The specific sizes of the two digested products were 440 and 194 bp, which could be investigated in P. polyphylla var. yunnanensis The PCR-RFLP technique developed in this study can be used to discriminate medicinal Paris and its related species. Key words: Paris polyphylla Smith var. yunnanensis, Melanthiaceae, internal transcribed spacer (ITS), molecular authentication, polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP).