Abstract
Cynanchum is a large genus with some important medicinal species in China. The medicinal species in Cynanchum are easily confused, leading to potential safety risks. In this study, the internal transcribed spacer 2 (ITS2) barcode was used to discriminate the medicinal plants in Cynanchum. The identifying capability of ITS2 was assessed using the specific genetic divergence, BLAST1, neighbor-joining (NJ) tree, maximum-likelihood (ML) tree, and single-nucleotide polymorphism (SNP) methods. Results indicated that the intra-specific genetic divergences of Cynanchum species were lower than their inter-specific genetic divergences. Of the 87 samples from 17 species, ITS2 showed a high identification efficiency of 90.8 and 87.4% at the species level through BLAST1 and the nearest distance methods. NJ tree and ML tree also demonstrated the suitability of ITS2 to differentiate Cynanchum species. Meanwhile, a stable SNP was found, and it could accurately authenticate Cynanchum paniculatum and Cynanchum atratum. Furthermore, we collected 64 commercial samples from three commonly used herbal medicines and evaluated the capability of ITS2 to survey their authentication. Of these samples, Cynanchi Atrati Radix et Rhizoma (Baiwei) showed a potential safety problem, and all the 11 test samples were adulterants. In conclusion, ITS2 can distinguish medicinal species in Cynanchum effectively, and its application could greatly improve the identification efficiency and accuracy of commercial herbal medicines in this genus.
Highlights
Traditional Chinese medicine (TCM), an integral part of Chinese culture, plays a predominant role in the healthcare system of China, and it is recognized as a primary treatment strategy
The capacity of the internal transcribed spacer 2 (ITS2) barcode to identify medicinal species in Cynanchum was evaluated using 87 sequences representing 17 species of Cynanchum, from 33 vouchers collected in this study and 54 accessions downloaded from NCBI GenBank
The ITS2 sequence obtained were submitted to GenBank under the following accession numbers: MF004207– MF004239
Summary
Traditional Chinese medicine (TCM), an integral part of Chinese culture, plays a predominant role in the healthcare system of China, and it is recognized as a primary treatment strategy. Herbal medicine accounts for more than 80% of Chinese medicine resources, taking an essential part in the TCM system and medicine market. Counterfeit drugs, misidentified drugs, and mislabeled drugs are sold in the market prevalently, resulting in side effects and drug resistance. Xin et al (2015) surveyed commercial Rhodiola products and found that only 40% of samples are authentic Rhodiola crenulata, indicating potential risks and safety problems of medicine use. Han et al (2016) investigated 295 medicinal species, including 1,436 samples from seven primary TCM Counterfeit drugs, misidentified drugs, and mislabeled drugs are sold in the market prevalently, resulting in side effects and drug resistance. Xin et al (2015) surveyed commercial Rhodiola products and found that only 40% of samples are authentic Rhodiola crenulata, indicating potential risks and safety problems of medicine use. Han et al (2016) investigated 295 medicinal species, including 1,436 samples from seven primary TCM
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
