AUTHOR=Zhang Gaixia , Liu Jinxin , Gao Mei , Kong Weijun , Zhao Qing , Shi Linchun , Wang Qiuling 

TITLE=Tracing the Edible and Medicinal Plant Pueraria montana and Its Products in the Marketplace Yields Subspecies Level Distinction Using DNA Barcoding and DNA Metabarcoding

JOURNAL=Frontiers in Pharmacology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2020.00336

DOI=10.3389/fphar.2020.00336

ISSN=1663-9812

ABSTRACT=<p>Increased public awareness of nutritional and health issues has resulted in the increasing consumption of food and herbal products made from the root of <italic>Pueraria montana</italic> var. <italic>lobata</italic> (Willd.) Maesen &amp; S. M. Almeida ex Sanjappa &amp; Predeep (kudzu vine) and <italic>P. montana</italic> var. <italic>thomsonii</italic> (Benth.) M. R. Almeida. The famous herbal medicine Yufeng Ningxin, which is used to treat cardiovascular diseases, can be legally produced only using <italic>P. montana</italic> var. <italic>lobata</italic>. However, precise identification at the subspecies level is usually challenging when these products’ ingredients lose their morphological characteristics after deep processing. Here, six herbarium specimens, 21 expert-identified original plant samples, 30 raw material samples, 10 food products and 12 herbal products were collected to test the subspecies-level authentication abilities of ITS2 sequences. The results showed that ITS2 sequences can distinguish <italic>P. montana</italic> var. <italic>lobata</italic> from <italic>P. montana</italic> var. <italic>thomsonii</italic> with stable single nucleotide polymorphism (SNP) sites. A total of 93.3% of raw material samples were consistent with the markings on their labels, but only 50% of Gegen Powder samples were made from <italic>P. montana</italic> var. <italic>lobata</italic>. High-quality ITS2 sequences were successfully obtained from nine of the 12 herbal products using Sanger sequencing. Substitution and fungal contamination were detected in 3 herbal products by further DNA metabarcoding, even though thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) tests verified that the products met existing quality standards. This study demonstrated that DNA barcoding is a powerful tool for the identification of <italic>P. montana</italic> var. <italic>lobata</italic> and <italic>P. montana</italic> var. <italic>thomsonii</italic> at the subspecies level, and we conclude that DNA barcodes can be broadly applied to trace the raw materials of food and herbal products.</p>