Investigation on species authenticity for herbal products of celastrus orbiculatus and tripterygum wilfordii from markets using ITS2 Barcoding

Abstract

Herbal material is both a medicine and a commodity. Accurate identification of herbal materials is necessary to ensure the safety and effectiveness of medication. With this work, we initiated an identification method to investigate the species authenticity for herbal products of Celastrus orbiculatus and Tripterygum wilfordii utilizing DNA barcoding technology. An ITS2 (internal transcribed spacer two) barcode database including 59 sequences was successfully established to estimate the reliability of species-level identification for Celastrus and Tripterygium. Our findings showed that ITS2 can effectively and clearly distinguish C. orbiculatus, T. wilfordii and its congeners. Then, we investigated the proportions and varieties of adulterant species in the herbal markets. The data from ITS2 region indicated that 13 (62%) of the 21 samples labeled as “Nan-she-teng” and eight (31%) of the 26 samples labeled as “Lei-gong-teng” were authentic; the remaining were adulterants. Of the 47 herbal products, approximately 55% of the product identity were not in accordance with the label. In summary, we support the efficacy of the ITS2 barcode for the traceability of C. orbiculatus and T. wilfordii, and the present study provides one method and reference for the identification of the herbal materials and adulterants in the medicinal markets.