Identification of Andrographis Herba and its common products using mini-barcode

Andrographis Herba, the aerial part of Andrographis paniculata (Burm. f.) Wall. ex Nees (Acanthaceae), has a wide geographic distribution and has been used for the treatment of fever, cold, inflammation, and other infectious diseases. In markets, sellers and buyers commonly inadvertently confuse with related species. In addition, most Chinese medicinal herbs are subjected to traditional processing procedures, such as steaming and boiling, before they are sold at dispensaries; therefore, it is very difficult to identify Andrographis Herba when it is processed into Chinese medicines. The identification of species and processed medicinal materials is a growing issue in the marketplace. However, conventional methods of identification have limitations, while DNA barcoding has received considerable attention as a new potential means to identify species and processed medicinal materials. In this study, 17 standard reference materials of A. paniculata, 2 standard decoctions, 27 commercial products and two adulterants were collected. Based on the ITS2 sequence, it could successfully identify A. paniculata and adulterants. Moreover, a nucleotide signature consisting of 71 bp was designed, this sequence is highly conserved and specific within A. paniculata while divergent among other species. Then, we used these new primers to amplify the nucleotide signature region from processed materials. In conclusion, the DNA barcoding method developed in the present study for authenticating A. paniculata is rapid and cost-effective. It can be used in the future to guarantee the quality of Andrographis Herba of each regulatory link for clinical use.