| Herbal medicine has quickly become the new commodity in health treatment. However, herbal medicines are not regulated by the U.S. Food and Drug Administration (FDA) as conventional medicine but are treated as dietary supplements. The FDA relinquishes all responsibilities if therapeutic claims are made. This lack of regulation may result in anything from unintentional misidentification to deliberate deception, and thus to illness and even death in consumers. Misidentification may be easily addressed with the technology of DNA barcoding. DNA barcoding is a molecular tool for distinguishing species based on sequence variation of a short (<1000 bp) genetic marker common to a target group. DNA barcoding is extensively used as a method of quality control in the seafood industry, but has yet to become a fully established practice in herbal medicine. In this study, DNA barcoding was used to investigate the taxonomic accuracy of herbal medicines sold in New York City using the plastid markers rbcL, matK and the nuclear ribosomal region ITS2. Forty-nine samples were purchased from two major herbal stores in New York City, representing different plant structures: 26 leaf samples, 12 root samples, and 11 bark samples. Of the three barcodes, ITS2 had the most success being amplified and sequenced in 21 of the 49 samples (43%), mostly leaf samples. Comparative sequence and phylogenetic analyses were performed to verify the taxonomic identity of the samples. Seventeen of the 21 sequenced samples matched their purported species. Three could not be accurately identified. Only one sample did not match its purported species on the label. Thus, care is advised in consuming herbal remedies. Given its higher amplification success rate barcoding with 1TS2 was found to be a more practical solution for taxonomic evaluation of herbal medicinal products. |
