title: Identification of common horsetail (Equisetum arvense L.; Equisetaceae) using Thin Layer Chromatography versus DNA barcoding.
abstract: The global herbal products market has grown in recent years, making regulation of these products paramount for public healthcare. For instance, the common horsetail (Equisetum arvense L.) is used in numerous herbal products, but it can be adulterated with closely related species, especially E. palustre L. that can produce toxic alkaloids. As morphology-based identification is often difficult or impossible, the identification of processed material can be aided by molecular techniques. In this study, we explore two molecular identification techniques as methods of testing the purity of these products: a Thin Layer Chromatography approach (TLC-test) included in the European Pharmacopoeia and a DNA barcoding approach, used in recent years to identify material in herbal products. We test the potential of these methods for distinguishing and identifying these species using material from herbarium collections and commercial herbal products. We find that both methods can discriminate between the two species and positively identify E. arvense. The TLC-test is more cost- and time-efficient, but DNA barcoding is more powerful in determining the identity of adulterant species. Our study shows that, although DNA barcoding presents certain advantages, other established laboratory methods can perform as well or even better in confirming species' identity in herbal products.
authors.affiliation: Evolutionary Genomics Section, Natural History Museum of Denmark, Sølvgade 83S, Copenhagen, DK-1307, Denmark.
authors.forename: C Haris
authors.initials: CH
authors.lastname: Saslis-Lagoudakis
authors.affiliation: Evolutionary Genomics Section, Natural History Museum of Denmark, Sølvgade 83S, Copenhagen, DK-1307, Denmark.
authors.forename: Sam
authors.initials: S
authors.lastname: Bruun-Lund
authors.affiliation: Evolutionary Genomics Section, Natural History Museum of Denmark, Sølvgade 83S, Copenhagen, DK-1307, Denmark.
authors.forename: Natalie E
authors.initials: NE
authors.lastname: Iwanycki
authors.affiliation: Evolutionary Genomics Section, Natural History Museum of Denmark, Sølvgade 83S, Copenhagen, DK-1307, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Seberg
authors.affiliation: Evolutionary Genomics Section, Natural History Museum of Denmark, Sølvgade 83S, Copenhagen, DK-1307, Denmark.
authors.forename: Gitte
authors.initials: G
authors.lastname: Petersen
authors.affiliation: Natural Products Research, Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, Copenhagen, DK-2100, Denmark.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Jäger
authors.affiliation: Evolutionary Genomics Section, Natural History Museum of Denmark, Sølvgade 83S, Copenhagen, DK-1307, Denmark.
authors.forename: Nina
authors.initials: N
authors.lastname: Rønsted
mesh_terms: D002855:Chromatography, Thin Layer; D004247:DNA / Q000032:analysis*; D058893:DNA Barcoding, Taxonomic; D020829:Equisetum / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004247:DNA