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Identification of common horsetail (Equisetum arvense L.; Equisetaceae) using Thin Layer Chromatography versus DNA barcoding.

Saslis-Lagoudakis CH, Bruun-Lund S, Iwanycki NE, Seberg O, Petersen G, Jäger AK, Rønsted N - Sci Rep (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Evolutionary Genomics Section, Natural History Museum of Denmark, Sølvgade 83S, Copenhagen, DK-1307, Denmark.

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.

No MeSH data available.


TLC chromatogram of commercial products sold as Equisetum arvense.We only provide the acronym of each product and its country of manufacture. The distinctive greenish-blue band area that indicates presence of E. palustre material is highlighted inside the red rectangle.
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f4: TLC chromatogram of commercial products sold as Equisetum arvense.We only provide the acronym of each product and its country of manufacture. The distinctive greenish-blue band area that indicates presence of E. palustre material is highlighted inside the red rectangle.

Mentions: The distinction between the two species based on the TLC-test of the European Pharmacopoeia is based on the presence of a combination of marker bands in each species, shown in Fig. 2. The results of the TLC-test recommended by the European Pharmacopoeia are shown in Fig. 3 for the E. arvense - E. palustre comparison. The two bands at the bottom of the plate that are used for the identification of E. palustre are present in all accessions of this species, but not in any of the E. arvense accessions. Although some of the marker bands used to identify E. arvense can be found in E. palustre accessions, the combination of the four marker bands (Fig. 2) is not seen in any E. palustre accessions (Fig. 3). Therefore, the marker zones used as the distinguishing characters between the two species in the monograph (Fig. 2) could consistently distinguish between E. arvense and E. palustre. We observed a typical E. arvense TLC chromatogram for five out of eight commercial products included in the analysis (Fig. 4). In one product (B – Bulgaria), we observed the marker bands that are used to identify both E. arvense and E. palustre in the TLC-test of the European Pharmacopoeia, suggesting this product includes a mixture of the two species (Fig. 4). One product (I – UK) seemed to not contain any Equisetum material at all and another one (HB – UK) returned no chromatogram (Fig. 4).


Identification of common horsetail (Equisetum arvense L.; Equisetaceae) using Thin Layer Chromatography versus DNA barcoding.

Saslis-Lagoudakis CH, Bruun-Lund S, Iwanycki NE, Seberg O, Petersen G, Jäger AK, Rønsted N - Sci Rep (2015)

TLC chromatogram of commercial products sold as Equisetum arvense.We only provide the acronym of each product and its country of manufacture. The distinctive greenish-blue band area that indicates presence of E. palustre material is highlighted inside the red rectangle.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4499799&req=5

f4: TLC chromatogram of commercial products sold as Equisetum arvense.We only provide the acronym of each product and its country of manufacture. The distinctive greenish-blue band area that indicates presence of E. palustre material is highlighted inside the red rectangle.
Mentions: The distinction between the two species based on the TLC-test of the European Pharmacopoeia is based on the presence of a combination of marker bands in each species, shown in Fig. 2. The results of the TLC-test recommended by the European Pharmacopoeia are shown in Fig. 3 for the E. arvense - E. palustre comparison. The two bands at the bottom of the plate that are used for the identification of E. palustre are present in all accessions of this species, but not in any of the E. arvense accessions. Although some of the marker bands used to identify E. arvense can be found in E. palustre accessions, the combination of the four marker bands (Fig. 2) is not seen in any E. palustre accessions (Fig. 3). Therefore, the marker zones used as the distinguishing characters between the two species in the monograph (Fig. 2) could consistently distinguish between E. arvense and E. palustre. We observed a typical E. arvense TLC chromatogram for five out of eight commercial products included in the analysis (Fig. 4). In one product (B – Bulgaria), we observed the marker bands that are used to identify both E. arvense and E. palustre in the TLC-test of the European Pharmacopoeia, suggesting this product includes a mixture of the two species (Fig. 4). One product (I – UK) seemed to not contain any Equisetum material at all and another one (HB – UK) returned no chromatogram (Fig. 4).

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Evolutionary Genomics Section, Natural History Museum of Denmark, Sølvgade 83S, Copenhagen, DK-1307, Denmark.

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.

No MeSH data available.