Veronica officinalis Product Authentication Using DNA Metabarcoding and HPLC-MS Reveals Widespread Adulteration with Veronica chamaedrys

Abstract

Studying herbal products derived from local and traditional knowledge and their value chains is one of the main challenges in ethnopharmacology. The majority of these products have a long history of use, but non-harmonized trade and differences in regulatory policies between countries impact their value chains and lead to concerns over product efficacy, safety and quality. Veronica officinalis L. (common speedwell), a member of Plantaginaceae family, has a long history of use in European traditional medicine, mainly in central eastern Europe and the Balkans. However, no specified control tests are available either to establish the quality of derived herbal products or for the discrimination of its most common substitute, V. chamaedrys L. (germander speedwell). In this study, we use DNA metabarcoding and high performance liquid chromatography coupled with mass spectrometry (HPLC-MS) to authenticate sixteen V. officinalis herbal products and compare the potential of the two approaches to detect substitution, adulteration and the use of unreported constituents. HPLC-MS showed high resolution in detecting phytochemical target compounds, but did not enable detection of specific plant species in the products. DNA metabarcoding detected V. officinalis in only 15% of the products, whereas it detected V. chamaedrys in 62% of the products. The results confirm that DNA metabarcoding can be used to test for the presence of Veronica species, and detect substitution and/or admixture of other Veronica species, as well as simultaneously detect all other species present. Our results confirm that none of the herbal products contained exactly the species listed on the label, and all included substitutes, contaminants or fillers. This study highlights the need for authentication of raw herbals along the value chain of these products. An integrative methodology can assess both the quality of herbal products in terms of target compound concentrations and species composition, as well as admixture and substitution with other chemical compounds and plants.

PhytoAuthent: Molecular authentication of complex herbal food supplements for safety and efficacy

“…DNA metabarcoding was used to authenticate herbal products containing Echinacea (Raclariu et al 2017b), Hypericum (Raclariu et al 2017c) and Veronica (Raclariu et al 2017d). DNA metabarcoding of 78 herbal products containing Hypericum perforatum L. (St. John's wort) detected the target species in only 68% of products (Raclariu et al 2017d).…”

PhytoAuthent: Molecular authentication of complex herbal food supplements for safety and efficacy

“…If the safety of the herbal products is interpreted to the limit of specific bioactive compounds, then methods of chemical analysis are more relevant than analysis of the composition based on the DNA sequence data, but when analysing product authenticity, species substitution or falsification, DNA barcoding and DNA metabarcoding offer uncomparable resolution in species diversity detection (Raclariu et al 2018a). …”

“…Authentication of 16 herbal products containing Veronica officinalis L. (common speedwell) though DNA metabarcoding detected the target species in only 15% of the products, but detected a related species, V. chamaedrys (germander speedwell) as an undeclared ingredient in 62% of the products (Raclariu et al 2017a). Three common species of Echinacea were targeted in 53 herbal products and using DNA metabarcoding, Echinacea species were detected in 34 out of the 38 retained products (89%), but with a lack of discriminatory resolution at the species level (Raclariu et al 2018b).…”

“…DNA metabarcoding was used to authenticate herbal products containing Echinacea (Raclariu et al 2018b), Hypericum (Raclariu et al 2017a) and Veronica (Raclariu et al 2017a) DNA metabarcoding of 78 herbal products containing Hypericum perforatum L. (St. John's wort) detected the target species in only 68% of products (Raclariu et al 2017b). Authentication of 16 herbal products containing Veronica officinalis L. (common speedwell) though DNA metabarcoding detected the target species in only 15% of the products, but detected a related species, V. chamaedrys (germander speedwell) as an undeclared ingredient in 62% of the products (Raclariu et al 2017a).…”

“…The EMA supports the use of innovative analytical technologies, such as DNA barcoding, to complement traditional chromatographic identification methods for substitute, filler and adulterant detection in herbal products. Many herbal preparations and products have a history of safe use, but there is growing concern about their quality, efficacy and safety, as a result of studies showing major discrepancies between label information and analysed composition (Raclariu et al 2018a). …”