What’s in the box? Authentication ofEchinaceaherbal products using DNA metabarcoding and HPTLC

Abstract

AbstractBackgroundDifferences in regulatory policies between countries as well as a lack of appropriate standardized methods for authentication and quality control of herbal products lead to concerns over quality and safety.Echinaceaproducts are among the top selling herbal products in Europe and the United States with indications for broad range of ailments.PurposeThis study approached the need for a novel analytical strategy in authentication of herbal products.MethodsA combination of high performance thin layer chromatography (HPTLC) and DNA metabarcoding was employed. Fifty-threeEchinaceaherbal products marketed across Europe were tested to evaluate the accuracy of these methods in plant identification and their potential in detecting substitutes, adulterants and other unreported plant constituents.ResultsHPTLC provides a high resolution in detectingEchinaceaphytochemical target compounds, but does not offer information on the other species within the product. Alternatively, we showed that the limitation of HPTLC to detect non-targeted species can be overcome through the complementary use of DNA metabarcoding. Using DNA metabarcoding,Echinaceaspecies were detected in 34 out of the 38 retained products (89 %), but with a lack of discriminatory resolution at the species level due to the low level of molecular divergence within theEchinaceagenus. All herbal products showed considerable discrepancies between ingredients listed on the label and the ones detected using DNA metabarcoding registering an overall ingredient fidelity of 43 %.ConclusionThe results confirm that DNA metabarcoding can be used to test for the presence ofEchinaceaand simultaneously to detect other species present in even highly processed and multi-ingredient herbal products.AbbreviationsEMAEuropean Medicines AgencyBLASTbasic local alignment search toolFTIRFourier-transformed infrared spectroscopyIRinfrared spectrometryHPTLChigh performance thin layer chromatographymatKmaturase KMSmass spectrometryMOTUmolecular taxonomic unitnrITSnuclear ribosomal internal transcribed spacerPh.Eur.European PharmacopoeiarbcLribulose bisphosphate carboxylaseTLCthin-layer chromatographyUV-VISultraviolet-visible