Horizon scan of DNA-based methods for quality control and monitoring of herbal preparations

Abstract

Herbal medicines and preparations are widely used in healthcare systems globally, but concerns remain about their quality and safety. New herbal products are constantly being introduced to the market under varying regulatory frameworks, with no global consensus on their definition or characterization. These biologically active mixtures are sold through complex globalized value chains, which create concerns around contamination and profit-driven adulteration. Industry, academia, and regulatory bodies must collaborate to develop innovative strategies for the identification and authentication of botanicals and their preparations to ensure quality control. High-throughput sequencing (HTS) has significantly improved our understanding of the total species diversity within DNA mixtures. The standard concept of DNA barcoding has evolved over the last two decades to encompass genomic data more broadly. Recent research in DNA metabarcoding has focused on developing methods for quantifying herbal product ingredients, yielding meaningful results in a regulatory framework. Techniques, such as loop-mediated isothermal amplification (LAMP), DNA barcode-based Recombinase Polymerase Amplification (BAR-RPA), DNA barcoding coupled with High-Resolution Melting (Bar-HRM), and microfluidics-based methods, offer more affordable tests for the detection of target species. While target capture sequencing and genome skimming are considerably increasing the species identification resolution in challenging plant clades, ddPCR enables the quantification of DNA in samples and could be used to detect intended and unwanted ingredients in herbal medicines. Here, we explore the latest advances in emerging DNA-based technologies and the opportunities they provide as taxa detection tools for evaluating the safety and quality of dietary supplements and herbal medicines.

Three-tiered authentication of herbal traditional Chinese medicine ingredients used in women’s health provides progressive qualitative and quantitative insight

“…However DNA barcoding is exclusively fit for unprocessed and single species plant materials, which have not been exposed to processing techniques resulting in DNA degradation ( Raclariu et al, 2018 ). Evolving high-throughput sequencing techniques, like DNA metabarcoding overcome limitations of conventional DNA barcoding and are used for investigation of total species diversity and non-targeted species in processed herbal products ( Arulandhu et al, 2017 ; Raclariu et al, 2018 ; Omelchenko et al, 2019 ; Seethapathy et al, 2019 ; Anthoons et al, 2021 ; Raclariu-Manolică and de Boer, 2022 ; Raclariu-Manolică et al, 2023a ; Mück et al, 2023 ). More recent genomics approaches, including genome skimming and shotgun metagenomics, have the potential to overcome limitations of PCR-based methods, like PCR biases due to primer mismatch, limited number of applicable barcodes, limited DNA degradation, and are expected to yield higher discriminatory power ( Wu and Shaw, 2022 ; Raclariu-Manolică, 2023a ).…”

“…Evolving high-throughput sequencing techniques, like DNA metabarcoding overcome limitations of conventional DNA barcoding and are used for investigation of total species diversity and non-targeted species in processed herbal products ( Arulandhu et al, 2017 ; Raclariu et al, 2018 ; Omelchenko et al, 2019 ; Seethapathy et al, 2019 ; Anthoons et al, 2021 ; Raclariu-Manolică and de Boer, 2022 ; Raclariu-Manolică et al, 2023a ; Mück et al, 2023 ). More recent genomics approaches, including genome skimming and shotgun metagenomics, have the potential to overcome limitations of PCR-based methods, like PCR biases due to primer mismatch, limited number of applicable barcodes, limited DNA degradation, and are expected to yield higher discriminatory power ( Wu and Shaw, 2022 ; Raclariu-Manolică, 2023a ). High operational costs currently limit wider application of genomics approaches ( Manzanilla et al, 2022 ), and to date only a few metagenomic studies have been conducted in the field of herbal authentication ( Xin et al, 2018 ; Handy et al, 2021 ).…”

“…Monographs on “herbal drugs” of the European Pharmacopoeia allow for up to 2% of foreign matter unless differently stated in a specific herb monograph ( EMA, 2006 ; EMA, 2011 ). Overall, DNA metabarcoding is limited by the quality, processing state, or product type of isolated material, the DNA purification procedure, primer choice, amplification procedure, library preparation, sequencing technique, bioinformatic filtering and qualitative and clustering thresholds ( Raclariu-Manolică, 2023a ).…”

“…DNA barcoding techniques, as described in the British Pharmacopoeia ( British Pharmacopoeia Commission, 2018 ), are a valuable screening tool for raw, single species botanical materials. Metabarcoding techniques have been successfully used for ingredient profiling of commercial herbal products, which are composed of varying, processed botanical materials, such as CHMs and provide information about unknown ingredients ( Coghlan et al, 2012 ; Arulandhu et al, 2017 ; Seethapathy et al, 2019 ; Anthoons et al, 2021 ; Zhu et al, 2022 ; Raclariu-Manolică, 2023a ; Raclariu-Manolicăet al, 2023b ). Chromatographic authentication gives high resolutions for the detection of target compounds of known ingredients and are basic authentication tools for herbal remedies ( Liang et al, 2010 ; Booker et al, 2016 ; Heinrich et al, 2022 ).…”

Investigation of Epilobium hirsutum L. Optimized Extract’s Anti-Inflammatory and Antitumor Potential

“…As a result, several investigations have been initiated to establish scientific-evidence-backed rational herbal therapies [ 17 , 18 ]. To ensure the effectiveness, consistency, and safe usage of traditional herbal remedies, the quality control of medicinal plant extracts and the identification of their active constituents represent essential steps in the development of properly standardized and accessible herbal medicines [ 19 , 20 , 21 , 22 , 23 , 24 ].…”