Differentiating Authentic Adenophorae Radix from Its Adulterants in Commercially-Processed Samples Using Multiplexed ITS Sequence-Based SCAR Markers

Existing status and future advancements of adulteration detection techniques in herbal products

BACKGROUND

Herbal products have been commonly used all over the world for centuries. Its products have gained remarkable acceptance as therapeutic agents for a variety of disorders. However, following recent research disclosing discrepancies between labeling and actual components of herbal products, there is growing concern about the efficacy, quality and safety of the products. The admixture and adulteration of herbal medicinal products pose a risk of serious health compromise and the well-being of the consumers. To prevent adulteration in raw ingredients and final herbal products, it is necessary to use approaches to assess both genomes as well as metabolomics of the products; this offers quality assurance in terms of product identification and purity. The combinations of molecular and analytical methods are inevitable for thorough verification and quality control of herbal medicine.

METHODS AND RESULTS

This review discusses the combination of DNA barcoding, DNA metabarcoding, mass spectroscopy as well as HPLC for the authentication of herbal medicine and determination of the level of adulteration. It also discusses the roles of PCR and real-time PCR techniques in validating and ensuring the quality, purity and identity of the herbal products.

CONCLUSIONS

In conclusion, each technique has its own pros and cons, but the cumulative of both the chemical and molecular methods is proven to be the best strategy for adulteration detection. Moreover, CRISPR diagnosis tools equipped with multiplexing techniques may be implemented for screening adulteration from herbal drugs, this will play a crucial role in herbal product authentication in the future.

The effective approach for the quality control of Codonopsis radix based on quality markers of immune activity

Codonopsis radix is an important edible and medicinal plant resource for immunomodulation in China and Southeast Asia. However, the chemical quality evaluation of Codonopsis radix in Chinese Pharmacopoeia (2020 Version) is still lacking; therefore, it is necessary to develop an effective method to evaluate its quality accurately and systematically. Herein, a reliable method for a comprehensive chemical analysis of bioactive compounds in Codonopsis radix by ultra-performance liquid chromatography-diode array detector was developed based on the quality marker (Q-marker) concept, which can efficiently reflect its immune activity. Our previous research explored the seven potential bioactive compounds reflecting the immune regulation activities of Codonopsis radix by spectrum-effect relationship analysis. Therefore, in this study, we researched on establishing a quality control method and selected the modern pharmacodynamic experiment of immune regulation to verify the potential bioactive compounds as quality markers. A real quality control method that reflected the traditional efficacy of Codonopsis radix in strengthening the spleen and tonifying lungs was developed. Furthermore, the Codonopsis radix extract and the seven bioactive compounds could promote the proliferation of immune-related cells and regulate the secretion of inflammatory factors, thus playing a role in immune regulation. This article is protected by copyright. All rights reserved.

A Review on Application of DNA Barcoding Technology for Rapid Molecular Diagnostics of Adulterants in Herbal Medicine

The rapid molecular diagnostics of adulterants in herbal medicine using DNA barcoding forms the core of this meticulously detailed review, based on two decades of data. With 80% of the world's population using some form of herbal medicine, authentication, quality control, and detection of adulterants warrant DNA barcoding. A combined group of keywords were used for literature review using the PubMed, the ISI Web of Knowledge, Web of Science (WoS), and Google Scholar databases. All the papers (N = 210) returned by the search engines were downloaded and systematically analyzed. Detailed analysis of conventional DNA barcodes were based on retrieved sequences for internal transcribed spacer (ITS) (412,189), rbcL (251,598), matK (210,835), and trnH-psbA (141,846). The utility of databases such as The Barcode of Life Data System (BOLD), NCBI, GenBank, and Medicinal Materials DNA Barcode Database (MMDBD) has been critically examined for the identification of unknown species from known databases. The current review gives an overview of the ratio of adulterated to authentic drugs for some countries along with the state of the art technology currently being used in the identification of adulterated medicines. In this review, efforts were made to systematically analyze and arrange the research and reviews on the basis of technical progress. The review concludes with the future of DNA-based herbal medicine adulteration detection, forecasting the reliance on the metabarcoding technology. DNA barcoding technology for differentiating adulterated herbal medicine.

Establishment of conventional PCR and real-time PCR assays for accurate, rapid and quantitative authentication of four mistletoe species

Adulterants in processed food and herbal medicines reduce their safety, quality control, or pharmacological efficacy. Four mistletoe species, including Viscum coloratum, inhabit Korea. Leaves and branches of V. coloratum, defined as edible or medicinal mistletoe species in Korean, are used to prepare Korean herbal medicines as well as leached tea. However, other mistletoe species including Taxillus sutchuenensis var. duclouxii, Korthalsella japonica, and Loranthus tanakae are frequently distributed as authentic V. coloratum in Korean markets because of similarities in the branches morphology and Korean names of these species with V. coloratum. Although herbal medicines and food products prepared from the other mistletoe species are inauthentic, they are sold at high prices because of the rarity of these species. Thus, it is important to distinguish between authentic and inauthentic adulterant mistletoe species. In this study, we developed species-specific primer, based on matK sequences, suitable for both conventional PCR and real time PCR (qPCR) assay. These assays allowed rapid discrimination among all four mistletoe species. Moreover, qPCR assay enabled the detection of trace amounts of adulterant mistletoe species in V. coloratum samples. Furthermore, we used these assays to monitor commercial mistletoe products distributed in Korean markets. Our data suggest that these methods would serve as a reliable genetic tool to prevent adulteration and standardize the quality of commercial V. coloratum products.

Accurate and Rapid Identification of Longan Arillus and Litchi Semen by a Multiplex PCR Assay

Dimocarpus longan, Litchi chinensis, and Nephelium lappaceum are commercially valuable subtropical and tropical fruits of the Sapindaceae family. Arillus and seeds of the three species have very similar morphologies; however, the arillus of D. longan is used as the herbal medicine Longan Arillus and seeds of L. chinensis are used as Litchi Semen in Korean and Chinese pharmacopoeias. The adulteration of herbal medicines with inauthentic species, including the use of Aril and seed fractions acquired from a single species for two herbal medicines (e.g., Longan Arillus and Litchi Semen), is often driven by economic motives. DNA markers are a tool for the detection of adulterants in commercial products. To establish rapid and reliable assays for the genetic identification of authentic Longan Arillus and Litchi Semen, we developed DNA markers with high specificity and sensitivity based on internal transcribed spacer (ITS) sequences. The newly developed DNA markers and multiplex PCR assay may contribute to efforts to protect against adulteration, quality control, and the standardization of herbal medicines.

Rapid and Simple Species Identification of Cicada Exuviae Using COI-Based SCAR Assay

Cicadidae periostracum (CP), the medicinal name of cicada exuviae, is well-known insect-derived traditional medicine with various pharmacological effects, e.g., anticonvulsive, anti-inflammatory, antitussive, and anticancer effects; it is also beneficial for the treatment of Parkinson’s disease. For appropriate CP application, accurate species identification is essential. The Korean pharmacopoeia and the pharmacopoeia of the People’s Republic of China define Cryptotympana atrata as the only authentic source of CP. Species identification of commercially distributed CP based on morphological features, however, is difficult because of the combined packaging of many cicada exuviae in markets, damage during distribution, and processing into powder form. DNA-based molecular markers are an excellent alternative to morphological detection. In this study, the mitochondrial cytochrome c oxidase subunit I sequences of C. atrata, Meimuna opalifera, Platypleura kaempferi, and Hyalessa maculaticollis were analyzed. On the basis of sequence alignments, we developed sequence-characterized amplified-region (SCAR) markers for efficient species identification. These markers successfully discriminated C. atrata from the three other cicada species, and detected the adulteration of market CP samples. This SCAR assay is a rapid, simple, cheap, reliable, and reproducible method for species identification, regardless of sample form and status, and contributes to CP quality control.

Development of conventional PCR and real-time PCR assays to discriminate the origins of Chinese pepper oil and herbal materials from Zanthoxylum

BACKGROUND

To ensure the safety, quality and therapeutic efficacy of processed foods and herbal medicines, it is important to identify and discriminate economically motivated adulterants. Zanthoxylum schinifolium is sold at a higher price than other Zanthoxylum species and is frequently adulterated with closely related Zanthoxylum species because of its high demand as a Korean food ingredient and medicinal material in markets. In addition, the pericarps of three Zanthoxylum species (Z. schinifolium, Z. bungeanum and Z. piperitum) are defined as herbal medicine Zanthoxyli Pericarpium in Korean pharmacopoeias, but not Z. piperitum in Chinese pharmacopoeias. Further confusion arises in the morphological similarity between Z. armatum (adulterant) and Z. bungeanum. Therefore, the aim of this study was to develop a sequence characterized amplified region (SCAR) marker for discrimination of four Zanthoxylum species.

RESULTS

With the goal of developing rapid and reliable tools for genetic discrimination of authentic Zanthoxyli Pericarpium, we designed species-specific SCAR markers, based on ITS2 sequences, that generate amplicons of less than 200 bp. Using these markers, we established both conventional and real-time PCR assay methods capable of differentiating samples at the species level. We validated the ability of SCAR markers to authenticate edible oil and herbal medicine, and confirmed that some herbal medicines contaminated with Z. armatum are being distributed as Zanthoxyli Pericarpium in Korean and Chinese markets.

CONCLUSIONS

The SCAR markers and PCR methods described represent powerful tools for protecting against adulteration and ensuring standardization of processed foods and herbal medicine. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Codonopsis lanceolata attenuates allergic lung inflammation by inhibiting Th2 cell activation and augmenting mitochondrial ROS dismutase (SOD2) expression

Allergic asthma is a chronic inflammatory disease induced by the inhalation of allergens, which trigger the activation of T helper type 2 (Th2) cells that release Th2 cytokines. Recently, herbal medicines are being considered a major source of novel agents to treat various diseases. In the present study, we evaluated the anti-asthmatic effects of a Codonopsis lanceolata extract (CLE) and the mechanisms involved in its anti-inflammatory effects. Treatment with CLE reduced infiltration of inflammatory cells, especially eosinophils, and the production of mucus in lung tissues. Levels of Th2 cytokines, such as IL-4, IL-5, and IL-13, and chemokines were also decreased following treatment with CLE. Moreover, Th2 cell proportion in vivo and differentiation in vitro were reduced as evidenced by the decreased expression of GATA3⁺. Furthermore, the expression of superoxide dismutase (SOD)2, a mitochondrial ROS (mROS) scavenger, was increased, which was related to Th2 cell regulation. Interestingly, treatment with CLE increased the number of macrophages in the lungs and enhanced the immune-suppressive property of macrophages. Our findings indicate that CLE has potential as a novel therapeutic agent to inhibit Th2 cell differentiation by regulating mROS scavenging.

Authentication of the Herbal Medicine Angelicae Dahuricae Radix Using an ITS Sequence-Based Multiplex SCAR Assay

The accurate identification of plant species is of great concern for the quality control of herbal medicines. The Korean Pharmacopoeia and the Pharmacopoeia of the People's Republic of China define Angelicae Dahuricae Radix (Baek-Ji in Korean and Bai-zhi in Chinese) as the dried roots of Angelica dahurica or A. dahurica var. formosana belonging to the family Apiaceae. Discrimination among Angelica species on the basis of morphological characteristics is difficult due to their extremely polymorphic traits and controversial taxonomic history. Furthermore, dried roots processed for medicinal applications are indistinguishable using conventional methods. DNA barcoding is a useful and reliable method for the identification of species. In this study, we sequenced the internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes in A. dahurica, A. dahurica var. formosana, and the related species A. anomala and A. japonica. Using these sequences, we designed species-specific primers, and developed and optimized a multiplex sequence-characterized amplified region (SCAR) assay that can simply and rapidly identify respective species, and verify the contamination of adulterant depending on the polymerase chain reaction (PCR) amplification without sequencing analysis in a single PCR reaction. This assay successfully identified commercial samples of Angelicae Dahuricae Radix collected from Korean and Chinese herbal markets, and distinguished them from adulterants. This multiplex SCAR assay shows a great potential in reducing the time and cost involved in the identification of genuine Angelicae Dahuricae Radix and adulterant contamination.

Establishment of a PCR Assay for the Detection and Discrimination of Authentic Cordyceps and Adulterant Species in Food and Herbal Medicines

Accurate detection and differentiation of adulterants in food ingredients and herbal medicines are crucial for the safety and basic quality control of these products. Ophiocordyceps sinensis is described as the only fungal source for the authentic medicinal ingredient used in the herbal medicine "Cordyceps", and two other fungal species, Cordyceps militaris and Isaria tenuipes, are the authentic fungal sources for food ingredients in Korea. However, substitution of these three species, and adulteration of herbal material and dietary supplements originating from Cordyceps pruinosa or Isaria cicadae, seriously affects the safety and reduces the therapeutic efficacy of these products. Distinguishing between these species based on their morphological features is very difficult, especially in commercially processed products. In this study, we employed DNA barcode-based species-specific sequence characterized amplified region (SCAR) markers to discriminate authentic herbal Cordyceps medicines and Cordyceps-derived dietary supplements from related but inauthentic species. The reliable authentication tool exploited the internal transcribed spacer (ITS) region of a nuclear ribosomal RNA gene (nrDNA). We used comparative nrDNA-ITS sequence analysis of the five fungal species to design two sets of SCAR markers. Furthermore, we used a set of species-specific SCAR markers to establish a real-time polymerase chain reaction (PCR) assay for the detection of species, contamination, and degree of adulteration. We confirmed the discriminability and reproducibility of the SCAR marker analysis and the real-time PCR assay using commercially processed food ingredients and herbal medicines. The developed SCAR markers may be used to efficiently differentiate authentic material from their related adulterants on a species level. The ITS-based SCAR markers and the real-time PCR assay constitute a useful genetic tool for preventing the adulteration of Cordyceps and Cordyceps-related dietary supplements.

Authentication of Herbal Medicines Dipsacus asper and Phlomoides umbrosa Using DNA Barcodes, Chloroplast Genome, and Sequence Characterized Amplified Region (SCAR) Marker

Dried roots of Dipsacus asper (Caprifoliaceae) are used as important traditional herbal medicines in Korea. However, the roots are often used as a mixture or contaminated with Dipsacus japonicus in Korean herbal markets. Furthermore, the dried roots of Phlomoides umbrosa (Lamiaceae) are used indiscriminately with those of D. asper, with the confusing Korean names of Sok-Dan and Han-Sok-Dan for D. asper and P. umbrosa, respectively. Although D. asper and P. umbrosa are important herbal medicines, the molecular marker and genomic information available for these species are limited. In this study, we analysed DNA barcodes to distinguish among D. asper, D. japonicus, and P. umbrosa and sequenced the chloroplast (CP) genomes of D. asper and D. japonicus. The CP genomes of D. asper and D. japonicus were 160,530 and 160,371 bp in length, respectively, and were highly divergent from those of the other Caprifoliaceae species. Phylogenetic analysis revealed a monophyletic group within Caprifoliaceae. We also developed a novel sequence characterised amplified region (SCAR) markers to distinguish among D. asper, D. japonicus, and P. umbrosa. Our results provide important taxonomic, phylogenetic, and evolutionary information on the Dipsacus species. The SCAR markers developed here will be useful for the authentication of herbal medicines.

Peptide Nucleic Acid Based Molecular Authentication for Identification of Four Medicinal Paeonia Species Using Melting Array Analysis of the Internal Transcribed Spacer 2 Region

Accurate taxonomic identification of plant materials in herbal medicines is important for product quality control. The genus Paeonia (Saxifragales) is the source of the herbal preparations Paeoniae Radix (Paeoniae Radix Alba and Paeoniae Radix Rubra) and Moutan Radicis Cotex. However, confusion has arisen regarding their contents due to linguistic and taxonomic ambiguities, similar morphologies and different definitions of Paeoniae Radix in the Korean and Chinese national pharmacopoeias, leading to the distribution of adulterated products. To develop a method for identifying the four Paeonia species used in these medicines, three fluorescently-labeled peptide nucleic acid (PNA) probes were designed against ITS2 sequences containing single nucleotide polymorphisms (SNPs) and used in a real-time PCR melting curve assay. Each of the four Paeonia species was accurately identified using this analysis. The accuracy and analytical stability of the PNA melting curve assay was confirmed using commercially available samples of the four Paeonia species. This assay is a reliable genetic tool to distinguish between different Paeonia-derived herbal medicines and identify the botanical origins of Paeoniae Radix and Moutan Radicis Cortex. This technique may also contribute to quality control and standardization of herbal medicines by providing a reliable authentication tool and preventing the distribution of inauthentic adulterants.