A systematic approach for authentication of medicinal Patrinia species using an integration of morphological, chemical and molecular methods.

Four common Patrinia species, including P. heterophylla, P. monandra, P. scabiosifolia and P. villosa, have been documented as herbal medicines with various clinical applications, such as anti-cancer, anti-diarrhea and sedative. However, the authentication of medicinal Patrinia species poses a problem, particularly with the processed herbal materials. This study aimed to systematically authenticate the four medicinal Patrinia species in the market using morphological and chemical characterization, as well as DNA markers. We found the species identity authenticated by traditional morphologies were in good agreement with both chemical and molecular results. The four species showed species-specific patterns in chromatographic profiles with distinct chemical markers. We also revealed the power of complete chloroplast genomes in species authentication. The sequences of targeted loci, namely atpB, petA, rpl2-rpl23 and psaI-ycf4, contained informative nucleotides for the species differentiation. Our results also facilitate authentication of medicinal Patrinia species using new DNA barcoding markers. To the best of our knowledge, this is the first report on the application of morphology, chemical fingerprinting, complete chloroplast genomes and species-specific Insertion-Deletions (InDels) in differentiating Patrinia species. This study reported on the power of a systematic, multidisciplinary approach in authenticating medicinal Patrinia species.

Ethnopharmacology of five flowers herbal tea, a popular traditional beverage in Hong Kong and South China.

BACKGROUND: It has been a long-standing tradition of using herbal tea for preventive and therapeutic healthcare in Hong Kong and South China and Five Flowers Tea is one of the most popular herbal teas. Based on the principle of traditional Chinese medicine, the pharmacological functions are to clear heat and dispel dampness in the body. Heat and dampness are thought to contribute to a range of health problems, especially during the hot and humid season in South China and Hong Kong. The most prevalent herbs in the formula contain bioactive compounds including flavonoids, alkaloids and terpenoids, which have a wide range of pharmacological properties including anti-inflammation, antivirus, antidiarrhoea, antibacteria, and antioxidation. However, with the composition varies widely, the ethnopharmacological benefits described may not be delivered uniformly. This study is to provide a comprehensive analysis on the composition of the Five Flowers Tea sold in Hong Kong and investigate the rationale behind the selection of herbs used in the formula. This study also provides information on the variation and quality of the Five Flowers Tea in the market. METHODS: Thirty-three Five Flowers Tea samples were collected from various locations in Hong Kong. The size, texture, colour and organoleptic properties were documented. Macroscopic and molecular authentication methods were employed to identify the individual components. RESULTS: Macroscopic identification revealed there were 23 herbs belonging to 18 plant families. The most prevalent herb was Bombax ceiba L., followed by Chrysanthemum morifolium. Ten adulterants and the existence of insect Lasioderma serricorne were confirmed by DNA barcoding techniques. CONCLUSION: This study employed a comprehensive approach to authenticate the herbs in Five Flowers Tea samples collected from various locations in Hong Kong. Macroscopic and molecular methods were used to identify the herbs and adulterants. The findings revealed the varied composition in Five Flowers Tea and the occurrence of adulterants in some samples. This shows that quality assurance of Five Flowers Tea is essential for the effective use of this popular folk medicine.

Application of a modified tetra-primer ARMS-PCR assay for rapid Panax species identity authentication in ginseng products.

Panax ginseng products can be adulterated with materials from other Panax species. The purpose of this study is to provide a rapid P. ginseng authentication method for simultaneous identification of P. ginseng and detection of adulteration in ginseng products at different processing stages. First, a tetra-primer ARMS-PCR assay was designed based on a single-nucleotide polymorphism (SNP) within the trnL-trnF region and was tested at 28 PCR cycles with DNA extracted from Botanical Reference Materials (BRMs). Next, 5' end random nucleotide and 3' terminus phosphorothioates linkage modifications were incorporated into the inner primers to improve sensitivity and specificity at 40 PCR cycles. Finally, the modified assay was validated using characterized market ginseng materials and the detection limit was determined. The modified tetra-primer ARMS-PCR assay can achieve the desired sensitivity and specificity using one set of reaction conditions in ginseng materials at different stages. In validation, it was able to correctly identify target species P. ginseng and differentiate it from closely related species. This study suggests that the modified tetra-primer ARMS-PCR assay can be used for the rapid, species identity authentication of P. ginseng material in ginseng products. This assay can be used to complement chemical analytical methods in quality control, so both species identity and processing attributes of ginseng products can be efficiently addressed.

Comparative Analysis of Chloroplast Genomes of Dalbergia Species for Identification and Phylogenetic Analysis.

Dalbergia L.f. is a pantropical genus consisting of 269 species of trees, shrubs, and woody lianas. This genus is listed in CITES Appendices because of illegal logging and trafficking driven by the high economic value of its heartwood. Some species are also used medicinally. Species identification of Dalbergia timber and herbs is challenging but essential for CITES implementation. Molecular methods had been developed for some timber species, mostly from Madagascar and Southeast Asia, but medicinal species in south China were usually not included in those studies. Here, we sequenced and assembled the chloroplast genomes of five Dalbergia species native to Hong Kong, four of which are medicinal plants. Our aim is to find potential genetic markers for the identification of medicinal Dalbergia species based on divergence hotspots detected in chloroplast genomes after comparative and phylogenetic analysis. Dalbergia chloroplast genomes displayed the typical quadripartite structure, with the 50 kb inversion found in most Papilionoideae lineages. Their sizes and gene content are well conserved. Phylogenetic tree of Dalbergia chloroplast genomes showed an overall topology similar to that of ITS sequences. Four divergence hotspots (trnL(UAA)-trnT(UGU), ndhG-ndhI, ycf1a and ycf1b) were identified and candidate markers for identification of several Dalbergia species were suggested.

Strategies for molecular authentication of herbal products: from experimental design to data analysis.

Molecular herbal authentication has gained worldwide popularity in the past decade. DNA-based methods, including DNA barcoding and species-specific amplification, have been adopted for herbal identification by various pharmacopoeias. Development of next-generating sequencing (NGS) drastically increased the throughput of sequencing process and has sped up sequence collection and assembly of organelle genomes, making more and more reference sequences/genomes available. NGS allows simultaneous sequencing of multiple reads, opening up the opportunity of identifying multiple species from one sample in one go. Two major experimental approaches have been applied in recent publications of identification of herbal products by NGS, the PCR-dependent DNA metabarcoding and PCR-free genome skimming/shotgun metagenomics. This review provides a brief introduction of the use of DNA metabarcoding and genome skimming/shotgun metagenomics in authentication of herbal products and discusses some important considerations in experimental design for botanical identification by NGS, with a specific focus on quality control, reference sequence database and different taxon assignment programs. The potential of quantification or abundance estimation by NGS is discussed and new scientific findings that could potentially interfere with accurate taxon assignment and/or quantification is presented.

Specific DNA identification of Pheretima in the Naoxintong capsule.

BACKGROUND: Pheretima is a minister drug in Naoxintong capsule (NXTC), a well-known traditional Chinese medicine (TCM) formula for the treatment of cardiovascular and cerebrovascular diseases. Owing to the loss of morphological and microscopic characteristics and the lack of recognized chemical marker, it is difficult to identify Pheretima in NXTC. This study aims to evaluate the feasibility of using DNA techniques to authenticate Pheretima, especially when it is processed into NXTC. METHODS: DNA was extracted from crude drugs of the genuine and adulterant species, as well as nine batches of NXTCs. Based on mitochondrial cytochrome c oxidase subunit I (COI) gene, specific primers were designed for two genera of genuine species, Metaphire and Amynthas, respectively. PCR amplification was performed with the designed primers on crude drugs of Pheretima and NXTCs. The purified PCR products were sequenced and the obtained sequences were identified to species level with top hit of similarity with BLAST against GenBank nucleotide database. RESULTS: Primers MF2R2 and AF3R1 could amplify specific DNA fragments with sizes around 230-250 bp, both in crude drugs and NXTC. With sequencing and the BLAST search, identities of the tested samples were found. CONCLUSION: This study indicated that the molecular approach is effective for identifying Pheretima in NXTC. Therefore, DNA identification may contribute to the quality control and assurance of NXTC.

Medicinal Materials DNA Barcode Database (MMDBD) version 1.5-one-stop solution for storage, BLAST, alignment and primer design.

Authentication of medicinal materials by deoxyribonucleic acid (DNA) technology is gaining popularity. In 2010, our team has created Medicinal Materials DNA Barcode Database (MMDBD) version 1.0 to provide an interactive database for documenting DNA barcode sequences of medicinal materials. This database now contains DNA barcode sequences of medicinal materials listed in the Chinese Pharmacopoeia, Dietary Supplements Compendium and Herbal Medicine Compendium of the US Pharmacopoeia and selected adulterants. The data archive is regularly updated and currently it stores 62 011 DNA sequences of 2111 medicinal materials. Our team has recently completed the major improvement on the interfaces and incorporated essential bioinformatics tools to facilitate the authentication work. MMDBD version 1.5 contains detailed information of each medicinal material including their material names, medical part, pharmacopeia information, biological classification in rank of family and status on the Convention on International Trade in Endangered Species of Wild Fauna and Flora and the International Union for Conservation of Nature's Red List of Threatened Species, if any. DNA sequences can be retrieved by search in Latin scientific name, Chinese name, family name, material name, medical part and simplified Chinese character stroke. A `BLAST'-based engine for searching DNA sequences is included in the MMDBD version 1.5. Since primer design is a key step in DNA barcoding authentication, we have integrated the `Clustal Omega alignment tool' and `Primer3' in the form of web interface. These new tools facilitate multiple sequence comparison and the design of primers for amplification of a target DNA barcode region, allowing DNA barcoding authentication.

Isolation of novel biflavonoids from Cardiocrinum giganteum seeds and characterization of their antitussive activities.

ETHNOPHARMACOLOGICAL RELEVANCE: Seeds of Cardiocrinum giganteum var. yunnanense (Leichtlin ex Elwes) Stearn (Liliaceae), also known as Doulingzi, have been used as a folk substitute for conventional antitussive herb "Madouling" (Aristolochia species) to treat chronic bronchitis and pertussis. The active antitussive phytochemicals in C. giganteum seeds are not known. AIM OF THE STUDY: The present work aims at isolating the active phytochemicals in C. giganteum seeds and confirming their antitussive effects. MATERIALS AND METHODS: Active chemicals were isolated from C. giganteum seeds ethanol extract and identified their structures. Antitussive effects were evaluated with the cough frequency of guinea pigs exposed to citric acid. Electrical stimulation of the superior laryngeal nerve in guinea pigs was performed to differentiate the acting site of potential antitussives. RESULTS: Two racemic biflavonoids (CGY-1 and CGY-2) were isolated from C. giganteum seeds. CGY-1 was identified as (S)-2″R,3″R- and (R)-2″S,3″S-dihydro-3″-hydroxyamentoflavone-7- methyl ether, which are new compounds and firstly isolated from C. giganteum seeds. Racemic CGY-2 was identified as (S)-2″R,3″R- and (R)-2″S,3″S-dihydro-3″-hydroxyamentoflavone. Both CGY-1 and CGY-2 could significantly inhibit coughs induced by inhalation of citric acid. Further, they acted on the peripheral reflex pathway to inhibit cough after electrical stimulation of the superior laryngeal nerve in guinea pigs. CONCLUSIONS: These chemicals isolated from C. giganteum seeds showed good antitussive effects. The data provide scientific evidence to support the traditional use of C. giganteum seeds as an antitussive herbal medicine.

Isolation and identification of polyphenols from Marsilea quadrifolia with antioxidant properties in vitro and in vivo.

Marsilea quadrifolia is an edible aquatic medicinal plant used as a traditional health food in Asia. Four new polyphenols including kaempferol 3-O-(2″-O-E-caffeoyl)-ß-d-glucopyranoside (1), kaempferol 3-O-(3″-O-E-caffeoyl)-α-l-arabinopyranoside (3), 4-methy-3'-hydroxypsilotinin (4) and (±)-(E)-4b-methoxy-3b,5b-dihydroxyscirpusin A (18) together with 14 known ones (2, 5-17) were isolated from the ethanol extract of M. quadrifolia. Structures of the new compounds were elucidated by extensive spectroscopic analyses. In DPPH and oxygen radical absorbance capacity antioxidant assays, some compounds showed stronger antioxidant activities and quercetin (9) was the most potent antioxidant in both assays. In a restraint-induced oxidative stress model in mice, quercetin significantly attenuated the increase in plasma ALT and AST levels as well as liver MDA content of restrained mice. Liver SOD activity was also significantly increased by quercetin, indicating a significant in vivo antioxidant activity. As a rich source of polyphenols with strong antioxidant activities, M. quadrifolia may be developed to a product for relieving oxidative stress.

Structures and Chemotaxonomic Significance of Stemona Alkaloids from Stemona japonica.

A pair of new alkaloid stereo-isomers, stemocochinin (1) and isostemocochinin (2), was obtained from the roots of Stemona japonica Miq., along with seven known alkaloids, stemonamine (3), isostemonamine (4), maistemonine (5), isomaistemonine (6), croomine (7), stemonine (8), and protostemonine (9). The complete structure and stereochemistry of the pair of isomers were established by extensive analysis of the spectral data. Furthermore, our results indicated that S. japonica is chemically closer to S. sessilifolia than S. tuberosa, which are consistent with our previous DNA study on Stemona species.