Species identification of Radix Astragali (Huangqi) by DNA sequence of its 5S-rRNA spacer domain

Identify production area, growth mode, species, and grade of Astragali Radix using metabolomics "big data" and machine learning

BACKGROUND

Astragali Radix (AR) is a widely used herbal medicine. The quality of AR is influenced by several key factors, including the production area, growth mode, species, and grade. However, the markers currently used to distinguish these factors primarily focus on secondary metabolites, and their validation on large-scale samples is lacking.

PURPOSE

This study aims to discover reliable markers and develop classification models for identifying the production area, growth mode, species, and grade of AR.

METHODS

A total of 366 batches of AR crude slices were collected from six provinces in China and divided into learning (n = 191) and validation (n = 175) sets. Three ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) methods were developed and validated for determining 22 primary and 10 secondary metabolites in AR methanol extract. Based on the quantification data, seven machine learning algorithms, such as Nearest Neighbors and Gradient Boosted Trees, were applied to screen the potential markers and build the classification models for identifying the four factors associated with AR quality.

RESULTS

Our analysis revealed that secondary metabolites (e.g., astragaloside IV, calycosin-7-O-β-D-glucoside, and ononin) played a crucial role in evaluating AR quality, particularly in identifying the production area and species. Additionally, fatty acids (e.g., behenic acid and lignoceric acid) were vital in determining the growth mode of AR, while amino acids (e.g., alanine and phenylalanine) were helpful in distinguishing different grades. With both primary and secondary metabolites, the Nearest Neighbors algorithm-based model was constructed for identifying each factor of AR, achieving good classification accuracy (>70%) on the validation set. Furthermore, a panel of four metabolites including ononin, astragaloside II, pentadecanoic acid, and alanine, allowed for simultaneous identification of all four factors of AR, offering an accuracy of 86.9%.

CONCLUSION

Our findings highlight the potential of integrating large-scale targeted metabolomics and machine learning approaches to accurately identify the quality-associated factors of AR. This study opens up possibilities for enhancing the evaluation of other herbal medicines through similar methodologies, and further exploration in this area is warranted.

Simple and robust differentiation of Ganoderma species by high performance thin-layer chromatography coupled with single quadrupole mass spectrometry QDa

In this study, a high performance thin-layer chromatography/single quadrupole mass spectrometry QDa (HPTLC-QDa) method for robust authentication of Ganoderma lucidum, a popular and valuable herbal medicine, has been developed. This method is simple and practical, which allows direct generation of characteristic mass spectra from the HPTLC plates automatically with the application of in situ solvent desorption interface. The HPTLC silica gel plates were developed with toluene-ethyl formate-formic acid (5 : 5 : 0.2, V/V) and all bands were transferred to QDa system directly in situ using 80% methanol with 0.1% formic acid as desorption solvent. The acquired HPTLC-QDa spectra showed that luminous yellow band b3, containing ganoderic acid B/G/H and ganodeneric acid B, the major active components of Ganoderma, could be found only in G. lucidum and G. lucidum (Antler-shaped), but not in G. sinense and G. applanatum. Moreover, bands b13 and b14 with m/z 475/477 and m/z 475/491/495, respectively, could be detected in G. lucidum (Antler-shaped), but not in G. lucidum, thus allowing simple and robust authentication of G. lucidum with confused species. This method is proved to be simple, practical and reproducible, which can be extended to analyze other herbal medicines.

A Comparative Study of 5S rDNA Non-Transcribed Spacers in Elaeagnaceae Species

5S rDNA is organized as a cluster of tandemly repeated monomers that consist of the conservative 120 bp coding part and non-transcribed spacers (NTSs) with different lengths and sequences among different species. The polymorphism in the 5S rDNA NTSs of closely related species is interesting for phylogenetic and evolutional investigations, as well as for the development of molecular markers. In this study, the 5S rDNA NTSs were amplified with universal 5S1/5S2 primers in some species of the Elaeagnaceae Adans. family. The polymerase chain reaction (PCR) products of five Elaeagnus species had similar lengths near 310 bp and were different from Shepherdia canadensis (L.) Nutt. and Sh. argentea (Pusch.) Nutt. samples (260 bp and 215 bp, respectively). The PCR products were cloned and sequenced. An analysis of the sequences revealed that intraspecific levels of NTS identity are high (approximately 95–96%) and similar in the Elaeagnus L. species. In Sh. argentea, this level was slightly lower due to the differences in the poly-T region. Moreover, the intergeneric and intervarietal NTS identity levels were studied and compared. Significant differences between species (except E. multiflora Thunb. and E. umbellata Thunb.) and genera were found. Herein, a range of the NTS features is discussed. This study is another step in the investigation of the molecular evolution of Elaeagnaceae and may be useful for the development of species-specific DNA markers in this family.

Phylogenetic relationships of Atractylodes lancea, A. chinensis and A. macrocephala, revealed by complete plastome and nuclear gene sequences

Atractylodes lancea, A. chinensis, and A. macrocephala are the three most widely used medicinal species of the Atractylodes genus. Their similar morphological features cause disagreement as whether they are three unique species, leading to their frequent misuses in medical products. Our study aimed to understand their relationships through both the complete plastome sequences and nuclear sequences, to identify molecular markers for their differentiation and explore the evolutionary relationships among three species. We sequenced, annotated, and analyzed the plastomes of these three species. The plastomes are 153,201, 153,258, and 153,265 bps in length for A. lancea, A. chinensis, and A. macrocephaly, respectively. Similar to other Asteraceae species, their plastomes exhibit typical quadripartite structures. Each plastome consists of 119 distinct genes, including 78 protein-coding, 37 tRNA, and 4 rRNA genes. Analyses of indels, single-nucleotide polymorphisms and simple sequence repeats, and comparison of plastomes showed high degree of conservation, leading to difficulty in the discovery of differentiating markers. We identified eleven potential molecular markers using an algorithm based on interspecific and intraspecific nucleotide diversity gaps. Validation experiments with fifty-five individuals from the three species collected from the botanical garden and fields confirmed that the marker cz11 could effectively distinguish samples from the three different species. Analysis of the several nuclear sequences suggests that the species of A. macrocephala may be a hybrid of A. lancea and A. chinensis. In summary, the results from this study highlight the complex relationships among of these three medicinal plants.

Cysteine-Rich Peptide Fingerprinting as a General Method for Herbal Analysis to Differentiate Radix Astragali and Radix Hedysarum

Species misidentification and adulteration are major concerns in authenticating herbal medicines. Radix Astragali (RA), the roots of Astragalus membranaceus, is a traditional herbal medicine used for treating diabetes. However, it is often substituted by Radix Hedysarum (RH), the roots of Hedysarum polybotrys from the same plant family Fabaceae, which possesses different bioactivities. Current authentication methods, focusing on the chemical composition differences of herbal medicines based on small molecules, have limitations when these chemical markers are found in many species. Herein, we describe a rapid and general method using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), coupled with multivariate analyses to differentiate herbal medicines. We used cysteine-rich peptide (CRP) fingerprinting, a method that exploits an underexplored chemical space between 2 to 6 kDa and which is populated by highly stable CRPs. To show the generality of the method, we screened 100 medicinal plant extracts and showed that CRP fingerprints are unique chemical markers. In addition, CRP fingerprinting was many-fold faster than the conventional authentication method using ultra-performance liquid chromatography (UPLC). Multivariate analyses showed that it has comparable classification accuracy as UPLC fingerprinting. Together, our findings revealed that CRP fingerprinting coupled with multivariate analyses is a rapid and general method for authentication and quality control for natural products in medicinal plants.

Comparison and application of fluorescence EEMs and DRIFTS combined with chemometrics for tracing the geographical origin of Radix Astragali

Selection of the appropriate method for traceability may be of great interest for the characterization of food authenticity and to reveal falsifications. The possibility of tracing the geographical origins of Radix Astragali based on diffuse reflectance mid-infrared Fourier transform spectroscopy (DRIFTS) technique and fluorescence fingerprints (EEMs) technique was investigated in this work. DRIFTS technique combined with PCA and PLS-DA and EEMs technique combined with M-PCA and N-PLS-DA were used to determine the geographical origin of Radix Astragali samples, respectively. DRIFTS-PLS-DA provided total recognition rates of 98.4% for all Radix Astragali samples in the training sets and 94.6% in the predicted sets. Compared with the DRIFTS, EEMs combined with chemometrics obtained more accurate recognition results. The total recognition rates (RRs) of the training sets and prediction sets obtained with EEMs-N-PLS-DA were all 100%. The good classification results of fluorescence fingerprints technique should be attributed mainly to two reasons. One reason is that three-dimensional fluorescence spectrum can provide more information than two-dimensional DRIFTS, and the other reason is that fluorescence spectrum has higher sensitivity and selectivity than the DRIFTS. Therefore, fluorescence fingerprint (EEMs) technique combined with chemometrics results more adequate for tracing the food geographical origin. It should be noted that the more the analysis target contains fluorescent substances, the more accurate results are obtained by using the fluorescent fingerprint method. Conversely, if the classification object contains very few fluorescent substances, the classification result may not be as good as the DRIFTS method. Furthermore, due to relatively cumbersome operation of fluorescence method, EEMs fluorescence method is unsuitable for rapid analysis as compared to infrared method.

Evaluation of the Pharmaceutical Properties and Value of Astragali Radix

Astragali Radix (AR), a Chinese materia medica (CMM) known as Huangqi, is an important medicine prescribed in herbal composite formulae (Fufang) by Traditional Chinese medicine (TCM) practitioners for thousands of years. According to the literature, AR is suggested for patients suffering from “Qi”- and “Blood”-deficiencies, and its clinical effects are reported to be related to anti-cancer cell proliferation, anti-oxidation, relief of complications in cardiovascular diseases, etc. The underlying cell signaling pathways involved in the regulation of these various diseases are presented here to support the mechanisms of action of AR. There are two botanical sources recorded in China Pharmacopoeia (CP, 2015): Astragalus membranaceus (Fisch.) Bge. Var. mongohlicus, (Bge.) Hsiao, and Astragalus membranaceus (Fisch.) Bge. (Fam. Leguminosae), whose extracts of dried roots are processed via homogenization-assisted negative pressure cavitation extraction. Geographic factors and extraction methods have impacts on the pharmaceutical and chemical profiles of AR. Therefore, the levels of the major bioactive constituents of AR, including polysaccharides, saponins, and flavonoids, may not be consistent in different batches of extract, and the pharmaceutical efficacy of these bioactive ingredients may vary depending on the source. Therefore, the present review mainly focuses on the consistency of the available sources of AR and extracts and on the investigation of the biological functions and mechanisms of action of AR and of its major bioactive constituents. Furthermore, it will also include a discussion of the most popular AR composite formulae to further elucidate their chemical and biological profiles and understand the pharmaceutical value of AR.

Danggui Buxue Tang (Astragali Radix and Angelicae Sinensis Radix) for menopausal symptoms: A review

BACKGROUND

Traditional Chinese medicine (TCM) has contributed greatly to human health in past several thousand years. Today, the development of TCM is facing two obstacles: (i) quality control of herbal extract; and (ii) action mechanisms not known.

OBJECTIVES

Among thousands of complex TCM formulations, Danggui Buxue Tang (DBT) is the simplest one. DBT is used to treat ailments in women and contains only two herbs, Astragali Radix (Huangqi; AR) and Angelicae Sinensis Radix (Danggui; ASR). The weight ratio of AR to ASR in DBT must be 5:1, as stipulated in AD 1247. By using DBT as a model formula, we develop a strategy to reveal the complexity of a traditional TCM formula.

RESULTS

There are 3 levels of research directions: (i) the preparation of DBT and its rationale behind; (ii) the traditional theory of DBT is elucidated by chemical and biological determinations; and (iii) the action mechanisms of DBT are revealed.

CONCLUSION

Through the chemical, biological, genomic and proteomic studies, a possible direction in resolving the preparation mythologies, pharmacological and mechanistic analyses of a TCM decoction is being proposed here.

Evaluation of Medicinal Categorization of Atractylodes japonica Koidz. by Using Internal Transcribed Spacer Sequencing Analysis and HPLC Fingerprinting Combined with Statistical Tools

Atractylodes rhizomes have been used as the herbal medicine “Changchul” or “Baekchul,” according to their clinical purpose, in Korea, China, and Japan. Among the Atractylodes species, the medicinal use of Atractylodes japonica has been controversial, as it is categorized as both Changchul and Baekchul in those countries, and, moreover, parts of the rhizome have been differently used, depending on age of the plant, in Korea. Chromatographic fingerprinting by using HPLC combined with chemometric analyses and internal transcribed spacer (ITS) sequencing analysis were conducted to classify and identify 34 crude drugs derived from Atractylodes rhizomes. The identification of the samples, authenticated by their morphological features as A. japonica Koidz. (Changchul and Baekchul), A. chinensis Koidz., and A. macrocephala Koidz., was confirmed as A. japonica, A. chinensis, and A. macrocephala by ITS sequencing. The results from chemometric analyses showed that the chemical components of the crude drugs from A. japonica were significantly different from those from A. macrocephala but were similar to those from A. chinensis. The analyses also suggested that the categorization by age of A. japonica as Changchul or Baekchul is not recommended. The results indicate that A. japonica should be categorized as “Changchul” and should not be further categorized by age.

Intraspecific and heteroplasmic variations, gene losses and inversions in the chloroplast genome of Astragalus membranaceus

Astragalus membranaceus is an important medicinal plant in Asia. Several of its varieties have been used interchangeably as raw materials for commercial production. High resolution genetic markers are in urgent need to distinguish these varieties. Here, we sequenced and analyzed the chloroplast genome of A. membranaceus (Fisch.) Bunge var. mongholicus (Bunge) P.K. Hsiao using the next generation DNA sequencing technology. The genome was assembled using Abyss and then subjected to gene prediction using CPGAVAS and repeat analysis using MISA, Tandem Repeats Finder, and REPuter. Finally, the genome was subjected phylogenetic and comparative genomic analyses. The complete genome is 123,582 bp long, containing only one copy of the inverted repeat. Gene prediction revealed 110 genes encoding 76 proteins, 30 tRNAs, and four rRNAs. Five intra-specific hypermutation loci were identified, three of which are heteroplasmic. Furthermore, three gene losses and two large inversions were identified. Comparative genomic analyses demonstrated the dynamic nature of the Papilionoideae chloroplast genomes, which showed occurrence of numerous hypermutation loci, frequent gene losses, and fragment inversions. Results obtained herein elucidate the complex evolutionary history of chloroplast genomes and have laid the foundation for the identification of genetic markers to distinguish A. membranaceus varieties.

TaqMan probe real-time polymerase chain reaction assay for the quantification of canine DNA in chicken nugget

This paper describes a short-amplicon-based TaqMan probe quantitative real-time PCR (qPCR) assay for the quantitative detection of canine meat in chicken nuggets, which are very popular across the world, including Malaysia. The assay targeted a 100-bp fragment of canine cytb gene using a canine-specific primer and TaqMan probe. Specificity against 10 different animals and plants species demonstrated threshold cycles (Ct) of 16.13 ± 0.12 to 16.25 ± 0.23 for canine DNA and negative results for the others in a 40-cycle reaction. The assay was tested for the quantification of up to 0.01% canine meat in deliberately spiked chicken nuggets with 99.7% PCR efficiency and 0.995 correlation coefficient. The analysis of the actual and qPCR predicted values showed a high recovery rate (from 87% ± 28% to 112% ± 19%) with a linear regression close to unity (R(2) = 0.999). Finally, samples of three halal-branded commercial chicken nuggets collected from different Malaysian outlets were screened for canine meat, but no contamination was demonstrated.

Integrated analysis for identifying radix astragali and its adulterants based on DNA barcoding

Radix Astragali is a popular herb used in traditional Chinese medicine for its proimmune and antidiabetic properties. However, methods are needed to help distinguish Radix Astragali from its varied adulterants. DNA barcoding is a widely applicable molecular method used to identify medicinal plants. Yet, its use has been hampered by genetic distance, base variation, and limitations of the bio-NJ tree. Herein, we report the validation of an integrated analysis method for plant species identification using DNA barcoding that focuses on genetic distance, identification efficiency, inter- and intraspecific variation, and barcoding gap. We collected 478 sequences from six candidate DNA barcodes (ITS2, ITS, psbA-trnH, rbcL, matK, and COI) from 29 species of Radix Astragali and adulterants. The internal transcribed spacer (ITS) sequence was demonstrated as the optimal barcode for identifying Radix Astragali and its adulterants. This new analysis method is helpful in identifying Radix Astragali and expedites the utilization and data mining of DNA barcoding.

Restriction fragment length polymorphism of the 5S-rRNA-NTS region: a rapid and precise method for plant identification

Molecular genetic methods have several advantages over classical morphological and chemical analyses. The genetic method requires genotype instead than phenotype, therefore PCR-based techniques have been widely used for a rapid identification of plant species, varieties and chemotypes. Recently, the molecular discrimination of some higher plant species has been evaluated using sequences of a 5S-rRNA gene spacer region. The variation in the nontranscribed sequence (NTS) region has been used in a number of plant species for studying intraspecific variation, genome evolution, and phylogenetic reconstruction. Here, we describe a rapid method based on the use of the 5S-rRNA-NTS region as a tool for plant DNA fingerprinting, which combines PCR, sequencing and restriction fragment length polymorphism analyses.

Deep sequencing of plant and animal DNA contained within traditional Chinese medicines reveals legality issues and health safety concerns

Traditional Chinese medicine (TCM) has been practiced for thousands of years, but only within the last few decades has its use become more widespread outside of Asia. Concerns continue to be raised about the efficacy, legality, and safety of many popular complementary alternative medicines, including TCMs. Ingredients of some TCMs are known to include derivatives of endangered, trade-restricted species of plants and animals, and therefore contravene the Convention on International Trade in Endangered Species (CITES) legislation. Chromatographic studies have detected the presence of heavy metals and plant toxins within some TCMs, and there are numerous cases of adverse reactions. It is in the interests of both biodiversity conservation and public safety that techniques are developed to screen medicinals like TCMs. Targeting both the p-loop region of the plastid trnL gene and the mitochondrial 16S ribosomal RNA gene, over 49,000 amplicon sequence reads were generated from 15 TCM samples presented in the form of powders, tablets, capsules, bile flakes, and herbal teas. Here we show that second-generation, high-throughput sequencing (HTS) of DNA represents an effective means to genetically audit organic ingredients within complex TCMs. Comparison of DNA sequence data to reference databases revealed the presence of 68 different plant families and included genera, such as Ephedra and Asarum, that are potentially toxic. Similarly, animal families were identified that include genera that are classified as vulnerable, endangered, or critically endangered, including Asiatic black bear (Ursus thibetanus) and Saiga antelope (Saiga tatarica). Bovidae, Cervidae, and Bufonidae DNA were also detected in many of the TCM samples and were rarely declared on the product packaging. This study demonstrates that deep sequencing via HTS is an efficient and cost-effective way to audit highly processed TCM products and will assist in monitoring their legality and safety especially when plant reference databases become better established.

Molecular Analysis of Leonurus Species in China Based on ITS and matK Sequences

The genus Leonurus has long been recognized as a natural group, but its interspecific relationship has not yet been studied in the light of sequence data. The ITS regions and matK sequences of all subgenera of Leonurus in China were amplified, sequenced and investigated. Phylogenies generated by maximum parsimony and neighbor-joining methods and division of the genus into two major clades. The phylogenetic results indicated that L. chaituroides has the very close phylogenetic relationship with Subg. Cardiochilium and supported the notion that L. macranthus acts as the bridge between Subg. cardiochilium and Subg. Leonurus. According to the analysis of information given by ITS and matK sequences, we suggest that ITS sequences would be more suitable to serve as markers for authentication of Herba Leonuri than matK does.

Polysaccharides from astragali radix restore chemical-induced blood vessel loss in zebrafish

Background

Astragali Radix has been used widely for the treatment of cardiovascular and cerebrovascular diseases, and to enhance endurance and stamina in traditional Chinese medicine (TCM) for over 2000 years. The polysaccharide constituents of Astragali Radix (ARP) are considered as one of the major constituents contributing to the multiple pharmacological effects of this medicinal plant. The purpose of the study is to evaluate the vascular regenerative activities of ARPs in a chemically-induced blood vessel loss model in zebrafish.

Methods

Blood vessel loss was induced in both Tg(fli-1a:EGFP)y1 and Tg(fli-1a:nEGFP)y7 embryos by administration of 300 nM VEGFR tyrosine kinase inhibitor II (VRI) for 3 h at 24 hpf (hour post-fertilization). Then, the blood vessel damaged zebrafish were treated with ARPs for 21 h and 45 h after VRI withdrawal. Morphological changes in intersegmental vessels (ISVs) of zebrafish larvae were observed under the fluorescence microscope and measured quantitatively. The rescue effect of ARPs in the zebrafish models was validated by measuring the relative mRNA expressions of Kdrl, Kdr and Flt-1 using real-time PCR.

Results

Two polysaccharide fractions, P4 (50000 D < molecular weight & diameter < 0.1 μm) and P5 (molecular diameter > 0.1 μm), isolated from Astragali Radix by ultrafiltration, produced a significant and dose-dependent recovery in VRI-induced blood vessel loss in zebrafish. Furthermore, the down-regulation of Flk-1 and Flt-1 mRNA expression induced by VRI was reversed by treatment with P4.

Conclusion

The present study demonstrates that P4 isolated from Astragali Radix reduces VRI-induced blood vessel loss in zebrafish. These findings support the hypothesis that polysaccharides are one of the active constituents in Astragali Radix, contributing to its beneficial effect on treatment of diseases associated with a deficiency in angiogenesis.

Plant genetics for forensic applications

An emerging application for plant DNA fingerprinting and barcoding involves forensic investigations. Examples of DNA analysis of botanical evidence include crime scene analysis, identifying the source of commercial plant products, and investigation of trade in illicit drugs. Here, we review real and potential applications of DNA-based forensic botany and provide a protocol for microsatellite genotyping of leaf material, a protocol that could be used to link a suspect to a victim or to a crime scene.

Study of the relationship between genetics and geography in determining the quality of Astragali Radix

Astragali Radix (AR), prepared from the roots of Astragalus membranaceus (FISCH. ex LINK) BUNGE or its variey, A. membranaceus (FISCH. ex LINK) BUNGE var. mongholicus (BUNGE) HSIAO., is one of the most used and valuable traditional Chinese medicines (TCMs). Historically, Hunyuan, Shanxi Province in China is the geo-authentic producing area of AR and crude AR from here called "geo-authentic." According to tradition, geo-authentic TCMs define both authenticity and quality. However, no scientific investigation has ever determined whether the superior quality of Hunyuan AR is due to the genetic characteristics or to the local environment. In our study, seeds of 30 AR samples representing the two varieties from different regions were cultivated in Hunyuan under the same conditions. A method, using ultra-performance liquid chromatography coupled with photodiode array detector and evaporative light scattering detectors, was developed to evaluate the quality through a simultaneous determination of four major isoflavonoids and four major saponins. The two AR varieties were successfully distinguished by principal component analysis while samples of the same species with different seeds origins could not be distinguished. A genetic study demonstrated that the internal transcribed spacer sequences of the nuclear ribosomal DNA in A. membranaceus var. mongholicus samples from different geographical regions were highly conservative. These results indicate that the content of active components in AR depends on the interaction of genotype and environment. At the varietal level, genetic properties appear to be more important for pharmaceutical quality than environmental factors, while on the intraspecific level environmental factors might be more important than genetic properties.

Chemical and genetic assessment of variability in commercial Radix Astragali (Astragalus spp.) by ion trap LC-MS and nuclear ribosomal DNA barcoding sequence analyses

Radix Astragali (Huangqi) has been demonstrated to have a wide range of immunopotentiating effects and has been used as an adjuvant medicine during cancer therapy. Identity issues in the collection of Radix Astragali exist because many sympatric species of Astragalus occur in the northern regions of China. In order to assess the quality, purity, and uniformity of commercial Radix Astragali, 44 samples were purchased from herbal stores in Hong Kong and New York City. The main constituents, including four isoflavonoids and three saponins, were quantitatively determined by liquid chromatography mass spectrometry (LC-MS). There was significant sample-to-sample variability in the amounts of the saponins and isoflavonoids measured. Furthermore, DNA barcoding utilizing the variable nuclear ITS spacer regions of the 44 purchased Radix Astragali samples were sequenced, aligned and compared. Eight polymorphic point mutations were identified which separated the Radix Astragali samples into three groups. These results indicate that the chemical and genetic variability that exists among Radix Astragali medicinal products is still a consistency and quality issue for this herbal. Two-way ANOVA analysis showed significant effects on the contents of the seven tested compounds when both phylogenetic and geographic (i.e., point of purchase) factors were considered. Therefore, chemical profiles determined by LC-MS and DNA profiles in ITS spacer domains could serve as barcode markers for quality control of Radix Astragali.

Radix Astragali extract promotes angiogenesis involving vascular endothelial growth factor receptor-related phosphatidylinositol 3-kinase/Akt-dependent pathway in human endothelial cells

Angiogenesis plays an important role in a wide range of physiological processes and many diseases are associated with dysregulation of angiogenesis. Radix Astragali, commonly used in traditional Chinese medicine, is a potential candidate for treating such diseases. However, the biological effects of Radix Astragali on angiogenesis and its underlying mechanisms are yet to be elucidated fully. This study describes the angiogenic effects of Radix Astragali extract (RAE) on human umbilical vein endothelial cells (HUVEC) in vitro. It was shown that RAE treatment stimulated HUVEC to proliferate. A significant increase in migration was observed in RAE-treated HUVEC using the wound healing migration assay. In addition, a significant increase in the number of branching points was observed during endothelial cell capillary formation after RAE treatment. It was shown that RAE enhances vascular endothelial growth factor (VEGF) mRNA expression, and that a specific blocker of VEGF receptor 2 (KDR/Flk) inhibited the RAE-induced HUVEC proliferation. In addition, a decrease in the RAE-induced HUVEC proliferation was observed after treatment with inhibitors of phosphatidylinositol 3-kinase (PI3K), Akt and endothelial nitric oxide synthase (eNOS). Taken together, these data suggest that RAE is a potent stimulator of angiogenesis and that its pro-angiogenic effects involve the VEGF-KDR/Flk and PI3K-Akt-eNOS pathways.

Molecular analyses of the Chinese herb Leigongteng (Tripterygium wilfordii Hook.f.)

Tripterygium wilfordii Hook.f., known as Leigongteng (Thunder God Vine) in traditional Chinese medicine, has attracted much attention for its applications in relieving autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus, and for treating cancer. Molecular analyses of the ITS and 5S rDNA sequences indicate that T. hypoglaucum and T. doianum are not distinct from T. wilfordii, while T. regelii should be recognized as a separate species. The results also demonstrate potential value of rDNA sequence data in forensic detection of adulterants derived from Celastrus angulatus in commercial samples of Leigongteng.

DNA barcoding provides distinction between Radix Astragali and its adulterants

Based on variable nuclear and/or organellar DNA sequences among vastly divergent species as well as morphologically indistinguishable species, DNA barcoding is widely applicable in species identification, biodiversity studies, forensic analyses, and authentication of medicinal plants. The roots of Astragalus membranaceus and A. membranaceus var. mongholica are commonly used as Radix Astragali in several Asian countries, including China, Japan, and Korea. However, in addition to the two species recorded in the Chinese Pharmacopoeia, there are twenty-three species from different genera including Astragalus, Oxytropis, Hedysarum, and Glycyrrhiza, which have been used as adulterants not only in trading markets but also by the herbal medicine industry. Therefore, a simple, reliable, and accurate classification method is important for distinguishing authentic Radix Astragali from its adulterants. In this study, we acquired data for 37 samples from four related genera within the family Fabaceae. Then we compared four candidate DNA barcoding markers using ITS, matK, rbcL, and coxI sequences from nuclear, chloroplast, and mitochondrial genomes, all commonly used for plants to identify genetic variations among genera, intraspecies, and interspecies. We observed higher divergences among genera and interspecies for ITS, which have the average Kimura 2-parameter distances of 4.5% and 14.1%, respectively, whereas matK was found to have sufficient divergence at the intraspecific level. Moreover, two indels detected in the matK sequence are useful for PCR studies in distinguishing Radix Astragali from its adulterants. This study suggests that the combined barcoding regions of ITS and matK are superior barcodes for Radix Astragali and further studies should focus on evaluating the applicability and accuracy of such combined markers for a wide range of traditional Chinese herbs.

Systematic review of the renal protective effect of Astragalus membranaceus (root) on diabetic nephropathy in animal models

GOALS

Diabetic nephropathy (DN) has long been recognized as the leading cause of end-stage renal disease. Recent experimental studies have shown that Astragalus membranaceus (AM) (root) has an inhibitory effect on the oxidative stress that characterizes early DN. This systematic review assesses the efficacy and safety of AM (root), used as a single herb, in slowing the progression of DN in diabetic rat models.

METHODS

We conducted both an electronic search and a search by hand of randomized, controlled AM (root) treatment studies (including its effective components) focusing on animal models of DN. Two reviewers independently selected and assessed the studies.

RESULTS

Among the 41 articles identified, 13 reports that fulfilled the inclusion criteria were included. Significant beneficial effects were observed in the AM (root) treated groups compared to controls regarding fasting blood glucose levels (standardized mean difference [SMD]: -2.86, 95% confidential interval (CI): -4.26, -1.46, P < 0.001), glomerular filtration rate (SMD: -3.36, 95% CI: -4.69, -2.03, P < 0.00001), urinary albumin excretion rate (SMD: -2.46, 95% CI: -3.75, -1.16, P = 0.0002), and thickness of the glomerular basement membrane (SMD: -3.51, 95% CI: -6.68, -0.34, P = 0.03).

CONCLUSIONS

AM (root) and its effective components are effective in reducing fasting blood glucose and albuminuria levels, in reversing the glomerular hyperfiltration state, and in ameliorating the pathological changes of early DN in rat models.

Phenylalanine ammonia lyase functions as a switch directly controlling the accumulation of calycosin and calycosin-7-O-beta-D-glucoside in Astragalus membranaceus var. mongholicus plants

Previously it had been shown that calycosin and calycosin-7-O-beta-D-glucoside (CGs) accumulate in whole plants, mainly in leaves, of Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao (A. mongholicus) plants in response to low temperature. In this work, it was demonstrated that the influences of different conditions on CGs biosynthesis, by examining the changes in CGs content, as well as the expression of related genes, including phenylalanine ammonia lyase (PAL1), cinnamic acid 4-hydroxylase (C4H), chalcone synthase (CHS), chalcone reductase (CHR), chalcone isomerase (CHI), isoflavone synthase (IFS), and isoflavone 3'-hydroxylase (I3'H). The seven gene mRNAs accumulated in leaves of A. mongholicus upon exposure to low temperature in a light-dependent manner, though they exhibited different expression patterns. Transcriptions of CHS, CHR, CHI, IFS, and I3'H of the calycosin-7-O-beta-D-glucoside pathway were all up-regulated when plants were transferred from 16 degrees C to 2 degrees C or 25 degrees C or from 2 degrees C (kept for 24 h) to 25 degrees C. However, fluctuations in temperature influenced differently the transcriptions of PAL1 and C4H of the general phenylpropanoid pathway in leaves. Moreover, the amount of PAL1 expression changed sharply up and down, consistent with the variation of the content of CGs. PAL enzyme activity appears to be the limiting factor in determining the CGs levels. The inhibitor of PAL enzyme, L-alpha-aminooxy-beta-phenylpropionic acid, almost entirely shut down CGs accumulation at low temperature. All these results confirmed that PAL1, as a smart gene switch, directly controls the accumulation of CGs in A. mongholicus plants, in a light-dependent manner, during low temperature treatment.

Verification of the formulation and efficacy of Danggui Buxue Tang (a decoction of Radix Astragali and Radix Angelicae Sinensis): an exemplifying systematic approach to revealing the complexity of Chinese herbal medicine formulae

This article exemplifies a systematic approach to revealing the complexity of Chinese herbal medicine formulae through three levels of scientific research: standardization of herbs, verification of ancient formulae and mechanism studies. We use Danggui Buxue Tang (DBT) as an example for this approach. Among thousands of traditional Chinese medicine herbal formulae, almost all of which consist of multiple herbs, DBT is one of the simplest. Containing only two herbs, namely Radix Astragali (RA) and Radix Angelicae Sinensis (RAS), DBT is traditionally used to treat ailments in women. The weight ratio of RA to RAS in DBT was prescribed to be 5:1 as early as in 1247 AD. In addition to advanced chemical analysis of herbal constituents, DNA genotyping techniques have been developed for reliable standardization of RA and RAS. Chemical evaluation shows that main active constituents in DBT, including astragaloside IV, calycosin, formononetin and ferulic acid, were most abundant after extraction at the RA to RAS ratio of 5:1, whereas other tested RA to RAS ratios only gave sub-optimal levels of the active constituents. Biological evaluation indicates that bioactivities of DBT, e.g. immuno-modulatory, oesteotropic and estrogenic effects are also best exerted at the RA to RAS ratio of 5:1. Correlation analysis demonstrates statistically significant relationship between the tested chemical constituents and tested bioactivities. Up- and down-regulation of expression of some genes as potential biomarkers has been detected by using gene chip technology. This systematic approach on the basis of herbal standardization, chemical and biological verification and mechanism studies, as exemplified in this article, will be useful to reveal the complexity of not only DBT but also other Chinese medicine herbal formulae.

A novel compound from Hedysarum polybotrys

A polyhydroxyl constituent (1), named as polybotrin, along with two known compounds, were isolated from the roots of Hedysarum polybotrys. Their structures were identified based on chemical and spectroscopic evidence.

Molecular Analysis of the Genus Mitragyna Existing in Thailand Based on rDNA ITS Sequences and Its Application to Identify a Narcotic Species: Mitragyna speciosa

In Thailand, there are four Mitragyna species; M. speciosa, M. hirsuta, M. diversifolia, and M. rotundifolia. One, M. speciosa, is a narcotic plant and has medicinal importance for its opium-like effect. Since the use of M. speciosa has been forbidden in Thailand, the leaves of M. diversifolia or others are frequently used as substitutes but are not considered as effective. Therefore, accurate authentication of M. speciosa is essential for both medicinal and forensic purposes. The nucleotide sequences of internal transcribed spacers (ITS) and the 5.8S coding region of nuclear ribosomal DNA (rDNA) of the Mitragyna species were analyzed. The whole length of ITS1-5.8S-ITS2 region was 608 bp in M. speciosa, 607 bp in the other species. Nineteen sites of nucleotide substitutions and 3 sites of 1-bp indels were observed, and M. speciosa showed specific sequence differed from the others. Based on the ITS sequences, a distinctive site recognized by a restriction enzyme XmaI in M. speciosa was found and then PCR-restriction fragment length polymorphism (RFLP) analysis was established to differentiate M. speciosa from the others. By the method, a 409-bp PCR fragment of ITS1-5.8S (partial) rDNA region from M. speciosa was cleaved into two fragments of 119 bp and 290 bp while the other species remained undigested. This method provides an effective and accurate identification of M. speciosa.

PCR and PCR-RFLP of the 5S-rRNA-NTS region and salvinorin A analyses for the rapid and unequivocal determination of Salvia divinorum

Salvia divinorum Epling & Játiva-M. is a perennial herb belonging to the Lamiaceae family; its active ingredient, the neoclerodane diterpene salvinorin A, is a psychotropic molecule that produces hallucinations. A comparative evaluation of S. divinorum fresh and dried leaves, S. officinalis fresh leaves, and dried powdered leaves claimed to be S. divinorum was done. HPLC-MS data confirmed the presence of salvinorin A in both S. divinorun leaf extracts and the powdered leaves, whereas no salvinorin A was found in S. officinalis. The non-transcribed spacer (NTS) in the 5S-rRNA gene of all leaf samples and the dried powdered leaves was amplified by PCR using a pair of primers located at the 3' and 5' ends of the coding sequence of 5S-rRNA gene. The resulting PCR products (about 500bp for S. divinorum and 300bp for S. officinalis) were gel purified, subcloned into pGEM-T Easy vector and sequenced. By aligning the isolated nucleotide sequences, great diversities were found in the spacer region of the two species. Specific S. divinorum primers were designed on the sequence of the 5S-rRNA gene spacer region. In addition, a PCR-restriction fragment length polymorphism (PCR-RFLP) method was applied using NdeI and TaqI restriction enzymes. An NdeI site, absent in S. officinalis, was found in S. divinorum NTS region at 428-433bp. For TaqI, multiple sites (161-164, 170-173, and 217-220bp) were found in S. officinalis, whereas a unique site was found in S. divinorum (235-238bp). The results of this work show that the combined use of analytical chemical (HPLC-MS) and molecular (DNA fingerprinting) methods lead to the precise and unequivocal identification of S. divinorum.

A novel homodimeric lectin from Astragalus mongholicus with antifungal activity

A novel lectin (AMML) was isolated from a Chinese herb, i.e., the roots of Astragalus mongholicus, using a combination of ammonium sulfate fraction and ion exchange chromatographies. The molecular mass of intact AMML was determined to be 66,396 Da by MALDI-TOF mass spectrometry and 61.8 kDa by gel filtration, respectively. AMML was a dimeric protein composed of two identical subunits each with a molecular mass of 29.6 kDa. The lectin was a glycoprotein with a neutral carbohydrate content of 19.6%. The purified lectin hemagglutinated both rabbit and human erythrocytes, and showed preference for blood types O (native) and AB (trypsin-treated). Among various carbohydrates tested, the lectin was best inhibited by D-galactose and its derivatives with pronounced preference for lactose (3.13 mM). N-terminal amino acid sequence of AMML was determined as ESGINLQGDATLANN. The optimal pH range for lectin activity was between pH 4.5 and 7.5, and the lectin was active up to 65 degrees C. It also exerted antifungal activity against Botrytis cincerea, Fusarium oxysporum, Colletorichum sp., and Drechslera turcia but not against Rhizoctonia solani and Mycosphaerella arachidicola.

Genetic distinction of radix adenophorae from its adulterants by the DNA sequence of 5S-rRNA spacer domains

Radix Adenophorae (Shashen), a traditional Chinese medicine commonly used as an antitussive and expectorant, is derived from roots of Adenophora stricta Miq. and Adenophora tetraphylla (Thunb.) Fisch. Twelve species and varieties of Adenophora and Glehnia, however, could act as substitutes or adulterants of Radix Adenophorae on the commercial markets in South East Asia, and roots of Adenophora hunanensis Nannf. and Glihnia littoralis F. Schmidt ex Miq. are the most common examples. The authentic identification of dried roots of A. stricta and A. tetraphylla, however, is difficult on the basis of appearance and morphology. A molecular genetic approach was developed here to identify the species of Radix Adenophorae. The 5S-rRNA spacer domains (approximately 250 bp) were amplified by the polymerase chain reaction (PCR) from genomic DNAs isolated from A. stricta, A. tetraphylla, A. hunanensis and G. littoralis, and subsequently, the nucleotide sequences were determined. Diversity in DNA sequence and restriction enzyme mapping among various species were found in their 5S-rRNA spacer domains, which could serve as markers for authentic identification of Radix Adenophorae.