DNA Barcode for Identifying Folium Artemisiae Argyi from Counterfeits

A review of the research progress on Artemisia argyi Folium: botany, phytochemistry, pharmacological activities, and clinical application

As a kind of well-known moxibustion material across the world, Artemisia argyi Folium (AAF) has a definite curative effect. From 1996 to now, various studies on AAF have been increasing year by year. That is why this paper is conducted because of no comprehensive summary except for an essential oil review recently published in 2023. Using "AAF" and "mugwort" as keywords, the related literature was summarized in four internationally recognized databases: PubMed, Web of Science, ACS, and ScienceDirect, mainly include four aspects such as botany, phytochemistry, pharmacology, and clinical application. Four traditional identification methods and two new ones were reported. A total of 136 compounds were identified, among which 23 new terpenoids and two new flavonoids were discovered. The pharmacological effects of AAF mainly focus on anti-inflammatory, anti-tumor, antioxidant, antibacterial, and other aspects. Clinically, it is mainly used in respiratory, immune, digestive, and nervous systems in addition to gynecology. The current research mainly focuses on the composition and pharmacology of AAF. Future studies should thoroughly establish the quality criteria and pharmacokinetics of AAF. According to the different application fields, the corresponding quality standards should be formulated to ensure the efficacy of drugs in the actual treatment.

Metabolomic and transcriptomic analyses provide insights into variations in flavonoids contents between two Artemisia cultivars

BACKGROUND

Plants in the genus Artemisia are rich in active ingredients and specialized metabolites. Many of these compounds, especially flavonoids, have potential medicinal and nutritional applications, and are of growing interest to scientists due to their wide range of pharmacological and biological activities. Artemisia cultivars are commonly used as raw materials for medicine, food, and moxibustion in China. However, most of the metabolites produced by Artemisia species have not been identified, and few studies have addressed differences in active compounds between species and cultivars.

RESULTS

We here investigated two Artemisia cultivars, 'Nanyangshiyong' (NYSY) and 'Nanyangyaoyong' (NYYY), which are commonly used in foods and moxibustion, respectively. NYSY and NYYY were confirmed to be Artemisia argyi cultivars. Total flavonoids contents and antioxidant activities were higher in NYYY than in NYSY. A total of 882 metabolites were identified in the samples; most of the potentially medicinally active compounds, especially flavonoids (e.g., flavone, flavonol, isoflavone, and anthocyanin), were up-regulated in NYYY compared to NYSY. Furthermore, most of the genes related to flavonoids biosynthesis were up-regulated in NYYY. Correlation analysis was used to identify putative members of transcription factor families that may regulate genes encoding key flavonoids biosynthesis enzymes.

CONCLUSIONS

We found that the antioxidant activities and flavonoids contents significantly varied between two Artemisia cultivars of the same species. We also uncovered metabolomic and transcriptomic evidence of the molecular phenomena underlying those differences in flavonoids contents between the two Artemisia cultivars. This study provides a wealth of data for future utilization and improvements of Artemisia cultivars, and highlights a need to study the specific metabolite profiles of plants that are used in foods and medicines.

Integrative analysis of metabolite and transcriptome reveals biosynthetic pathway and candidate genes for eupatilin and jaceosidin biosynthesis in Artemisia argyi

Artemisia argyi (A. argyi) is a medicinal plant belonging to the Asteraceae family and Artemisia genus. Flavonoids abundant in A. argyi are associated with anti-inflammatory, anticancer, and antioxidative effects. Eupatilin and jaceosidin are representative polymethoxy flavonoids with medicinal properties significant enough to warrant the development of drugs using their components. However, the biosynthetic pathways and related genes of these compounds have not been fully explored in A. argyi. This study comprehensively analyzed the transcriptome data and flavonoids contents from four different tissues of A. argyi (young leaves, old leaves, trichomes collected from stems, and stems without trichomes) for the first time. We obtained 41,398 unigenes through the de-novo assembly of transcriptome data and mined promising candidate genes involved in the biosynthesis of eupatilin and jaceosidin using differentially expressed genes, hierarchical clustering, phylogenetic tree, and weighted gene co-expression analysis. Our analysis led to the identification of a total of 7,265 DEGs, among which 153 genes were annotated as flavonoid-related genes. In particular, we were able to identify eight putative flavone-6-hydroxylase (F6H) genes, which were responsible for providing a methyl group acceptor into flavone basic skeleton. Furthermore, five O-methyltransferases (OMTs) gene were identified, which were required for the site-specific O-methylation during the biosynthesis of eupatilin and jaceosidin. Although further validation would be necessary, our findings pave the way for the modification and mass-production of pharmacologically important polymethoxy flavonoids through genetic engineering and synthetic biological approaches.

Genome sequencing reveals chromosome fusion and extensive expansion of genes related to secondary metabolism in Artemisia argyi

Artemisia argyi, as famous as Artemisia annua, is a medicinal plant with huge economic value in the genus of Artemisia and has been widely used in the world for about 3000 years. However, a lack of the reference genome severely hinders the understanding of genetic basis for the active ingredient synthesis of A. argyi. Here, we firstly report a complex chromosome-level genome assembly of A. argyi with a large size of 8.03 Gb, with features of high heterozygosity (2.36%), high repetitive sequences (73.59%) and a huge number of protein-coding genes (279 294 in total). The assembly reveals at least three rounds of whole-genome duplication (WGD) events, including a recent WGD event in the A. argyi genome, and a recent burst of transposable element, which may contribute to its large genome size. The genomic data and karyotype analyses confirmed that A. argyi is an allotetraploid with 34 chromosomes. Intragenome synteny analysis revealed that chromosomes fusion event occurred in the A. argyi genome, which elucidates the changes in basic chromosome numbers in Artemisia genus. Significant expansion of genes related to photosynthesis, DNA replication, stress responses and secondary metabolism were identified in A. argyi, explaining the extensive environmental adaptability and rapid growth characteristics. In addition, we analysed genes involved in the biosynthesis pathways of flavonoids and terpenoids, and found that extensive gene amplification and tandem duplication contributed to the high contents of metabolites in A. argyi. Overall, the reference genome assembly provides scientific support for evolutionary biology, functional genomics and breeding in A. argyi and other Artemisia species.

Sequence Characteristics and Phylogenetic Analysis of the Artemisia argyi Chloroplast Genome

Artemisia argyi Levl. et Van is an important Asteraceae species with a high medicinal value. There are abundant A. argyi germplasm resources in Asia, especially in China, but the evolutionary relationships of these varieties and the systematic localization of A. argyi in the family Asteraceae are still unclear. In this study, the chloroplast (cp) genomes of 72 A. argyi varieties were systematically analyzed. The 72 varieties originated from 47 regions in China at different longitudes, latitudes and altitudes, and included both wild and cultivated varieties. The A. argyi cp genome was found to be ∼151 kb in size and to contain 114 genes, including 82 protein-coding, 28 tRNA, and 4 rRNA genes. The number of short sequence repeats (SSRs) in A. argyi cp genomes ranged from 35 to 42, and most of them were mononucleotide A/T repeats. A total of 196 polymorphic sites were detected in the cp genomes of the 72 varieties. Phylogenetic analysis demonstrated that the genetic relationship between A. argyi varieties had a weak relationship with their geographical distribution. Furthermore, inverted repeat (IR) boundaries of 10 Artemisia species were found to be significantly different. A sequence divergence analysis of Asteraceae cp genomes showed that the variable regions were mostly located in single-copy (SC) regions and that the coding regions were more conserved than the non-coding regions. A phylogenetic tree was constructed using 43 protein-coding genes common to 67 Asteraceae species. The resulting tree was consistent with the traditional classification system; Artemisia species were clustered into one group, and A. argyi was shown to be closely related to Artemisia lactiflora and Artemisia montana. In summary, this study systematically analyzed the cp genome characteristics of A. argyi and compared cp genomes of Asteraceae species. The results provide valuable information for the definitive identification of A. argyi varieties and for the understanding of the evolutionary relationships between Asteraceae species.

Moxa Wool in Different Purities and Different Growing Years Measured by Terahertz Spectroscopy

Moxa wool is a traditional Chinese herbal medicine, which can warm channels to dispel coldness. At present, there is no unified index to evaluate the purity and growing years of moxa wool in the market. Terpineol is one of the effective substances in the volatile oil of moxa wool. Here, we characterize the purity and growing years of moxa wool by studying terpineol. Gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) are the methods for monitoring terpineol at present, all of which have defects of complicated procedures. We established linear fitting to distinguish the different purities of moxa wool through the intensities (areas) of terpineol, the characteristic peaks, and the consequence presented; the coefficient of determination (R2) was higher than 0.90. Furthermore, based on the characteristic peak position of standard terpineol, the correlation model with the purity and growing year of moxa wool was set up, thereby differentiating the quality of moxa wool. We have built the partial least squares (PLS) model of the growing years of moxa wool with high accuracy, and the determination coefficient is greater than 0.98. In addition, we compare the quantitative accuracy of Raman spectroscopy with terahertz technology. Finally, a new method of terahertz spectroscopy to evaluate quality of moxa wool was found. It provides a new idea for the identification of inferior moxa wool in the market and a new method for identifying the quality of moxa wool in traditional Chinese medicine.

Genetic and chemical markers for authentication of three Artemisia species: A. capillaris, A. gmelinii, and A. fukudo

The genus Artemisia is an important source of medicines in both traditional and modern pharmaceutics, particularly in East Asia. Despite the great benefits of herbal medicine, quality assessment methods for these medicinal herbs are lacking. The young leaves from Artemisia species are generally used, and most of the species have similar morphology, which often leads to adulteration and misuse. This study assembled five complete chloroplast genomes of three Artemisia species, two accessions of A. gmelinii and A. capillaris, and one A. fukudo. Through comparative analysis, we revealed genomic variations and phylogenetic relationships between these species and developed seven InDel-based barcode markers which discriminated the tested species from each other. Additionally, we analyzed specialized metabolites from the species using LC-MS and suggested chemical markers for the identification and authentication of these herbs. We expect that this integrated and complementary authentication method would aid in reducing the misuse of Artemisia species.

Identification of Novel Biomarkers for Pre-diabetic Diagnosis Using a Combinational Approach

Reliable protein markers for pre-diabetes in humans are not clinically available. In order to identify novel and reliable protein markers for pre-diabetes in humans, healthy volunteers and patients diagnosed with pre-diabetes and stroke were recruited for blood collection. Blood samples were collected from healthy and pre-diabetic subjects 12 h after fasting. BMI was calculated from body weight and height. Fasting blood glucose (FBG), glycated hemoglobin (HbA1C), triglyceride (TG), total cholesterol, high-density lipoprotein, low-density lipoprotein (LDL), insulin and albumin were assayed by automated clinical laboratory methods. We used a quantitative proteomics approach to identify 1074 proteins from the sera of pre-diabetic and healthy subjects. Among them, 500 proteins were then selected using Mascot analysis scores. Further, 70 out of 500 proteins were selected via volcano plot analysis according to their statistical significance and average relative protein ratio. Eventually, 7 serum proteins were singled out as candidate markers for pre-diabetes due to their diabetic relevance and statistical significance. Immunoblotting data demonstrated that laminin subunit alpha 2 (LAMA2), mixed-lineage leukemia 4 (MLL4), and plexin domain containing 2 (PLXDC2) were expressed in pre-diabetic patients but not healthy volunteers. Receiver operating characteristic curve analysis indicated that the combination of the three proteins has greater diagnostic efficacy than any individual protein. Thus, LAMA2, MLL4 and PLXDC2 are novel and reliable serum protein markers for pre-diabetic diagnosis in humans.

Determination of Mineral Elements in Nanyang Mugwort (Artemisia argyi) Leaves Harvested from Different Crops by Inductively Coupled Plasma Mass Spectrometry and Inductively Coupled Plasma Atomic Emission Spectrometry

Due to high need for medical purposes, multiple harvests of mugwort (Artemisia argyi) have been extensively applied in China for the increase of mugwort yield recently. However, the investigation on the mineral elements in different crops, which are significantly related to mugwort growth and the clinical efficacy of this medicinal herb, has not been conducted. This study provided an analytical method and quality evaluation for mineral elements in Nanyang mugwort leaves harvested from three different crops. The contents of 35 mineral elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). ANOVA, principal component analysis and factor analysis were applied to evaluate the results. Four principal components were identified and their comprehensive evaluation function was as follows: F = 0.7008Fl + 0.1236F2 + 0.0936F3 + 0.0321F4. The comprehensive scores of the mugwort leaves from different crops were ranked as follows: 3rd crop > 2nd crop ≈ 1st crop. These findings can provide a reference for the quality control and clinical use of mugwort leaves, and a guidance of differential nourishing strategies for different crops.

Authentication, phytochemical characterization and anti-bacterial activity of twoArtemisiaspecies

Artemisia species are aromatic herbs used as food and/or ethnomedicine worldwide; however, the use of these plants is often impeded by misidentification. Here, molecular and chemotaxonomic approaches were combined to assist in the morphology-based authentication of Artemisia species, and Artemisia indica and Artemisia argyi were identified. The plant extracts and compounds obtained from these species, 1,8-cineole, carveol, α-elemene, α-farnesene, methyl linolenate, diisooctyl phthalate inhibited the growth of food-borne harmful bacteria. Mechanistic studies showed that the extract and active compounds of A. indica killed Gram-negative and -positive bacteria via destruction of the bacterial membrane. Finally, in vivo data demonstrated that A. indica protected against bacterial infection in mice as evidenced by survival rate, bacterial load in organs, gut pathology, diarrhea, body weight, food consumption, stool weight, and pathology score. A. indica and its active compounds have potential for use as food supplements for food-borne bacterial diseases and thus improve human health.

Comparative chloroplast genome analysis of Artemisia (Asteraceae) in East Asia: insights into evolutionary divergence and phylogenomic implications

BACKGROUND

Artemisia in East Asia includes a number of economically important taxa that are widely used for food, medicinal, and ornamental purposes. The identification of taxa, however, has been hampered by insufficient diagnostic morphological characteristics and frequent natural hybridization. Development of novel DNA markers or barcodes with sufficient resolution to resolve taxonomic issues of Artemisia in East Asia is significant challenge.

RESULTS

To establish a molecular basis for taxonomic identification and comparative phylogenomic analysis of Artemisia, we newly determined 19 chloroplast genome (plastome) sequences of 18 Artemisia taxa in East Asia, de novo-assembled and annotated the plastomes of two taxa using publicly available Illumina reads, and compared them with 11 Artemisia plastomes reported previously. The plastomes of Artemisia were 150,858-151,318 base pairs (bp) in length and harbored 87 protein-coding genes, 37 transfer RNAs, and 8 ribosomal RNA genes in conserved order and orientation. Evolutionary analyses of whole plastomes and 80 non-redundant protein-coding genes revealed that the noncoding trnH-psbA spacer was highly variable in size and nucleotide sequence both between and within taxa, whereas the coding sequences of accD and ycf1 were under weak positive selection and relaxed selective constraints, respectively. Phylogenetic analysis of the whole plastomes based on maximum likelihood and Bayesian inference analyses yielded five groups of Artemisia plastomes clustered in the monophyletic subgenus Dracunculus and paraphyletic subgenus Artemisia, suggesting that the whole plastomes can be used as molecular markers to infer the chloroplast haplotypes of Artemisia taxa. Additionally, analysis of accD and ycf1 hotspots enabled the development of novel markers potentially applicable across the family Asteraceae with high discriminatory power.

CONCLUSIONS

The complete sequences of the Artemisia plastomes are sufficiently polymorphic to be used as super-barcodes for this genus. It will facilitate the development of new molecular markers and study of the phylogenomic relationships of Artemisia species in the family Asteraceae.

Comparison of the abilities of universal, super, and specific DNA barcodes to discriminate among the original species of Fritillariae cirrhosae bulbus and its adulterants

Fritillariae cirrhosae bulbus is a famous type of traditional Chinese medicine used for cough relief and eliminating phlegm. The medicine originates from dried bulbs of five species and one variety of Fritillaria. Recently, immature bulbs from other congeneric species, such as F. ussuriensis, have been sold as adulterants of Fritillariae cirrhosae bulbus in medicine markets owing to the high price and limited availability of the genuine medicine. However, it is difficult to accurately identify the bulbs from different original species of Fritillariae cirrhosae bulbus and its adulterants based on traditional methods, although such medicines have different prices and treatment efficacies. The present study adopted DNA barcoding to identify these different species and compared the discriminatory power of super, universal, and specific barcodes in Fritillaria. The results revealed that the super-barcode had strong discriminatory power (87.5%). Among universal barcodes, matK provided the best species resolution (87.5%), followed by ITS (62.5%), rbcL (62.5%), and trnH-psbA (25%). The combination of these four universal barcodes provided the highest discriminatory power (87.5%), which was equivalent to that of the super-barcode. Two plastid genes, ycf1 and psbM-psbD, had much better discriminatory power (both 87.5%) than did other plastid barcodes, and were suggested as potential specific barcodes for identifying Fritillaria species. Phylogenetic analyses indicated that F. cirrhosa was not a "good" species that was composed of multiple lineages, which might have affected the evaluation of the discriminatory ability. This study revealed that the complete plastid genome, as super barcode, was an efficient and reliable tool for identifying the original species of Fritillariae cirrhosae bulbus and its adulterants.

Study of the Variation of Phenolic Acid and Flavonoid Content from Fresh Artemisiae argyi Folium to Moxa Wool

Artemisiae argyi Folium (AAF) is a popular herbal medicine that is always employed in moxa sticks and by oral dosage in clinical use. Less attention has been paid to nonvolatile compounds as active compounds, such as phenolic acids and flavonoids. In this study, we focused on the variation rule of phenolic acids and flavonoids in the various transformations of Artemisiae argyi Folium. Using the established ultra-performance liquid chromatography (UPLC) method with an excellent methodology under “spider-web” mode, six phenolic acids and three flavonoids were simultaneously quantified in fresh and drying Artemisiae argyi Folium as well as in moxa wool and residue. Some interesting phenomena about the variation rule of phenolic acids and flavonoids were uncovered. First, a sharp increase was observed in the detected compounds’ content as the moisture gradually decreased, when fresh Artemisiae argyi Folium was exposed to sunlight and ambient or high temperature. Nevertheless, the increased phenolic acids were subjected to high temperature, leading to obvious degradation under oven-drying (60 °C and 80 °C). Second, a wide content distribution was revealed for the detected compounds in Artemisiae argyi Folium from different habitats, especially rutin, caffeic acid, chlorogenic acid, jaceosidin, eupatilin, and cryptochlorogenic acid. Third, accompanied by the elevated ratio of Artemisiae argyi Folium/moxa wool, the detected compounds conspicuously decreased in moxa wool and the correspondingly removed powder as residue. Importantly, a greater variation was found in moxa wool. Our findings contribute to the optimization of the drying process, the quality evaluation of the various transformations of Artemisiae argyi Folium, and the distinctive characterization of moxa wool produced at different ratios of Artemisiae argyi Folium/moxa wool.