Application of Partial Internal Transcribed Spacer Sequences for the Discrimination of Artemisia capillaris from Other Artemisia Species

Artemisia anomala Herba Alleviates 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis-Like Skin Lesions in Mice and the Production of Pro-Inflammatory Mediators in Tumor Necrosis Factor Alpha-/Interferon Gamma-Induced HaCaT Cells

Artemisia anomala S. Moore is a perennial herbaceous plant classified as Asteraceae of the genus Artemisia. Many species of Artemisia have been used as medicinal materials. Artemisia anomala S. Moore has been widely used in China to treat inflammatory diseases. However, the mechanism of its action on the keratinocyte inflammatory response is poorly understood. Here, we investigated the anti-inflammatory reaction of Artemisia anomala S. Moore ethanol extract (EAA) using human keratinocyte (HaCaT) cells, which involved investigating the nuclear factor kappa B (NF-κB), signal transducer, and activator of transcription-1 (STAT-1), as well as mitogen-activated protein kinase (MAPK) signaling pathways and atopic dermatitis-like skin lesions in mice. We elucidated the anti-inflammatory effects of EAA on tumor necrosis factor-α/interferon-γ (TNF-α/IFN-γ)-treated human keratinocyte cells and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD)-like mice. The levels of chemokines and cytokines (IL-8, IL-6, TARC, and RANTES) were determined by an enzyme-linked immunosorbent assay. The NF-κB, STAT-1, and MAPK signaling pathways in HaCaT cells were analyzed by western blotting. Thickening of the mice dorsal and ear skin was measured and inflammatory cell infiltration was observed by hematoxylin and eosin staining. Results showed that EAA suppressed IL-8, IL-6, TARC, and RANTES production. EAA inhibited nuclear translocation of NFκB and STAT-1, as well as reduced the levels of phosphorylated ERK MAPKs. EAA improved AD-like skin lesions in DNCB-treated mice. These findings suggest that EAA possesses stronger anti-inflammatory properties and can be useful as a functional food or candidate agent for AD.

Guaianolide Sesquiterpenes With Significant Antiproliferative Activities From the Leaves of Artemisia argyi

Four new guaiane-type sesquiterpenes, argyin H–K (1–4), and two known analogues (5 and 6) were isolated from the leaves of Artemisia argyi Lévl et Vant. The new compounds were characterized by the basic analysis of the spectroscopic data obtained (¹H NMR, ¹³C NMR, HMBC, and NOESY experiments), and their absolute configurations were determined by empirical approaches, combined with the exciton chirality method and electronic circular dichroism calculations. To further understand the antitumor effects of A. argyi, the antiproliferative activities of these compounds against A549, MCF-7, and HepG2 cell lines were tested in vitro using CCK-8 assays. The results showed that these compounds had significant antiproliferative effects on MCF-7, with IC₅₀ values of 15.13–18.63 μM, which were superior to that of oxaliplatin (i.e., IC₅₀ 22.20 μM).

Identification of medicinal plants within the Apocynaceae family using ITS2 and psbA-trnH barcodes

To ensure the safety of medications, it is vital to accurately authenticate species of the Apocynaceae family, which is rich in poisonous medicinal plants. We identified Apocynaceae species by using nuclear internal transcribed spacer 2 (ITS2) and psbA-trnH based on experimental data. The identification ability of ITS2 and psbA-trnH was assessed using specific genetic divergence, BLAST1, and neighbor-joining trees. For DNA barcoding, ITS2 and psbA-trnH regions of 122 plant samples of 31 species from 19 genera in the Apocynaceae family were amplified. The PCR amplification for ITS2 and psbA-trnH sequences was 100%. The sequencing success rates for ITS2 and psbA-trnH sequences were 81% and 61%, respectively. Additional data involved 53 sequences of the ITS2 region and 38 sequences of the psbA-trnH region were downloaded from GenBank. Moreover, the analysis showed that the inter-specific divergence of Apocynaceae species was greater than its intra-specific variations. The results indicated that, using the BLAST1 method, ITS2 showed a high identification efficiency of 97% and 100% of the samples at the species and genus levels, respectively, via BLAST1, and psbA-trnH successfully identified 95% and 100% of the samples at the species and genus levels, respectively. The barcode combination of ITS2/psbA-trnH successfully identified 98% and 100% of samples at the species and genus levels, respectively. Subsequently, the neighbor joining tree method also showed that barcode ITS2 and psbA-trnH could distinguish among the species within the Apocynaceae family. ITS2 is a core barcode and psbA-trnH is a supplementary barcode for identifying species in the Apocynaceae family. These results will help to improve DNA barcoding reference databases for herbal drugs and other herbal raw materials.

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.

Identification and Monitoring of Amomi Fructus and its Adulterants Based on DNA Barcoding Analysis and Designed DNA Markers

Amomi Fructus is one of the traditional medicines derived from the ripe fruits of the Zingiberaceae family of plants, which include Amomum villosum, A. villosum var. xanthioides, and A. longiligulare. Owing to their highly similar morphological traits, several kinds of adulterants of Amomi Fructus have been reported. Therefore, accurate and reliable methods of identification are necessary in order to ensure drug safety and quality. We performed DNA barcoding using five regions (ITS, matK, rbcL, rpoB, and trnL-F intergenic spacer) of 23 Amomi Fructus samples and 22 adulterants. We designed specific DNA markers for Amomi Fructus based on the single nucleotide polymorphisms (SNPs) in the ITS. Amomi Fructus was well separated from the adulterants and was classified with the species of origin based on the detected SNPs from the DNA barcoding results. The AVF1/ISR DNA marker for A. villosum produced a 270 bases amplified product, while the ALF1/ISF DNA marker produced a 350 bases product specific for A. longiligulare. Using these DNA markers, the monitoring of commercially distributed Amomi Fructus was performed, and the monitoring results were confirmed by ITS analysis. This method identified samples that were from incorrect origins, and a new species of adulterant was also identified. These results confirmed the accuracy and efficiency of the designed DNA markers; this method may be used as an efficient tool for the identification and verification of Amomi Fructus.

A comprehensive study on in vitro and in vivo toxicological evaluation of Artemisia capillaris

Artemisia capillaris (AC) has been used as an alternative therapy in obesity, atopic dermatitis, and liver diseases through several biological activity including anti-steatotic, antioxidant, and anti-inflammatory activities. Despite its ethnomedicinal benefits, no sufficient background information is available about the long-term safety and genotoxicity of the AC extract. Therefore, the present study was carried out to investigate the 13-week subchronic toxicity and genotoxicity of the AC extract according to the test guidelines published by the Organization for Economic Cooperation and Development. In the 13-week toxicity study using doses of 25, 74, 222, 667, and 2000 mg/kg body weight, oral administration of the AC extract in male and female rats did not result in any significant adverse effects in food/water consumption, body weight, mortality, hematology, serum biochemistry, organ weight and histopathology. Accordingly, the no-observed-adverse-effect level in rats of both genders was established for the AC extract at 2000 mg/kg/day, the highest dose level tested. In addition, the AC extract was not genotoxic in a battery of tests including Ames test, in vitro chromosome aberration assay and in vivo micronucleus assay. In conclusion, we demonstrated that the AC extract is considered as a safe traditional medicine for human consumption.

Suppression of Primary Splenocyte Proliferation by Artemisia capillaris and Its Components

The host immune system is the first line of host defense, consisting mainly of innate and adaptive immunity. Immunity must be maintained, orchestrated, and harmonized, since overactivation of immune responses can lead to inflammation and autoimmune diseases, while immune deficiency can lead to infectious diseases. We investigated the regulation of innate and adaptive immune cell activation by Artemisia capillaris and its components (ursolic acid, hyperoside, scopoletin, and scopolin). Macrophage phagocytic activity was determined using fluorescently labeled Escherichia coli, as an indicator of innate immune activation. Concanavalin A (ConA)- and lipopolysaccharide (LPS)-induced splenocyte proliferation was analyzed as surrogate markers for cellular and humoral adaptive immunity, respectively. Neither A. capillaris water extract (WAC) nor ethanol extract (EAC) greatly inhibited macrophage phagocytic activity. In contrast, WAC suppressed ConA- and LPS-induced proliferation of primary mouse splenocytes in a dose-dependent manner. Similarly, EAC inhibited ConA- and LPS-induced splenocyte proliferation. Oral administration of WAC in mice decreased ConA- and LPS-induced splenocyte proliferation, while that of EAC suppressed LPS-induced splenocyte proliferation. Repeated administration of WAC in mice inhibited ConA- and LPS-induced splenocyte proliferation. Ursolic acid, scopoletin, and scopolin reduced ConA- and LPS-induced primary mouse splenocyte proliferation, while hyperoside did not show such activity. These results indicate that A. capillaris and its components, ursolic acid, scopoletin, and scopolin, suppress ConA- and LPS-induced adaptive immune cell activation. The results suggest that A. capillaris is useful as a regulator of adaptive immunity for diseases involving excessive immune response activation.