Phytochemistry and Ethnopharmacology of Epimedium L. Species

Exploring regulatory network of icariin synthesis in Herba Epimedii through integrated omics analysis

Herba Epimedii's leaves are highly valued in traditional Chinese medicine for their substantial concentration of flavonoids, which play a crucial role in manifesting the plant's therapeutic properties. This study investigated the metabolomic, transcriptomic and proteomic profiles of leaves from two Herba Epimedii cultivars, Epipremnum sagittatum (J) and Epipremnum pubescens (R), at three different developmental stages. Metabolite identification and analysis revealed a total of 1,412 and 1,421 metabolites with known structures were found. Flavonoids made up of 33%, including 10 significant accumulated icariin analogues. Transcriptomic analysis unveiled totally 41,644 differentially expressed genes (DEGs) containing five encoded genes participated in icariin biosynthesis pathways. Totally, 9,745 differentially expressed proteins (DEPs) were found, including Cluster-47248.2.p1 (UDP-glucuronosy/UDP-glucosyltransferase), Cluster-30441.2.p1 (O-glucosyltransferase), and Cluster-28344.9.p1 (anthocyanidin 3-O-glucoside 2 "-O-glucosyltransferase-like) through proteomics analysis which are involved to icariin biosynthesis. Protein-protein interaction (PPI) assay exhibited, totally 12 proteins showing a strong relationship of false discovery rate (FDR) <0.05 with these three proteins containing 2 leucine-rich repeat receptor kinase-like protein SRF7, and 5 methyl jasmonate esterase 1. Multi-omics connection networks uncovered 237 DEGs and 72 DEPs exhibited significant associations with the 10 icariin analogues. Overall, our integrated omics approach provides comprehensive insights into the regulatory network underlying icariin synthesis in Herba Epimedii, offering valuable resources for further research and development in medicinal plant cultivation and pharmaceutical applications.

Production of Rhamnosyl Icariside II by snailase hydrolysis of Epimedium wushanense extracts

Rhamnosyl Icariside II is a rare secondary flavonoid glycoside isolated from Epimedium L. plants. It has better stability and physiological activity than the primary flavonoid glycosides of Epimedium L., therefore, conversion of the primary flavonoid glycoside into Rhamnosyl Icariside II would be desirable. In this study, a method for the enzymatic production of Rhamnosyl Icariside II from the total flavonoids of Epimedium wushanense was established, and the conditions were optimized. Six commercial enzymes were screened, and the reaction conditions for the best enzyme were optimized. Snailase was the most effective hydrolase, and the highest yield was obtained under the optimized conditions. To facilitate industrial production of Rhamnosyl Icariside II, a scaled-up pilot test was performed. The reaction solution was extracted with n-butanol to obtain the Rhamnosyl Icariside II crude product, which was then subjected to silica gel column chromatography and preparative chromatography. Finally, a product of Rhamnosyl Icariside II with purity of 99.1 % was achieved, in a total yield of 46.8 %. Compared to direct extraction and acid hydrolysis, this method improves the product yield and purity, which is of great significance for the large-scale production of Rhamnosyl Icariside II. This study provides a basis for the physiological activity study of Rhamnosyl Icariside II, and offers possibilities for future applications in the healthcare sector.

A systematic review of traditional uses, phytochemistry, pharmacology and toxicity of Epimedium koreanum Nakai

ETHNOPHARMACOLOGICAL RELEVANCE

Epimedium koreanum Nakai (E. koreanum), a member of the genus Epimedium in the family Berberidaceae, is a well-known and well-liked traditional herb used as a "kidney tonic". For thousands of years, it has been utilized for renal yang deficiency, impotence, spermatorrhea, impotence, weakness of tendons and bones, rheumatic paralysis and discomfort, numbness, and constriction.

AIM OF THE STUDY

The paper aims to comprehensively in-depth, and methodically review the most recent research on the traditional uses, phytochemistry, pharmacology, and toxicity of E. koreanum.

MATERIALS AND METHODS

Scientific databases including Web of Science, PubMed, Google Scholar, Elsevier, Springer, ScienceDirect, Baidu Scholar, and CNKI and medicine books in China were searched for relevant information on E. koreanum.

RESULTS

In traditional uses, E. koreanum is frequently used to treat various diseases like erectile dysfunction, infertility, rheumatoid arthritis, osteoporosis, asthma, kidney-yang deficiency syndrome, etc. To date, more than 379 compounds have been discovered from various parts of E. koreanum, including flavonoids, lignans, organic acids, terpenoids, hydrocarbons, dihydrophenanthrene derivatives, alkaloids, and others. Research has revealed that the compounds and crude extracts have a wide range of pharmacological effects on the reproductive, cardiovascular, and nervous systems, as well as anti-osteoporosis, anti-tumor, antioxidant, anti-inflammatory, immunomodulatory, hepatoprotective, and antiviral properties. Besides, the crude extracts show potential hepatotoxicity.

CONCLUSION

Based on recent domestic and international research investigations, E. koreanum contains a wealth of chemical components with pronounced pharmacological activities. Its traditional uses are numerous, and the majority of these traditional uses have been supported by contemporary pharmacological investigations. Crude extracts, on the other hand, can result in hepatotoxicity. Therefore, additional in vivo and in vitro experimental research on the pharmacology and toxicology of E. koreanum are required in the future to assess its safety and efficacy. This will give a firmer scientific foundation for its safe application and the development of new drugs in the future.

DNA barcoding and comparative RNA-Seq analysis provide new insights into leaf formation using a novel resource of high-yielding Epimedium koreanum

Epimedium koreanum Nakai, a well-known traditional Chinese medicinal herb, has been widely used to treat osteoporosis and sexual dysfunction for thousands of years. However, due to the decreasing population of East Asian natural resources, yearly output of Epimedium crude herb has been in low supply year by year. In this study, an unusual variety of E. koreanum was discovered in Dunhua, Jilin Province, the northernmost area where this variety was found containing 6 individuals, with three branches that had 27 leaflets, which is much more than the typical leaflet number of 9. Firstly, the novel E. koreanum varety was identified using DNA barcodes. Then, 1171 differentially expressed genes (DEGs) were discovered through parallel RNA-seq analysis between the newly discovered variety and wild type (WT) E. koreanum plant. Furthermore, the results of bioinformatics investigation revealed that 914 positively and 619 negatively correlated genes associated with the number of leaflets. Additionally, based on RNA-Seq and qRT-PCR analysis, two homologous hub TCP genes, which were commonly implicated in plant leaf development, and shown to be up regulated and down regulated in the discovered newly variety, respectively. Thus, our study discovered a novel wild resource for leaf yield rewarding medicinal Epimedium plant breeding, provided insights into the relationship between plant compound leaf formation and gene expression of TCPs transcription factors and other gene candidates, providing bases for creating high yield cultivated Epimedium variety by using further molecular selection and breeding techniques in the future.

Icariin induces developmental toxicity via thyroid hormone disruption in zebrafish larvae

Icariin (ICA) is a natural flavonoid isolated from the traditional Chinese medicinal herb, Epimedium brevicornu Maxim. Although previous studies have reported that ICA exhibits various pharmacological activities, little is known about its toxicology. Herein, zebrafish embryos were exposed to ICA at 0, 2.5, 10, and 40 μM. In developmental analysis, reduced hatching rates, decreased body length, and abnormal swim bladder were found after treatment with 10 and 40 μM ICA. In addition, the ability of locomotor behavior was impaired by ICA. Two important thyroid hormones (THs), triiodothyronine (T3) and thyroxine (T4), were tested. The exposure resulted in a remarkable alteration of T4 level and a significant decrease of the T3/T4 ratio in the 40 μM, indicating thyroid endocrine disruption. Furthermore, gene transcription analysis showed that genes involved in thyroid development (nkx2.1) and THs synthesis (tg) were up-regulated after ICA exposure. Significant down-regulation of iodothyronine deiodinase (dio1) was also observed in the 10 and 40 μM groups compared to the control. Taken together, our study first demonstrated that ICA caused developmental toxicity possibly through disrupting thyroid development and hormone synthesis. These results show that it is necessary to perform risk assessments of ICA in clinical practice.

Insights into the Biological Activity and Cytotoxic Mechanism of Epimedium pubigerum

In this work, the phytochemical characterization, biological activity, and cytotoxic mechanism of aerial and rhizome methanol extracts (SME and RME) of Epimedium pubigerum were investigated to demonstrate its potential usage in the treatment of lung cancer. LC-HRMS analysis, total phenolic/flavonoid content assay, DPPH radical scavenging assay, DNA interaction, cytotoxicity, and western blotting were investigated using different methods. Fumaric acid was found to be the most abundant compound in both extracts. SME and RME were cytotoxic on A549 cells concentration-dependently. Also, in vitro scratch assay showed that SME and RME led to a significant anti-migratory effect at 1 mg/mL. Cytochrome c, p53, and caspase 3 expression significantly increased in the presence of RME compared to the control. All of these results claimed that RME might be suggested as a theoretically more effective phytotherapeutic agent for lung cancer compared to the effect seen with the SME.

Effects of genus Epimedium in the treatment of osteoarthritis and relevant signaling pathways

Osteoarthritis (OA) is a common chronic degenerative joint disease in clinical practice with a high prevalence, especially in the elderly. Traditional Chinese Medicine (TCM) believes that OA belongs to the category of "Bi syndrome" and the "bone Bi syndrome". The etiology and pathogenesis lie in the deficiency of the liver and kidney, the deficiency of Qi and blood, and external exposure to wind, cold, and dampness. Epimedium is a yang-reinforcing herb in TCM, which can tonify the liver and kidney, strengthen muscles and bones, dispel wind, cold and dampness, and can treat both the symptoms and the root cause of "bone Bi syndrome". In addition, Epimedium contains a large number of ingredients. Through modern science and technology, more than 270 compounds have been found in Epimedium, among which flavonoids are the main active ingredients. Therefore, our study will review the effects and mechanisms of genus Epimedium in treating OA from two aspects: (1) Introduction of Epimedium and its main active ingredients; (2) Effects of Epimedium and its active ingredients in treating OA and relevant signaling pathways, in order to provide more ideas for OA treatment.

A Comprehensive Analysis to Elucidate the Effects of Spraying Mineral Elements on the Accumulation of Flavonoids in Epimedium sagittatum during the Harvesting Period

The harvesting period is a critical period for the accumulation of flavonoids in the leaves of the important medicinal plant Epimedium sagittatum. In this study, we conducted an experiment on E. sagittatum leaves sprayed with mineral elements with the aim of improving the quality of the herbal leafage during the harvesting period. We elucidated the changes in flavonoids (icariin, epimedin A, epimedin B, and epimedin C) in E. sagittatum leaves. The sum of main flavonoids content reached a maximum (11.74%) at 20 days after the high-concentration Fe²⁺ (2500 mg·L^-1) treatment. We analyzed the FT-IR spectra characteristics of E. sagittatum leaf samples using the FT-IR technique, and constructed an OPLS-DA model and identified characteristic peaks to achieve differentiated identification of E. sagittatum. Further, widely untargeted metabolomic analysis identified different classes of metabolites. As the most important characteristic flavonoids, the relative contents of icariin, icaritin, icariside I, and icariside II were found to be up-regulated by high-Fe²⁺ treatment. Our experimental results demonstrate that high-concentration Fe²⁺ treatment is an effective measure to increase the flavonoids content in E. sagittatum leaves during the harvesting period, which can provide a scientific basis for the improvement of E. sagittatum leaf cultivation agronomic measures.

Potential of Icariin–Glucosamine Combination in the Treatment of Osteoarthritis by Topical Application: Development of Topical Formulation and In Vitro Permeation Study

The aim of this study was to develop a topically applied formulation with the potential to alleviate arthritis ailments. A combination of two active ingredients, icariin from Epimedium L. (Species: Epimedium Koreanum) extract as a potential promoter of chondrogenesis and glucosamine sulfate as a precursor of cartilage tissues, was tested. In permeation studies, the potential for skin permeation of both substances was confirmed; however, the in vitro release test did not accurately reflect the degree of skin permeation. The in vitro release of icariin was at a level of 15.0–19.0% for the plant-extract-derived icariin and 29.0–35.0% for the pure substance. The level of glucosamine sulfate release was 38.4% (on average). For icariin of both origins, the release results were higher than those obtained via oral administration (about 12.0%), which shows the potential superiority of topical application. In addition, the physicochemical parameters that affect the in vitro release and performance of topical formulations were addressed. This preliminary research and permeation analysis of the formulation produced a promising picture of its prospects regarding arthritis treatment, although further investigation is needed.

Purification and Characterization of a Novel α-L-Rhamnosidase from Papiliotrema laurentii ZJU-L07 and Its Application in Production of Icariin from Epimedin C

Icariin is the most effective bioactive compound in Herba Epimedii. To enhance the content of icariin in the epimedium water extract, a novel strain, Papiliotrema laurentii ZJU-L07, producing an intracellular α-L-rhamnosidase was isolated from the soil and mutagenized. The specific activity of α-L-rhamnosidase was 29.89 U·mg⁻¹ through purification, and the molecular mass of the enzyme was 100 kDa, as assayed by SDS-PAGE. The characterization of the purified enzyme was determined. The optimal temperature and pH were 55 °C and 7.0, respectively. The enzyme was stable in the pH range 5.5–9.0 for 2 h over 80% and the temperature range 30–40 °C for 2 h more than 70%. The enzyme activity was inhibited by Ca²⁺, Fe²⁺, Cu²⁺, and Mg²⁺, especially Fe²⁺. The kinetic parameters of K_m and V_max were 1.38 mM and 24.64 μmol·mg⁻¹·min⁻¹ using pNPR as the substrate, respectively. When epimedin C was used as a nature substrate to determine the kinetic parameters of α-L-rhamnosidase, the values of K_m and V_max were 3.28 mM and 0.01 μmol·mg⁻¹·min⁻¹, respectively. The conditions of enzymatic hydrolysis were optimized through single factor experiments and response surface methodology. The icariin yield increased from 61% to over 83% after optimization. The enzymatic hydrolysis method could be used for the industrialized production of icariin. At the same time, this enzyme could also cleave the α-1,2 glycosidic linkage between glucoside and rhamnoside in naringin and neohesperidin, which could be applicable in other biotechnological processes.

Transcriptomic and metabolomic analysis reveals the difference between large and small flower taxa of Herba Epimedii during flavonoid accumulation

Herba Epimedii, as a traditional Chinese herb, is divided into large and small flower taxa, and can invigorate sexuality and strengthen muscles and bones. Herba Epimedii is rich in flavonoids, which largely contribute to its medicinal benefits. In our previous studies, we have found that the flavonoids content was much more in small than large flower taxa. To further identify molecular mechanisms of flavonoids metabolism in Herba Epimedii, combined metabolome and transcriptomic analyses were performed to profile leaves and flowers. Association analysis revealed that the expression of genes involved in flavonoid biosynthesis showed significant differences between small and large flower taxa. Eleven flavonols significantly increased in small compared to large flower taxa. Moreover, genes encoding O-methyltransferase played crucial roles in flavonoids metabolism by an integrated analysis. Taken together, these data highlight the breeding tendency of small flower taxa to improve the quality of Herba Epimedii.

Polysaccharides derived from Chinese medicinal herbs: A promising choice of vaccine adjuvants

Adjuvants have been used in vaccines for a long time to promote the body's immune response, reducing vaccine dosage and production costs. Although many vaccine adjuvants are developed, the use in human vaccines is limited because of either limited action or side effects. Therefore, the development of new vaccine adjuvants is required. Many studies have found that natural polysaccharides derived from Traditional Chinese medicine (TCM) possess good immune promoting effects and simultaneously improve humoral, cellular and mucosal immunity. Recently polysaccharide adjuvants have attracted much attention in vaccine preparation because of their intrinsic characteristics: immunomodulation, biocompatibility, biodegradability, low toxicity and safety. This review article systematically analysed the literature on polysaccharides possessing vaccine adjuvant activity from TCM plants, such as Astragalus polysaccharide (APS), Rehmannia glutinosa polysaccharide (RGP), Isatis indigotica root polysaccharides (IRPS), etc. and their derivatives. We believe that polysaccharide adjuvants can be used to prepare the vaccines for clinical use provided their mechanisms of action are studied in detail.

Taxonomy of Epimedium (Berberidaceae) with special reference to Chinese species

Epimedii Herba is a commonly used traditional Chinese herbal medicine. Five Epimedium species are included in Chinese Pharmacopoeia and most species of Epimedium are used as Epimedii Herba in practical application. However, as the largest herbaceous genus of the Berberidaceae, Epimedium has many taxonomic controversies which hinder the effective use of Epimedii Herba. This paper reviewed the taxonomic research related to Epimedium, including taxonomic history, taxonomic values of morphological characters, species and distribution, infra-genera taxonomic system and the taxonomic research of Chinese Epimedium. For instance, we recognized Epimedium wushanense and clarified that the species, as described in Flora Reipublicae Popularis Sinicae and Flora of China, actually includes four Epimedium species similar in leaflet shape. In general, it was recognized here that Epimedium comprises 62 species, of which 52 species are distributed in China. For Chinese Epimedium species with the most taxonomic problems, the taxonomic research on the taxa was reviewed and the newest species key was proposed along with proposals for those taxonomic problems needing further resolution. This review is of great implication for the identification, exploration and utilization of Epimedii Herba.

The complete chloroplast genome of Epimedium fargesii Franch. (Berberidaceae), a rare plant species endemic to China

Epimedium L. is a medicinally important herbaceous genus in the family Berberidaceae. Epimedium fargesii Franch. is only narrowly inhabited in the Daba Mountains in China. Here, we sequenced and assembled the first complete chloroplast genome of Epimedium fargesii Franch. The chloroplast genome of E. fargesii was 157,208 bp in length, with a total GC content of 38.77%. A total of 112 unique genes were identified, including 78 protein-coding genes, 30 tRNA genes, and four rRNA genes. Phylogenetic analysis indicated that E. fargesii formed a sister relationship with E. wushanense T. S. Ying. Our results provided fundamental data for further taxonomic and phylogenetic research of the genus Epimedium.

Attenuation of Inflammatory Symptoms by Icariside B2 in Carrageenan and LPS-Induced Inflammation Models via Regulation of MAPK/NF-κB Signaling Cascades

Prolonged inflammatory responses can lead to the development of several chronic diseases, such as autoimmune disorders and the development of natural therapeutic agents is required. A murine model was used to assess the anti-inflammatory effects of the megastigmane glucoside, icariside B2 (ICSB), and the assessment was carried out in vitro, and in vivo. The in vitro anti-inflammatory effects of ICSB were tested using LPS-stimulated BV2 cells, and the protein expression levels of inflammatory genes and cytokines were assessed. Mice were subcutaneously injected with 1% carrageenan (CA) to induce acute phase inflammation in the paw. Inflammation was assessed by measuring paw volumes hourly; subsequently, the mice were euthanized and the right hind paw skin was expunged and processed for reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analyses. ICSB inhibits LPS-stimulated nitric oxide (NO) and prostaglandin E2 (PGE₂) generation by reducing the expression of inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2). ICSB also inhibits the COX-2 enzyme with an IC50 value of 7.80 ± 0.26 µM. Molecular docking analysis revealed that ICSB had a strong binding affinity with both murine and human COX-2 proteins with binding energies of −8 kcal/mol and −7.4 kcal/mol, respectively. ICSB also reduces the manifestation of pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1β, at their transcriptional and translational level. ICSB hinders inhibitory protein κBα (IκBα) phosphorylation, thereby terminating the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) nuclear translocation. ICSB also represses the mitogen-activated protein kinases (MAPKs) signaling pathways. ICSB (50 mg/kg) showed an anti-edema effect in CA-induced mice and suppressed the CA-induced increases in iNOS and COX-2 protein levels. ICSB attenuated inflammatory responses by downregulating NF-κB expression through interference with extracellular signal-regulated kinase (ERK) and p38 phosphorylation, and by modulating the expression levels of iNOS, COX-2, TNF-α, IL-1β, and IL-6.

The complete chloroplast genome of Epimedium pubescens Maxim. (Berberidaceae), a traditional Chinese medicine herb

Epimedium pubescens Maxim. is a well-known traditional Chinese medicine herb. In this study, the complete chloroplast genome of E. pubescens was sequenced. The genome was 158 956 bp in length, with a large single-copy region of 86,345 bp, a small single-copy region of 17,075 bp, and 2 inverted repeat regions of 27,768 bp. The genome consisted of 113 genes, including 79 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. The GC contents were 38.82%. Phylogenetic analysis showed that E. pubescens of series Brachyrcerae was firstly clustered with E. acumiantum Franch. of ser. Dolichocerae, but not with E. brevicornu Maxim. from the same series.

A novel herbal formulation consisting of red ginseng extract and Epimedium koreanum Nakai-attenuated dextran sulfate sodium-induced colitis in mice

Background

Ulcerative colitis (UC) is a commonly encountered large intestine disease in the contemporary world that terminates into colorectal cancer; therefore, the timely treatment of UC is of major concern. Panax ginseng Meyer is an extensively consumed herbal commodity in South East Asian countries, especially Korea. It exhibits a wide range of biologically beneficial qualities for almost head-to-toe ailments in the body. Epimedium koreanum Nakai (EKN) is also a widely used traditional Korean herbal medicine used for treating infertility, rheumatism, and cardiovascular diseases.

Materials and methods

Separately the anti-inflammatory activities of both red ginseng extracts (RGEs) and EKNs had been demonstrated in the past in various inflammatory models; however, we sought to unravel the anti-inflammatory activities of the combination of these two extracts in dextran sulfate sodium (DSS)-induced ulcerative colitis in mice model because the allopathic remedies for UC involve more side effects than benefits.

Results

Our results have shown that the combination of RGE + EKN synergistically alleviated the macroscopic lesions in DSS-induced colitic mice such as colon shortening, hematochezia, and weight loss. Moreover, it restored the histopathological lesions in mice and decreased the levels of pro-inflammatory mediators and cytokines through the repression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP-3) expression. In vitro, this combination also reduced the magnitude of nitric acid (NO), pro-inflammatory mediators and cytokine through NF-κB and mitogen-activated protein kinase (MAPK) pathways in RAW 264.7 mouse macrophage cells.

Conclusion

In the light of these findings, we can endorse this combination extract as a functional food for the prophylactic as well as therapeutic treatment of UC in humans together with allopathic remedies.

The complete chloroplast genome of Epimedium brevicornu Maxim (Berberidaceae), a traditional Chinese medicine herb

Epimedium brevicornu Maxim. is a traditional Chinese medicine herb with good effects on many diseases. In the present paper, the complete chloroplast genome of E. brevicornu was sequenced. The complete chloroplast genome of E. brevicornu was 159572 bp in length with 38.83% GC content, including four distinct regions: large single-copy region (86535 bp), small single-copy region (17641 bp), and a pair of inverted repeat regions (27698 bp). The chloroplast genome encoded 112 unique genes, which included 78 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Phylogenetic analysis with the previously reported chloroplast genomes of Epimedium showed that E. brevicornu with small flowers at first clustered with large-flowered E. acuminatum into a strongly supported branch, but not with Epimedium species having similar floral characters.

Pharmacological effects of icariin

Icariin (ICA) is a principal active component from traditional Chinese medicine Epimedium grandiflorum. To explain its traditional medical usages by modern science, a variety of pharmacological effects have been studied for ICA. In this review, we summarized the pharmacokinetics of ICA as well as its pharmacological mechanisms in neurodegenerative disease, cardiovascular disease, anti-osteoporosis, anti-inflammation, anti-oxidative stress, anti-depression and anti-tumors.

The complete chloroplast genome of Epimedium qingchengshanense G. Y. Zhong et B. L. Guo (Berberidaceae), an endangered species endemic to China

Epimedium qingchengshanense G. Y. Zhong & B. L. Guo is an endangered species with high ornamental value and medicinal value in China. In this study, we reported the first complete chloroplast (cp) genome of E. qingchengshanense. The whole cp genome of E. qingchengshanense is 159,087 bp in length, comprising a pair of inverted repeat regions (IRs) (27,709 bp) that are separated by a large single-copy (LSC) region (86,607 bp) and a small single-copy (SSC) region (17,062 bp). The circular genome contains 112 unique genes, of which 78 are protein-coding genes, 30 tRNA, and 4 rRNA genes. Phylogenetic analysis shows that E. qingchengshanense has a closer relationship with other Epimedium species.

A Widely Metabolomic Analysis Revealed Metabolic Alterations of Epimedium Pubescens Leaves at Different Growth Stages

Epimedium folium is the major medicinally-used organ of Epimedium species and its metabolic changes during the leaf growth have not been studied at the metabolomic level. E. pubescens is one of five recorded species in the Pharmacopoeia of the People’s Republic of China and widely grows in China. A UPLC-ESI-MS/MS-based targeted metabolomic analysis was implemented to explore the metabolite composition in E. pubescens leaves under the cultivation condition and further to investigate their temporal variations among four representative growth stages. A total of 403 metabolites, including 32 hitherto known in Epimedium species, were identified in E. pubescens leaf, of which 302 metabolites showed the growth/development-dependent alterations. Flavonoid-type compounds were the major composition of the metabolites identified in this study. Most flavonoids, together with tannin-type and lignans and coumarin-type compounds, were up-regulated with E. pubescens leaf growth and maturation after the full flowering stage. Our results not only greatly enriched the existing Epimedium phytochemical composition database and also, for the first time, provided the metabolomics-wide information on metabolic changes during E. pubescens leaf growth and development, which would facilitate in the choice of an optimum harvest time to balance a higher biomass yield of Epimedium folium with its better medicinal quality.

In vitro screening and toxic mechanism exploring of leading components with potential hepatotoxicity of Herba Epimedii extracts

Herba Epimedii is a famous Chinese edible herb, and due to its potential hepatotoxic effects, the safety associated with this herb has attracted a great deal of attention. In this study, the components of four types of the Herba Epimedii extracts were identified by HPLC-MS/MS. Among these components, 11 components that were present in all four extracts and could be obtained as reference substances were evaluated for their ability of cytotoxicity in HL-7702 and HepG2 cells, resulting in the identification of icarisid I and sagittatoside A as the most relevant with respect to the toxicity of the extracts. The targeted toxicological effects were further investigated using a series of correlated biological indicators to elucidate potentially hepatotoxic mechanisms. The results showed that the extracts and the selected compounds had varying degrees of influence on the leakage of ALT, AST and LDH; the activity of SOD, GSH and MDA; the increase in intercellular ROS; and the decrease in MMP. Among the tested substances, the ethanol extracts exhibited stronger hepatotoxicity, with icarisid I and sagittatoside A correlating with this toxic effect, and the hepatoxic mechanisms of which may be associated with damaged cell structure, increased oxidative stress and induction of apoptosis.

The complete chloroplast genome of Epimedium sagittatum (Sieb. Et Zucc.) Maxim. (Berberidaceae), a traditional Chinese herb

Epimedium sagittatum is an important traditional medicinal plant in China. In this study, we assembled the complete chloroplast (cp) genome of E. sagittatum. The whole cp genome of E. sagittatum is 157,114 bp in length, comprising a pair of inverted repeat (IR) regions (25,775 bp) separated by a large single copy (LSC) region (88,507 bp) and a small single copy (SSC) region (17,057 bp). The E. sagittatum cp genome contains 133 genes, of which 82 protein-coding genes, 38 tRNA genes, 8 rRNA genes and 5 pseudogenes. Phylogenetic analysis shows that E. sagittatumis closely clustered with E. lishihchenii. This genome provides a wealth of information for distinguishing of Epimedium species.

A Systematic Study on DNA Barcoding of Medicinally Important Genus Epimedium L. (Berberidaceae)

Genus Epimedium consists of approximately 50 species in China, and more than half of them possess medicinal properties. The high similarity of species’ morphological characteristics complicates the identification accuracy, leading to potential risks in herbal efficacy and medical safety. In this study, we tested the applicability of four single loci, namely, rbcL, psbA-trnH, internal transcribed spacer (ITS), and ITS2, and their combinations as DNA barcodes to identify 37 Epimedium species on the basis of the analyses, including the success rates of PCR amplifications and sequencing, specific genetic divergence, distance-based method, and character-based method. Among them, character-based method showed the best applicability for identifying Epimedium species. As for the DNA barcodes, psbA-trnH showed the best performance among the four single loci with nine species being correctly differentiated. Moreover, psbA-trnH + ITS and psbA-trnH + ITS + rbcL exhibited the highest identification ability among all the multilocus combinations, and 17 species, of which 12 are medicinally used, could be efficiently discriminated. The DNA barcode data set developed in our study contributes valuable information to Chinese resources of Epimedium. It provides a new means for discrimination of the species within this medicinally important genus, thus guaranteeing correct and safe usage of Herba Epimedii.

A simple and selective LC-MS/MS method for quantification of ikarisoside A in rat plasma and its application to a pharmacokinetic study

Ikarisoside A is a natural flavonoid isolated from Epimedium plants. To further evaluate its medicinal potential, a sensitive and robust LC-MS/MS method was developed and validated for the assay of ikarisoside A in rat plasma. Orientin was used as an internal standard. The electrospray ionization was operated in its negative ion mode while ikarisoside A and IS were measured by selected reaction monitoring using precursor-to-product ion transitions of m/z 499.1 → 353.0 and m/z 446.9 → 327.6, respectively. This LC-MS/MS method had good sensitivity (LLOQ = 1.5 ng/mL), accuracy (both intra- and inter-day RE ≤ ±11.9%) and precision (both intra- and inter-day RSD ≤8.5%). The pharmacokinetics of ikarisoside A was subsequently profiled in Sprague-Dawley rats. Following oral administration (35 mg/kg), ikarisoside A reached maximum plasma concentration (C_max , 207.6 ± 96.7 ng/mL) attained at 1.10 ± 0.42 h. Following oral administration, the clearance and terminal half-life were 42.9 ± 26.5 L/h/kg and 3.15 ± 0.80 h by oral route, respectively.

Development and Validation of a HPLC-MS/MS Method for Simultaneous Determination of Twelve Bioactive Compounds in Epimedium: Application to a Pharmacokinetic Study in Rats

A rapid and reliable HPLC-MS/MS method has been developed and validated for the simultaneous quantification of twelve bioactive compounds (baohuoside II, baohuoside I, sagittatoside A, sagittatoside B, magnoflorine, epimedin A, epimedin B, epimedin C, chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid and icariin) in rat plasma. The collected plasma samples were prepared by protein precipitate with acetonitrile. The twelve compounds were separated on a CORTECS^®C18 column (4.6 mm × 150 mm, 2.7 μm) with a gradient mobile phase system of 0.1% (v/v) formic acid and acetonitrile at a flow rate of 0.3 mL/min. All of the analytes were quantitated using electrospray ionization (ESI) in negative ion mode with selected reaction monitoring (SRM). The intra- and inter-day accuracy ranged from −5.6% to 13.0%, and the precisions of the analytes were less than 10.9%. The mean recoveries of the analytes were in the range of 60.66% to 99.77% and the matrix effect ranged from 93.08% to 119.84%. Stability studies proved that the analytes were stable under the tested conditions, with a relative standard deviation (RSD) lower than 11.7%. The developed method was successfully applied to evaluating the pharmacokinetic study of twelve bioactive compounds after oral administration of Epimedium extract in rat.

Quality Evaluation of the Traditional Medicine Majun Mupakhi ELA via Chromatographic Fingerprinting Coupled with UHPLC-DAD-Quadrupole-Orbitrap-MS and the Antioxidant Activity In Vitro

By merging a high-performance liquid chromatography diode array detector (HPLC-DAD) method with high-performance thin-layer chromatography (HPTLC), an assay was developed for chemical fingerprinting and quantitative analysis of traditional medicine Majun Mupakhi ELA (MME), and constituent compounds were identified using HPLC coupled with UHPLC-DAD-Quadrupole-Orbitrap-MS method. In addition, the antioxidant capacity of MME was assessed based on the ability of components to scavenge radicals using in vitro method. Using a HPLC-DAD method with HPTLC easily validated the chemical fingerprinting results and quantified three characteristic components, namely, gallic acid (1), daidzein (2), and icariin (3), in commercial MMEs. The three compounds presented excellent regression values (R² = 0.9999) in the ranges of the test and the method recovery was in the range from 100.49% to 100.68%. The fingerprints had 27 common characteristic peaks, of which 13 were verified by rapid UHPLC-DAD-Q-Orbitrap-MS analysis. In vitro antioxidant assays rapidly assessed and contrasted antioxidant activity or the free radical scavenging activity of the main polyphenolic classes in MMEs, and the antioxidant capacity was mostly affected by the presence of gallic acid. Thus, this study establishes a powerful and meaningful approach for MME quality control and for assessing in vitro antioxidant activity.

Functional Characterization of a Novel R2R3-MYB Transcription Factor Modulating the Flavonoid Biosynthetic Pathway from Epimedium sagittatum

Epimedium species have been widely used both as traditional Chinese medicinal plants and ornamental perennials. Both flavonols, acting as the major bioactive components (BCs) and anthocyanins, predominantly contributing to the color diversity of Epimedium flowers belong to different classes of flavonoids. It is well-acknowledged that flavonoid biosynthetic pathway is predominantly regulated by R2R3-MYB transcription factor (TF) as well as bHLH TF and WD40 protein at the transcriptional level. MYB TFs specifically regulating anthocyanin or flavonol biosynthetic pathway have been already isolated and functionally characterized from Epimedium sagittatum, but a R2R3-MYB TF involved in regulating both these two pathways has not been functionally characterized to date in Epimedium plants. In this study, we report the functional characterization of EsMYB9, a R2R3-MYB TF previously isolated from E. sagittatum. The previous study indicated that EsMYB9 belongs to a small subfamily of R2R3-MYB TFs containing grape VvMYB5a and VvMYB5b TFs, which regulate flavonoid biosynthetic pathway. The present studies show that overexpression of EsMYB9 in tobacco leads to increased transcript levels of flavonoid pathway genes and increased contents of anthocyanins and flavonols. Yeast two-hybrid assay indicates that the C-terminal region of EsMYB9 contributes to the autoactivation activity, and EsMYB9 interacts with EsTT8 or AtTT8 bHLH regulator. Transient reporter assay shows that EsMYB9 slightly activates the expression of EsCHS (chalcone synthase) promoter in transiently transformed leaves of Nicotiana benthamiana, but the addition of AtTT8 or EsTT8 bHLH regulator strongly enhances the transcriptional activation of EsMYB9 against five promoters of the flavonoid pathway genes except EsFLS (flavonol synthase). In addition, co-transformation of EsMYB9 and EsTT8 in transiently transfected tobacco leaves strongly induces the expressions of flavonoid biosynthetic genes. The potential role of EsMYB9 in modulating the biosynthesis and accumulation of sucrose-induced anthocyanin and flavonol-derived BCs is also discussed. These findings suggest that EsMYB9 is a novel R2R3-MYB TF, which regulates the flavonoid biosynthetic pathway in Epimedium, but distinctly different with the anthocyanin or flavonol-specific MYB regulators identified previously in Epimedium plants.

A R2R3-MYB Transcription Factor Regulates the Flavonol Biosynthetic Pathway in a Traditional Chinese Medicinal Plant, Epimedium sagittatum

Flavonols as plant secondary metabolites with vital roles in plant development and defense against UV light, have been demonstrated to be the main bioactive components (BCs) in the genus Epimedium plants, several species of which are used as materials for Herba Epimedii, an important traditional Chinese medicine. The flavonol biosynthetic pathway genes had been already isolated from Epimedium sagittatum, but a R2R3-MYB transcription factor regulating the flavonol synthesis has not been functionally characterized so far in Epimedium plants. In this study, we isolated and characterized the R2R3-MYB transcription factor EsMYBF1 involved in regulation of the flavonol biosynthetic pathway from E. sagittatum. Sequence analysis indicated that EsMYBF1 belongs to the subgroup 7 of R2R3-MYB family which contains the flavonol-specific MYB regulators identified to date. Transient reporter assay showed that EsMYBF1 strongly activated the promoters of EsF3H (flavanone 3-hydroxylase) and EsFLS (flavonol synthase), but not the promoters of EsDFRs (dihydroflavonol 4-reductase) and EsANS (anthocyanidin synthase) in transiently transformed Nicotiana benthamiana leaves. Both yeast two-hybrid assay and transient reporter assay validated EsMYBF1 to be independent of EsTT8, or AtTT8 bHLH regulators of the flavonoid pathway as cofactors. Ectopic expression of EsMYBF1 in transgenic tobacco resulted in the increased flavonol content and the decreased anthocyanin content in flowers. Correspondingly, the structural genes involved in flavonol synthesis were upregulated in the EsMYBF1 overexpression lines, including NtCHS (chalcone synthase), NtCHI (chalcone isomerase), NtF3H and NtFLS, whereas the late biosynthetic genes of the anthocyanin pathway (NtDFR and NtANS) were remarkably downregulated, compared to the controls. These results suggest that EsMYBF1 is a flavonol-specific R2R3-MYB regulator, and involved in regulation of the biosynthesis of the flavonol-derived BCs in E. sagittatum. Thus, identification and functional characterization of EsMYBF1 provide insight into understanding the biosynthesis and regulation of the flavonol-derived BCs in Epimedium plants, and also provide an effective tool gene for genetic manipulation to improve the flavonol synthesis.

The Complete Chloroplast Genome Sequences of Five Epimedium Species: Lights into Phylogenetic and Taxonomic Analyses

Epimedium L. is a phylogenetically and economically important genus in the family Berberidaceae. We here sequenced the complete chloroplast (cp) genomes of four Epimedium species using Illumina sequencing technology via a combination of de novo and reference-guided assembly, which was also the first comprehensive cp genome analysis on Epimedium combining the cp genome sequence of E. koreanum previously reported. The five Epimedium cp genomes exhibited typical quadripartite and circular structure that was rather conserved in genomic structure and the synteny of gene order. However, these cp genomes presented obvious variations at the boundaries of the four regions because of the expansion and contraction of the inverted repeat (IR) region and the single-copy (SC) boundary regions. The trnQ-UUG duplication occurred in the five Epimedium cp genomes, which was not found in the other basal eudicotyledons. The rapidly evolving cp genome regions were detected among the five cp genomes, as well as the difference of simple sequence repeats (SSR) and repeat sequence were identified. Phylogenetic relationships among the five Epimedium species based on their cp genomes showed accordance with the updated system of the genus on the whole, but reminded that the evolutionary relationships and the divisions of the genus need further investigation applying more evidences. The availability of these cp genomes provided valuable genetic information for accurately identifying species, taxonomy and phylogenetic resolution and evolution of Epimedium, and assist in exploration and utilization of Epimedium plants.