The effect of aqueous extract of Xinjiang Artemisia rupestris L. (an influenza virus vaccine adjuvant) on enhancing immune responses and reducing antigen dose required for immunity

Discovery of novel adjuvants: Identification of saponins from Hylomecon japonica (Thunb.) Prantl & Kündig and insights into their in vitro and in vivo activities

Bioassay-guided approach resulted in the isolation of fourteen triterpenoid saponins were isolated from the herba of Hylomecon japonica (Thunb.) Prantl & Kündig including eight novel saponins (1-8) and six known saponins (9-14). Their chemical structures were unequivocally determined through comprehensive spectral data analysis. By screening all compounds to enhance the ability of RAW 264.7 cells to produce NO, the novel compound 1 (HA) was identified as a candidate for immune adjuvant. In vitro experiments demonstrated that HA promotes the proliferation of spleen lymphocytes, DC 2.4, and RAW 264.7 cells, while also enhancing the phagocytic activity of DC 2.4 and RAW 264.7 cells. HA also counteracts the LPS-induced decline in dendritic cell phagocytosis and works with LPS to further improve macrophage phagocytosis. The network pharmacology analysis identified a total of 46 targets and 20 pathways through which HA exerts its immune-enhancing effects. In vivo experiments, HA enhanced immune organ development, boosted specific serum antibodies, increased Th1 and Th2 cytokines, and amplified related gene expression. And HA could boost lymphocyte proliferation, increased CD3+ T cells and altered CD4+ and CD8+ levels. It also promoted dendritic cell maturation in lymph nodes, raised MHC II molecules and co-stimulatory factors. HA triggered the upregulation of TL4, MyD88, and IKK proteins and promoted the phosphorylation of NF-κB P65 and P-IkBα within the TLR4/NF-κB signaling pathway, while simultaneously suppressing IκBα protein expression. HA has the characteristics and functions of enhancing immunity and could be applied as an immune adjuvant. The findings presented herein establish a fundamental basis for investigating the immune adjuvant effect of triterpenoid saponins.

Luteolin 7-Glucuronide in Artemisia rupestris L. Extract Attenuates Pulmonary Fibrosis by Inhibiting Fibroblast Activation and FMT via Targeting of TGF-β1

Pulmonary fibrosis (PF) is a chronic pulmonary disease characterized by excessive extracellular matrix (ECM) deposition, with cigarette smoking being a major risk factor and no effective treatment at present. Transforming growth factor beta 1 (TGF-β1) plays a key role in PF and regulating oxidative stress. This study investigated the effects and mechanisms of Artemisia rupestris L. ethanol extract (ER) on cigarette smoke (CS)-induced PF. We used pull-down and LC-MS analyses to screen and identify compounds that bind to TGF-β1 in ER. We demonstrated that ER inhibits CS-induced PF, lung inflammation, and oxidative stress, thereby improving pulmonary structural injury. The ER inhibits fibroblast activation and fibroblast-to-myofibroblast transition (FMT), reducing collagen deposition for the treatment of PF. We identified the active ingredient in ER that binds to TGF-β1, namely, Luteolin 7-glucuronide (LG). LG inhibits the TGF-β1 signaling pathway through targeted binding to TGF-β1, downregulates the expression of downstream proteins (including collagen I, α-SMA, MMP-2, and MMP-9), and inhibits fibronectin expression. It also inhibits fibroblast activation and FMT, enhances E-cadherin expression to promote fibroblast adhesion, and suppresses collagen deposition, alleviating PF. Based on these findings, we propose that LG might be a promising therapeutic drug candidate for treating PF.

Dietary artemisinin boosts intestinal immunity and healthy in fat greenling (Hexagrammos otakii)

Introduction

Artemisinin (ART) is very common as a diet additive due to its immunoregulatory activities. Nonetheless, the immunoregulatory mechanism of ART in marine fish remains unknown. This study comprehensively examined the effects and explored the potential mechanism of ART ameliorating intestinal immune disease (IID) in fat greenlings (Hexagrammos otakii).

Methods and results

The targets of ART were screened using the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. Here, eight putative targets of ART were collected and identified with the Uniprot database, and 1419 IID-associated target proteins were filtered through the Drugbank, Genecards, OMIM, and PHARMGKB Databases. The results of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways point out that ART may have immunoprotective effects by regulating cellular responses to stress, hypoxia, inflammation, and vascular endothelial growth factor stimulus through the hypoxia-inducible factor 1 (HIF-1) signaling pathway. The findings of molecular docking indicated that ART contains one active ingredient and three cross-targets, which showed a kind combination with hypoxia-inducible factor 1-alpha (HIF1-a), transcription factor p65 (RELA), and vascular endothelial growth factor A (VEGF-A), respectively. Furthermore, an ART feeding model was established to assess the ART's immunoprotect effect on the intestine of H.otakii in vivo. The D48 group showed smaller intestinal structural changes after being challenged by Edwardsiella tarda. The supplementation of ART to the diet improved total superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and reduced the malondialdehyde (MDA) in intestine of H. otakii. The expression of transcription factor p65, HIF1-α, VEGF-A, cyclin D1, matrix metalloprotease 9 (MMP9), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) was decreased after dietary ART in the intestinal of H. otakii.

Discussion

The present results demonstrated that dietary ART improved antioxidants and immunity, optimized the intestinal structure, and increased resistance to E. tarda through the SOD2/nuclear-factor-kappa- B (NFkB)/HIF1-a/VEGF-A pathway in the intestinal tract of H.otakii. This study integrated pharmacological analysis and experimental validation and revealed the mechanism of ART on IID, which provides insight into the improvement of IID in H. otakii.

Improving adjuvanticity of crude polysaccharides from cultivated Artemisia rupestris L. for influenza vaccine by promoting long-term immunity and TH1/TH2 response with dose-sparing effect

ETHNOPHARMACOLOGICAL RELEVANCE

Influenza virus vaccines (IVV) with balanced T_H1/T_H2 responses are critical for controlling seasonal influenza. Emerging evidences suggest that herbal polysaccharides can induce potent T_H1 or mixed T_H1/T_H2 responses.

AIM OF STUDY

The study aims to determine the efficacy and safety of crude polysaccharides from cultivated Artemisia rupestris L. (CPCAR) as an adjuvant for IVV.

MATERIALS AND METHODS

CPCAR was prepared with hot extraction and ethanol precipitation method and primary physico-chemical characters were tested. Mice were vaccinated by subcutaneous route with IVV formulated with different dose of CPCAR to detecting the elicited T_H1/T_H2 responses and long-term immune responses with dose-sparing sparing effect.

RESULTS

IVV formulated with CPCAR without LPS contamination could augment balanced T_H1/T_H2 responses, as indicated by early IgG response, hemagglutination inhibition (HAI) antibodies, effector T-cells, and cytotoxic T lymphocytes (CTL). Moreover, CPCAR elicited long-term IgG, HAI antibodies, memory T cells, and balanced CD4/CD8 responses within 168 days after vaccination. Compared with IVV alone, a low or high dose of IVV formulated with CPCAR improved the levels of IgG, IgG1, and IgG2a and enhanced memory T cells and balanced CD4/CD8 responses, displaying a 10-fold dose-sparing effect. As determined by IgE response and monitoring results of weekly body weight and daily symptoms after vaccination, anaphylaxis or adverse effect was not observed.

CONCLUSIONS

Collectively, the study demonstrated the potential of CPCAR as an aqueous polysaccharide adjuvant for IVV to induce rapid and balanced T_H1/T_H2 responses and long-lasting immunity with dose-sparing effect.

The Effects of Artemisia Plant and Its Components Against Respiratory Viruses Like Influenza and Their Mechanisms of Action

Context: Artemisia genus and its chemical constituents show antiviral activity against different viruses. The aim of this study was to review the effects of selected Artemisia species and their components against respiratory viruses like influenza and coronavirus. Methods: All the articles published in English or Persian related to the effects of Artemisia and its components on viral respiratory infections and relevant mechanisms of action were searched throughout Medline, Science Direct, Scopus, Ebsco, Google Scholar, and Cochrane Library Database from 1966 up to April 2020. Results: A few numbers of Artemisia species such as A. scoparia, A. rupestris, and A. annua and their components showed efficacy against the influenza virus and coronaviruses. Furthermore, some chemical compounds isolated from Artemisia species, like rupestonic acid, showed potent anti-influenza activity. The mechanism of antiviral activity was also determined for some of these compounds. Conclusions: The present study summarized the efficacy of a number of Artemisia species and their components against respiratory viruses like influenza and coronavirus. Future studies on other Artemisia species may lead to the discovery of new antiviral drugs against the influenza virus and coronaviruses.

The Adjuvant Effects on Vaccine and the Immunomodulatory Mechanisms of Polysaccharides From Traditional Chinese Medicine

Vaccination is still the most successful strategy to prevent and control the spread of infectious diseases by generating an adequate protective immune response. However, vaccines composed of antigens alone can only stimulate weak immunogenicity to prevent infection in many cases. Adjuvant can enhance the immunogenicity of the antigens. Therefore, adjuvant is urgently needed to strengthen the immune response of the vaccines. An ideal adjuvant should be safe, cheap, biodegradable and biologically inert. In addition to having a long shelf life, it can also promote cellular and humoral immune responses. Traditional Chinese medicine (TCM) has many different ingredients, such as glycosides, polysaccharides, acids, terpenes, polyphenols, flavonoids, alkaloids, and so on. TCM polysaccharides are one of the main types of biologically active substances. They have a large range of pharmacological activities, especially immunomodulatory. TCM polysaccharides can regulate the immune system of animals by binding to multiple receptors on the surface of immune cells and activating different signal pathways. This review focuses on a comprehensive summary of the most recent developments in vaccine adjuvant effects of polysaccharides from many important TCM, such as Artemisia rupestris L., Cistanche deserticola, Pinus massoniana, Chuanminshen violaceum, Astragalus, Ganoderma lucidum, Codonopsis pilosula, Lycium barbarum, Angelica, Epimedium, and Achyranthes bidentata. Moreover, this review also introduces their immunomodulatory effects and the molecular mechanisms of action on animal bodies, which showed that TCM polysaccharides can activate macrophages, the signal pathway of T/B lymphocytes, regulate the signal pathway of natural killer cells, activate the complement system, and so on.

Enhancing immune responses to inactivated foot-and-mouth virus vaccine by a polysaccharide adjuvant of aqueous extracts from Artemisia rupestris L

BACKGROUND

New-generation adjuvants for foot-and-mouth disease virus (FMDV) vaccines can improve the efficacy of existing vaccines. Chinese medicinal herb polysaccharide possesses better promoting effects.

OBJECTIVES

In this study, the aqueous extract from Artemisia rupestris L. (AEAR), an immunoregulatory crude polysaccharide, was utilized as the adjuvant of inactivated FMDV vaccine to explore their immune regulation roles.

METHODS

The mice in each group were subcutaneously injected with different vaccine formulations containing inactivated FMDV antigen adjuvanted with three doses (low, medium, and high) of AEAR or AEAR with ISA-206 adjuvant for 2 times respectively in 1 and 14 days. The variations of antibody level, lymphocyte count, and cytokine secretion in 14 to 42 days after first vaccination were monitored. Then cytotoxic T lymphocyte (CTL) response and antibody duration were measured after the second vaccination.

RESULTS

AEAR significantly induced FMDV-specific antibody titers and lymphocyte activation. AEAR at a medium dose stimulated Th1/Th2-type response through interleukin-4 and interferon-γ secreted by CD4⁺ T cells. Effective T lymphocyte counts were significantly elevated by AEAR. Importantly, the efficient CTL response was remarkably provoked by AEAR. Furthermore, AEAR at a low dose and ISA-206 adjuvant also synergistically promoted immune responses more significantly in immunized mice than those injected with only ISA-206 adjuvant and the stable antibody duration without body weight loss was 6 months.

CONCLUSIONS

These findings suggested that AEAR had potential utility as a polysaccharide adjuvant for FMDV vaccines.

Immune-Enhancing Activity of Aqueous Extracts from Artemisia rupestris L. via MAPK and NF-kB Pathways of TLR4/TLR2 Downstream in Dendritic Cells

Artemisia rupestris L. has long been used as a traditional herbal medicine owing to its immunomodulatory activity. Aqueous extracts of Artemisia rupestris L. (AEAR) contain the main functional component and can activate the maturation of dendritic cells (DCs) and enhance the adaptive immunity as the adjuvant against infections. To explore the underlying mechanism of immunomodulatory activities of AEAR, DCs were produced from bone-marrow cells of mice and the effects of AEAR on cell viability were assessed by the Cell Counting Kit 8 (CCK8) method and annexin V/propidium iodide staining assays. Then, the effects of AEAR on the morphology, maturation, and function of DCs were detected using a microscope, flow cytometry-based surface receptor characterization, and endocytosis assays. The secretion levels of cytokines were then analyzed with enzyme-linked immunosorbent assay (ELISA). The activation state of DCs was evaluated by the mixed lymphocyte reaction (MLR). The activity of MAPKs and NF-κB pathways, which were involved in the regulation of AEAR on DCs, was further detected by Western blot. AEAR did not have a cytotoxic effect on DCs or mouse splenocytes. AEAR remarkably enhanced the phenotypic maturation of DCs and promoted the expression of costimulatory molecules and the secretion of cytokines in DCs. AEAR also significantly decreased the phagocytic ability of DCs and augmented the abilities of DCs to present antigens and stimulate allogeneic T-cell proliferation. Simultaneously, AEAR potently activated toll-like receptor (TLR)4-/TLR2-related MAPKs and induced the degradation of IκB and the translocation of NF-κB. In short, AEAR can profoundly enhance the immune-modulating activities of DCs via TLR4-/TLR2-mediated activation of MAPKs and NF-κB signaling pathways and is a promising candidate immunopotentiator for vaccines.

Traditional Chinese Medicine: an effective treatment for 2019 novel coronavirus pneumonia (NCP)

The novel coronavirus pneumonia broke out in 2019 and spread rapidly. In 30 different countries, there are over seventy thousand patients have been diagnosed in total. Therefore, it is urgent to develop the effective program to prevent and treat for the novel coronavirus pneumonia. In view of Traditional Chinese Medicine has accumulated a solid theoretical foundation of plague in ancient and recent decades. Meanwhile, Traditional Chinese Medicine can provide the more effective and personalized treatment via adjusting the specific medicine for each patient based on the different syndromes. In addition, TCM often has different effect on the distinct stages of diseases, contributing to the prevention, treatment and rehabilitation. Nowadays, TCM has exhibited decent effect in the in the fight against NCP. Therefore, it is convinced that Traditional Chinese Medicine is an effective treatment for 2019 novel coronavirus pneumonia.

Chemical constituents from Artemisia rupestris and their neuraminidase inhibitory activity

Two new thiophene derivatives (1 and 2), a new sesquiterpene (3), and 15 known compounds (4-18) were isolated from the whole plants of Artemisia rupestris. The new compounds (1-3) were elucidated by extensive spectroscopic techniques including 1 D (¹H and ¹³C) and 2 D NMR experiments (COSY, HSQC, HMBC and NOESY), and HR-ESI-MS. Most of the isolates (1-6, 8, 10-18) exhibited the neuraminidase inhibitory activity with IC₅₀ values ranging from 74.07-986.54 μM by a fluorescence-based assay. Two known flavonoids (chrysosplenetin B and luteolin) showed a comparable activity to oseltamivir acid on neuraminidase inhibition.

Flavonoids from Artemisia rupestris and their synergistic antibacterial effects on drug-resistant Staphylococcus aureus

This study seeks to discover flavonoids from a traditional Chinese herb, Artemisia rupestris L., with synergistic antibacterial effects against multidrug-resistant Staphylococcus aureus. Five flavonoids, artemetin (1), chrysosplenetin (2), pachypodol (3), penduletin (4) and chrysoeriol (5) were obtained by various column chromatographic methods. Their chemical structures were determined on the basis of comprehensive spectroscopic analysis and comparison with literature data. Three of the compounds (2, 4 and 5) exhibited synergistic activity when combined with norfloxacin against SA1199B, an effluxing fluoroquinolone-resistant strain. The fractional inhibitory concentration indices (FICIs) of 2, 4 and 5 in combination with norfloxacin were 0.375, 0.079 and 0.266 respectively, suggesting synergy. Compound 5 also showed synergistic effects against EMRSA-15 and EMRSA-16 when combined with ciprofloxacin and oxacillin exhibiting FICIs of 0.024 and 0.375 respectively. Real time ethidium bromide (EtBr) efflux assay, qRT-PCR and molecular docking were employed to explore the mechanisms of the synergistic effects.