Coadministration of the fungal immunomodulatory protein FIP-Fve and a tumour-associated antigen enhanced antitumour immunity

Exploring the Bioactive Mycocompounds (Fungal Compounds) of Selected Medicinal Mushrooms and Their Potentials against HPV Infection and Associated Cancer in Humans

Medicinal mushrooms have been used as a medicinal tool for many centuries and, nowadays, are used in the prevention and therapy of various diseases, including as an adjunct to cancer treatment. It is estimated that 14-16% of global cancer cases are caused by infectious events; one well-known infectious agent that leads to cancer is the human papillomavirus (HPV). HPV is responsible for more than 99.7% of cervical cancer cases and also may play a role in vaginal, vulvar, penile, anal, rectal, and oropharyngeal carcinogenesis. Coriolus versicolor, a basidiomycetes class mushroom, consists of glycoproteins called polysaccharide-K (PSK) and polysaccharopeptide (PSP), which are mainly responsible for its effectiveness in the fight against a variety of cancers. Its beneficial effect lies in its ability to arrest different phases of the cell cycle, immunomodulation or induction of apoptosis. Coriolus versicolor extractcan reduces BCL-2 expression or increases the expression of p53 tumour suppressor genes in breast tumour cell lines. Inhibition of proliferation was also demonstrated with HeLa cells, while cervical cytology abnormalities improved in patients who locally applied Coriolus versicolor-based vaginal gel. Coriolus versicolor extract itself, and also its combination with another medicinal mushroom, Ganoderma lucidum, leads to improved HPV clearance in HPV cervical or oral-positive patients. Medicinal mushrooms can also increase the effectiveness of vaccination. This review considers the use of medicinal mushrooms as a suitable adjunct to the treatment of many cancers or precanceroses, including those caused by the HPV virus.

A concise review of mushrooms antiviral and immunomodulatory properties that may combat against COVID-19

The World Health Organization (WHO) declared COVID-19 as a pandemic on March 11, 2020, because of its widespread transmission and infection rates. The unique severe disease was found in Wuhan, China, since December 2019, and swiftly spread throughout the world. Natural chemicals derived from herbal medicines and medicinal mushrooms provide a significant resource for the development of novel antiviral drugs. Many natural drugs have been proven to have antiviral properties against a variety of virus strains, such as the coronavirus and the herpes simplex virus (HSV).. In this research, successful dietary treatments for different COVID illnesses were compared to potential of mushroom products in its therapy. In Google Scholar, Science Direct, PubMed, and Scopus, search keywords like COVID, COVID-19, SARS, MERS, mushrooms, and their compounds were utilized. In this review of the literature we foucsed popular mushrooms such as Agaricus subrufescens Peck, Agaricus blazei Murill, Cordyceps sinensis (Berk.) Sacc., Ganoderma lucidum (Curtis.) P. Karst., Grifola frondosa (Dicks.) Gray, Hericium erinaceus (Bull.) Pers., Inonotus obliquus (Arch. Ex Pers.) Pilát., Lentinula edodes (Berk.) Pegler, Pleurotus ostreatus (Jacq.) P. Kumm., Poria cocos F.A. Wolf, and Trametes versicolor (L.) Lloyd.,. Changed forms of β-Glucan seem to have a good impact on viral replication suppression and might be used in future studies. However, the results seems terpenoids, lectins, glycoproteins, lentinan, galactomannan, and polysaccharides from mushrooms are promising prophylactic or therapeutic agents against COVID-19.

Mushrooms and immunity

In the wide field of nutraceuticals, the effects of mushrooms on immunity, cancer and including autoimmunity have been proposed for centuries but in recent years a growing interest has led scientists to elucidate which specific compounds have bioactive properties and through which mechanisms. Glucans and specific proteins are responsible for most of the biological effects of mushrooms, particularly in terms of immunomodulatory and anti-tumor results. Proteins with bioactive effects include lectins, fungal immunomodulatory proteins (FIPs), ribosome inactivating proteins (RIPs), ribonucleases, laccases, among others. At the present status of knowledge, numerous studies have been performed on cell lines and murine models while only a few clinical trials have been conducted. As in most cases of dietary components, the multitude of variables implicated in the final effect and an inadequate standardization are expected to affect the observed differences, thus making the available evidence insufficient to justify the treatment of human diseases with mushrooms extracts. We will herein provide a comprehensive review and critically discussion the biochemical changes induced by different mushroom compounds as observed in in vitro studies, particularly on macrophages, dendritic cells, T cells, and NK cells, compared to in vivo and human studies. Additional effects are represented by lipids which constitute a minor part of mushrooms but may have a role in reducing serum cholesterol levels or phenols acting as antioxidant and reducing agents. Human studies provide a minority of available data, as well illustrated by a placebo-controlled study of athletes treated with β-glucan from Pleurotus ostreatus. Variables influencing study outcomes include different mushrooms strains, growing conditions, developmental stage, part of mushroom used, extraction method, and storage conditions. We foresee that future rigorous research will be needed to determine the potential of mushroom compounds for human health to reproduce the effects of some compounds such as lentinan which a metaanalysis demonstrated to increase the efficacy of chemotherapy in the treatment of lung cancer and in the improvement of the patients quality of life.

New advances and potentials of fungal immunomodulatory proteins for therapeutic purposes

Fungal immunomodulatory proteins (FIPs) are fascinating small and heat-stable bioactive proteins in a distinct protein family due to similarities in their structures and sequences. They are found in fungi, including the fruiting bodies producing fungi comprised of culinary and medicinal mushrooms. Structurally, most FIPs exist as homodimers; each subunit consisting of an N-terminal α-helix dimerization and a C-terminal fibronectin III domain. Increasing numbers of identified FIPs from either different or same fungal species clearly indicates the growing research interests into its medicinal properties which include immunomodulatory, anti-inflammation, anti-allergy, and anticancer. Most FIPs increased IFN-γ production in peripheral blood mononuclear cells, potentially exerting immunomodulatory and anti-inflammatory effects by inhibiting overproduction of T helper-2 (Th2) cytokines common in an allergy reaction. Recently, FIP from Ganoderma microsporum (FIP-gmi) was shown to promote neurite outgrowth for potential therapeutic applications in neuro-disorders. This review discussed FIPs' structural and protein characteristics, their recombinant protein production for functional studies, and the recent advances in their development and applications as pharmaceutics and functional foods.

Current Understanding of the Structure and Function of Fungal Immunomodulatory Proteins

Fungal immunomodulatory proteins (FIPs) are a group of proteins found in fungi, which are extensively studied for their immunomodulatory activity. Currently, more than 38 types of FIPs have been described. Based on their conserved structure and protein identity, FIPs can be classified into five subgroups: Fve-type FIPs (Pfam PF09259), Cerato-type FIPs (Pfam PF07249), PCP-like FIPs, TFP-like FIPs, and unclassified FIPs. Among the five subgroups, Fve-type FIPs are the most studied for their hemagglutinating, immunomodulating, and anti-cancer properties. In general, these small proteins consist of 110–125 amino acids, with a molecular weight of ~13 kDa. The other four subgroups are relatively less studied, but also show a noticeable influence on immune cells. In this review, we summarized the protein modifications, 3-dimensional structures and bioactivities of all types of FIPs. Moreover, structure-function relationship of FIPs has been discussed, including relationship between carbohydrate binding module and hemagglutination, correlation of oligomerization and cytokine induction, relevance of glycosylation and lymphocyte activation. This summary and discussion may help gain comprehensive understanding of FIPs' working mechanisms and scope future studies.

Anticancer potentiality and mode of action of low-carbohydrate proteins and peptides from mushrooms

Severe side effects of chemotherapy as well as drug resistance highlight the ongoing need to discover novel natural bioactive compounds with anticancer potentiality. Mushroom-derived proteins are among the naturally occurring compounds that have been the subject of a body of research on their potentiality in cancer therapy. The greatest attention in relevant review articles has been paid to well-known mushroom-derived glycoproteins such as lectins and protein-bound polysaccharide complexes such as polysaccharide-K (PSK) or krestin and polysaccharopeptide (PSP), which contain substantial amounts of carbohydrates (50-90%). These complex compounds exert their anticancer activity mainly by binding to cell membranes leading to extrinsic (death receptor) apoptosis or intrinsic (mitochondrial) apoptotic pathways. However, several other research studies have reported pure, well-characterized, proteins or peptides from mushrooms, which are carbohydrate-free or have very low amounts of carbohydrate. These proteins may fall into four categories including fungal immunomodulatory proteins, ubiquitin-like proteins, enzymes, and unclassified proteins. Well-defined chemical structure, elucidated full amino acid or N-terminal sequences, purity, and having some distinct and specific pathways compared to glycoproteins have made these low-carbohydrate proteins attractive for cancer research. The aim of this review was therefore to improve the current understanding of mushroom-derived low-carbohydrate proteins and to consolidate the existing knowledge of the most promising mushroom species from which low-carbohydrate proteins have been derived, characterized, and examined for their anticancer activity. In addition, molecular targets and mechanisms of action of these proteins have been discussed. Key points • Mushroom-derived low-carbohydrate proteins lack or have low carbohydrate. • Low-carbohydrate proteins show potent anticancer activities in vitro and in vivo. • There are specific pathways for low-carbohydrate proteins to inhibit cancer cells.

Efficacy of fungal immunomodulatory protein to promote swine immune responses against porcine reproductive and respiratory syndrome virus infection

Fungal immunomodulatory protein (FIP) is one of the bioactive compounds of edible mushrooms, which has been shown to trigger type 1 T helper (Th1) pathway activation in research with mice. This study was designated to assess immunomodulatory effects of recombinant FIP-Flammulina velutipes (rFIP-fve) on swine and the protective efficacy against PRRSV infection. In the in vitro evaluations, rFIP-fve significantly triggered up-regulation of IL-2 and IFN-γ mRNA in porcine PBMCs and stimulated natural killer cytotoxicity. Porcine pulmonary alveolar macrophages (PAMs) treated with rFIP-fve showed prolonged life times, up-regulation of both MHC I and II molecules and enhanced abilities to present antigen. In the in vivo trial, two doses of 2 mg rFIP-fve significantly reduced drops in the CD4/CD8 ratio after PRRSV challenge, and the cytokine mRNA profile of PBMC revealed a tendency of IFN-γ up-regulation and a decrease in IL-10 in the rFIP-treated group. Moreover, administration of rFIP-fve also decreased the PRRSV viremia with 1 log10 in titer (p = 0.07) and alleviated the severity of clinical signs after PRRSV challenge. Conclusively, these results illustrate the in vitro and in vivo immunological changes of rFIP-fve administered to pigs and reveal its potential to be used as an immunomodulatory therapeutic against PRRSV infection.

Characterization of a new fungal immunomodulatory protein, FIP-dsq2 from Dichomitus squalens

FIP-dsq2, a new immunomodulatory protein, was identified in Basidiomycota Dichomitus squalens by gene mining. FIP-dsq2 contained 111 amino acids with a molecular weight of 12.51kDa. FIP-dsq2 had a homology range of 51-65% to the reported FIPs. The predicted 3-dimensional model had more similar identical folding patterns in LZ-8 than for FIP-fve. Evolutionary analysis indicated substantial phylogenetic differences were existed with the other FIPs. Overexpression of a 14.07kDa soluble recombinant FIP-dsq2 (rFIP-dsq2) was achieved in Rosetta (pGEX-6P-1) and the purified recombinant protein was homodimer verified by gel filtration chromatography analysis. Antitumour ability of rFIP-dsq2 to human lung adenocarcinoma A549 cells was between LZ-8 and FIP-fve. The cytotoxic effect of rFIP-dsq2 in A549 cancer cells was dose-dependent and the half-maximal inhibitory concentration (IC₅₀) was 15.08μg/mL. Furthermore, rFIP-dsq2 at 8μg/mL could significantly induce apoptosis and interrupt migration in A549 cells. In addition, the antitumour-mechanism exploration suggested that rFIP-dsq2 inhibited A549 proliferation uniquely via apoptotic cell death pathway. The results stated that rFIP-dsq2 was a promising candidate for use in future lung cancer therapy.

FIP-sch2, a new fungal immunomodulatory protein from Stachybotrys chlorohalonata, suppresses proliferation and migration in lung cancer cells

Fungal immunomodulatory protein (FIP)-sch2, an immunomodulatory protein identified in the ascomycete Stachybotrys chlorohalonata by a sequence similarity search, is a novel member of the FIP family. FIP-sch2 shares high sequence identity, structure, and evolutionary conservation with previously reported FIPs. It was satisfactorily expressed in Escherichia coli with a glutathione S-transferase (GST) tag and purified by GST-affinity magnetic beads. To characterize the direct antitumor effects, human lung adenocarcinoma A549 cells were treated with different concentrations of recombinant FIP (rFIP)-sch2 in vitro, and the results showed that rFIP-sch2 could reduce cell viability dose-dependently with a half-maximal inhibitory concentration (IC₅₀) of 9.48 μg/mL. Furthermore, rFIP-sch2 at 8 μg/mL could significantly induce apoptosis and interrupt migration in A549 cells. Notably, the antitumor effect of rFIP-sch2 was equivalent to that of rLZ-8 but was obviously increased compared to rFIP-fve. In addition, the exploration of the antitumor mechanism suggested that rFIP-sch2 induced lung cancer cell death by activating apoptosis and inhibiting migration. Our results indicated that rFIP-sch2 was a promising candidate for use in future cancer therapy.

Golden Needle Mushroom: A Culinary Medicine with Evidenced-Based Biological Activities and Health Promoting Properties

Flammulina velutipes (enoki, velvet shank, golden needle mushroom or winter mushroom), one of the main edible mushrooms on the market, has long been recognized for its nutritional value and delicious taste. In recent decades, research has expanded beyond detailing its nutritional composition and delved into the biological activities and potential health benefits of its constituents. Many bioactive constituents from a range of families have been isolated from different parts of the mushroom, including carbohydrates, protein, lipids, glycoproteins, phenols, and sesquiterpenes. These compounds have been demonstrated to exhibit various biological activities, such as antitumour and anticancer activities, anti-atherosclerotic and thrombosis inhibition activity, antihypertensive and cholesterol lowering effects, anti-aging and antioxidant properties, ability to aid with restoring memory and overcoming learning deficits, anti-inflammatory, immunomodulatory, anti-bacterial, ribosome inactivation and melanosis inhibition. This review aims to consolidate the information concerning the phytochemistry and biological activities of various compounds isolated from F. velutipes to demonstrate that this mushroom is not only a great source of nutrients but also possesses tremendous potential in pharmaceutical drug development.

Antioxidative Effects and Inhibition of Human Low Density Lipoprotein Oxidation In Vitro of Polyphenolic Compounds in Flammulina velutipes (Golden Needle Mushroom)

Dietary polyphenolic compounds mediate polynomial actions in guarding against multiple diseases. Atherosclerosis is an oxidative stress driven pathophysiological complication where free radical induced oxidative modification of low density lipoprotein (LDL) plays the ground breaking role. Mushrooms have been highly regarded for possessing an antioxidant arsenal. Polyphenolic compounds present in dietary mushrooms seem pertinent in withstanding LDL oxidation en route to controlling atherosclerosis. In this study, the antioxidative effect of five solvent fractions consisting of methanol : dichloromethane (M : DCM), hexane (HEX), dichloromethane (DCM), ethyl acetate (EA), and aqueous residue (AQ) of Flammulina velutipes was evaluated. M : DCM fraction showed the most potent 2,2-diphenyl-1-picrylhydrazyl radical scavenging effect with IC₅₀ of 0.86 mg/mL and total phenolic content of 56.36 gallic acid equivalent/g fraction. In LDL oxidation inhibitory tests, M : DCM fraction at 1 µg/mL concentration mostly lengthened the lag time (125 mins) of conjugated diene formation and inhibited the formation of thiobarbituric acid reactive substances (48.71%, at 1 mg/mL concentration). LC-MS/MS analyses of M : DCM fraction identified the presence of polyphenolic substances protocatechuic acid, p-coumaric, and ellagic acid. These chain-breaking polyphenolics might impart the antioxidative effects of F. velutipes. Thus, mushroom-based dietary polyphenolic compounds might be implicated in slowing down the progression of atherosclerosis.

Effect of the fungal immunomodulatory protein FIP-fve on airway inflammation and cytokine production in mouse asthma model

The allergy is dependent on the balance between Th1 and Th2. The fungal immunodulatory protein (FIP-fve) was isolated from Flammulina velutipes. FIP-fve has been demonstrated to skew the response to Th1 cytokine production. We investigated whether oral administrations of FIP-fve inhibited allergen (OVA)-induced chronic airway inflammation in the mouse asthma model. After intranasal challenge with OVA, the airway inflammation and hyperresponsiveness were determined by bronchoalveolar lavage fluid (BALF) analysis and ELISA assay. Both pre-treated and post-treated with FIP-fve suppressed the airway hyperresponsiveness by methacholine challenge and significantly decreased the number of infiltrating inflammatory cells and Th2 cytokines in bronchoalveolar lavage fluid (BALF) and serum compared with the OVA sensitized mice. In addition, FIP-fve reduced OVA-specific IgE levels in serum. FIP-fve markedly alleviated the OVA-induced airway hyperresponsiveness (AHR) to inhaled methacholine. Based on lung histopathological studies using hematoxylin and Liu's staining, FIP-fve inhibited inflammatory cell infiltration compared with the OVA-sensitized mice. Oral FIP-fve had an anti-inflammatory effect on OVA-induced airway inflammations and might posses the potential for alternative therapy for allergic airway diseases.

IFN-γ induction on carbohydrate binding module of fungal immunomodulatory protein in human peripheral mononuclear cells

FIP-fve is a protein that is isolated from Flammulina velutipes . Its known immunomodulatory activities are elicitation of the production of type II interferon from human peripheral mononuclear cells (hPBMCs) and hemagglutination. How the target receptors mediate activation of FIP-fve-induced immunomodulatory effects remains to be elucidated. This study postulates the three-dimensional structures to determine whether the carbohydrate binding module family 34 (CBM-34) on FIP-fve is conserved to site N of Thermoactinomyces vulgaris R-47 α-amylase I. Experimental site-directed mutagenesis data as well as ligand-specific binding competition assay are adopted to identify the key residues W24, T28, D34, T90, I91, and W111 of FIP-fve that participate in binding to polysaccharides that are linked to the membrane of immune cells. Treatments of hPBMCs with tunicamycin and deglycosylation enzymes that removed the carbohydrate moieties reduced the secretion of IFN-γ induction from hPBMCs. In conclusion, the experiments herein demonstrated the ligand-binding CBM-34 on FIP-fve and ligand-like glycoproteins on the surface of hPBMCs must be required to induce physiological immunomodulatory effects.

The contribution of NT-gp96 as an adjuvant for increasing HPV16 E7-specific immunity in C57BL /6 mouse model

To control cervical cancer, efficient vaccination against human papillomavirus (HPV) is highly required. Despite the advantages and safety of the protein vaccines, additional strategies to enhance their immunogenicity are needed. E7 is a transforming protein which represents a perfect target antigen for vaccines or immunotherapies. Heat shock proteins (HSPs) facilitate cellular immune responses to antigenic peptides or proteins bound to them. Regarding to previous studies, vaccination with purified HSP/antigen complexes efficiently elicit antigen-specific immune responses in mice model. The N-terminal of glycoprotein 96 (NT-gp96) has adjuvant effect and can induce effective cumulative immune response against clinical disorders, especially cancers. In this study, the recombinant HPV16 E7 and E7 linked to NT-gp96 (E7-NT-gp96) proteins were generated in prokaryotic expression system. Mice were vaccinated twice with this recombinant proteins and the immunogenicity of the fusion protein was determined. The preventive efficacy of E7-NT-gp96 fusion protein was also evaluated and compared to E7 protein after challenging with cancerous TC-1 cell line. In vitro re-stimulated splenocytes of mice vaccinated with rE7-NT-gp96 protein induced higher IFN-γ response in comparison with E7 protein immunization. Moreover, immunization with E7-NT-gp96 protein displayed low but stable humoral responses at post-challenge time. The data showed that vaccination with fused E7-NT-gp96 protein delayed the tumour occurrence and growth as compared to protein E7 alone. These results suggest that fused adjuvant-free E7-NT-gp96 protein vaccination could direct the immune responses towards Th1 immunity. Furthermore, the linkage of NT-gp96 to E7 could enhance protective anti-tumour immunity.

Applied modern biotechnology for cultivation of Ganoderma and development of their products

A white-rot basidiomycete Ganoderma spp. has long been used as a medicinal mushroom in Asia, and it has an array of pharmacological properties for immunomodulatory activity. There have been many reports about the bioactive components and their pharmacological properties. In order to analyze the current status of Ganoderma products, the detailed process of cultivation of Ganoderma spp. and development of their products are restated in this review article. These include the breeding, cultivating, extracting bioactive component, and processing Ganoderma products, etc. This article will expand people's common knowledge on Ganoderma, and provide a beneficial reference for research and industrial production.

A novel adjuvant Ling Zhi-8 enhances the efficacy of DNA cancer vaccine by activating dendritic cells

DNA vaccine has been suggested to use in cancer therapy, but the efficacy remains to be improved. The immunostimulatory effect of a fungal immunomodulatory protein Ling Zhi-8 (LZ-8) isolated from Ganoderma lucidum has been reported. In this study, we tested the adjuvanticity of LZ-8 for HER-2/neu DNA vaccine against p185(neu) expressing tumor MBT-2 in mice. We found that recombinant LZ-8 stimulated mouse bone marrow-derived dendritic cells (DCs) via TLR4 and its stimulatory effect was not due to any microbe contaminant. In addition, LZ-8 enhanced the ability of DCs to induce antigen-specific T cell activation in vitro and in a subunit vaccine model in vivo. Surprisingly, LZ-8 cotreatment strongly improved the therapeutic effect of DNA vaccine against MBT-2 tumor in mice. This increase in antitumor activity was attributed to the enhancement of vaccine-induced Th1 and CTL responses. Consistent with the results from DCs, the promoting effect of LZ-8 on DNA vaccine was diminished when the MBT-2 tumor cells were grown in TLR4 mutant mice. Thus, we concluded that LZ-8 may be a promising adjuvant to enhance the efficacy of DNA vaccine by activating DCs via TLR4.

Airway inflammation and IgE production induced by dust mite allergen-specific memory/effector Th2 cell line can be effectively attenuated by IL-35

CD4(+) memory/effector T cells play a central role in orchestrating the rapid and robust immune responses upon re-encounter with specific Ags. However, the immunologic mechanism(s) underlying these responses are still not fully understood. To investigate this, we generated an allergen (major house dust mite allergen, Blo t 5)-specific murine Th2 cell line that secreted IL-4, IL-5, IL-10, and IL-13, but not IL-9 or TNF-α, upon activation by the cognate Ag. These cells also exhibited CD44(high)CD62L(-) and CD127(+) (IL-7Rα(+)) phenotypes, which are characteristics of memory/effector T cells. Experiments involving adoptive transfer of this Th2 cell line in mice, followed by three intranasal challenges with Blo t 5, induced a dexamethasone-sensitive eosinophilic airway inflammation. This was accompanied by elevation of Th2 cytokines and CC- and CXC-motif chemokines, as well as recruitment of lymphocytes and polymorphic mononuclear cells into the lungs. Moreover, Blo t 5-specific IgE was detected 4 d after the last intranasal challenge, whereas elevation of Blo t 5-specific IgG1 was found at week two. Finally, pulmonary delivery of the pVAX-IL-35 DNA construct effectively downregulated Blo t 5-specific allergic airway inflammation, and i.m. injection of pVAX-IL-35 led to long-lasting suppression of circulating Blo t 5-specific and total IgE. This model provides a robust research tool to elucidate the immunopathogenic role of memory/effector Th2 cells in allergic airway inflammation. Our results suggested that IL-35 could be a potential therapeutic target for allergic asthma through its attenuating effects on allergen-specific CD4(+) memory/effector Th2 cell-mediated airway inflammation.

Shikonin inhibits maturation of bone marrow-derived dendritic cells and suppresses allergic airway inflammation in a murine model of asthma

BACKGROUND AND PURPOSE

Shikonin exhibits a wide range of anti-inflammatory actions. Here, we assessed its effects on maturation of murine bone marrow-derived dendritic cells (BM-DCs) and on allergic reactions in a murine model of asthma.

EXPERIMENTAL APPROACH

Cultured murine BM-DCs were used to investigate the effects of shikonin on expression of cell surface markers and their stimulation of T-cell proliferation and cytokine production. The therapeutic potential of shikonin was evaluated in a model of allergic airway disease.

KEY RESULTS

Shikonin dose-dependently inhibited expression of major histocompatibility complex class II, CD80, CD86, CCR7 and OX40L on BM-DCs, induced by a mixture of ovalbumin (OVA; 100µg·mL(-1) ) and thymic stromal lymphopoietin (TSLP; 20ng·mL(-1) ). Shikonin-treated BM-DCs were poor stimulators of CD4(+) T lymphocyte and induced lower levels of interleukin (IL)-4, IL-5, IL-13 and tumour necrosis factor (TNF)-α release by responding T-cells. After intratracheal instillation of shikonin in OVA-immunized mice, OVA challenge induced lower IL-4, IL-5, IL-13, TNF-α and eotaxin release in bronchial alveolar lavage fluid, lower IL-4 and IL-5 production in lung cells and mediastinal lymph node cells and attenuated OVA-induced lung eosinophilia and airway hyperresponsiveness.

CONCLUSION AND IMPLICATIONS

Shikonin effectively suppressed OVA + TSLP-induced BM-DC maturation in vitro and inhibited allergic inflammation and airway hyperresponsiveness in a murine model of asthma, showing good potential as a treatment for allergic asthma. Also, our model provides a novel platform for screening drugs for allergic diseases.