A rapid and sensitive assay based on particle analysis for cell degranulation detection in basophils and mast cells

Lipid matrix-specific pretreatment method for enhancing the extractability and allergenicity maintenance of bovine milk allergens in ELISA detection

The presence of various components in the food matrix makes allergen detection difficult and inaccurate, and pretreatment is an innovative breakthrough point. Food matrices were categorised based on their composition. Subsequently, a pretreatment method was established using a combination of ultrasound-assisted n-hexane degreasing and weakly alkaline extraction systems to enhance the detection accuracy of bovine milk allergens. Results showed that more allergens were obtained with less structural destruction, as demonstrated using immunological quantification and spectral analysis. Concurrently, allergenicity preservation was confirmed through liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, a KU812 cell degranulation model, and western blotting. The method exhibited good accuracy (bias, 8.47%), repeatability (RSDr, 1.52%), and stability (RSDR, 5.65%). In foods with high lipid content, such as chocolate, the allergen content was 2.29-fold higher than that of commercial kits. Laser confocal scanning microscopy (LCSM) and scanning electron microscopy (SEM) analyses revealed a significant decrease in fat content after post-pretreatment using our method. In addition, colloidal stability surpassed that achieved using commercial kits, as indicated through the PSA and zeta potential results. The results demonstrated the superiority of the extractability and allergenicity maintenance of lipid matrix-specific pretreatment methods for improving the accuracy of ELISA based allergen detection in real food.

Inhibitory effects of compounds isolated from Geranium wilfordii on IL-4 production and β-hexosaminidase release in RBL-2H3 cells

This study aimed to investigate the anti-allergic activity of compounds isolated from Geranium wilfordii Maxim. and to suggest potential therapeutic agents for allergies. Nine compounds were isolated from an ethanolic G. wilfordii extract using chromatographic methods and identified chemically and by spectroscopic analysis. These compounds were identified using reported literature data as brevifolin carboxylic acid (1), chlorogenic acid (2), corilagin (3), ellagic acid (4), geraniol (5), kaempferol 3-O-dirhamnoside (6), kaempferol 3-O-neohesperidoside (7), protocatechuic acid (8), and gallic acid (9). All nine identified compounds were assessed for including IL-4 mRNA expression and β-hexosaminidase release in RBL-2H3 cells stimulated with PMA/ionomycin or IgE + DNP-BSA. IL-4 gene expression assay showed that corilagin (3) potently inhibited IL-4 production, and β-hexosaminidase release assay showed that protocatechuic acid (8) markedly reduced histamine release. The study shows that of the nine compounds isolated from G. wilfordii, corilagin (3), and protocatechuic acid (8) are potential treatments for allergy-related diseases.

The cytoskeletal protein profilin is an important allergen in saltwort (Salsola kali)

Pollen from Salsola kali, i.e., saltwort, Russian thistle, is a major allergen source in the coastal regions of southern Europe, in Turkey, Central Asia, and Iran. S. kali-allergic patients mainly suffer from hay-fever (i.e., rhinitis and conjunctivitis), asthma, and allergic skin symptoms. The aim of this study was to investigate the importance of individual S. kali allergen molecules. Sal k 1, Sal k 2, Sal k 3, Sal k 4, Sal k 5, and Sal k 6 were expressed in Escherichia coli as recombinant proteins containing a C-terminal hexahistidine tag and purified by nickel affinity chromatography. The purity of the recombinant allergens was analyzed by SDS-PAGE. Their molecular weight was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and their fold and secondary structure were studied by circular dichroism (CD) spectroscopy. Sera from clinically well-characterized S. kali-allergic patients were used for IgE reactivity and basophil activation experiments. S. kali allergen-specific IgE levels and IgE levels specific for the highly IgE cross-reactive profilin and the calcium-binding allergen from timothy grass pollen, Phl p 12 and Phl p 7, respectively, were measured by ImmunoCAP. The allergenic activity of natural S. kali pollen allergens was studied in basophil activation experiments. Recombinant S. kali allergens were folded when studied by CD analysis. The sum of recombinant allergen-specific IgE levels and allergen-extract-specific IgE levels was highly correlated. Sal k 1 and profilin, reactive with IgE from 64% and 49% of patients, respectively, were the most important allergens, whereas the other S. kali allergens were less frequently recognized. Specific IgE levels were highest for profilin. Of note, 37% of patients who were negative for Sal k 1 showed IgE reactivity to Phl p 12, emphasizing the importance of the ubiquitous cytoskeletal actin-binding protein, profilin, for the diagnosis of IgE sensitization in S. kali-allergic patients. rPhl p 12 and rSal k 4 showed equivalent IgE reactivity, and the clinical importance of profilin was underlined by the fact that profilin-monosensitized patients suffered from symptoms of respiratory allergy to saltwort. Accordingly, profilin should be included in the panel of allergen molecules for diagnosis and in molecular allergy vaccines for the treatment and prevention of S. kali allergy.

Double Emulsion-Mediated Delivery of Polyphenol Mixture Alleviates Atopic Dermatitis

Although the polyphenols have been studied to alleviate inflammation, there are still challenges to delivering the polyphenols with stabilized formulation due to their low water solubility and susceptibility to oxidation. Herein, the transdermal delivery system of polyphenol mixture (PM), including quercetin (Q), phloretin (P), and ellagic acid (E), is developed using double emulsion for applying to atopic dermatitis (AD). Through the in vitro anti-degranulation assay, the optimal molar ratio of each polyphenol (Q:P:E = 5:1:1) is obtained, and the PM shows at most a 43.6% reduction of degranulation of immune cells, which is the primary factor of AD. Moreover, the water-in-oil-in-water double emulsion (W/O/W) enhances the PM's stability and has a higher anti-degranulation effect than the oil-in-water emulsion (O/W). In the in vivo 1-chloro-2,4-dinitrobenzene (DNCB)-induced mice AD model, PM reduces more AD symptoms than every single polyphenol. The PM-encapsulated W/O/W (PM_W/O/W) shows the most effectiveness in AD by decreasing dermatitis score, i.e., skin/ear thickness, mast cells, and serum IgE level. Finally, this suggests that the findings on the optimal ratio of PM and double emulsion-based delivery would be beneficial in treating AD and can be applied to other allergic diseases.

Essential Oils: Chemistry and Pharmacological Activities

In this review, we provide an overview of the current understanding of the main mechanisms of pharmacological action of essential oils and their components in various biological systems. A brief introduction on essential oil chemistry is presented to better understand the relationship of chemical aspects with the bioactivity of these products. Next, the antioxidant, anti-inflammatory, antitumor, and antimicrobial activities are discussed. The mechanisms of action against various types of viruses are also addressed. The data show that the multiplicity of pharmacological properties of essential oils occurs due to the chemical diversity in their composition and their ability to interfere with biological processes at cellular and multicellular levels via interaction with various biological targets. Therefore, these natural products can be a promising source for the development of new drugs.

Repeated stress-induced crosstalk between the sympathetic nervous system and mast cells contributes to delayed cutaneous wound healing in mice

The study identifies a link between the neuroimmune interaction and the impairment of wound healing induced by repeated stress. Stress increased mast cell mobilization and degranulation, levels of IL-10, and sympathetic reinnervation in mouse wounds. In contrast to mast cells, macrophage infiltration into wounds was significantly delayed in stressed mice. Chemical sympathectomy and the blockade of mast cell degranulation reversed the effect of stress on skin wound healing in vivo. In vitro, high epinephrine levels stimulated mast cell degranulation and IL-10 release. In conclusion, catecholamines released by the sympathetic nervous system stimulate mast cells to secrete anti-inflammatory cytokines that impair inflammatory cell mobilization, leading to a delay in the resolution of wound healing under stress conditions.

Mast Cells as a Target-A Comprehensive Review of Recent Therapeutic Approaches

Mast cells (MCs) are the immune cells distributed throughout nearly all tissues, mainly in the skin, near blood vessels and lymph vessels, nerves, lungs, and the intestines. Although MCs are essential to the healthy immune response, their overactivity and pathological states can lead to numerous health hazards. The side effect of mast cell activity is usually caused by degranulation. It can be triggered by immunological factors, such as immunoglobulins, lymphocytes, or antigen-antibody complexes, and non-immune factors, such as radiation and pathogens. An intensive reaction of mast cells can even lead to anaphylaxis, one of the most life-threatening allergic reactions. What is more, mast cells play a role in the tumor microenvironment by modulating various events of tumor biology, such as cell proliferation and survival, angiogenesis, invasiveness, and metastasis. The mechanisms of the mast cell actions are still poorly understood, making it difficult to develop therapies for their pathological condition. This review focuses on the possible therapies targeting mast cell degranulation, anaphylaxis, and MC-derived tumors.

Systematic comparisons of various markers for mast cell activation in RBL-2H3 cells

Mast cell activation plays a key role in various allergic diseases and anaphylaxis. Several methods/techniques can be used for detection of mast cell activation. However, there was no previous systematic evaluation to compare the efficacy of each method/technique. The present study thus systematically compared various markers for mast cell activation induced by IgE cross-linking. The widely used RBL-2H3 mast cells were sensitized with anti-DNP (dinitrophenyl) IgE overnight and activated with DNP-BSA (bovine serum albumin) for up to 4 h. The untreated cells and those with anti-DNP IgE sensitization but without DNP-BSA activation served as the controls. Intracellular calcium level gradually increased to ~2-fold at 1 h, reached its peak (~5-fold) at 2 h, and returned to the basal level at 3-h post-activation. The increases in cellular tryptase level (by Western blotting) (~0.3- to 0.4-fold) and average cell size (~2.5-fold) and decrease of nucleus/cytoplasm ratio (~0.4- to 0.5-fold) were marginal at all time-points. By contrast, β-hexosaminidase release and CD63 expression (by both flow cytometry and immunofluorescence detection/localization), secreted tryptase level (by Western blotting), and tryptase expression (by immunofluorescence detection/localization) stably and obviously increased (~10-fold as compared with the untreated control and sensitized-only cells or detectable only after activation). Based on these data, the stably obvious increases (by ≥ 10-fold) in β-hexosaminidase release, CD63 expression (by both flow cytometry and immunofluorescence staining), secreted tryptase level (by Western blotting), and tryptase expression (by immunofluorescence staining) are recommended as the markers of choice for the in vitro study of mast cell activation using RBL-2H3 cells.

Resveratrol Attenuates Mast Cell Mediated Allergic Reactions: Potential for Use as a Nutraceutical in Allergic Diseases?

Allergic diseases are one of the most common health disorders affecting about 30% of the world population. Mast cells (MCs) are key effector cells of allergic reactions by releasing proinflammatory mediators including histamine, lipid mediators, and cytokines/chemokines. Natural substances like secondary plant substances such as resveratrol (RESV), which can contribute to prevention and treatment of diseases, are becoming increasingly interesting for use as nutraceuticals. In this review, the anti-inflammatory effects of RESV on MC-mediated allergic reactions in vitro and in vivo models are summarized. The studies indicate that RESV inhibits MC degranulation, synthesis of arachidonic acid metabolites, expression of cytokines and chemokines as well as activation of signal molecules involved in proinflammatory mechanisms. Also, beneficial impacts by this polyphenol are reported in randomized controlled trials with allergic rhinitis patients. Although it cannot yet be concluded that RESV can be used successfully in allergy patients in general, there are many results that indicate a possible role for RESV for use as an anti-inflammatory nutraceutical. However, strategies to favorably influence the poor bioavailability of RESV would be helpful.

Inorganic food additive nanomaterials alter the allergenicity of milk proteins

While inorganic nanomaterials are copiously incorporated in food products, their impact on the allergenicity food proteins is largely unknown. This study analyzed the effect of widely used food additive nanomaterials (silica and titania) on the antigenicity and allergenicity of milk proteins (β-lactoglobulin and casein) and skimmed milk. Changes in the antigenicity of milk proteins in the presence of dietary nanomaterials were identified using an indirect-ELISA assay, while the change in allergenicity was studied using mast cell (LAD2) sensitized using allergic human sera. Results showed an enhancement in the allergenicity of milk proteins/skimmed milk interacted with particles (both silica and titania). Similarly, mast cell degranulation (a proxy for allergenicity) was higher when exposed to particle interacted skim milk where nanomaterials of titania showed the highest effect, and this tendency was retained even after subjecting to simulated gut digestion. Particles induced alterations in the structure of milk proteins, as evidenced by our studies, are reasoned to expose epitopes that increase allergenicity of milk proteins.

Development of a High-Throughput Calcium Mobilization Assay for CCR6 Receptor Coupled to Hydrolase Activity Readout

CCR6 is a chemokine receptor highly implicated in inflammatory diseases and could be a potential therapeutic target; however, no therapeutic agents targeting CCR6 have progressed into clinical evaluation. Development of a high-throughput screening assay for CCR6 should facilitate the identification of novel compounds against CCR6. To develop a cell-based assay, RBL-2H3 cells were transfected with plasmids encoding β-hexosaminidase and CCR6. Intracellular calcium mobilization of transfected cells was measured with a fluorescent substrate using the activity of released hexosaminidase as readout of the assay. This stable, transfected cell showed a specific signal to the background ratio of 19.1 with low variability of the signal along the time. The assay was validated and optimized for high-throughput screening. The cell-based calcium mobilization assay responded to the specific CCR6 ligand, CCL20, in a dose-dependent manner with an EC₅₀ value of 10.72 nM. Furthermore, the assay was deemed robust and reproducible with a Z’ factor of 0.63 and a signal window of 7.75. We have established a cell-based high-throughput calcium mobilization assay for CCR6 receptor. This assay monitors calcium mobilization, due to CCR6h activation by CCL20, using hexosaminidase activity as readout. This assay was proved to be robust, easy to automate and could be used as method for screening of CCR6 modulators.

Rapid discovery of potential ADR compounds from injection of total saponins from Panax notoginseng using data-independent acquisition untargeted metabolomics

Injection of total saponins from Panax notoginseng (ISPN) is a modern preparation derived from traditional Chinese medicine (TCM) and is widely applied in the treatment of cardiovascular, cerebrovascular, ophthalmology, and endocrine system diseases. With the increase in the clinical application of ISPN, its adverse drug reactions (ADRs) and related safety issues have attracted much attention. In the present study, a data-independent acquisition (DIA) strategy was proposed to comprehensively characterize the saponins contained in ISPN based on the ultra-high-performance liquid chromatography/quadrupole-Orbitrap MS (UHPLC/Q-Orbitrap MS) platform. As many as 276 saponins were detected, and 250 compounds were identified or tentatively identified based on the retention times and MS/MS data. Furthermore, a metabolomic strategy was utilized to discover the discriminative saponins between normal and ADR batches. The results showed that six saponins, including ginsenoside Rh4, ginsenoside Rk3, ginsenoside Rg5, ginsenoside Rk1, ginsenoside Rg6, and 20(S)-ginsenoside Rh2, were significantly different between the two groups. According to cytotoxicity analysis and degranulation detection of RBL-2H3 cells, ginsenoside Rg5, ginsenoside Rk1, and 20(S)-ginsenoside Rh2 were considered the potential compounds responsible for clinical ADRs, ultimately. In addition, the quantitative analysis showed that the content of these three compounds in ISPN samples with ADRs was generally higher than that in samples without ADRs. This study demonstrated that it is advisable to screen out potential markers related to ADRs for developing the quality standard of ISPN by the integration of untargeted metabolomic analysis and cell biology study, and thus reduce its ADRs in the clinic.

MiR-154-5p-MCP1 Axis Regulates Allergic Inflammation by Mediating Cellular Interactions

In a previous study, we have demonstrated that p62, a selective receptor of autophagy, can regulate allergic inflammation. In the present study, microRNA array analysis showed that miR-154-5p was increased by antigen (DNP-HSA) in a p62-dependent manner in rat basophilic leukemia cells (RBL2H3). NF-kB directly increased the expression of miR-154-5p. miR-154-5p mediated in vivo allergic reactions, including passive cutaneous anaphylaxis and passive systemic anaphylaxis. Cytokine array analysis showed that antigen stimulation increased the expression of MCP1 in RBL2H3 cells in an miR-154-5p-dependent manner. Reactive oxygen species (ROS)-ERK-NF-kB signaling increased the expression of MCP1 in antigen-stimulated RBL2H3 cells. Recombinant MCP1 protein induced molecular features of allergic reactions both in vitro and in vivo. Anaphylaxis-promoted tumorigenic potential has been known to be accompanied by cellular interactions involving mast cells, and macrophages, and cancer cells. Our experiments employing culture medium, co-cultures, and recombinant MCP1 protein showed that miR-154 and MCP1 mediated these cellular interactions. MiR-154-5p and MCP1 were found to be present in exosomes of RBL2H3 cells. Exosomes from PSA-activated BALB/C mouse induced molecular features of passive cutaneous anaphylaxis in an miR-154-5p-dependent manner. Exosomes from antigen-stimulated RBL2H3 cells enhanced both tumorigenic and metastatic potentials of B16F1 melanoma cells in an miR-154-5p-dependent manner. Exosomes regulated both ROS level and ROS mediated cellular interactions during allergic inflammation. Our results indicate that the miR-154-5p-MCP1 axis might serve as a valuable target for the development of anti-allergy therapeutics.

Stand out from matrix: Ultra-sensitive LC-MS/MS method for determination of histamine in complex biological samples using derivatization and solid phase extraction

The determination of low abundant endogenous components is a challenge for the clinical samples. Histamine, a crucial endogenous component, fulfils various regulatory and mediatory functions in human, and the change of content is a critical index for the diagnosis of some diseases, especially allergy, asthma, and anaphylactic shock. However, it is challenging to detect histamine because of the low stability and concentration in complex biological samples. Here we developed an ultra-sensitive and accurate LC-MS/MS quantification method based on derivatization, isotope dilution, and solid phase extraction. The derivatization of histamine with diisopropyl phosphite (DIPP) not only enhanced the retention on the LC column but also improved the ionization efficiency. Next, solid phase extraction was applied to remove the interference, which finally resulted in standing out of the trace histamine from the high contents of the matrix. The lowest limit of quantification (LLOQ) was 0.1 pg/mL that is enough low to determine the histamine in one cell and low nano-liter of serum. This approach was successfully applied for the quantification of histamine in clinical serum samples of asthma patients and mast cell treated with chemicals modulating histamine release.

Anti-Inflammatory Effects of a Cordyceps sinensis Mycelium Culture Extract (Cs-4) on Rodent Models of Allergic Rhinitis and Asthma

Allergic rhinitis and asthma are common chronic allergic diseases of the respiratory tract, which are accompanied by immunoglobulin E (IgE)-mediated inflammation and the involvement of type 2 T helper cells, mast cells, and eosinophils. Cordyceps sinensis (Berk.) Sacc is a fungal parasite on the larva of Lepidoptera. It has been considered to be a health-promoting food and, also, one of the best-known herbal remedies for the treatment of airway diseases, such as asthma and lung inflammation. In the present study, we demonstrated the antiallergic rhinitis effect of Cs-4, a water extract prepared from the mycelium culture of Cordyceps sinensis (Berk) Sacc, on ovalbumin (OVA)-induced allergic rhinitis in mice and the anti-asthmatic effect of Cs-4 in a rat model of asthma. Treatment with Cs-4 suppressed the nasal symptoms induced in OVA-sensitized and challenged mice. The inhibition was associated with a reduction in IgE/OVA-IgE and interleukin (IL)-4/IL-13 levels in the nasal fluid. Cs-4 treatment also decreased airway responsiveness and ameliorated the scratching behavior in capsaicin-challenged rats. It also reduced plasma IgE levels, as well as IgE and eosinophil peroxidase levels, in the bronchoalveolar fluid. Cs-4 treatment completely suppressed the increases in IL-4, IL-5, and IL-13 levels in rat lung tissue. In conclusion, our results suggest that Cs-4 has the potential to alleviate immune hypersensitivity reactions in allergic rhinitis and asthma.

Mast cell activation markers for in vitro study

Mast cells (MCs) are well known for their role in allergic conditions. This cell can be activated by various types of secretagogues, ranging from a small chemical to a huge protein. Mast cell activation by secretagogues triggers the increase in intracellular calcium (iCa²⁺) concentration, granule trafficking, and exocytosis. Activated mast cells release their intra-granular pre-stored mediator or the newly synthesized mediator in the exocytosis process, in the form of degranulation or secretion. There are at least three types of exocytosis in mast cells, which are suggested to contribute to the release of different mediators, i.e.,, piecemeal, kiss-and-run, and compound exocytosis. The status of mast cells, i.e., activated or resting, is often determined by measuring the concentration of the released mediator such as histamine or β-hexosaminidase. This review summarizes several mast cell components that have been and are generally used as mast cell activation indicator, from the classical histamine and β-hexosaminidase measurement, to eicosanoid and granule trafficking observation. Basic principle of the component determination is also explained with their specified research application and purpose. The information will help to predict the experiment results with a certain study design.

Influence of molecular weight and concentration of carboxymethyl chitosan on biomimetic mineralization of collagen

The objective of the present study was to systematically investigate the influence of molecular weight (MW) and concentration of carboxymethyl chitosan (CMC), which served as non-collagenous protein (NCP) surrogates, on biomimetic mineralization of type I collagen. Supersaturated CMC-stabilized amorphous calcium-phosphate (CMC-ACP) dispersions containing different MWs (20 kDa, 60 kDa, 150 kDa) and concentrations (25, 50, 100, 200, 400 μg ml⁻¹) of CMC were prepared. After mineralization in the aforementioned dispersions for 7 days, the pattern and extent of biomimetic mineralization of collagen scaffolds were investigated. Our study showed that increasing CMC concentration resulted in increasing stability and decreasing particle size of CMC-ACP dispersions. Images from scanning and transmission electron microscopy revealed that intrafibrillar mineralization of collagen was obtained with 20k-200, 60k-100, 60k-200 and 150k-200 CMC-ACP dispersions, with hydroxyapatite (HAp) formation confirmed by Fourier transform infrared spectroscopy and X-ray diffraction measurements, whereas HAp formed extrafibrillar clusters in other collagen scaffolds. Thermogravimetric analysis showed that the combined effect of MW and concentration of CMC contributed to different extents of biomimetic mineralization, and was correlated with the stability and particle size of CMC-ACP dispersions, and the size-exclusion characteristics of type I collagen. The results of this work support the effective function of CMC as NCP analogs, and provide parameters of MWs and concentrations of CMC for applications in hard tissue engineering as well as insights into intersections of mechanisms in biomimetic mineralization.

The study systematically investigated the influence of molecular weight and concentration of CMC on CMC-ACP nanoparticles and biomimetic mineralization.

Lamiaceae: An Insight on Their Anti-Allergic Potential and Its Mechanisms of Action

The prevalence of allergic diseases such as asthma, allergic rhinitis, food allergy and atopic dermatitis has increased dramatically in recent decades. Conventional therapies for allergy can induce undesirable effects and hence patients tend to seek alternative therapies like natural compounds. Considering the fact above, there is an urgency to discover potential medicinal plants as future candidates in the development of novel anti-allergic therapeutic agents. The Lamiaceae family, or mint family, is a diverse plant family which encompasses more than 7,000 species and with a cosmopolitan distribution. A number of species from this family has been widely employed as ethnomedicine against allergic inflammatory skin diseases and allergic asthma in traditional practices. Phytochemical analysis of the Lamiaceae family has reported the presence of flavonoids, flavones, flavanones, flavonoid glycosides, monoterpenes, diterpenes, triterpenoids, essential oil and fatty acids. Numerous investigations have highlighted the anti-allergic activities of Lamiaceae species with their active principles and crude extracts. Henceforth, this review has the ultimate aim of compiling the up-to-date (2018) findings of published scientific information about the anti-allergic activities of Lamiaceae species. In addition, the botanical features, medicinal uses, chemical constituents and toxicological studies of Lamiaceae species were also documented. The method employed for data collection in this review was mainly the exploration of the PubMed, Ovid and Scopus databases. Additional research studies were obtained from the reference lists of retrieved articles. This comprehensive summarization serves as a useful resource for a better understanding of Lamiaceae species. The anti-allergic mechanisms related to Lamiaceae species are also reviewed extensively which aids in future exploration of the anti-allergic potential of Lamiaceae species.

Fermented red ginseng and ginsenoside Rd alleviate ovalbumin-induced allergic rhinitis in mice by suppressing IgE, interleukin-4, and interleukin-5 expression

Background

To increase the pharmacological effects of red ginseng (RG, the steamed root of Panax ginseng Meyer), RG products modified by heat process or fermentation have been developed. However, the antiallergic effects of RG and modified/fermented RG have not been simultaneously examined. Therefore, we examined the allergic rhinitis (AR)-inhibitory effects of water-extracted RG (wRG), 50% ethanol-extracted RG (eRG), and bifidobacteria-fermented eRG (fRG) in vivo.

Methods

RBL-2H3 cells were stimulated with phorbol 12-myristate-13-acetate/A23187. Mice with AR were prepared by treatment with ovalbumin. Allergic markers IgE, tumor necrosis factor-α, interleukin (IL)-4, and IL-5 were assayed in the blood, bronchoalveolar lavage fluid, nasal mucosa, and colon using enzyme-linked immunosorbent assay. Mast cells, eosinophils, and Th2 cell populations were assayed using a flow cytometer.

Results

RG products potently inhibited IL-4 expression in phorbol 12-myristate-13-acetate/A23187-stimulated RBL-2H3 cells. Of tested RG products, fRG most potently inhibited IL-4 expression. RG products also alleviated ovalbumin-induced AR in mice. Of these, fRG most potently reduced nasal allergy symptoms and blood IgE levels. fRG treatment also reduced IL-4 and IL-5 levels in bronchoalveolar lavage fluid, nasal mucosa, and reduced mast cells, eosinophils, and Th2 cell populations. Furthermore, treatment with fRG reduced IL-4, IL-5, and IL-13 levels in the colon and restored ovalbumin-suppressed Bacteroidetes and Actinobacteria populations and ovalbumin-induced Firmicutes population in gut microbiota. Treatment with ginsenoside Rd significantly alleviated ovalbumin-induced AR in mice.

Conclusion

fRG and ginsenoside Rd may alleviate AR by suppressing IgE, IL-4, IL-5, and IL-13 expression and restoring the composition of gut microbiota.

Identification of Soluble Mediators in IgG-Mediated Anaphylaxis via Fcγ Receptor: A Meta-Analysis

Background: Anaphylaxis is an acute and life-threatening allergic response. Classically and most commonly, it can be mediated by the crosslinking of allergens to immunoglobulin E (IgE)- high affinity IgE receptor (FcεRI) complex found mostly on mast cells. However, there is another pathway of anaphylaxis that is less well-studied. This pathway known as the alternative pathway is mediated by IgG and its Fc gamma receptor (Fcγ). Though it was not documented in human anaphylaxis, a few studies have found that IgG-mediated anaphylaxis can happen as demonstrated in rodent models of anaphylaxis. In these studies, a variety of soluble mediators were being evaluated and they differ from each study which causes confusion in the suitability, and reliability of choice of soluble mediators to be analyzed for diagnosis or therapeutic purposes. Hence, the objective of this meta-analysis is to identify the potential soluble mediators that are involved in an IgG-mediated anaphylaxis reaction.

Methods: Studies related to IgG-mediated anaphylaxis were sourced from five search engines namely PubMed, Scopus, Ovid, Cochrane Library, and Center for Agricultural Bioscience International (CABI) regardless of publication year. Relevant studies were then reviewed based on specific inclusion factors. The means and standard deviations of each soluble mediator studied were then extracted using ImageJ or Get Data Graph Digitiser software and the data were subjected to meta-analysis.

Results: From our findings, we found that histamine, serotonin, platelet activating factor (PAF), β-hexosaminidase, leukotriene C4 (LTC₄), mucosal mast cell protease-1 (MMCP-1), interleukins (IL)-4,−6, and−13; tumor necrosis factor alpha (TNF-α), and macrophage inflammatory protein-1α (MIP-1α) were often being analyzed. Out of these soluble mediators, histamine, PAF, β-hexosaminidase, IL-6, and−13, MIP-1α and TNF-α were more significant with positive effect size and p < 0.001. As study effect was relatively small, we performed publication bias and found that there was publication bias and this could be due to the small sample size studied.

Conclusion: As such, we proposed that through meta-analysis, the potential soluble mediators involved in rodent IgG-mediated anaphylaxis to be histamine, PAF, β-hexosaminidase, IL-6 and−13 and MIP-1α, and TNF-α but will require further studies with larger sample size.

Research Advances and Prospects on Mechanism of Sinomenin on Histamine Release and the Binding to Histamine Receptors

Sinomenine (SIN) is widely used in China to treat a variety of rheumatic diseases (RA), and has various pharmacological effects such as anti-inflammatory, analgesic, and anti-tumor effects. However, due to the histamine release characteristics of SIN, its adverse reactions such as allergic reactions, gastrointestinal reactions, and circulatory systemic reactions have been drawing increasing attention. We present here a systematic review of the chemical structure, pharmacological effects, clinical application, and adverse reactions of SIN, a detailed discussion on the relationship between histamine/histamine receptor and mechanism of action of SIN. In addition, we simulated the binding of SIN to four histamine receptors by using a virtual molecular docking method and found that the bonding intensity between SIN and receptors varied in the order shown as follows: H1R > H2R ~ H3R > H4R. The docking results suggested that SIN might exhibit dual regulatory effects in many processes such as cyclooxygenase-2 (COX-2) expression, NF-κB pathway activation, and degranulation of mast cells to release histamine, thereby exhibiting pro-inflammatory (adverse reactions)/anti-inflammatory effects. This study provides a theoretical basis for the clinical treatment of inflammations seen such as in RA using SIN, and also suggests that SIN has great potential in the field of cancer treatment and will have very important social and economic significance.