Improvement of Therapeutic Efficacy of Oral Immunotherapy in Combination with Regulatory T Cell-Inducer Kakkonto in a Murine Food Allergy Model

Astragalus root increases Treg and Th17 involvement in embryo implantation and pregnancy maintenance by decreasing CTLA-4+ Tregs

Maintenance of pregnancy is highly dependent on the maternal immune system. High levels of regulatory T cells (Tregs) accumulate in the maternal placenta to suppress immunoreactivity against fetal antigens. We assessed whether Astragalus root (AsR) and AsR-containing Kampo medicines modulate immunoreactivity and thereby increase mouse litter size. AsR-exposed murine splenocytes exhibited significantly increased IL-2 secretion. In AsR-exposed mice, total Tregs were significantly increased, whereas cytotoxic T lymphocyte antigen 4 (CTLA-4)-positive Tregs were decreased in AsR-exposed mice. Tregs express IL-2 receptor subunit alpha and are activated by IL-2. CTLA-4 interacts with B7 expressed in antigen-presenting cells (APCs) with high affinity, and CTLA-4/B7 signaling plays a critical role in inhibiting APC activity, thereby suppressing CD4+ T cell proliferation and activation. The decrease in CTLA-4+ Tregs in AsR-exposed mice is thought to induce an increase in CD4+ T cells, leading to increased IL-2 secretion from CD4+ T cells followed by Treg activation. Th17 cells prevent trophoblast apoptosis, resulting in trophoblast invasion into the decidua. AsR increases Th17 cells, thereby inducing dose-dependent increases in litter size. Although Keishikaogito (KO)- and Ogikenchuto (OK)-exposed mice exhibited increased IL-2 secretion and splenic Tregs, KO also increased CTLA-4+ Tregs. Therefore, KO promoted immunosuppression by increasing CTLA-4+ Tregs, which induced a decrease in Th17 and exerted little effect on litter size. Therefore, an increase in both Tregs and Th17 cells can be considered necessary for embryo implantation and pregnancy maintenance.

Neuro-immune crosstalk and food allergy: Focus on enteric neurons and mucosal mast cells

The nervous system and the immune system individually play important roles in regulating the processes necessary to maintain physiological homeostasis, respond to acute stress and protect against external threats. These two regulating systems for maintaining the living body had often been assumed to function independently. Allergies develop as a result of an overreaction of the immune system to substances that are relatively harmless to the body, such as food, pollen and dust mites. Therefore, it has been generally supposed that the development and pathogenesis of allergies can be explained through an immunological interpretation. Recently, however, neuro-immune crosstalk has attracted increasing attention. Consequently, it is becoming clear that there is close morphological proximity and physiological and pathophysiological interactions between neurons and immune cells in various peripheral tissues. Thus, researchers are now beginning to appreciate that neuro-immune interactions may play a role in tissue homeostasis and the pathophysiology of immune-mediated disease, but very little information is available on the molecular basis of these interactions. Mast cells are a part of the innate immune system implicated in allergic reactions and the regulation of host-pathogen interactions. Mast cells are ubiquitous in the body, and these cells are often found in close proximity to nerve fibers in various tissues, including the lamina propria of the intestine. Mast cells and neurons are thought to communicate bidirectionally to modulate neurophysiological effects and mast cell functions, which suggests that neuro-immune interactions may be involved in the pathology of allergic diseases.

FcεRI: A Master Regulator of Mast Cell Functions

Mast cells (MCs) perform multiple functions thought to underlie different manifestations of allergies. Various aspects of antigens (Ags) and their interactions with immunoglobulin E (IgE) cause diverse responses in MCs. FcεRI, a high-affinity IgE receptor, deciphers the Ag–IgE interaction and drives allergic responses. FcεRI clustering is essential for signal transduction and, therefore, determines the quality of MC responses. Ag properties precisely regulate FcεRI dynamics, which consequently initiates differential outcomes by switching the intracellular-signaling pathway, suggesting that Ag properties can control MC responses, both qualitatively and quantitatively. Thus, the therapeutic benefits of FcεRI-targeting strategies have long been examined. Disrupting IgE–FcεRI interactions is a potential therapeutic strategy because the binding affinity between IgE and FcεRI is extremely high. Specifically, FcεRI desensitization, due to internalization, is also a potential therapeutic target that is involved in the mechanisms of allergen-specific immunotherapy. Several recent findings have suggested that silent internalization is strongly associated with FcεRI dynamics. A comprehensive understanding of the role of FcεRI may lead to the development of novel therapies for allergies. Here, we review the qualitatively diverse responses of MCs that impact the attenuation/development of allergies with a focus on the role of FcεRI toward Ag exposure.

Lycopene intake induces colonic regulatory T cells in mice and suppresses food allergy symptoms

BACKGROUND

Food allergy (FA) is a common disease in children; thus, a high level of safety is required for its prevention and treatment. Colonic regulatory T cells (Tregs) have been suggested to attenuate FA. We investigated the Treg-inducing ability and anti-FA effects of carotenoids, a pigment contained in vegetables and fruits.

METHODS

C57BL/6N mice were fed a diet containing 0.01% (w/w) of lycopene, β-carotene, astaxanthin or lutein for 4 weeks, and the population of colonic Tregs was assessed. Subsequently, to evaluate the Treg-inducing ability of lycopene, splenic naïve CD4⁺ T cells from BALB/c mice were cultured with anti-CD3/CD28 antibody, TGF-β and lycopene, and the frequencies of Tregs were examined. The effect of 0.1% (w/w) lycopene containing diet on FA was investigated in OVA-induced FA model BALB/c mice.

RESULTS

In screening, only lycopene significantly increased the frequency and number of colonic Tregs. Lycopene also increased Treg differentiation in splenic naïve CD4⁺ T cells. In FA mice, lycopene feeding significantly increased the number of colonic Tregs and attenuated allergic symptoms. The expression levels of IL-4, IL-9 and IL-13 mRNA in colonic mucosa were also significantly reduced by lycopene. IL-9 is known to induce proliferation of mast cells, and we found that lycopene feeding significantly reduced the number of mast cells in the colonic mucosa of FA mice.

CONCLUSION

Our results suggest that lycopene, a carotenoid present in many common foods on the market, may have the potential to induce colonic Tregs and suppress FA symptoms.

The Role of Regulatory T Cells in Epicutaneous Immunotherapy for Food Allergy

In recent decades, a rapid increase in the prevalence of food allergies has led to extensive research on novel treatment strategies and their mechanisms. Mouse models have provided preliminary insights into the mechanism of epicutaneous immunotherapy (EPIT)-induced immune tolerance. In EPIT, antigen applied on the skin surface can be captured, processed, and presented in the lymph nodes (LNs) by Antigen-presenting cells (APCs). In the LNs, induction of regulatory T cells (Treg cells) requires both direct contact during antigen presentation and indirect mechanisms such as cytokines. Foxp3+CD62L+ Treg cells can exhibit the characteristics of hypomethylation of Foxp3 TSDR and Foxp3-LAP+ Treg cells, which increase the expression of surface tissue-specific homing molecules to exert further sustained systemic immune tolerance. Studies have shown that EPIT is a potential treatment for food allergies and can effectively induce immune tolerance, but its mechanism needs further exploration. Here, we review Treg cells' role in immune tolerance induced by EPIT and provide a theoretical basis for future research directions, such as the mechanism of EPIT and the development of more effective EPIT treatments.

Modulating oxidative stress counteracts specific antigen-induced regulatory T-cell apoptosis in mice

Treg are known to have a central role in orchestrating immune responses, but less is known about the destiny of Treg after being activated by specific Ags. This study aimed to investigate the role of superoxide dismutase, an active molecule in the regulation of oxidative stress in the body, in the prevention of Treg apoptosis induced by specific Ags. Ag-specific Tregs were isolated from the DO11.10 mouse intestine. A food allergy mouse model was developed with ovalbumin as the specific Ag and here, we observed that exposure to specific Ag induced Treg apoptosis through converting the precursor of TGF-β to its mature form inside the Tregs. Oxidative stress was induced in Tregs upon exposure to specific Ags, in which Smad3 bound the latency-associated peptide to induce its degradation, converting the TGF-β precursor to its mature form, TGF-β. Suppressing oxidative stress in Tregs alleviated the specific Ag-induced Treg apoptosis in in vitro experiments and suppressed experimental food allergy by preventing the specific Ag-induced Treg apoptosis in the intestine. In conclusion, exposure to specific Ags induces Treg apoptosis and it can be prevented by upregulating superoxide dismutase or suppressing reactive oxidative species in Tregs.

Traditional Chinese medicine for food allergy and eczema

OBJECTIVE

To summarize the recent evidence of traditional Chinese medicine (TCM) for food allergy and eczema.

DATA SOURCES

Published literature from PubMed database and abstract conference presentations.

STUDY SELECTIONS

Studies relevant to TCM for food allergy and eczema were included.

RESULTS

TCM is the main component of complementary and alternative medicine in the United States. Food Allergy Herbal Formula 2 (FAHF-2) (derived from the classical formula Wu Mei Wan) prevented systemic anaphylaxis in murine models and was found to have safety and preliminary immunomodulatory effects on T cells and basophils. The phase II trial of combined TCM with oral immunotherapy and omalizumab for multiple food allergy is ongoing. Retrospective practice-based evidence study revealed that comprehensive TCM therapy effectively prevented frequent and severe food anaphylaxis triggered by skin contact or protein inhalation. The traditional Japanese herbal medicine Kakkonto suppressed allergic diarrhea and decreased mast cells in intestinal mucosa in a murine model. The active compounds from TCM were found to have potent inhibition of immunoglobulin (Ig) E, mast cell activation, and proinflammatory cytokine or signaling pathway (tumor necrosis factor alpha, interleukin 8, NF-κB) suggesting value for both IgE and non-IgE-mediated food allergy. Triple TCM therapy including ingestion, bath, and cream markedly improved skin lesion, itching, and sleep loss in patients with corticosteroid dependent, recalcitrant, or topical steroid withdrawal. Xiao Feng San and Japanese and Korean formulas were found to have effectiveness in eczema. Furthermore, acupuncture reduced wheal size, skin itching, and basophil activation in atopic dermatitis. Moreover, TCM is generally safe.

CONCLUSION

TCM has potential as safe and effective therapy for food allergy and eczema. Further research is needed for botanical drug development and to further define the mechanisms of actions.

TRIAL REGISTRATION

FAHF-2: https://ichgcp.net/clinical-trials-registry/NCT00602160; ethyl acetate and butanol purified FAHF-2: https://clinicaltrials.gov/ct2/show/NCT02879006.

Isoflavones Suppress Cyp26b1 Expression in the Murine Colonic Lamina Propria

Isoflavones have many biological activities and are major bioactive components of kakkonto, a traditional Japanese herbal medicine. We previously reported that the combined therapy of oral immune therapy (OIT) and kakkonto downregulates the mRNA expression of Cyp26b1, a major retinoic acid (RA)-degrading enzyme, in the colon of food allergy mice and thereby ameliorates allergic symptoms. In this study, we evaluated the effects of various isoflavones on Cyp26b1 expression in primary cultured lamina propria (LP) cells isolated from the mouse colon. The mRNA expression of Cyp26b1 was extremely downregulated by all isoflavones tested in the LP cells except for puerarin. In particular, genistein and genistin markedly suppressed Cyp26b1 mRNA expression without affecting RA-synthesizing enzyme expression. Moreover, to evaluate the effects of isoflavones on allergic reactions, genistein and genistin were administered to ovalbumin (OVA)-induced food allergy mice. Oral administration of genistin suppressed the development of allergic symptoms. These results raise the possibility that isoflavones elevated the level of RA in the colon by inhibiting RA degradation and then the high concentration of RA in the colon might exert immunosuppressive and antiallergic effects on food allergy mice.

Interleukin-4 Receptor α Subunit Deficiency Alleviates Murine Intestinal Inflammation In Vivo Through the Enhancement of Intestinal Mucosal Barrier Function

Disturbance of epithelial barrier function causes chronic intestinal inflammation such as inflammatory bowel disease. Several studies have reported that Th2 cytokines such as interleukin (IL)-4 and IL-13 play an important role in the regulation of intestinal barrier function. However, the precise role of the IL-4 receptor α subunit (IL-4Rα) in intestinal inflammation remains unclear. Thus, we used an experimental colitis model to investigate the role of IL-4Rα in intestinal inflammation. IL-4Rα-deficient (IL-4Rα-/-) mice and their littermate wild-type (WT) mice were used. Experimental colitis was induced by administration of 3% dextran sulfate sodium (DSS) in the drinking water for seven days. Treatment with DSS caused body weight loss, an increase in the disease activity index and histological abnormalities in WT colitis mice, all of which were significantly attenuated in IL-4Rα-/- colitis mice. Neutrophil infiltration in the colonic mucosa was reduced in IL-4Rα-/- colitis mice compared with WT colitis mice. NADPH oxidase 1 expression and reactive oxygen species production were increased in the colons of IL-4Rα-/- mice. Furthermore, elevated intestinal permeability induced by DSS treatment was suppressed in IL-4Rα-/- colitis mice. These results demonstrate that IL-4Rα-/- mice exhibit reduced susceptibility to DSS-induced colitis. Our present findings suggest that IL-4Rα deficiency enhances intestinal mucosal barrier function through the upregulation of NADPH oxidase 1-dependent reactive oxygen species production, thereby suppressing the development of intestinal inflammation.

Effect of traditional Chinese medicine formula GeGen decoction on primary dysmenorrhea: A randomized controlled trial study

ETHNOPHARMACOLOGICAL RELEVANCE

GeGen Decoction, a well-known Chinese herbal formula, is widely used in China and other Asian countries to treat gynecological diseases, including primary dysmenorrhea. Pharmacological studies have confirmed that GeGen Decoction is able to inhibit spasmodic contractions of the uterus in vivo and in vitro.

AIM OF THE STUDY

The objective of this study is to examine the efficacy and safety of GeGen Decoction on primary dysmenorrheic patients.

METHODS

This was a randomized, double-blinded, placebo-controlled trial. GeGen Decoction or placebo was administered a week before the expected start of each cycle for three consecutive menstrual periods. Between-group differences in pain intensity were detected by visual analogue scale (VAS). In addition, serum levels of arginine vasopressin (AVP) and estrogen (E) were examined by enzyme-linked immunosorbent assay. Metabolomic analysis was further used to evaluate the influence of GeGen Decoction on the metabolomics of primary dysmenorrheic patients.

RESULTS

A total of 71 primary dysmenorrheic women were recruited and 30 participants met the criteria were randomized into GeGen Decoction or placebo group. After three consecutive menstrual cycles' treatments, the VAS score of the GeGen Decoction group was significantly lower than that of the placebo group. Both serum levels of AVP and E decreased after GeGen Decoction administration, while the placebo seemed to have little effect on either of the index. Moreover, after GeGen Decoction treatment, seven important metabolites were identified by metabolomic analysis compared to the placebo group. No abnormalities in blood biochemical and routine physical examination pre and post GeGen Decoction intervention were observed.

CONCLUSIONS

GeGen Decoction can remarkably relieve the severity of menstrual pain without obvious adverse effects. Its therapeutic effect on primary dysmenorrhea might be related to the regulation of pituitary hypothalamic ovarian hormones, and interfering with the metabolic change.

Traditional Chinese Medicine (TCM) and Allergic Diseases

PURPOSE OF REVIEW

This paper purports to review recent relevant publications on the efficacy of traditional Chinese medicine in treating allergic diseases, to illustrate the pertinent mechanisms of action of TCM, and to explore the possible role of TCM in the management of allergic diseases in the foreseeable future. As TCM embodies multiple treatment modalities, only the most popular two, namely CHM (Chinese herbal medicine) and acupuncture, were discussed. Publications, especially reviews involving randomized controlled trials (RCTs) on the use of TCM on allergic diseases, published up to June 2019 were reviewed and analyzed. Papers reporting the mechanisms of action of TCM in allergic diseases were also included. Other publications in Chinese were also discussed.

RECENT FINDINGS

A startling escalation in the incidence of allergic diseases in the last several decades has posed tremendous social and financial burdens on the community. Failing to locate a cure for these chronic diseases, patients have resorted to using alternative medications of which traditional Chinese medicine (TCM) is a popular one. Thus CHM has been extensively employed for treating allergic diseases. Some investigations have been conducted to ascertain the therapeutic efficacy of CHM for allergic diseases. Although CHM has been widely deployed for treating allergic diseases, it appears from the published data that there is a dearth of conclusive evidence to establish the effectiveness of CHM for allergic diseases. It is recommended that more large- scale RCTs with prolonged durations be carried out to corroborate the efficacy of CHM for allergic diseases. On the other hand, there is ample evidence indicating that acupuncture is useful when administered alone in allergic rhinitis and asthma or when applied as an adjunct to conventional western therapy. Evidence of its utility in atopic eczema and urticaria is not definitive. It is recommended that acupuncture be integrated into the therapy of allergic rhinitis and asthma, and that CHM be used as an adjunct in the treatment of allergic diseases on an individual basis.

Retinoic Acid Ameliorates the Severity of Food Allergy under Allergen Exposure in a Mouse Model with Food Allergy

Effectiveness of retinoic acid (RA) in treating food allergy is not yet clear. Using an allergic mouse model, we examined the amelioration of the severity of food allergy by daily RA intake with allergen or without. Female Balb/c mice were systemically sensitized to egg white (EW) and alum by intraperitoneal injection. Sensitized mice were provided diets supplemented with 0% (non-treated group), 0.1% EW (allergen group), 0.0017% RA (RA group), or 0.1% EW plus 0.0017% RA (RA+allergen group) with 20% casein for 4 wk. Oral food challenge (OFC) and allergic biomarkers were quantified. The decrease in rectal temperature post-OFC was significantly suppressed in the RA and RA+allergen groups compared to those in the non-treated and allergen groups, respectivety. The plasma levels of ovalbumin-specific IgE, IgA and IgG1 at the study endpoint were higher in the allergen and RA+allergen groups than those in the non-treated and RA+allergen groups, respectivety. Plasma ovalbumin-specific IgG2a levels at the study endpoint were significantly higher in the RA+allergen group than those in the RA groups. The supernatant concentrations of interleukin-10 and interferon-γ in the cultured spleen lymphocytes were highest in the RA+allergen group compared to those in the other groups. Thus, continuous intake of RA under allergen exposure ameliorated the severity of food allergy in a mouse model with food allergy.

A Comprehensive Review on Natural Bioactive Compounds and Probiotics as Potential Therapeutics in Food Allergy Treatment

Food allergy is rising at an alarming rate and is a major public health concern. Globally, food allergy affects over 500 million people, often starting in early childhood and increasingly reported in adults. Commercially, only one approved oral immunotherapy-based treatment is currently available and other allergen-based immunotherapeutic are being investigated in clinical studies. As an alternative approach, a substantial amount of research has been conducted on natural compounds and probiotics, focusing on the immune modes of action, and therapeutic uses of such sources to tackle various immune-related diseases. Food allergy is primarily mediated by IgE antibodies and the suppression of allergic symptoms seems to be mostly modulated through a reduction of allergen-specific IgE antibodies, upregulation of blocking IgG, and downregulation of effector cell activation (e.g., mast cells) or expression of T-helper 2 (Th-2) cytokines. A wide variety of investigations conducted in small animal models or cell-based systems have reported on the efficacy of natural bioactive compounds and probiotics as potential anti-allergic therapeutics. However, very few lead compounds, unlike anti-cancer and anti-microbial applications, have been selected for clinical trials in the treatment of food allergies. Natural products or probiotic-based approaches appear to reduce the symptoms and/or target specific pathways independent of the implicated food allergen. This broad range therapeutic approach essentially provides a major advantage as several different types of food allergens can be targeted with one approach and potentially associated with a lower cost of development. This review provides a brief overview of the immune mechanisms underlying food allergy and allergen-specific immunotherapy, followed by a comprehensive collection of current studies conducted to investigate the therapeutic applications of natural compounds and probiotics, including discussions of their mode of action and immunological aspects of their disease-modifying capabilities.

The gut microbiota, environmental factors, and links to the development of food allergy

Food allergy appears to have its roots in an insufficient exposure to a diverse range of environmental microbiota during early life. Microbial exposure ensures the colonization of the gastrointestinal tract with commensal microbes, which is necessary for the induction of a balanced and tolerogenic immune function. High-throughput sequencing technology has facilitated in-depth studies of the gut microbiota as well as bacterial-derived metabolites. Although the role of the microbiota in allergies is now widely studied, its importance for food allergy was only recently noted. Studies in human cohorts have shown that there is an association of dysbiosis and pathogenesis of food allergy, while studies from animal models have demonstrated the capacity of specific species in the gut microbiota to alter immune response, which may lead to the desensitization of food allergy. This article reviews the role of the gut microbiota in food allergy, and discusses the influence of environmental factors as well as prevention and management strategies relating to such regulatory mechanism.

Ginger Increases ALDH1A1 Expression and Enhances Retinoic Acid Signaling in a Human Colonic Epithelial Cell Line

Aldehyde dehydrogenase 1A1 (ALDH1A1) in intestinal epithelial cells (IECs) plays a critical role in regulating immune responses through the production of retinoic acid (RA). However, little is known about its regulation by dietary components. We previously demonstrated that kakkonto, a Japanese traditional herbal medicine, and its constituent puerarin induce the expression of ALDH1A1 mRNA in colonic IECs and thereby attenuate food allergy symptoms in mice. This study aims to investigate the cellular responses of IECs to ALDH1A1 expression as a result of natural food components. The seven medicinal herbs that compose kakkonto were used to treat cultured an IEC line: Caco-2 cells. Expressions levels of ALDH1A1 were analyzed in Caco-2 cells by quantitative RT-PCR, immunocytochemistry and western blotting. Ginger increased the expression levels of ALDH1A1 mRNA and protein in Caco-2 cells. In addition, ginger significantly upregulated the gene expression of retinoic acid receptor (RAR) alpha (RARA), thereby enhancing RA signaling. Furthermore, ginger downregulated the expression of histone deacetylase (HDAC)2 (HDAC2) and HDAC3 in Caco-2 cells. The present study suggests the possibility that food ingredients such as a ginger modulate vitamin A metabolism in the gut through the regulation of RA synthesis, which may contribute to RA-mediated regulation of immune responses and the regulation of allergic inflammation.

Comprehensive comparison of the anti-inflammatory activity and chemical consistency of traditional Chinese medicine formula granules with Ge-Gen decoction as a representative sample

Traditional Chinese medicine formula granules (TCMFGs), an advanced dosage form of traditional Chinese medicine, are entering the market on a large scale. However, little attention has been paid to the simultaneous efficacy assessment and quality control of this advanced dosage form. In this study, a comprehensive comparison of the pharmacological activity and chemical consistency of TCMFGs from different manufacturers was performed. Ge-Gen decoction (GGD) samples were used as the target TCMFG. The in vitro anti-inflammatory effects among different types of GGDs indicate that all of them showed different abilities to reduce the lipopolysaccharide-activated production of nitric oxide, interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α. The results from a dimethylbenzene-induced inflammation model in mice indicated that the nine samples in this study showed significant in vivo anti-inflammatory effects. Qualitative and quantitative analyses were performed by multiwavelength ultra-high-performance liquid chromatography with diode array detection and electrospray ionization with quadrupole time-of-flight-tandem mass spectrometry. To visually interpret the differences in the chemical materials, a scatter plot analysis was performed. According to the scatter plot analysis, nine compounds were evaluated as important contributors to the differences. This is the first report of TCMFGs on the basis of the spectrum-effect consistency.

The isoflavone puerarin induces Foxp3+ regulatory T cells by augmenting retinoic acid production, thereby inducing mucosal immune tolerance in a murine food allergy model

The disruption of intestinal mucosal immune tolerance can lead to the development of intestinal immune diseases such as food allergy (FA). Regulatory T cells (Tregs) in the mucosa play a critical role in maintaining peripheral immune tolerance in the intestine, and retinoic acid (RA) is absolutely required for the induction of Tregs. We have previously reported that kakkonto, a traditional Japanese herbal medicine, suppresses FA in a murine FA model due to the induction of Tregs in the colonic mucosa. However, the precise molecular mechanisms underlying the induction of Tregs remain unclear. Puerarin, an isoflavone derivative, is a major constituent of kakkonto. Thus, we investigated the effect of puerarin on the induction of Tregs. BALB/c mice were systemically sensitized and then orally challenged with ovalbumin (OVA) as an FA model. Puerarin treatment suppressed the development of allergic diarrhea in FA mice. The gene expression levels of IL-4 and mast cell protease I (mMCP-1) were significantly upregulated in the proximal colon of FA mice but were reduced by puerarin. The proportions of Foxp3⁺CD4⁺ cells and CD103⁺CD11c⁺ dendritic cells (DCs) were significantly higher among the colonic lamina propria (cLP) cells of puerarin-treated FA mice than among those of untreated FA mice. The gene expression of Aldh1a1, an RA synthesis enzyme, in colonic epithelial cells (CECs) was significantly higher in the puerarin-treated FA mouse colon than in the untreated FA mouse colon. In addition, the preventive effect of puerarin was suppressed in the FA model by pretreatment with LE540, an RA receptor (RAR) antagonist. The induction of Foxp3⁺CD4⁺ cells and CD103⁺CD11c⁺ DCs by puerarin was reduced by pretreatment with LE540. The present findings indicate that the augmentation of RA production in CECs induced by puerarin enhances the induction of Tregs and suppresses the development of FA in a mouse model. Thus, a natural enhancer of RA production, such as puerarin, has the potential to treat immune diseases attributed to Treg deficiency.

Detection of serum and salivary IgE and IgG1 immunoglobulins specific for diagnosis of food allergy

Given the growing incidence and prevalence of life-threatening food allergies, health concerns have raised new perspectives for in vivo and in vitro diagnostic methodologies, pointing to saliva as a promising material, already used to diagnose other pathologies. Based on the above considerations, this study aimed to verify the possible use of saliva for the detection of IgE and IgG₁ in the diagnosis of food allergy. This was a randomized, cross-sectional clinical study with a quantitative approach, developed at a hospital referral center in allergy in the state of Ceará, from January to July 2015. The sample consisted of 36 children of both sexes, aged between 1 and 60 months, with a diagnosis of cow's milk protein allergy (CMPA) by the RAST test. Children hospitalized or under immunosuppressive drugs were excluded from the study. Serum and saliva samples of the participants were collected and subsequently subjected to the indirect immunoenzymatic assay (ELISA) for the detection of specific serum and salivary immunoglobulins for food: corn, papaya, cow's milk, egg white, wheat, soybeans, peanuts, nuts, kiwi, cacao, fish, shrimp, bananas and tomatoes. For comparison of serum and saliva results, the T-test of independent samples and Mann-Whitney were adopted, for samples with normal and non-normal distribution respectively. A confidence interval of 95% was adopted for significant results. It was observed that 100% (n = 36) of the participants presented cow's milk allergy through the indirect ELISA, detecting IgE or IgG₁ in serum and saliva. When serum IgE and IgG₁ concentrations were compared, there was no statistical difference (p > 0.05) in 12 of the 14 foods evaluated. The same amount (n = 12) of non-significant differences (p > 0.05) was observed in the comparison of the 14 foods under IgE and IgG₁ contractions in saliva. In the verification of the average values of IgE present in the serum and saliva of the foods, only cow's milk, fish and papaya showed statistically significant differences (p < 0.05). Of the total food evaluated, only the average levels of IgG₁ present in serum and saliva showed a significant value (p < 0.05) in banana and tomato. These findings indicate that the detection of IgE and IgG₁ in saliva proves to be as efficient as in the serum. The use of the salivary technique for use in the diagnosis of food allergy is suggested.

Human umbilical cord-derived mesenchymal stem cells ameliorate the enteropathy of food allergies in mice

Food allergy prevalence has steadily increased worldwide over the past decades and immunotherapeutic treatment strategies are gaining attention. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) exhibit similar immune regulatory properties to bone marrow-derived MSCs. hUC-MCSs can be prepared with fewer ethical constraints and are potential candidates for allergic disorder therapies. The current study aimed to investigate potential antiallergic properties of hUC-MSCs in mice with ovalbumin (OVA)-induced food allergy. Administration of hUC-MSCs cells intraperitoneally combined with oral gavage of the culture medium significantly alleviated OVA-induced diarrhea symptoms. Additionally, this treatment significantly decreased IgE levels and the percentage of T helper 2 cells in the blood, which were increased in mice with OVA-induced food allergy. The mRNA levels of the inflammatory cytokines interleukin-4 and tumor necrosis factor-α, and inflammatory cell infiltration in mouse colons were significantly decreased in hUC-MSCs-treated animals compared with mice with OVA-induced food allergy. Goblet cells were detected in colons of allergy-induced mice and their numbers were reduced following treatment with hUC-MSCs. In addition, treatment with hUC-MSCs reestablished the gut flora. The results revealed that hUC-MSCs may have a potential application in food allergy therapy.

Stepwise oral immunotherapy for 10 days in an egg-white allergy mouse model did not ameliorate the severity of allergy but induced the production of allergen-specific IgA

We examined whether the stepwise oral immunotherapy (OIT) for 10 days ameliorates the severity of allergy and the biomarkers in an allergy mouse model. The OIT could not protect anaphylaxis symptoms after allergen challenges but promote the production of antibodies, especially allergen-specific IgA. It was suggested that this OIT influenced the function of immuno response against the allergen. Abbreviations: EW: egg white; IFC: intraperitoneal food challenge; IFN-γ: interferon-γ; IL: interleukin; OVA: ovalbumin; OM: ovomucoid; OFC: oral food challenge; OIT: oral immunotherapy.

Safety and efficacy of Galgeun-tang-ga-cheongung-sinyi, a herbal formula, for the treatment of chronic rhinosinusitis: A study protocol for a randomized controlled trial

INTRODUCTION

A herbal formula, Galgeun-tang-ga-cheongung-sinyi (GGTCS), is traditionally used for the treatment of rhinosinusitis in East Asian countries. However, there is a dearth of clinical evidence supporting the effects of this medication. Here, we describe the protocol for a randomized controlled study designed to investigate the efficacy and safety of GGTCS for the treatment of chronic rhinosinusitis (CRS).

METHODS AND ANALYSIS

To investigate the clinical efficacy and safety of GGTCS for the treatment of CRS, a randomized, double-blind, placebo-controlled, parallel group, clinical trial has been designed. A total of 58 participants with CRS will be recruited and randomly allocated to a GGTCS or placebo group in a 1:1 ratio. The participants will be administered GGTCS or placebo granules 3 times a day for 8 weeks. Data will be collected from the participants at baseline and at 1, 2, 4, and 8 weeks after random allocation. The primary outcome measure will be the mean change in the Sino-Nasal Outcome Test-22 score from baseline to 8 weeks. The secondary outcomes will include the Total Nasal Symptom Score, EuroQoL 5 Dimensions 5 Levels score, Nasal Endoscopy Index, Lund-Mackay score, and total serum immunoglobulin E level.

DISCUSSION

The key elements for conducting a high-quality randomized clinical trial have been addressed in this protocol. In summary, the findings of this study are expected to provide a base for large-scale randomized controlled trials to confirm the safety and efficacy of GGTCS for the treatment of CRS and may consequently serve to improve future treatment strategies for this condition.

TRIAL REGISTRATION

This study has been registered at the Korean National Clinical Trial Registry, Clinical Research Information Service (KCT0002835).