Gallic acid alleviates nasal inflammation via activation of Th1 and inhibition of Th2 and Th17 in a mouse model of allergic rhinitis

Gallic acid attenuates murine ulcerative colitis by promoting group 3 innate lymphocytes, affecting gut microbiota, and bile acid metabolism

Gallic acid (GA), a plant phenol that is widely distributed in fruits and vegetables, and exhibits a protective role against ulcerative colitis (UC). UC is an inflammatory disease characterized by immune response disorders. However, the role and mechanism of action of GA in gut immunity remain unknown. Here, we observed that GA treatment improved enteritis symptoms, decreased the concentrations of cytokines TNF-α, IFN-γ, IL-6, IL-17A, and IL-23, increased the concentrations of cytokines IL-10, TGF-β and IL-22, and increased the proportion of group 3 innate lymphoid cells (ILC3) in mesenteric lymph nodes and lamina propria. However, GA did not upregulate ILC3 or impair UC in antibody-treated sterile mice. Notably, transplantation of fecal bacteria derived from GA-treated UC mice, instead of UC mice, increased ILC3 levels. Therefore, we analyzed the gut microbiota and related metabolites to elucidate the mechanism promoting ILC3. We determined that GA treatment altered the diversity of the gut microbiota and activated the bile acid (BA) metabolic pathway. We evaluated three BAs, namely, UDCA, isoalloLCA, and 3-oxoLCA that were significantly upregulated after GA treatment, improved UC symptoms, and elevated the proportion of ILC3 in vivo and in vitro. Collectively, these data indicate that GA attenuates UC by elevating ILC3 proportion, regulating the gut microbiota, and impacting BA metabolism. Additionally, we highlight the modulatory effects of BAs on ILC3 for the first time. Our findings provide novel insights into the multiple roles of GA in alleviating UC and provide a mechanistic explanation that supports the dietary nutrition in UC therapy.

Physicochemical Characteristics of Porous Starch Obtained by Combined Physical and Enzymatic Methods-Part 2: Potential Application as a Carrier of Gallic Acid

Wettability measurements were performed for aqueous dispersions of native and modified corn, potato, and pea starch granules deposited on glass plates by the thin layer method using test liquids of a different chemical nature (polar water and formamide or non-polar diiodomethane). High values of the determination coefficient R2 confirm that the linear regression model describes the relationship between the wetting time and the square of the penetration distance very well, indicating the linear nature of the Washburn relationship. A change in free energy (enthalpy) during the movement of the liquid in the porous layer was determined for all starches before and after modification in contact with test liquids. Wetting times for polar liquids increased significantly (from 3 to 4 fold), especially for corn starch. The lower the value of the adhesive tension, the easier the wetting process takes place, and consequently, the adsorption process is facilitated. Adhesive tension for polar substances applies to the adsorption of hydrophilic substances, while in the case of apolar substances, adhesive tension applies to the adsorption of hydrophobic substances. For the adsorption of gallic acid on starch, the relationships obtained for polar substances are crucial. The adsorption of gallic acid by forming hydrogen bonds or, more generally, donor-acceptor (acid-base) bonds is definitely higher for corn starch than other starches. Therefore, this starch has the most significant potential for use as a carrier of gallic acid or, more broadly, compounds from the polyphenol group.

The potential application and molecular mechanisms of natural products in the treatment of allergic rhinitis: A review

BACKGROUNDS

Allergic rhinitis (AR) is a non-infectious chronic inflammation of the nasal mucosa mainly mediated by immunoglobulin E (IgE) in atopic individuals after exposure to allergens. The application of AR guideline-recommended pharmacotherapies can rapidly relieve symptoms of AR but with poor long-term efficacy, and many of these therapies have side effects. Many natural products and their derivatives have shown potential therapeutic effects on AR with fewer side effects.

OBJECTIVES

This review aims to expand understanding of the roles and mechanisms of natural compounds in the treatment of AR and to highlight the importance of utilizing natural products in the treatment of AR.

MATERIAL AND METHOD

We conducted a systematic literature search using PubMed, Web of Science, Google Scholar, and Clinical Trials. The search was performed using keywords including natural products, natural compounds, bioproducts, plant extracts, naturally derived products, natural resources, allergic rhinitis, hay fever, pollinosis, nasal allergy. Comprehensive research and compilation of existing literature were conducted.

RESULTS

This article provided a comprehensive review of the potential therapeutic effects and mechanisms of natural compounds in the treatment of AR. We emphasized that natural products primarily exert their effects by modulating signalling pathways such as NF-κB, MAPKs, STAT3/ROR-γt/Foxp3, and GATA3/T-bet, thereby inhibiting the activation and expansion of allergic inflammation. We also discussed their toxicity and clinical applications in AR therapy.

CONCLUSION

Taken together, natural products exhibit great potential in the treatment of AR. This review is also expected to facilitate the application of natural products as candidates for treating AR. Furthermore, drug discovery based on natural products has a promising prospect in AR treatment.

Anti-Allergic and Anti-inflammatory Effects of Bakuchiol on Ovalbumin-Induced Allergic Rhinitis in Mice

Allergic rhinitis (AR) is a prevalent inflammatory disease primarily affecting the nasal mucosa and is caused by allergies. The common symptoms of AR include rhinorrhea, sneezing, itchy nose, congestion, teary eyes, and nasal rubbings. The present study assessed the beneficial properties of bakuchiol on OVA-induced AR in mice via the regulation of inflammatory responses. AR was induced by injecting (i.p.) OVA (50 µg) and aluminum hydroxide (1 mg) into mice at various time intervals. The bakuchiol treatment was done at dosages of 10 and 20 mg/kg with dexamethasone (2.5 mg/kg) as a positive control. The body weight and nasal symptoms were measured on the day of the last OVA challenge. For in vitro tests, mouse splenocytes were isolated, sensitized with 20 µL OVA, and then treated with 10 µM bakuchiol. The levels of pro-inflammatory cytokines, immunoglobulins, histamine, leukotriene C4 (LTC-4), and prostaglandin D2 (PGD2) were assayed using the corresponding assay kits. The assay kits were also used to analyze the status of oxidative stress markers. The Th1/Th2 cell proportion was assessed using flow cytometry. The bakuchiol (10 and 20 mg/kg) treatment reduced the nasal symptoms in AR mice. Bakuchiol decreased the levels of IL-4, IL-5, IL-13, Igs (IgE and IgG1), histamine, IL-10, IL-33, and TNF-α in AR mice. Bakuchiol also reduced PGDA and LTC-4 levels in the NLF of AR mice. The ROS and MDA levels were decreased, whereas boosted SOD activity was observed in the bakuchiol-treated AR mice. The eosinophil count was decreased in the nasal tissues of bakuchiol-treated AR mice. Bakuchiol also influenced the Th1 and Th2 cell proportions in AR mice. The present findings suggest that bakuchiol is effective against OVA-mediated allergic and inflammatory responses in AR mice through its strong anti-inflammatory properties.

Gallic acid ameliorates endometrial hyperplasia through the inhibition of the PI3K/AKT pathway and the down-regulation of cyclin D1 expression

BACKGROUND

Gallic acid (GA) is an organic compound with phenolic properties that occurs naturally and can be found in Guizhi Fuling capsules, showcasing a wide range of biological functionalities.

PURPOSE

The objective of this study was to examine the influence of GA on endometrial hyperplasia (EH) and elucidate its underlying mechanism.

METHODS

Initially, the induction of EH was achieved by administering estradiol to mice via continuous subcutaneous injection for a duration of 21 days. Concurrently, GA treatment was administered, and subsequently, the uterine tissue structure was assessed using hematoxylin and eosin (H&E) staining. Following this, the proliferation of human endometrial cells treated by GA was determined utilizing the CCK-8 method. Furthermore, network pharmacology and single-cell-RNA-seq data were employed to identify the target of GA action. In addition, we will employ immunofluorescence (IF), immunohistochemistry (IHC), flow cytometry, western blot and RT-qPCR methodologies to investigate the impact of GA on the expression level of cyclin D1, PI3K, p-PI3K, AKT, p-AKT.

RESULTS

GA treatment ameliorated histopathological alterations in the uterus and suppress proliferation. Estradiol stimulation can activate the PI3K/AKT pathway, leading to up-regulation of cyclin D1 expression, whereas GA treatment results in down-regulation of its expression.

CONCLUSIONS

The expression of cyclin D1 is down-regulated by GA through the inhibition of the PI3K/AKT pathway, effectively mitigating estradiol-induced EH in mice.

Integration of network pharmacology and proteomics to elucidate the mechanism and targets of traditional Chinese medicine Biyuan Tongqiao granule against allergic rhinitis in an ovalbumin-induced mice model

ETHNOPHARMACOLOGICAL RELEVANCE

Biyuan Tongqiao granule (BYTQ) is a traditional Chinese medicine that has been used in China to clinically treat patients with allergic rhinitis (AR), yet its underlying mechanism and targets remains unclear.

AIM OF THE STUDY

The study aimed to investigate the potential mechanism of BYTQ against AR using the ovalbumin (OVA) -induced AR mice model. Integrating network pharmacology and proteomics to investigate possible targets of BYTQ for AR.

MATERIALS AND METHODS

The compounds in BYTQ were analyzed using UHPLC-ESI-QE-Orbitrap-MS. The OVA/Al(OH)3 were used to induce the AR mice model. The nasal symptoms, histopathology, immune subsets, inflammatory factors, and differentially expressed proteins were examined. Proteomics analysis elucidated the potential mechanisms of BYTQ to improve AR, which was further validated by Western blot (WB) assay. The compounds and potential targets of BYTQ were systematically elucidated by integrating network pharmacology and proteomics analysis to explore the mechanism. The binding affinity between key potential targets and corresponding compounds was then validated using molecular docking. Molecular docking results were verified by a western blotting and cellular thermal shift assay (CETSA).

RESULTS

A total of 58 compounds were identified from BYTQ. BYTQ significantly suppressed AR symptoms by inhibiting the release of OVA-specific immunoglobulin E (IgE) and histamine, improving the pathological injury of nasal mucosal tissue, and regulating the proportions of lymphocytes to maintain immune balance. Proteomics analysis showed that the cell adhesion factors and focal adhesion pathway might be potential mechanism of BYTQ against AR. The levels of E-selectin, vascular endothelial cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) proteins in the nasal mucosal tissue were significantly downregulated in the BYTQ-H group compared to the AR group. Integrating network pharmacology and proteomics analysis identified that SRC, PIK3R1, HSP90AA1, GRB2, AKT1, MAPK3, MAPK1, TP53, PIK3CA, and STAT3 may be potential protein targets for BYTQ to treat AR. Molecular docking analysis indicated that the active compounds of BYTQ could bind tightly to these key targets. In addition, BYTQ could inhibit OVA-induced phosphorylation levels of PI3K, AKT1, STAT3 and ERK1/2. The CETSA data suggested that BYTQ could improve the heat stability of PI3K, AKT1, STAT3 and ERK1/2.

CONCLUSIONS

BYTQ suppresses E-selectin and VCAM-1 and ICAM1 expression by regulating PI3K/AKT and STAT3/MAPK signaling pathways, thus alleviating inflammation in AR mice. BYTQ is the aggressive treatment for AR.

Gallic Acid Alleviates Psoriasis Keratinization and Inflammation by Regulating BRD4 Expression

Psoriasis is a chronic non-contagious autoimmune disease. Gallic acid is a natural compound with potential health benefits, including antioxidant, anticancer, antiviral and antibacterial properties. Nevertheless, the influence of gallic acid on psoriasis has not been fully determined. This investigation aimed to discover the effect of gallic acid on psoriasis. Thirty-one pairs of psoriatic skin tissues and healthy adult human skin tissues were collected. Human keratinocytes (HaCaT cells) were transfected with interleukin 17A (IL-17A) to create the psoriatic keratinocyte model. The content of bromodomain-containing protein 4 (BRD4) microRNA was assessed using qRT-PCR testing. The content of BRD4 was detected by Western blotting. Cell migration was evaluated by conducting a wound healing assay. Cell proliferation was determined using an EdU assay. Apoptosis was detected by the TUNEL assay. The contents of interferon gamma (IFN-γ), IL-6, IL-8 and IL-17 were detected by ELISA. BRD4 was up-regulated in psoriatic skin tissues and in the IL-17A group compared to the healthy adult human skin tissues and the control group. Silencing BRD4 inhibited cell migration, proliferation and inflammatory response but induced apoptosis in IL-17A-treated HaCaT cells. Conversely, BRD4 over-expression promoted cell migration, proliferation and inflammatory response but suppressed apoptosis in IL-17A-treated HaCaT cells. Gallic acid repressed cell migration, proliferation and inflammatory response but indu-ced apoptosis in HaCaT cells transfected with IL-17A by down-regulating BRD4. Gallic acid represses cell migration, proliferation and inflammatory response but induces apoptosis in IL-17A-transfected HaCaT cells by down-regulating BRD4.

Effect of mesenchymal stem cell therapy in animal models of allergic rhinitis: A systematic review and meta-analysis

BACKGROUND

Allergic rhinitis (AR) is a worldwide problem that affects people of all ages, impairing patients' physical and mental health and causing great social expenditure. Animal studies have suggested the potential efficacy of mesenchymal stem cell (MSC) therapy in treating AR. Our meta-analysis was performed to evaluate the effect of MSC therapy in animal models of AR by pooling animal studies.

METHODS

The search was executed in PubMed, Embase, Web of Science, OVID, and the Cochrane Library for relevant studies up to February 2023. The applicable data were extracted from the eligible studies, and the risk of bias was assessed for each study. The meta-analysis was conducted using Review Manager (version 5.4.1) and Stata (version 15.1).

RESULTS

A total of 12 studies were included in the final analysis. Compared to the model control group, the MSC therapy group presented lower frequency of sneezing [(Standardized mean difference (SMD) -1.87, 95% CI -2.30 to -1.43)], nasal scratching (SMD -1.41, 95% CI -1.83 to -0.99), and overall nasal symptoms (SMD -1.88, 95% CI -3.22 to -0.54). There were also remarkable reductions after transplantation with MSCs in the levels of total immunoglobulin E (IgE) (SMD -1.25, 95% CI -1.72 to -0.79), allergen-specific IgE (SMD -1.79, 95% CI -2.25 to -1.32), and allergen-specific immunoglobulin G1 (SMD -1.29, 95% CI -2.03) in serum, as well as the count of eosinophils (EOS) in nasal mucosa (SMD -3.48, 95% CI -4.48 to -2.49). In terms of cytokines, MSC therapy significantly decreased both protein and mRNA levels of T helper cell 2 (Th2)-related cytokines, including interleukin (IL)-4, IL-5, IL-10, and IL-13.

CONCLUSION

MSC therapy has the potential to be an effective clinical treatment for AR patients by attenuating Th2 immune responses, reducing secretion of IgE and nasal infiltration of EOS, and consequently alleviating nasal symptoms.

RORα overexpression reduced interleukin-33 expression and prevented mast cell degranulation and inflammation by inducing autophagy in allergic rhinitis

BACKGROUND

Retinoid acid receptor related orphan receptor α (RORα) is a nuclear receptor that along with other bioactive factors regulates cell proliferation, differentiation, and immunomodulation in vivo.

AIMS

The objective of this study was to explore the function and mechanism of RORα in allergic rhinitis (AR).

MATERIALS AND METHODS

Derp1 was used to construct an AR cell model in HNEpC cells, and RORα was overexpressed or silenced in the AR HNEpC cells. Next, LAD2 cells were co-cultured with the Derp1-treated HNEpC cells. Additionally, an AR mouse model was established using by OVA, and a RORα Adenovirus was delivered by nebulizing. Pathological tissue structures were evaluated by hematoxylin-eosin staining, and the levels of RORα, interleukin-33 (IL-33), and other proteins were analyzed immunohistochemistry, western blotting, and immunofluorescence staining. IL-33, IL-4, IL-5, and IL-13 levels were detected using enzyme-linked immunosorbent assay kits and cell migration was assessed by Transwell assays.

RESULTS

Our data showed that RORα was downregulated in the nasal mucosa tissues of AR patients. Derp1 treatment could cause a downregulation of RORα, upregulation of IL-33, the induction of NLRP3 inflammasomes, and cell migration in HNEpC cells. Furthermore, RORα overexpression dramatically attenuated IL-33 levels, NLRP3 inflammasome activity, and the migration of AR HNEpC cells induced with Derp1. Moreover, RORα in AR HNEpC cells could prevent mast cell (MC) degranulation and inflammation by accelerating autophagy, RORα overexpression inhibited MC degranulation and NLRP3-induced inflammation in the AR model mice. RORα overexpression reduced IL-33 expression in nasal epithelial cells, and also suppressed MC degranulation and inflammation by promoting autophagy.

CONCLUSION

RORα inhibits NLRP3 inflammasome in HNEpC, and attenuated mast cells degranulation and inflammation through autophagy in AR.

Network Pharmacology-Based Approach for Investigating the Role of Xanthii Fructus in Treatment of Allergic Rhinitis

Xanthii Fructus (XF) has been used for treatment of allergic rhinitis (AR), but its pharmacological mechanism of action remains unclear. We aimed to explore the potential mechanism of XF in treatment of AR by using a network pharmacology approach combined with in vivo verification experiments in this study. We identified 945 AR-related pathogenic genes, 11 active components in XF and 178 targets of those active components by corresponding databases. Finally, 54 targets of active components from XF in treatment of AR were identified by the Protein-protein interaction (PPI) network, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, among which Tumor Necrosis Factor (TNF), Mitogen-activated Protein Kinase 3 (MAPK3), Prostaglandin G/H Synthase 2 (PTGS2), Epidermal Growth Factor Receptor (EGFR) showed strongest interactions. The molecular docking analysis showed that moupinamide could bind to EGFR at LEU704 and LEU703, and PTGS2 at TRP387; 24-Ethylcholest-4-en-3-one was identified to bind to MAPK3 at THR347. The validation of quantitative real-time reverse transcription PCR (RT-PCR) showed that XF decreased the levels of MAPK3, PTGS2, and EGFR expression in the nasal mucosa from AR mice gavaged with an XF water decoction. Meanwhile, the levels of interleukin (IL)-4, IL-5 and IL-13were also decreased after the treatment of XF by Enzyme-linked immunosorbent assay (ELISA). Our results provide the pharmacological mechanism and possible intervention targets of XF in treatment of AR.

Gallic acid diminishes pro-inflammatory interferon-γ- and interleukin-17-producing sub-populations in vitro in patients with psoriasis

Psoriasis is an inflammation of the skin mediated via the IL-23/Thl17/IL-17 pathway. We have previously demonstrated that the anthocyanin delphinidin diminishes in vitro the IL-17 and IFN-γ production of peripheral monocytes isolated by psoriasis patients (PBMCs). The degradation product of delphinidin is gallic acid (GA). This phenolic acid compound found in fruits, red wine, or green tea exerts pleiotropic antioxidant, anticarcinogenic, antimicrobial, and anti-inflammatory properties. Previous research has demonstrated the inhibitory effect of GA on pro-inflammatory transcription factors, such as STAT3, RORγt, and NF-κB, or cytokines as IL-1β and TNF, which contribute to psoriasis development. We investigated the effect of GA in vitro on PBMCs, which were stimulated ex vivo, from 40 individuals (28 diagnosed with psoriasis vulgaris and 12 healthy controls (HCs)). In our experiments, PBMCs were cultured untreated or were activated in the presence of phorbol 12-myristate 13-acetate/ionomycin with or without GA. We utilized multicolor flow cytometry to assess the production of inteleukin-17 (IL-17) and interferon-γ (IFN-γ) in T and NK cells. GA did not alter the fractions of IL-17- or IFN-γ-producing T and IFN-γ-producing NK cells in HCs. However, in psoriasis patients, the effect of GA on that cell population was significant. Specifically, GA decreased the frequency of IL-17-producing cells within the CD3⁺ (T) and CD3⁺CD4⁺ (Th) compartment; the frequency of IFN-γ-producing cells within the CD3⁺, CD3⁺CD4⁺, and CD3⁺CD4^- (Tc) compartment, and the frequency of IFN-γ-producing cells within the CD3^-CD56⁺ (NK) compartment. Whether GA's effect also appears in vivo needs to be investigated in future.

Bicalutamide, an androgen receptor antagonist, effectively alleviate allergic rhinitis via suppression of PI3K-PKB activity

OBJECTIVES

To investigate the therapeutic effect of Bicalutamide, an androgen receptor antagonist on the onset and development of allergic rhinitis in an animal model.

METHODS

40 male BALB/c mice were randomly divided into five groups (eight mice per group). Aluminum hydroxide powder was used as an adjuvant, combined with Ovalbumin (OVA) to establish the mouse model of allergic rhinitis via ultrasonic nebulization of OVA to stimulate the nasal cavity. Mice in Bica#1 group were intraperitoneally injected with 0.02 mg Bicalutamide/0.5 ml of normal saline daily for 7 consecutive days; mice in Bica#2 group were administered 0.02 mg Bicalutamide/0.5 ml of normal saline via intraperitoneal injection for 5 consecutive days, and then the same amount of normal saline was injected intraperitoneally for 2 consecutive days. Enzyme-linked immunosorbent assay was adopted to detect the serological levels of IgE, IL-4, and IL-6 production. Eosinophil infiltration was observed under microscope after hematoxylin and eosin staining of nasal mucosa. Quantitative PCR and Western blot were employed for determination of histamine receptors mRNA expression and PI3K/PKB associated protein levels, respectively.

RESULTS

Histological analysis shown that allergic lesion was induced after OVA sensitization. Intraperitoneal injection with 0.02 mg Bicalutamide daily for 7 consecutive days significantly reduced the allergic lesion; however, mice injected with the same amount of normal saline at the same time demonstrated no allergic rhinitis symptoms. In addition, there was a significant reduction in eosinophils number in Bicalutamide treated mice (n = 8) compared to the OVA group (n = 8) (OVA: 19.6 ± 5.3 vs. Bica#1: 7.7 ± 0.8 vs. Bica#2: 9.4 ± 1.2, both p < 0.01). Furthermore, ELISA results revealed that the serological levels of IgE (OVA: 17.3 ± 1.7 µg/ml vs. Bica#1: 9.2 ± 0.6 vs. Bica#2: 10.4 ± 2.3, both p < 0.05), IL-4 (OVA: 164.3 ± 5.1 pg/ml vs. Bica#1: 110.2 ± 3.1 vs. Bica#2: 115.3 ± 4.1, both p < 0.05) and IL-6 (OVA: 167.3 ± 3.7 pg/ml vs. Bica#1: 117.5 ± 6.5 vs. Bica#2: 114.8 ± 2.4, both p < 0.05) were significantly decreased after two different dosage of Bicalutamide treatment. Similarly, histamine receptors in mast cells were significantly reduced after two different dosage of Bicalutamide treatment. More importantly, p-PKB protein was notably reduced after two different dosage of Bicalutamide treatment compared to the OVA group, mTOR protein levels were also down regulated after two different dosage of Bicalutamide treatment.

CONCLUSIONS

Our data demonstrated that androgen receptor antagonist Bicalutamide can significantly alleviate allergic rhinitis lesion in the animal model. PI3K/PKB activity in mast cells was suppressed after Bicalutamide injection. Our results provide important implication in allergic rhinitis prevention and treatment.

Coassembly of Fiber Hydrogel with Antibacterial Activity for Wound Healing

Wound healing remains a critical challenge due to its vulnerability to bacterial infection and the complicated inflammatory microenvironment. Herein, we report a novel antibacterial hydrogel constructed only by gallic acid (GA) and phycocyanin (PC), which is expected for the treatment of bacteria-infected wounds. These GA/PC hydrogels (GP) was found to coassemble into fibrous networks with a diameter of around 2 μm mainly through noncovalent interactions of hydrogen bonds, van der Waals force, and π interaction. Notably, these GP hydrogels showed excellent rheological properties (i.e., storage modulus of more than 9.0 × 10⁴ Pa) and outstanding biocompatibility and antibacterial activities. Thanks to the incorporation of GA and PC, the GP hydrogels enabled adherence to the moist wound tissue and achieved a sustained release of GA and PC into the wound skin, therefore effectively attenuating inflammation and accelerating wound healing both in normal mice and bacteria-infected mice through regulating the expression of the tight junction protein and the alleviation of oxidative stress. Considering these results, these GP hydrogels are demonstrated to be a promising candidate for bacteria-infected wound healing.

Polyphenolic compounds from rapeseeds (Brassica napus L.): The major types, biofunctional roles, bioavailability, and the influences of rapeseed oil processing technologies on the content

The rapeseed (Brassica napus L.) are the important oil bearing material worldwide, which contain wide variety of bioactive components with polyphenolic compounds considered the most typical. The rapeseed polyphenols encompass different structural variants, and have been considered to have many bioactive functions, which are beneficial for the human health. Whereas, the rapeseed oil processing technologies affect their content and the biofunctional activities. The present review of the literature highlighted the major types of the rapeseed polyphenols, and summarized their biofunctional roles. The influences of rapeseed oil processing technologies on these polyphenols were also elucidated. Furthermore, the directions of the future studies for producing nutritional rapeseed oils preserved higher level of polyphenols were prospected. The rapeseed polyphenols are divided into the phenolic acids and polyphenolic tannins, both of which contained different subtypes. They are reported to have multiple biofunctional roles, thus showing outstanding health improvement effects. The rapeseed oil processing technologies have significant effects on both of the polyphenol content and activity. Some novel processing technologies, such as aqueous enzymatic extraction (AEE), subcritical or supercritical extraction showed advantages for producing rapeseed oil with higher level of polyphenols. The oil refining process involved heat or strong acid and alkali conditions affected their stability and activity, leading to the loss of polyphenols of the final products. Future efforts are encouraged to provide more clinic evidence for the practical applications of the rapeseed polyphenols, as well as optimizing the processing technologies for the green manufacturing of rapeseed oils.

Phenethyl Ester of Gallic Acid Ameliorates Experimental Autoimmune Encephalomyelitis

Gallic acid is a phenolic acid present in various plants, nuts, and fruits. It is well known for its anti-oxidative and anti-inflammatory properties. The phenethyl ester of gallic acid (PEGA) was synthesized with the aim of increasing the bioavailability of gallic acid, and thus its pharmacological potential. Here, the effects of PEGA on encephalitogenic cells were examined, and PEGA was found to modulate the inflammatory activities of T cells and macrophages/microglia. Specifically, PEGA reduced the release of interleukin (IL)-17 and interferon (IFN)-γ from T cells, as well as NO, and IL-6 from macrophages/microglia. Importantly, PEGA ameliorated experimental autoimmune encephalomyelitis, an animal model of chronic inflammatory disease of the central nervous system (CNS)-multiple sclerosis. Thus, PEGA is a potent anti-inflammatory compound with a perspective to be further explored in the context of CNS autoimmunity and other chronic inflammatory disorders.

Caesalpinia sappan Linn. Ameliorates Allergic Nasal Inflammation by Upregulating the Keap1/Nrf2/HO-1 Pathway in an Allergic Rhinitis Mouse Model and Nasal Epithelial Cells

Allergic rhinitis (AR) is a common upper-airway inflammatory disease of the nasal mucosa caused by immunoglobulin (IgE)-mediated inflammation. AR causes various painful clinical symptoms of the nasal mucosa that worsen the quality of daily life, necessitating the urgent development of therapeutic agents. Herein, we investigated the effects of Caesalpinia sappan Linn. heartwood water extract (CSLW), which has anti-inflammatory and antioxidant properties, on AR-related inflammatory responses. We examined the anti-inflammatory and anti-allergic effects of CSLW in ovalbumin (OVA)-induced AR mice and in primary human nasal epithelial cells (HNEpCs). Administration of CSLW mitigated allergic nasal symptoms in AR mice, decreased total immune cell and eosinophil counts in nasal lavage fluid, and significantly reduced serum levels of OVA-specific IgE, histamine, and Th2 inflammation-related cytokines. CSLW also inhibited the infiltration of several inflammatory and goblet cells, thereby ameliorating OVA-induced thickening of the nasal mucosa tissue. We found that CSLW treatment significantly reduced infiltration of eosinophils and production of periostin, MUC5AC, and intracellular reactive oxygen species through the Keap1/Nrf2/HO-1 pathway in HNEpCs. Thus, our findings strongly indicate that CSLW is a potent therapeutic agent for AR and can improve the daily life of patients by controlling the allergic inflammatory reaction of the nasal epithelium.

Hydrolyzable Tannins in the Management of Th1, Th2 and Th17 Inflammatory-Related Diseases

Plants rich in hydrolyzable tannins were traditionally used all over the world for a variety of chronic inflammatory disorders, including arthritis, colitis, and dermatitis. However, the knowledge of their immunological targets is still limited though fundamental for their rational use in phytotherapy. The recent advances regarding the pathogenesis of inflammatory-based diseases represent an opportunity to elucidate the pharmacological mechanism of plant-derived metabolites with immunomodulatory activity. This review collects recent articles regarding the role of hydrolyzable tannins and their gut metabolites in Th1, Th2, and Th17 inflammatory responses. In line with the traditional use, rheumatoid arthritis (RA), inflammatory bowel diseases (IBDs), psoriasis, atopic dermatitis (AD), and asthma were the most investigated diseases. A substantial body of in vivo studies suggests that, beside innate response, hydrolyzable tannins may reduce the levels of Th-derived cytokines, including IFN-γ, IL-17, and IL-4, following oral administration. The mode of action is multitarget and may involve the impairment of inflammatory transcription factors (NF-κB, NFAT, STAT), enzymes (MAPKs, COX-2, iNOS), and ion channels. However, their potential impact on pathways with renewed interest for inflammation, such as JAK/STAT, or the modulation of the gut microbiota demands dedicate studies.

Recent Studies on Protective Effects of Walnuts against Neuroinflammation

Neuroinflammation plays a significant role in the aging process and the pathophysiology of neurodegenerative diseases, such as Alzheimer’s disease. Accordingly, possible therapeutic strategies aimed at anti-inflammatory effects may be beneficial to brain health. Walnut kernels contain large quantities of unsaturated fatty acids, peptides, and phenolic compounds that have anti-inflammatory effects. The long-term intake of walnuts has been found to improve cognitive function and memory in rats and humans. However, the modulatory effect of walnuts on neuroinflammation has received much less attention. This review focuses on the potential influence and main regulating mechanisms of walnuts and their active ingredients on neuroinflammation, including the regulation of microglia activation induced by amyloid β or lipopolysaccharides, inhibition of peripheral inflammation mediated by macrophages, reduction in oxidative stress by decreasing free radical levels and boosting antioxidant defenses, and control of gut microbes to maintain homeostasis. However, the majority of evidence of the beneficial effects of walnuts or their components on neuroinflammation and neurodegeneration comes from experimental work, whereas evidence from clinical studies on the beneficial effects is scarcer and less conclusive. This review aims to provide new insights into the neuroinflammation-regulating mechanisms and natural active ingredients of walnuts and the development of walnut-based functional foods for the alleviation of neurodegenerative diseases.

Amauroderma rugosum Extract Suppresses Inflammatory Responses in Tumor Necrosis Factor Alpha/Interferon Gamma-Induced HaCaT Keratinocytes

Keratinocytes form the physical barrier of the skin and play an important role in the inflammatory process. Amauroderma rugosum is an edible mushroom; however, its pharmacological properties have seldom been studied. Although the anti-inflammatory effect of the organic solvent extract of Amauroderma rugosum has been previously reported, it is not known whether the aqueous extract has a similar effect. In addition, the effect of Amauorderma rugosum extract on skin has never been explored. Therefore, the objectives of the present study were to evaluate the anti-inflammatory effects of the aqueous extract of Amauroderma rugosum on HaCaT keratinocytes, to explore its mechanisms of action, and to study the possible active ingredients involved. The results showed that the aqueous extract of Amauroderm rugosum at a concentration of 1.5 mg/mL was non-toxic to HaCaT cells and inhibited the release of cytokine interleukin-1β, and chemokines interleukin-8 and monocyte chemoattractant protein-1 in tumor necrosis factor (TNF)-α- and interferon (IFN)-γ-stimulated HaCaT cells. Amauroderma rugosum extract reduced the intracellular levels of reactive oxygen species. In addition, Amauroderma rugosum extract reduced the total protein expression of nuclear factor-kappa B (NF-κB) and B-cells inhibitor alpha in HaCaT keratinocytes and inhibited the phosphorylation of mitogen-activated protein kinase kinase (MEK) 1/2, extracellular signal-regulated kinase (ERK) 1/2, protein kinase B (Akt), and mammalian target of rapamycin (mTOR) in TNF-α- and INF-γ-stimulated HaCaT keratinocytes. Chemical analysis revealed that the aqueous extract of Amauroderma rugosum contains polysaccharides, triterpenes, and phenolic compounds. Anti-inflammatory compounds, such as gallic acid, guanosine, and uridine, were also present. The anti-inflammatory effect of Amauroderma rugosum could be mimicked by a combination of gallic acid, guanosine, and uridine. In conclusion, our study suggests that the aqueous extract of Amauroderma rugosum exerts anti-inflammatory effects on keratinocytes through its antioxidant and inhibitory effects on MEK/ERK-, Akt/mTOR-, and NF-κB-dependent signaling pathways.

Allergen immunotherapy enhances the immunosuppressive effects of Treg cells to alleviate allergic rhinitis by decreasing PU-1+ Treg cell numbers

OBJECTIVE

To investigate the role of Tregs and their subtypes in the treatment of allergic rhinitis with allergen immunotherapy (AIT) as well as the underlying mechanism.

METHODS

1. Thirty-one healthy controls, 29 Allergic rhinitis (AR) patients and 16 AR patients treated with AIT were recruited. The total nasal symptom scores (TNSSs) were calculated. The serum levels of IgE, IL-2, TNF-α, IFN-γ, IL-4, IL-5, IL-6, IL-10 and IL-17 were measured. 2. Changes in the proportions of CD4+ T cells, Treg cells, Treg subtypes and Th1/Th2/Th9/Th17/Tfh cells in the peripheral blood of the subjects in the three groups were measured. 3. The correlations of Treg cells, Treg subtypes and TNSS with the levels of various cytokines in the AR group and AIT group were analysed.

RESULTS

1. Compared with the control group, the TNSS and IgE, IL-5 and IL-6 levels in the AR group were significantly increased, while the IL-2, IFN-γ and IL-10 levels were significantly decreased (P < 0.05). Compared with the AR group, the TNSS and IgE, IL-5 and IL-6 levels in the AIT group were significantly decreased, while the IL-2, IFN-γ and IL-10 levels were significantly increased (P < 0.05). 2. Compared with the control group, the proportions of Tregs, GATA3+ Tregs and Th1 cells in the AR group were significantly reduced, while the proportions of PU-1+ Tregs, T-bet+ Tregs and Th2 cells were significantly increased (P < 0.05). Compared with the AR group, the proportions of Tregs and Th1 cells in the AIT group were significantly increased, while the proportions of PU-1+ Tregs and Th2 cells were decreased (P < 0.05). 3. Correlation analysis showed that Treg cell proportions were negatively correlated with the TNSS, sIgE levels, IL-5 levels and IL-6 levels but positively correlated with the IL-2 and IL-10 levels (P < 0.05). PU-1+ Treg cell proportions were positively correlated with the TNSS, sIgE levels, IL-5 levels and IL-6 levels but negatively correlated with the Treg cell proportions, IL-2 levels and IL-10 levels (P < 0.05).

CONCLUSIONS

AIT can reduce the proportions of PU-1+ Treg subtypes in AR patients. PU-1+ Treg cell numbers can potentially be used as an indicator to monitor the therapeutic effect of AIT on AR.

7-Methoxyisoflavone ameliorates atopic dermatitis symptoms by regulating multiple signaling pathways and reducing chemokine production

7-Met, a derivative of soybean isoflavone, is a natural flavonoid compound that has been reported to have multiple signaling pathways regulation effects. This study investigated the therapeutic effects of 7-Met on mice with atopic dermatitis induced by fluorescein isothiocyanate (FITC), or oxazolone (OXZ). 7-Met ameliorated FITC or OXZ-induced atopic dermatitis symptoms by decreasing ear thickness, spleen index, mast cell activation, neutrophil infiltration and serum IgE levels in female BALB/c mice. In FITC-induced atopic dermatitis mice, 7-Met reduced Th1 cytokines production and regulated Th1/Th2 balance by downregulating the secretion of thymic stromal lymphopoietin (TSLP) via inactivation of the NF-κB pathway. In OXZ-induced atopic dermatitis, 7-Met functioned through the reduction of Th17 cytokine production. Our study showed that 7-Methoxyisoflavone alleviated atopic dermatitis by regulating multiple signaling pathways and downregulating chemokine production.

Therapeutic effects and mechanisms of Zhen-Wu-Bu-Qi Decoction on dextran sulfate sodium-induced chronic colitis in mice assessed by multi-omics approaches

BACKGROUND

Zhen-Wu-Bu-Qi Decoction (ZWBQD), a traditional Chinese medicine formula comprising Poria, Radix Paeoniae Alba, Rhizoma Atractylodis Macrocephalae, Rhizoma Zingiberis Recens, Radix Codonopsis and Rhizoma Coptidis, is used for treating ulcerative colitis (UC). In a previous study, we have reported ZWBQD mitigates the severity of dextran sulfate sodium (DSS)-induced colitis in mice.

HYPOTHESIS

In this study, we aimed to understand the systemic actions and underlying mechanisms of ZWBQD on experimental colitis in mice.

METHODS

We used multi-omics techniques and immunoblotting approach to study the pharmacological actions and mechanisms of ZWBQD in DSS-induced chronic colitic mice.

RESULTS

We showed that ZWBQD exhibited potent anti-inflammatory properties and significantly protected DSS-induced colitic mice against colon injury by regulating the PI3K-AKT, MAPK signaling pathway and NF-κB signaling pathways. We also revealed that ZWBQD significantly ameliorated gut microbiota dysbiosis and abnormalities of tryptophan catabolites induced by DSS.

CONCLUSIONS

We demonstrated that the therapeutic effects of ZWBQD on experimental colitis are mediated by regulating multiple signaling pathways and modulation of gut microbiota. Our study employed an integrative strategy to elucidate novel mechanisms of ZWBQD, which provides new insights into the development of Chinese herbal medicine-based therapeutics for UC.

MAF bZIP Transcription Factor B (MAFB) Protected Against Ovalbumin-Induced Allergic Rhinitis via the Alleviation of Inflammation by Restoring the T Helper (Th) 1/Th2/Th17 Imbalance and Epithelial Barrier Dysfunction

Purpose

This work aimed to investigate the effects of MAF bZIP transcription factor B (MAFB) on the progression of allergic rhinitis (AR).

Patients and Methods

Nasal mucosa was isolated from AR patients and healthy individuals from Shengjing Hospital of China Medical University. The experimental procedures were approved by the Medical Ethics Committee of Shengjing Hospital of China Medical University (2019PS341K) in accordance with the Declaration of Helsinki. Informed consents were signed by participants or a parent/legal guardian of the participants under 18 years old of age. Then, an AR mouse model with MAFB overexpression was established with 25 μg ovalbumin (OVA) sensitization on day 0, 7, 14, followed by an injection with 1×10⁷ TU/mL lentivirus MAFB on day 19 and a nasal challenge with 500 μg OVA from day 21 to 27.

Results

The results revealed that MAFB was down-regulated in the nasal mucosa of AR patients. The up-regulation of MAFB protected the AR mice against the OVA-induced allergic symptoms (sneezing and nasal rubbing) by alleviating the OVA-induced epithelial thicknesses, goblet cell hyperplasia, and inflammation including the eosinophil and mast cell infiltration. Moreover, MAFB facilitated the T helper (Th) 1 response and inhibited the Th2 and Th17 responses by the down-regulation of T-box transcription factor 21 and the up-regulation of GATA binding protein-3 as well as retinoid-related orphan receptor-γt in the splenocytes of AR mice. MAFB was found to repress the differentiation of naive CD4⁺ T cells into Th2 cells. Subsequently, MAFB overexpression reversed the OVA-induced enhancement of epithelial permeability, downregulation of tight junctions, and upregulation of cadherin-26, indicating the protective role of MAFB on epithelial barrier integrity.

Conclusion

MAFB protected against OVA-induced AR via the alleviation of inflammation by restoring the Th1/Th2/Th17 imbalance and epithelial barrier dysfunction.

Aberrant expressions of circulating lncRNA NEAT1 and microRNA‐125a are linked with Th2 cells and symptom severity in pediatric allergic rhinitis

Objective

Long noncoding RNA nuclear enriched abundant transcript 1 (lnc‐NEAT1) and its target microRNA‐125a (miR‐125a) are reported to regulate immune and inflammation process in allergic rhinitis (AR). Hence, this study intended to investigate the correlation between lnc‐NEAT1 and miR‐125a expressions, as well as their clinical values in pediatric AR patients.

Methods

Peripheral blood mononuclear cell samples from 80 pediatric AR patients, 40 disease controls (DCs), and 40 healthy controls (HCs) were collected to detect lnc‐NEAT1 and miR‐125a expressions by reverse transcription‐quantitative polymerase chain reaction. For pediatric AR patients only, serum interferon‐gamma (IFN‐γ) and interleukin (IL)‐10 were measured by enzyme linked immunosorbent assay; meanwhile, T helper (Th) 1 and Th2 cells in CD4⁺ T cells were analyzed by flow cytometry.

Results

Lnc‐NEAT1 was overexpressed, while miR‐125a downregulated in pediatric AR patients compared to DCs and HCs (all p < 0.001). Moreover, lnc‐NEAT1 expression negatively correlated with miR‐125a expression in pediatric AR patients (p = 0.002), but not in DCs (p = 0.226) or HCs (p = 0.237). Furthermore, in pediatric AR patients, lnc‐NEAT1 expression positively associated with TNSS (p < 0.001), sneezing score (p = 0.006), and congestion score (p = 0.008); miR‐125a expression was negatively related to TNSS (p < 0.001), itching score (p = 0.040), and sneezing score (p = 0.005). Additionally, lnc‐NEAT1 expression positively, while miR‐125a expression negatively correlated with Th2 cells and IL‐10 (all p < 0.05), but they were not correlated with Th1 cells or IFN‐γ in pediatric AR patients.

Conclusion

Circulating lnc‐NEAT1 and miR‐125a are aberrantly expressed and linked with Th2 cells and symptom severity in pediatric allergic rhinitis.

The Immuno-Modulatory Activities of Pentaherbs Formula on Ovalbumin-Induced Allergic Rhinitis Mice via the Activation of Th1 and Treg Cells and Inhibition of Th2 and Th17 Cells

Allergic rhinitis (AR) is a highly prevalent allergic disease induced by immunoglobulin (Ig) E-mediated hypersensitivity reaction at the nasal epithelium against inhaled allergens. Previous studies have demonstrated that Pentaherbs formula (PHF), a modified herbal formula comprising five herbal medicines (Flos Lonicerae, Herba Menthae, Cortex Phellodendri, Cortex Moutan and Rhizoma Atractylodis), could suppress various immune effector cells to exert anti-inflammatory and anti-allergic effects in allergic asthma and atopic dermatitis. The present study aimed to further determine the anti-inflammatory activities of PHF in an ovalbumin (OVA)-induced AR BALB/c mouse model. Nasal symptoms such as sneezing and nose rubbing were recorded and the serum total IgE and OVA-specific IgG1, as well as interleukin (IL)-4, IL-5, IL-10, IL-13, chemokines CXCL9 CXCL10, and tumor necrosis factor (TNF)-α concentrations in nasal lavage fluid (NALF) were measured during different treatments. Effects of PHF on the expression of inflammatory mediators in the sinonasal mucosa were quantified using real-time QPCR. PHF was found to suppress allergic symptoms, infiltration of inflammatory cells, and hyperplasia of goblet cells in the nasal epithelium of the OVA-induced AR mice. PHF could reduce OVA-specific IgG1 level in serum, and TNF-α and IL-10 in nasal lavage fluid (NALF), significantly up-regulate the splenic regulatory T (Treg) cell level, increase the Type 1 helper T cell (Th1)/Type 2 helper T cell (Th2) ratio, and reduce the Th17 cells (all p < 0.05). PHF could also alleviate in situ inflammation in sinonasal mucosa of OVA-induced AR mice. In conclusion, oral treatment of PHF showed immuno-modulatory activities in the OVA-induced AR mice by regulating the splenic T cell population to suppress the nasal allergy symptoms and modulating inflammatory mediators, implicating that PHF could be a therapeutic strategy for allergic rhinitis.

Gallic Acid Ameliorates Atopic Dermatitis-Like Skin Inflammation Through Immune Regulation in a Mouse Model

Background

Gallic acid (GA) has an anti-inflammatory effect by regulating inflammatory molecules. This study aimed to investigate the effect of GA on atopic dermatitis (AD)-like skin inflammation.

Methods

4-dinitrochlorobenzene (DNCB) was used to induce an AD-like skin inflammation model. The effect of GA on DNCB-induced inflammation was assessed by measuring the thickness and histopathological examination of the ear. Serum IgE and TNF-α levels were detected. The effect of GA on lymph nodes was determined by measuring the weights and mRNA/protein expression levels of TNF-α, IL-4, IFN-γ and IL-17. Ratio of Treg cells and Th17 cells was also analyzed.

Results

It was found that the thickness and pathology of the ear were significantly improved by GA in the DNCB-induced mice. Serum IgE and TNF-α levels were significantly reduced in GA-treated model mice compared to the model group. GA treatment lowered the weight of lymph node and the expression of mRNAs of TNF-α, IL-4, IFN-γ, and IL-17 of lymph node. In the ear, inflammatory factors (IL-4, IL-5, IL-17, or IL-23) showed a significant decrease in GA-treated model mice versus model mice, while the expression levels of IL-10 and TGF-β showed a great increase in GA-treated model mice. ROR-γt showed a decrease in GA-treated model group, along with an increase expression of SOCS3.

Conclusion

GA could ameliorate AD-like skin inflammation possibly through Th17 mediated immune regulation in a DNCB-induced mouse model.

Polyphenols affect the humoral response in cancer, infectious and allergic diseases and autoimmunity by modulating the activity of TH1 and TH2 cells

Polyphenols are a wide class of natural substances, pleiotropic molecules capable of modulating several processes, involved in the humoral and cellular immune response. The activation, differentiation of B cells, and production of antibodies to protein antigens by plasma cells depend on T helper (T_H) CD4⁺ cells and secreted cytokines. Cancer, infectious, allergic, and autoimmune diseases are characterized by an imbalance of T_H1/T_H2 immunity and abnormal activation of the humoral response. Accordingly, polyphenols modulate the T_H1/T_H2 ratio, the secretion of multiple cytokines, the levels of antibodies, and therefore could contribute to recovering the state of health in these diseases. In this review, we summarize the current knowledge on the effects of polyphenols in modulating the humoral response in cancer, infectious and allergic diseases and in autoimmunity by affecting the activity of T_H1 and T_H2 cells.

The extract of black cumin, licorice, anise, and black tea alleviates OVA-induced allergic rhinitis in mouse via balancing activity of helper T cells in lung

Background

A formulation of black cumin (Nigella sativa L.), licorice (Glycyrrhiza glabra L.), anise (Pimpinella anisum L.) and tea (Camellia sinensis (L.) Kuntze) (denoted BLAB tea) is traditionally used to relief allergy reaction including allergic rhinitis. However, little is known about its underlining mechanism of anti-allergic effects.

Methods

To investigate the anti-allergenic mechanism of BLAB tea, we treated ovalbumin (OVA)-induced allergic rhinitis (AR) model of mice with BLAB tea, and elucidated its possible mechanism of action. Mice in the control group were treated with phosphate-buffered saline only. Subsequently, the infiltration of different inflammatory cells was measured. In addition, histopathological changes in the nasal mucosa, and the levels of allergen-specific cytokines and OVA-specific immunoglobulins were measured.

Results

The aqueous extract of BLAB significantly alleviated the nasal symptoms and reduced the accumulation of inflammatory cells in the nasal mucosa and nasal lavage fluid of AR model of mice.

Conclusion

The aqueous extract of BLAB induced the production of Th1 and Treg cytokines and inhibited the release of Th2 cytokines and histamine in nasal mucosa and serum of mice while decreasing the serum levels of OVA-specific IgE, IgG1, and IgG2a. These results suggest the potential of the aqueous extract of BLAB as a treatment option for allergic diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-021-00587-6.

Long non-coding RNA growth arrest-specific 5 and its targets, microRNA-21 and microRNA-140, are potential biomarkers of allergic rhinitis

Objective

Long non‐coding RNA growth arrest‐specific 5 (lnc‐GAS5) and its targets (microRNA [miR]‐21 and miR‐140) are involved in the development and progression of allergic rhinitis (AR). However, the correlation of lnc‐GAS5 with miR‐21 and miR‐140 and their associations with disease risk, symptom severity, and Th1/Th2 cytokines in AR remain unclear. Thus, this study aimed to investigate this topic.

Methods

In total, 120 patients with AR and 60 controls were recruited. Nasal‐mucosa tissues were collected from all participants. Lnc‐GAS5, its targets (miR‐21 and miR‐140), interferon (IFN)‐γ, interleukin (IL)‐2, IL‐4, and IL‐10 were detected by reverse‐transcription quantitative polymerase chain reaction.

Results

Lnc‐GAS5 was elevated, while miR‐21 and miR‐140 was downregulated in AR patients than in controls (p < 0.001). In AR patients, lnc‐GAS5 was negatively correlated with miR‐21 (p < 0.001), miR‐140 (p < 0.001), IFN‐γ (p = 0.019), and IL‐2 (p = 0.039) and positively correlated with IL‐4 (p = 0.004) and IL‐10 (p < 0.001), individual nasal symptom scores (INSSs) for itching, sneezing, and congestion (p < 0.05), and total nasal symptom score (TNSS) (p < 0.001). Moreover, miR‐21 and miR‐140 were negatively correlated with some INSSs, total TNSS score, and IL‐10 and positively correlated with IFN‐γ and IL‐2 (p < 0.05).

Conclusion

Lnc‐GAS5 is negatively correlated with that of its targets (miR‐21 and miR‐140) in AR; meanwhile, lnc‐GAS5, miR‐21, and miR‐140 are correlated with disease risk, symptom severity, and Th1/Th2 imbalance in AR, suggesting the potential of these biomarkers in the development and progression of AR.

Antileishmanial potential of immunomodulator gallic acid against experimental murine visceral leishmaniasis

The menace of the enfeebling disease leishmaniasis prevails due to the inaccessibility of effective vaccine and chemotherapy. Hence in the pursuit of finding novel alternative options with reasonable efficacy, immunomodulation, leishmanicidal activity and fewer side effects, screening of compounds from natural sources is needed. This study was focused on in vitro and in vivo antileishmanial screening of gallic acid (GA) against Leishmania donovani infection in BALB/c mice. GA showed in vitro parasiticidal activity and IC₅₀  value of 19.59 ± 0.74 µg/ml and is able to arrest cell cycle at the sub-G0/G1 phase. The therapeutic potential of gallic acid was assessed in the L. donovani-infected BALB/c mice. GA reported a reduction in parasite burden and augmentation of CD4⁺ and CD8⁺ T lymphocytes. Also, the polarization of mouse immune status to protective Th1 response was evidenced by increased delayed-type hypersensitivity response and levels of IgG2a, reactive oxygen species and nitric oxide. GA was reported to be safe and non-toxic to human cell line THP-1 and also to the liver and kidney of mice. Hence, the findings of the present study indicate the possible role of GA in the strengthening of host immune system and thus facilitating the clearance of leishmanial infection and conferring protection.

Pharmacological Benefits of Triphala: A Perspective for Allergic Rhinitis

Allergic rhinitis (AR) is considered a major nasal condition impacting a large number of people around the world, and it is now becoming a global health problem. Because the underlying mechanisms of AR are complex, the development of single-drug treatment might not be enough to treat a wide spectrum of the disease. Although the standard guidelines classify and provide suitable diagnosis and treatment, the vast majority of people with AR are still without any means of controlling it. Moreover, the benefits of AR drugs are sometimes accompanied by undesirable side effects. Thus, it is becoming a significant challenge to find effective therapies with limited undesirable side effects for a majority of patients suffering from uncontrolled AR. Aller-7/NR-A2, a polyherbal formulation, has revealed promising results in patients by reducing nasal symptoms and eosinophil counts without serious adverse effects. Interestingly, three out of seven of the herbals in the Aller-7/NR-A2 formulation are also found in an Ayurvedic polyherbal formulation known as “Triphala,” which is a potential candidate for the treatment of AR. However, there are no current studies that have examined the effects of Triphala on the disease. This review aims to describe the complexity of AR pathophysiology, currently available treatments, and the effects of Triphala on AR in order to help develop it as a promising alternative treatment in the future.

Chlorogenic acid ameliorated allergic rhinitis-related symptoms in mice by regulating Th17 cells

Allergic rhinitis (AR) is a non-infectious chronic inflammatory disease of nasal mucosa provoking T helper cell (Th) 17 response. Chlorogenic acid (CGA), one of the most abundant polyphenol compounds in various agricultural products, possesses antiviral, anti-inflammatory, and antibacterial properties. However, the effect of CGA on AR is unclear. Thus, our study explored the effect of CGA in modulating AR-related symptoms and immunoreaction, especially Th17 response. AR mice were induced by ovalbumin (OVA) administration and further treated with CGA or dexamethasone (Dex). The frequencies of rubbing and sneezing of AR mice were recorded. Histopathological analysis of nasal mucosa was conducted by Hematoxylin–Eosin and Periodic acid–Schiff stainings. The serum and nasal mucosa levels of OVA-immunoglobulin (Ig)E, interferon (IFN)-γ, retinoic acid-associated nuclear orphan receptor (ROR)-γt, and interleukin (IL)-17A were measured by enzyme-linked immunosorbent assay, quantitative reverse-transcription polymerase chain reaction (qRT-PCR), or Western blot. The ratio of CD4⁺IL-17⁺Th17 cells to CD4⁺ T cells in peripheral blood of AR mice was assessed by flow cytometer. CGA diminished the frequencies of rubbing and sneezing of AR mice in a concentration-dependent manner. CGA attenuated histopathological abnormalities and decreased goblet cell number in nasal mucosa of AR mice. CGA decreased the serum levels of OVA-IgE, ROR-γt, and IL-17A, while increasing the serum level of IFN-γ in AR mice. Meanwhile, CGA decreased the ratio of CD4⁺IL-17⁺Th17 cells to CD4⁺T cells in peripheral blood and the mRNA and protein levels of IL-17A and ROR-γt in AR mice. CGA ameliorated AR-related symptoms in mice by regulating Th17 cells, which could be a candidate for the treatment of AR.

Association of interleukin-12B rs6887695 with susceptibility to allergic rhinitis

Interleukin-12 (IL-12) is a heterodimeric cytokine encoded by two separate genes, IL12A and IL12B, which may play a regulatory role in allergen-induced inflammation through CD4⁺ T-cell subsets polarization. The aim of this study was to investigate the association of single-nucleotide polymorphisms (SNPs) in the IL12B gene with susceptibility to allergic rhinitis (AR). We performed a case-control study including 130 AR patients and 130 healthy controls to evaluate the possible association between IL12B gene SNPs (rs3212227, rs6887695) and the risk of AR using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our results showed no significant association between IL12B rs3212227 A > C polymorphism with AR. In contrast, the GC genotype of rs6887695 G > C was associated with susceptibility to AR in comparison with the GG genotype (p = 0.049, OR = 1.684, 95% CI: 1.002-2.83). We also observed a statistically significant difference in the additive model (GC versus GG + CC, p = 0.03, OR = 1.705, 95% CI: 1.040-2.794) for SNPs rs6887695. Furthermore, haplotypes analysis demonstrated that C-C haplotype was associated with an increased risk of AR (p = 0.01, OR = 1.845, 95% CI: 1.114-3.057). Our findings suggest that IL12B rs6887695 polymorphism may be a potential biomarker for susceptibility to AR in an Iranian population.

Polyphenols and Cannabidiol Modulate Transcriptional Regulation of Th1/Th2 Inflammatory Genes Related to Canine Atopic Dermatitis

Canine atopic dermatitis (AD) is a multifactorial allergic disease associated with immune and abnormal skin barrier dysfunction and it is one of the primary causes of pruritus. Using a novel in vitro model of AD, here we tried to revert the alteration of transcriptional regulation of AD canine key genes testing a nutraceutical mixture containing flavonoids, stilbene, and cannabinoids, which are already well-known for their applications within dermatology diseases. The nutraceutical mixture induced in inflamed cells a significant downregulation (p < 0.05) of the gene expression of ccl2, ccl17, and tslp in keratinocytes and of ccl2, ccl17, and il31ra in monocytes. Consistent with the observed alterations of tslp, ccl2, ccl17, and il31ra messenger RNA (mRNA) levels, a significant increase (p < 0.05) of DNA methylation at specific CpG sites on the gene regulatory regions was found. These results lay the foundation for the use of these natural bioactives in veterinary medicine and provide a model for deeper understanding of their mechanisms of action, with potential translation to human research.

Rhodiola crenulata extract decreases fatty acid oxidation and autophagy to ameliorate pulmonary arterial hypertension by targeting inhibiton of acylcarnitine in rats

Pulmonary arterial hypertension (PAH) is a devastating pulmonary circulation disease lacking high-efficiency therapeutics. The present study aims to decipher the therapeutic mechanism of Rhodiola crenulata, a well-known traditional chinese medicine with cardiopulmonary protection capacity, on PAH by exploiting functional lipidomics. The rat model with PAH was successfully established for first, following Rhodiola crenulata water extract (RCE) treatment, then analysis of chemical constituents of RCE was performed, additional morphologic, hemodynamic, echocardiographic measurements were examined, further targeted lipidomics assay was performed to identify differential lipidomes, at last accordingly mechanism assay was done by combining qRT-PCR, Western blot and ELISA. Differential lipidomes were identified and characterized to differentiate the rats with PAH from healthy controls, mostly assigned to acylcarnitines, phosphatidylcholines, sphingomyelin associated with the PAH development. Excitingly, RCE administration reversed high level of decadienyl-L-carnitine by the modulation of metabolic enzyme CPT1A in mRNA and protein level in serum and lung in the rats with PAH. Furthermore, RCE was observed to reduce autophagy, confirmed by significantly inhibited PPARγ, LC3B, ATG7 and upregulated p62, and inactivated LKB1-AMPK signal pathway. Notably, we accurately identified the constituents in RCE, and delineated the therapeutic mechansim that RCE ameliorated PAH through inhibition of fatty acid oxidation and autophagy. Altogether, RCE might be a potential therapeutic medicine with multi-targets characteristics to prevent the progression of PAH. This novel findings pave a critical foundation for the use of RCE in the treatment of PAH.

Traditional Chinese medicine combined with pulmonary drug delivery system and idiopathic pulmonary fibrosis: Rationale and therapeutic potential

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Pathogenesis and characteristics of idiopathic pulmonary fibrosis (IPF) are presented.

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The history and current situation of traditional Chinese medicine (TCM) in treating lung diseases are introduced.

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Therapeutic mechanisms of different TCM to treat IPF are summarized.

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Advantages and types of pulmonary drug delivery systems (PDDS) are emphasized.

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Combining TCM with PDDS is a potential strategy to treat IPF.

Idiopathic pulmonary fibrosis (IPF) is a progressive pulmonary interstitial inflammatory disease of unknown etiology, and is also a sequela in severe patients with the Coronavirus Disease 2019 (COVID-19). Nintedanib and pirfenidone are the only two known drugs which are conditionally recommended for the treatment of IPF by the FDA. However, these drugs pose some adverse side effects such as nausea and diarrhoea during clinical applications. Therefore, it is of great value and significance to identify effective and safe therapeutic drugs to solve the clinical problems associated with intake of western medicine. As a unique medical treatment, Traditional Chinese Medicine (TCM) has gradually exerted its advantages in the treatment of IPF worldwide through a multi-level and multi-target approach. Further, to overcome the current clinical problems of oral and injectable intakes of TCM, pulmonary drug delivery system (PDDS) could be designed to reduce the systemic metabolism and adverse reactions of the drug and to improve the bioavailability of drugs. Through PubMed, Google Scholar, Web of Science, and CNKI, we retrieved articles published in related fields in recent years, and this paper has summarized twenty-seven Chinese compound prescriptions, ten single TCM, and ten active ingredients for effective prevention and treatment of IPF. We also introduce three kinds of inhaling PDDS, which supports further research of TCM combined with PDDS to treat IPF.

Tylophora hirsuta (Wall.) Extracts Ameliorate Diabetes Associated with Inflammation in Alloxan-induced Diabetic Rats

BACKGROUND

Tylophora hirsuta (Wall) has long been used as traditional medicine for the treatment of diabetes. The current study is designed to evaluate the anti-diabetic and anti-inflammatory activity of different extracts of aerial parts of Tylophora hirsuta.

METHODS

Sequential maceration was conducted to obtain extracts. Total phenolic contents were determined by the Folin-Ciocalteau method. The anti-oxidant activity was assessed by DPPH free radical scavenging assay. The extracts were tested for its inhibitory activity against α-amylase in-vitro. In-vivo anti-diabetic assay was conducted using alloxan-induced diabetic model and OGTT was conducted on normal rats. ELISA was used to determine the pro-inflammatory cytokines (TNF-α and IL-6). The polyphenolic composition of the extract was analyzed using an HPLC system.

RESULTS

Aqueous extract exhibited highest total phenolic contents (985.24± 3.82 mg GAE/100 g DW), antioxidant activity (IC50 = 786.70 ± 5.23 μg/mL), and alpha-amylase inhibition (IC50 =352.8 μg/mL). The aqueous extract of Tylophora hirsuta showed remarkable in-vivo anti-diabetic activity. Results were compared with standard drug glibenclamide. Alloxan induced diabetic mediated alterations in liver function enzymes, renal function determinants, and lipid parameters were significantly restored in aqueous extract treated diabetic rats. A significant reduction in pro-inflammatory cytokines (p<0.001) was observed when compared to the control group. HPLC analysis confirms the presence of quercetin, gallic acid, cinnamic acid, and p-coumaric acid.

CONCLUSION

These results showed that Tylophora hirsuta possesses strong anti-diabetic and anti-inflammatory potentials and justify its folklore use for the management of diabetes.

IL-37 relieves allergic inflammation by inhibiting the CCL11 signaling pathway in a mouse model of allergic rhinitis

Allergic rhinitis (AR) is the allergic inflammation of immune cells in the nasal mucosa, caused by an abnormal T-cell response. Interleukin (IL)-37, a unique member of the IL-1 family with broad anti-inflammatory roles in various autoimmune diseases, participates in the immune regulation of AR. However, the regulatory mechanism of IL-37 in AR has remained elusive. In the present study, a mouse model of AR was established by treating mice with ovalbumin (OVA). Following systemic administration of IL-37, the effects of the cytokine on allergic symptoms were evaluated. The nasal mucosal infiltration of eosinophils was assessed by histopathological observation. The serum and nasal lavage fluid concentrations of immunoglobulin (Ig)E, IgG1, IgG2a, interferon (IFN)-γ, IL-4, IL-13, IL-17a and C-C motif cytokine ligand (CCL)11 were determined by ELISA. Treatment with OVA resulted in allergic symptoms, including enhanced eosinophil infiltration in the nasal mucosa, increased thickness of the nasal mucosa and increased levels of IgE, IgG1, IgG2a, IL-4, IL-13, IL-17a and CCL11, but the level of IFN-γ was indicated to decrease. After IL-37 treatment, the frequency of nasal rubbing and sneezing was reduced compared with that in the OVA group. IL-37 administration also decreased the number of eosinophils in the nasal mucosa and the thickness of the nasal mucosa, as well as the serum and nasal lavage fluid levels of IgE, IgG1, IgG2a, IL-4, IL-13, IL-17a and CCL11, but the level of IFN-γ decreased. In addition, the OVA-induced increases in histamine and substance P levels were reversed by IL-37 administration. CCL11 expression levels were correlated with the expression levels of IFN-γ, IL-4, IL-13, IL-17a, histamine and substance P. In conclusion, IL-37 alleviated the OVA-induced allergic symptoms and allergic inflammatory response by reducing the serum cytokine levels via decreasing CCL11 expression levels in mice.

Anti-allergic rhinitis activity of α-lipoic acid via balancing Th17/Treg expression and enhancing Nrf2/HO-1 pathway signaling

An ovalbumin (OVA)-induced allergic rhinitis (AR) mouse model was established to investigate whether α-Lipoic acid (LA) has a protective effect against upper respiratory tract inflammation. BALB/c mice were sensitized by intraperitoneal injection and challenged by intranasal application of OVA. Mice were orally administered various doses of LA once daily (2, 10, 50 mg/kg) and dexamethasone (Dex; 2.5 mg/kg) 1 h before OVA challenge. Allergic nasal symptoms, levels of OVA-specific immunoglobulins, cytokines, and transcription factors were measured. Nasal and lung histopathology were evaluated. LA administration significantly alleviated the nasal symptoms such as rubbing and sneezing, markedly reduced both serum OVA-specific IgE and IgG1 levels. The LA treatment group showed markedly up-regulated levels of the Treg cytokine IL-10 and Treg transcription factor Foxp3. In contrast, it showed down-regulated levels of the Th17 cytokine IL-17 and the Th17 transcription factor STAT3, and RORγ. LA greatly enhanced the nuclear factor erythroid-derived 2/heme oxygenase 1 (Nrf2/HO-1) pathway signaling and inhibited the activation of NF-κB/IκB, markedly suppressed the levels of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, IL-8 and chemokine COX-2. The histologic alterations of nasal and lung tissues of AR mice were effectively ameliorated by LA. Based on these results, we suggest that LA could be a potential therapeutic agent in OVA-induced AR by virtue of its role in controlling the Th17/Treg balance and enhancing Nrf2/HO-1 pathway signaling.

Identification of lipophilic components in Citri Reticulatae Pericarpium cultivars by supercritical CO2 fluid extraction with ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry

To systematically identify the lipophilic constituents of Citri Reticulatae Pericarpium from different cultivars, supercritical CO₂ fluid extraction and ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry were integrated for the component analysis of 18 batches of Citri Reticulatae Pericarpium from 12 cultivars for the first time. A total of 57 components from the supercritical CO₂ fluid extracts were demonstrably or tentatively identified by the obtained parent peaks, fragment peaks, and retention times. In total, two flavonoids, six organic acids, nine coumarins, three aldehydes, seven esters, three terpenes, one limonoid, and five other compounds were detected for the first time; notably, coumarin components have not yet been reported in Citri Reticulatae Pericarpium. Furthermore, the extract constituents differed between cultivars. In particular, organic acids were more abundant in Citrus reticulata "Chachi" than in other cultivars, and pterostilbene was exclusively found in Citrus reticulata "Yichangju". The results showed that a greater variety of compounds in Citri Reticulatae Pericarpium could be extracted by supercritical CO₂ fluid extraction and detected by ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry. This study provides a more scientific basis for further analysis of the pharmacological activity and quality of Citri Reticulatae Pericarpium components from different cultivars.

Enriched-Baicalein Attenuates Allergy in Cells and Mice

Enriched-baicalein (baicalein) from baicalin was prepared by fermentation of an SB extract with mycelium of Laetiporus sulphureus. To investigate the pharmacologic effects of baicalein, its antiallergic effect was measured in vitro and in vivo. Allergy was induced by intraperitoneal injection of ovalbumin (OVA) into Balb/c mice. As a result, baicalein showed antiallergic effects by inhibiting the release of β-hexosaminidase from immunoglobulin E- (IgE-) stimulated rat basophilic leukemia (RBL-2H3) mast cells without cytotoxicity after the methodology. After four weeks, the decrease of OVA-specific IgE level, decrease of histamine and tryptase level in serum, and then the decrease of the levels of T helper type 2 (Th2) cell-derived cytokines interleukin- (IL-) 4 and IL-13 in the splenocyte were observed. In a histological analysis for lung, baicalein excellently reduced eosinophil infiltration with the inhibition of characteristic lesions and inflammation including OVA-induced necrosis, numbers of inflammatory cells, and pulmonary edema. Therefore, these results showed that baicalein had excellent efficacy in the antiallergic activity.

The Role of Th17 Cells and IL-17 in Th2 Immune Responses of Allergic Conjunctivitis

Allergic conjunctivitis (AC) is a common allergic disease that is often associated with the onset of rhinitis or asthma. The incidence of AC has increased significantly in recent years possibly due to air pollution and climate warming. AC seriously affects patients' quality of life and work efficiency. Th (T-helper) 2 immune responses and type I hypersensitivity reactions are generally considered the basis of occurrence of AC. It has been found that new subpopulations of T-helper cells, Th17 cells that produce interleukin-17 (IL-17), play an important role in the Th2-mediated pathogenesis of conjunctivitis. Studies have shown that Th17 cells are involved in a variety of immune inflammation, including psoriasis, rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, and asthma. However, the role of Th17 and IL-17 in AC is unclear. This paper will focus on how T-helper 17 cells and interleukin-17 are activated in the Th2 immune response of allergic conjunctivitis and how they promote the Th2 immune response of AC.

Identification of Active Compounds of Mahuang Fuzi Xixin Decoction and Their Mechanisms of Action by LC-MS/MS and Network Pharmacology

The decoction is an important dosage form of traditional Chinese medicine (TCM) administration. The Mahuang Fuzi Xixin decoction (MFXD) is widely used to treat allergic rhinitis (AR) in China. However, its active compounds and therapeutic mechanisms are unclear. The aim of this study was to establish an integrative method to identify the bioactive compounds and reveal the mechanisms of action of MFXD. LC-MS/MS was used to identify the compounds in MFXD, followed by screening for oral bioavailability. TCMSP, BindingDB, STRING, DAVID, and KEGG databases and algorithms were used to gather information. Cytoscape was used to visualize the networks. Twenty-four bioactive compounds were identified, and thirty-seven predicted targets of these compounds were associated with AR. DAVID analysis suggested that these compounds exert their therapeutic effects by modulating the Fc epsilon RI, B-cell receptor, Toll-like receptor, TNF, NF-κB, and T-cell receptor signaling pathways. The PI3K/AKT and cAMP signaling pathways were also implicated. Ten of the identified compounds, quercetin, pseudoephedrine, ephedrine, β-asarone, methylephedrine, α-linolenic acid, cathine, ferulic acid, nardosinone, and higenamine, seemed to account for most of the beneficial effects of MFXD in AR. This study showed that LC-MS/MS followed by network pharmacology analysis is useful to elucidate the complex mechanisms of action of TCM formulas.

Ameliorative effect of selective NLRP3 inflammasome inhibitor MCC950 in an ovalbumin-induced allergic rhinitis murine model

Allergic rhinitis (AR) is a complex IgE-mediated nasal allergic and inflammatory disease. Nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3) is essential in the process of allergic and inflammatory responses. MCC950 is a selective NLRP3 inhibitor. However, its role and mechanism in AR remains undetermined. The present study aimed to explore the effect and mechanism of MCC950 on an ovalbumin (OVA) induced mouse model of AR. The AR BALB/c mice were constructed using OVA and administrated intranasally with MCC950. Concentrations of OVA-specific IgE, histamines and leukotrienes C4 (LTC4) in serum, and OVA-specific IgE, ECP, IFN-γ, IL-4, IL-5, IL-13, IL-1β and IL-18 in nasal lavage fluid (NLF) were assayed by enzyme-linked immunosorbent assay (ELISA). Inflammatory cells were counted in NLF. HE and PAS staing were used for evaluating eosinophils and goblet cells. Immunohistochemistry (IHC) staining were employed to evaluate immunolabeling of NLRP3, Caspase-1, ASC, IL-1β and IL-18 in nasal mucosas of mice. Real-time PCR was conducted to assay NLRP3, Caspase-1, ASC, IL-1β and IL-18 mRNA levels. In vitro studies, western blotting, real-time PCR and ELISA were performed to evaluate the effects and mechanisms of OVA and NLRP3 inhibitor MCC950 on spleen mononuclear cells. We found significant downregulation of sneezing, nasal rubbing, inflammatory cytokines, inflammatory cells and NLRP3, Caspase-1, ASC, IL-1β and IL-18 expression in MCC950 treated mice compared with untreated AR mice. In spleen mononuclear cells culture and stimulation experiment, NLRP3, Caspase-1, ASC, IL-1β and IL-18 levels were upregulated by OVA but inhibited by MCC950. In conclusion, MCC950 could effectively exert its ameliorative effect in murine AR by inhibiting NLRP3 and leads to reduction of Caspase-1, ASC, IL-1β and IL-18, resulting in the attenuation of the allergic and inflammatory responses.

Reversal of Epithelial-Mesenchymal Transition by Natural Anti-Inflammatory and Pro-Resolving Lipids

Epithelial mesenchymal transition (EMT) is a key process in the progression of malignant cancer. Therefore, blocking the EMT can be a critical fast track for the development of anticancer drugs. In this paper, we update recent research output of EMT and we explore suppression of EMT by natural anti-inflammatory compounds and pro-resolving lipids.

Docosahexaenoyl ethanolamide mitigates IgE-mediated allergic reactions by inhibiting mast cell degranulation and regulating allergy-related immune cells

Docosahexaenoic acid (DHA) is a long-chain polyunsaturated fatty acid mainly found in fish oil. Although several studies have suggested that it can alleviate allergy symptoms, its mechanism of action remains to be elucidated. In the present study, we found that docosahexaenoyl ethanolamide (DHEA), a metabolite of DHA produced in the human body, exerts the anti-allergic activity in vitro and in vivo. DHEA suppressed degranulation of rat basophilic leukemia RBL-2H3 cells and bone marrow-derived mast cells in a dose-dependent manner without cytotoxicity. This occurred due to a decrease in Ca²⁺ influx, which is critical for mast cell degranulation. DHEA also suppressed IgE-mediated passive cutaneous anaphylaxis reaction in mice. In addition, DHEA was demonstrated to lessen an allergic symptom in a mouse model of pollinosis and to alter the production of IgE and cytokines secreted by splenocytes collected from the pollinosis mice. Taken together, this study indicates that DHEA is a promising anti-allergic agent as it inhibits mast cell degranulation and modulates other immune cells.