Anti-inflammatory effect of curcumin on mast cell-mediated allergic responses in ovalbumin-induced allergic rhinitis mouse

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.

Nasal instillation of povidone-iodine ameliorates ongoing mucosal inflammation in a pre-sensitized murine model of Der p1-induced allergic rhinitis

BACKGROUND

Interleukin (IL)-33, when cleaved into smaller fragments by proteases, becomes hyperactive, contributing to allergic inflammation. Povidone-iodine (PVP-I) is an iodine-based compound that exhibits antimicrobial properties and inhibits proteases. This study aimed to investigate whether PVP-I treatment inhibits IL-33 cleavage, improves allergic rhinitis (AR) symptoms, and suppresses allergic inflammation in a mouse model.

METHODS

In vitro experiments using full-length recombinant human IL-33 and allergens, including house dust mites or Dermatophagoides pteronyssinus 1, were conducted using western blotting. Fifty BALB/c mice were divided into five groups: control (CON), AR with phosphate-buffered saline treatment (AR), PVP-I treatment (AR + PVP), trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane (E64) treatment (AR + E64), and dexamethasone treatment (AR + Dexa). Nasal symptom scores, including rubbing and sneezing, were measured. The cytokine levels in the nasal lavage fluid (NLF) and the concentration of immunoglobulins in the blood serum were assessed. Nasal mucosa from each group was used for reverse transcriptase-polymerase chain reaction (RT-PCR) and histological analyses were conducted.

RESULTS

PVP-I treatment reduced nasal symptoms, suppressed allergic inflammation, and decreased the levels of IL-33, IL-5, and IL-13 in the NLF and total immunoglobulin E (IgE) and specific IgE in the serum. Histopathological analysis revealed a reduction in the number of eosinophils and goblet cells in the nasal mucosa of the AR + PVP group when compared to the AR group. RT-PCR and immunofluorescence staining confirmed the downregulation of genes and proteins associated with allergic inflammation.

CONCLUSIONS

These findings suggest that nasal irrigation with PVP-I may be a promising therapeutic option for managing AR by inhibiting IL-33 activation and suppressing allergic inflammation.

Development of fast-dissolving sublingual nanofibers containing allergen and curcumin for immune response modulation in a mouse model of allergic rhinitis

Curcumin (CUR) has been considered a potential therapeutic agent for allergic reactions due to its antioxidant and anti-inflammatory activities. Nanofibers have attracted increasing attention in drug delivery. The aim of this study was to investigate the combined therapeutic effects of curcumin and allergen in nanofiber-based treatments in order to increase the effectiveness of sublingual immunotherapy (SLIT) efficacy in a mouse model of allergic rhinitis. Nanofibers containing CUR (1.25% and 2.5%) and ovalbumin 2% (OVA) as an allergen were prepared via electrospinning and characterized. BALB/c mice were sensitized with OVA to the induced allergic rhinitis model. SLIT with free and/or nanofibers was carried out. IL-4, INF-γ, and IgE serum levels were measured using ELISA. Splenocyte proliferation was evaluated by the MTT assay. Lung and nasal histological examinations and nasal lavage fluid (NALF) cell counting were carried out. Nanofibers containing 1.25% CUR and 2% OVA were chosen as the optimal formulations. SLIT treatment with the CUR and OVA nanofiber co-administration led to a significantly decreased serum IgE. Nanofiber containing 2.5 µg of CUR/mouse combined with OVA nanofiber showed a significant decrease in IL-4 and an increase in IFN-γ compared to other groups. NALF assessment showed a significant decrease in specific cell and eosinophil counts in the treated nanofiber groups. The histopathological results of NAL in the optimal formulations were near normal, with diminished cellular infiltration and inflammation. Our findings suggest that co-sublingual administration of allergen and CUR nanofibers can be considered as potential immunomodulatory agents.

Advances in Nanocarrier Systems for Overcoming Formulation Challenges of Curcumin: Current Insights

Curcumin, an organic phenolic molecule that is extracted from the rhizomes of Curcuma longa Linn, has undergone extensive evaluation for its diverse biological activities in both animals and humans. Despite its favorable characteristics, curcumin encounters various formulation challenges and stability issues that can be effectively addressed through the application of nanotechnology. Nano-based techniques specifically focused on enhancing solubility, bioavailability, and therapeutic efficacy while mitigating toxicity, have been explored for curcumin. This review systematically presents information on the improvement of curcumin's beneficial properties when incorporated, either individually or in conjunction with other drugs, into diverse nanosystems such as liposomes, nanoemulsions, polymeric micelles, dendrimers, polymeric nanoparticles, solid-lipid nanoparticles, and nanostructured lipid carriers. Additionally, the review examines ongoing clinical trials and recently granted patents, offering a thorough overview of the dynamic landscape in curcumin delivery. Researchers are currently exploring nanocarriers with crucial features such as surface modification, substantial loading capacity, biodegradability, compatibility, and autonomous targeting specificity and selectivity. Nevertheless, the utilization of nanocarriers for curcumin delivery is still in its initial phases, with regulatory approval pending and persistent safety concerns surrounding their use.

Effects of Dietary Components on Mast Cells: Possible Use as Nutraceuticals for Allergies?

Allergic diseases affect an estimated 30 percent of the world's population. Mast cells (MC) are the key effector cells of allergic reactions by releasing pro-inflammatory mediators such as histamine, lipid mediators, and cytokines/chemokines. Components of the daily diet, including certain fatty acids, amino acids, and vitamins, as well as secondary plant components, may have effects on MC and thus may be of interest as nutraceuticals for the prevention and treatment of allergies. This review summarizes the anti-inflammatory effects of dietary components on MC, including the signaling pathways involved, in in vitro and in vivo models. Butyrate, calcitriol, kaempferol, quercetin, luteolin, resveratrol, curcumin, and cinnamon extract were the most effective in suppressing the release of preformed and de novo synthesized mediators from MC or in animal models. In randomized controlled trials (RCT), vitamin D, quercetin, O-methylated epigallocatechin gallate (EGCG), resveratrol, curcumin, and cinnamon extract improved symptoms of allergic rhinitis (AR) and reduced the number of inflammatory cells in patients. However, strategies to overcome the poor bioavailability of these nutrients are an important part of current research.

Curcumin suppressed the proliferation and apoptosis of HPV-positive cervical cancer cells by directly targeting the E6 protein

Most human papillomavirus (HPV) types, including HPV16 and HPV18, are closely related to the occurrence of cervical cancer, predominantly through the action of viral oncoproteins E6 and E7. Curcumin, the active ingredient of the turmeric plant, has been gaining attention over the past two decades as an antioxidant, anti-inflammatory, and anticancer agent. In the present study, the HPV-positive cervical cancer cells HeLa and CaSki were treated with curcumin, and the results showed that curcumin has a dose-dependent and time-dependent inhibitory effect on cell viability. In addition, apoptosis induction was further quantitatively confirmed through flow cytometric analysis. Furthermore, the influence of different concentrations of curcumin on the mitochondrial membrane potential was evaluated through JC-1 staining and found to dramatically decrease the membrane potential in treated HeLa and CaSki cells, suggesting the critical role of the mitochondrial pathway in their apoptosis-inducing effect. This study also demonstrated the wound-healing potential of curcumin, and the results of transwell assays showed that curcumin treatment inhibited HeLa and CaSki cell invasion and migration in a dose-dependent manner compared with the control treatment. Curcumin also downregulated the expression of Bcl-2, N-cadherin, and Vimentin and upregulated the expression of Bax, C-caspase-3, and E-cadherin in both cell lines. Further research showed that curcumin also selectively inhibited the expression of the viral oncoproteins E6 and E7, as demonstrated by western blot analysis; moreover, the downregulation of E6 was more significant than that of E7. Our research also showed that coculture with cells infected with siE6 lentivirus (siE6 cells) can inhibit the proliferation, invasion, and metastasis of HPV-positive cells. While the siE6 cells were also treated with curcumin, the effect of curcumin monotherapy was offset. In summary, our research shows that curcumin regulates the apoptosis, migration, and invasion of cervical cancer cells, and the mechanism may be related to its ability to downregulate E6. This study provides a foundation for future research on the prevention and treatment of cervical cancer.

Effects of Highly Bioavailable Curcumin Supplementation on Common Cold Symptoms and Immune and Inflammatory Functions in Healthy Japanese Subjects: A Randomized Controlled Study

This study aimed to investigate the effects of 12-week consumption of highly bioavailable curcumin (150 mg/day of Theracurmin Super [TS-P1] or Theracurmin [CR-033P]) on common cold symptoms, immune function, and inflammatory markers. A randomized, double-blind, placebo-controlled study was conducted from November 2021 to May 2022 on 99 healthy Japanese adults. Using a computerized random number generator, each subject was randomly assigned to one of the following three groups: TS-P1, CR-033P, or placebo (n = 33 per group). For 12 weeks, each group consumed the four capsules that were given to them daily. The cumulative number of days for which common cold symptoms persisted was set as the primary outcome. Immunity parameters, inflammatory parameters, liver function parameters, and physical examination results were additional outcomes. A safety assessment was also performed. Ninety-four subjects completed the study, and the per protocol set included 30 subjects in the placebo group, 32 subjects in the TS-P1 group, and 33 subjects in the CR-033P group. The cumulative number of days for which common cold symptoms persisted was significantly lower in the TS-P1 and CR-033P groups than that in the placebo group. No adverse effects were observed. Consumption of highly bioavailable curcumin, TS-P1 or CR-033P (150 mg/day), for 12 weeks reduced the number of days for which common cold symptoms persisted in healthy Japanese adults.

Plant-derived compounds for treating autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD), the most common monogenic hereditary kidney disease, is the fourth leading cause of end-stage kidney disease worldwide. In recent years, significant progress has been made in delaying ADPKD progression with different kinds of chemical drugs, such as tolvaptan, rapamycin, and somatostatin. Meanwhile, numerous plant-derived compounds have been investigated for their beneficial effects on slowing ADPKD progression. Among them, saikosaponin-d, Ganoderma triterpenes, curcumin, ginkgolide B, steviol, resveratrol, Sparganum stoloniferum Buch.-Ham, Cordyceps sinensis, triptolide, quercitrin, naringin, cardamonin, gambogic acid, and olive leaf extract have been found to retard renal cyst development by inhibiting cell proliferation or promoting cell apoptosis in renal cyst-lining epithelial cells. Metformin, a synthesized compound derived from French lilac or goat's rue (Galega officinalis), has been proven to retard the progression of ADPKD. This review focuses on the roles and mechanisms of plant-derived compounds in treating ADPKD, which may constitute promising new therapeutics in the future.

Identification of Potential Targets and Mechanisms of Sinomenine in Allergic Rhinitis Treatment Based on Network Pharmacology and Molecular Docking

This study aimed to investigate the potential targets and molecular mechanism of sinomenine in treating allergic rhinitis (AR) using network pharmacology and molecular docking. Relevant targets of sinomenine and AR were obtained from public databases, and differentially expressed genes (DEGs) for AR were identified in the Gene Expression Omnibus database. Using VennDiagram, we identified 22 potential targets of sinomenine against AR by crossing disease targets, drug targets, and DEGs. Functional analysis revealed that sinomenine may act via its anti-inflammatory and immunosuppressive effects, and its action pathways may include the MAPK, HIF-1, and JAK-STAT pathways. Furthermore, hub targets were identified using EPC, MCC, and MNC algorithms, and six hub targets (STAT3, EGFR, NFKB1, HIF1A, PTGS2, and JAK1) were selected by integrating the top 10 hub genes and 22 potential targets. Molecular docking analysis indicated that STAT3, EGFR, PTGS2, and JAK1 may be key targets of sinomenine against AR. Overall, our results suggest that sinomenine has potential therapeutic effects against AR, and its mechanism of action may involve the regulation of key targets and pathways related to inflammation and immunity.

Inhibitory Effect of Bisdemethoxycurcumin on DNCB-Induced Atopic Dermatitis in Mice

Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Bisdemethoxycurcumin (BDMC) is an ingredient from the rhizome of the traditional Chinese herbal medicine turmeric. BDMC has been reported to have important pharmacological properties, such as anti-inflammatory, antioxidant, antitumor and antiproliferative activities. However, its effect on atopic dermatitis has not been reported. The purpose of our study was to demonstrate the effectiveness of BDMC on TNF-α/IFNγ-stimulated HaCaT cells and on 2,4-dinitrochlorobenzene (DNCB)-induced AD mice. Our studies showed in vitro that BDMC was able to significantly inhibit the mRNA expression of chemokines and cytokines in TNF-α/IFN-γ-stimulated HaCaT cells and alleviate their inflammatory response. Our studies found in vivo that BDMC was able to significantly improve the symptoms of DNCB-induced AD skin lesions, decrease the number of scratches, ear thickness, and spleen index, improve inflammatory cells and mast cell infiltration and decrease skin thickness. Moreover, it was also able to inhibit the mRNA expression levels of chemokines and inflammatory cytokines and the activation of the MAPK and NF-κB signaling pathways. Thus, the results indicated that BDMC can improve atopic dermatitis in mice and that further clinical studies are warranted on its treatment of AD.

Curcumin does not significantly affect immediate skin tests

Background: Curcumin has been shown to decrease allergic symptoms and biomarkers in some animal and human studies. Objective: Our study aimed to determine if curcumin affects immediate skin-prick testing. Methods: We enrolled 34 participants sensitized to select antigens. The participants were randomized to treatment with curcumin or placebo in a double-blind fashion. The participants underwent titrated skin-prick testing before and after 1 week of treatment, and the pre- and posttreatment skin test wheals and flares were compared. Results: Curcumin did not have a statistically significant effect on immediate skin-prick test wheal or flare size. Conclusion: Although curcumin may attenuate allergic symptoms and biomarkers, it does not have a significant effect on immediate skin-prick test results and does not need to be discontinued before testing.

Therapeutic potency of curcumin for allergic diseases: A focus on immunomodulatory actions

In light of increasing research evidence on the molecular mechanisms of allergic diseases, the crucial roles of innate and acquired immunity in the disease's pathogenesis have been well highlighted. In this respect, much attention has been paid to the modulation of unregulated and unabated inflammatory responses aiming to suppress pathologic immune responses in treating allergic diseases. One of the most important natural compounds with a high potency of immune modulation is curcumin, an active polyphenol compound derived from turmeric, Curcuma longa L. Curcumin's immunomodulatory action mainly arises from its interactions with an extensive collection of immune cells such as mast cells, eosinophils, epithelial cells, basophils, neutrophils, and lymphocytes. Up to now, there has been no detailed investigation of curcumin's immunomodulatory actions in allergic diseases. So, the present review study aims to prepare an overview of the immunomodulatory effects of curcumin on the pathologic innate immune responses and dysregulated functions of T helper (T_H) subtypes, including T_H1, T_H2, T_H17, and regulator T cells (Tregs) by gathering evidence from several studies of In-vitro and In-vivo. As the second aim of the present review, we also discuss some novel strategies to overcome the limitation of curcumin in clinical use. Finally, this review also assesses the therapeutic potential of curcumin regarding its immunomodulatory actions in allergic diseases.

Antiallergic Effects of N,N-dicoumaroylspermidine Isolated from Lithospermum erythrorhizon on Mast Cells and Ovalbumin-Induced Allergic Rhinitis

In East Asia, the dried root of Lithospermum erythrorhizon has been utilized as an anti-inflammatory, antipyretic, detoxifying, and anti-inflammatory agent. Recently, we reported that L. erythrorhizon protects against allergic rhinitis; however, the component within L. erythrorhizon that exerts antiallergic activity remains unknown. The purpose of the current study was to isolate and characterize the antiallergic active components in an ethanolic extract of L. erythrorhizon roots. We examined the antiallergic effects of L. erythrorhizon reflux ethanol extracts in an ovalbumin (OVA)-induced allergic rhinitis mouse model, and compared the chemical compounds extracted using the hot reflux and cold extraction methods. Chromatographic separation identified two novel anthraquinones, erythrin A and B, one newly discovered compound from the Lithospermum genus, N1″,N3″-dicoumaroylspermidine, and nineteen other recognized compounds. Their chemical structures were elucidated by single (1D) and 2D analysis of nuclear magnetic resonance (NMR) spectroscopic data, as well as high resolution mass spectrometry. Among the identified compounds, N,N′-dicoumaroylspermidine strongly inhibited the release of β-hexosaminidase, as well as the production of IL-3, IL-4, and IL-13 by IgE-sensitized and BSA-stimulated RBL-2H3 cells. Using the OVA-induced allergic rhinitis mouse model, we showed that N,N′-dicoumaroylspermidine reduced the production of serum OVA-specific IgE and the number of inflammatory cells in nasal lavage fluid. N,N′-dicoumaroylspermidine isolated from L. erythrorhizon exhibits antiallergic properties, making it potentially effective for allergic rhinitis.

Roots of Lithospermum erythrorhizon Alleviated Ovalbumin-Induced Allergic Rhinitis and IgE-triggered Degranulation of RBL-2H3 Cells

Lithospermum erythrorhizon (L. erythrorhizon) root is used in traditional medicine for its anti-inflammatory, antibacterial, and antioxidant properties. However, no studies have examined its impact on allergic rhinitis (AR). Here, we explored the protective effects of L. erythrorhizon in immunoglobulin E (IgE)-stimulated RBL-2H3 cells and in an ovalbumin (OVA)-induced AR mouse model. In the latter, we examined nasal mucosal inflammation, allergen-specific cytokine production, and histological changes to the nasal mucosa. In the mouse model, oral administration of an ethanol extract of L. erythrorhizon (LE) led to a marked reduction in rubbing and sneeze frequency, a significant decrease in serum OVA-specific IgE and IgG1 levels, and a significant increase in the IgG2a/IgG1 ratio. LE also reduced expression of interleukin (IL)-4, IL-5, and IL-13 in nasal lavage fluid (NALF), and suppressed inflammatory cell infiltration and epithelial degradation in nasal tissues. In IgE-stimulated RBL-2H3 cells, LE suppressed release of degranulation markers such as β-hexosaminidase and histamine. Based on these findings, we suggest that LE may ameliorate OVA-induced AR by regulating mast cell-mediated inflammatory responses.

Curcuma longa and curcumin affect respiratory and allergic disorders, experimental and clinical evidence: A comprehensive and updated review

Curcuma longa and its constituents, mainly curcumin, showed various of pharmacological effects in previous studies. This review article provides updated and comprehensive experimental and clinical evidence regarding the effects of C. longa and curcumin on respiratory, allergic, and immunologic disorders. Using appropriate keywords, databases including PubMed, Science Direct, and Scopus were searched until the end of October 2021. C. longa extracts and its constituent, curcumin, showed the relaxant effect on tracheal smooth muscle, which indicates their bronchodilatory effect in obstructive pulmonary diseases. The preventive effects of extracts of C. longa and curcumin were shown in experimental animal models of different respiratory diseases through antioxidant, immunomodulatory, and anti-inflammatory mechanisms. C. longa and curcumin also showed preventive effects on some lung disorders in the clinical studies. It was shown that the effects of C. longa on pulmonary diseases were mainly due to its constituent, curcumin. Pharmacological effects of C. longa extracts and curcumin on respiratory, allergic, and immunologic disorders indicate the possible therapeutic effect of the plant and curcumin on these diseases.

Bisdemethoxycurcumin attenuates OVA‑induced food allergy by inhibiting the MAPK and NF‑κB signaling pathways

Bisdemethoxycurcumin (BDMC) is an important ingredient derived from turmeric in addition to curcumin. It has been reported that BDMC can be used to treat mast cell-mediated allergic diseases. In the present study, a food allergy (FA) murine model sensitized by intraperitoneal injection followed by oral challenge with ovalbumin (OVA) was established. BDMC was orally administered at 100 and 200 mg/kg for 11 days in the challenge phase to treat OVA-induced FA mice. FA symptoms such as diarrhea score, anaphylactic symptom score and rectal temperature were recorded. Intestinal tissue was also observed by hematoxylin and eosin staining. In addition, other allergic indicators were also analyzed by ELISA and western blot analysis. The present study demonstrated that BDMC could suppress the decreases in rectal temperature, diarrhea and anaphylactic symptoms in FA mice. BDMC could also ameliorate the inflammation of intestinal tissues in FA mice. BDMC not only decreased the production of OVA-specific immunoglobulin (OVA-sIg)E, IgG1, histamine, mouse mast cell protease-1, diamine oxidase, cytokines (IL-4, IL-5 and IL-13) but increased cytokines interferon-γ production. The protein expression results showed that the levels of Gata-3 were decreased but T-bet levels were increased. Furthermore, compared with the OVA group, phosphorylated (p)-p38, p-JNK, p-ERK and p-NF-κBp65 levels were decreased and p-IκBα level was increased. In conclusion, the results showed that BDMC possessed a protective effect on FA. Furthermore, BDMC was able to regulate the T-helper cells (Th)1/Th2 immune balance and inhibit the activation of MAPK and NF-κB pathways in FA mice.

Current Advancements of Plant-Derived Agents for Triple-Negative Breast Cancer Therapy through Deregulating Cancer Cell Functions and Reprogramming Tumor Microenvironment

Triple-negative breast cancer (TNBC) is defined based on the absence of estrogen, progesterone, and human epidermal growth factor receptor 2 receptors. Currently, chemotherapy is the major therapeutic approach for TNBC patients; however, poor prognosis after a standard chemotherapy regimen is still commonplace due to drug resistance. Abnormal tumor metabolism and infiltrated immune or stromal cells in the tumor microenvironment (TME) may orchestrate mammary tumor growth and metastasis or give rise to new subsets of cancer cells resistant to drug treatment. The immunosuppressive mechanisms established in the TME make cancer cell clones invulnerable to immune recognition and killing, and turn immune cells into tumor-supporting cells, hence allowing cancer growth and dissemination. Phytochemicals with the potential to change the tumor metabolism or reprogram the TME may provide opportunities to suppress cancer metastasis and/or overcome chemoresistance. Furthermore, phytochemical intervention that reprograms the TME away from favoring immunoevasion and instead towards immunosurveillance may prevent TNBC metastasis and help improve the efficacy of combination therapies as phyto-adjuvants to combat drug-resistant TNBC. In this review, we summarize current findings on selected bioactive plant-derived natural products in preclinical mouse models and/or clinical trials with focus on their immunomodulatory mechanisms in the TME and their roles in regulating tumor metabolism for TNBC prevention or therapy.

Ajwain oil attenuates allergic response of ovalbumin-induced allergic rhinitis via alteration of inflammatory, oxidative stress, and Th1/Th2 responses

BACKGROUND

Allergic rhinitis (AR) is an immune inflammatory-related disorder that affects the nasal mucosa. Free radicals play a crucial role in the expansion of allergic reaction and the researcher used the antioxidant therapy to treat the disease. Trachyspermum ammi L. (Ajwain oil) is popular traditional medicine. It has been proved their potential effect on various diseases. Ajwain oil showed anti-tumor, antioxidant, antidiabetic, anti-inflammatory, and anti-bacterial properties. Yet, the anti-allergic effect of Ajwain oil is still not explored. In this experimental study, an ovalbumin (OVX)-induced AR model was used to scrutinize the anti-allergic, antioxidant and anti-inflammatory effects of Ajwain oil.

MATERIALS AND METHODS

OVX was used to establish the AR model (sensitization days 1, 8, and 15) and given the oral treatment of Ajwain oil and Montelukast for 13 days. The spleen, lungs, and body weight were estimated. Sneezing, nasal discharge and rubbing are also estimated. Immunoglobin-E (IgE), histamine, malondialdehyde (MDA), superoxide dismutase (SOD), heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and inflammatory cytokines were scrutinized.

RESULTS

Ajwain oil significantly (p < .001) suppressed sneezing, nasal discharge and nasal rubbing along with increasing the spleen, lung and body weight. Ajwain oil significantly (p < .001) decreased the level of IgE, histamine, MDA, Nrf2, HO-1, and increased the level of SOD. Ajwain oil significantly (p < .001) suppressed the number of eosinophils, neutrophils, macrophages, and epithelial cells. Ajwain oil significantly prevented the activation of the NF-κBp65 and STAT3 signaling pathways that led to enhancing the synthesis of anti-inflammatory cytokines and reducing the inflammatory, allergen-specific type 2T helper cells (Th2), Th17 cytokines.

CONCLUSION

The obtained data suggests that Ajwain oil has a promising anti-allergic against allergic rhinitis in mice via anti-allergic, antioxidant, and anti-inflammatory effects.

PRACTICAL APPLICATIONS

Allergic rhinitis is a serious life-threatening disease. Inflammatory reaction plays an important role in the expansion of AR diseases. Ajwain oil considerably increased the spleen weight and reduced lung weight. Ajwain oil suppressed the nasal rubbing, sneezing, and nasal discharge. Ajwain oil considerably suppressed the immunoglobin and inflammatory cytokines. The result suggests that Ajwain oil having the potential effect against the allergic rhinitis.

The Complex Interplay between Immunonutrition, Mast Cells, and Histamine Signaling in COVID-19

There is an ongoing need for new therapeutic modalities against SARS-CoV-2 infection. Mast cell histamine has been implicated in the pathophysiology of COVID-19 as a regulator of proinflammatory, fibrotic, and thrombogenic processes. Consequently, mast cell histamine and its receptors represent promising pharmacological targets. At the same time, nutritional modulation of immune system function has been proposed and is being investigated for the prevention of COVID-19 or as an adjunctive strategy combined with conventional therapy. Several studies indicate that several immunonutrients can regulate mast cell activity to reduce the de novo synthesis and/or release of histamine and other mediators that are considered to mediate, at least in part, the complex pathophysiology present in COVID-19. This review summarizes the effects on mast cell histamine of common immunonutrients that have been investigated for use in COVID-19.

Ten-eleven translocation 2 modulates allergic inflammation by 5-hydroxymethylcytosine remodeling of immunologic pathways

Allergic rhinitis (AR) is an allergen specific IgE-mediated inflammatory disease. Both genetic and environmental factors could play a role in the pathophysiology of AR. 5-methylcytosine (5-mC) can be converted to 5-hydroxymethylcytosine (5hmC) by the Ten-Eleven Translocation (TET) family of proteins as part of active DNA de-methylation pathway. 5hmC plays an important role in regulation of gene expression and differentiation in immune cells. Here we show that loss of ten-eleven translocation protein 2 (Tet2) could impact the severity of AR in the ovalbumin-induced mouse model. Genome-wide 5hmC profiling of both wildtype and Tet2 KO mice in response to AR revealed that the loss of Tet2 could lead to 5hmC alteration at specific immune response genes. Both partial loss and complete loss of Tet2 alters the 5hmC dynamic remodeling for the adaptive immune pathway, as well as cytokines. Thus, our results reveal a new role of Tet2 in immunology, and Tet2 may serve as a promising target in regulating the level of immune response.

Turmeric and its bioactive constituents trigger cell signaling mechanisms that protect against diabetes and cardiovascular diseases

Turmeric, the rhizome of Curcuma longa plant belonging to the ginger family Zingiberaceae, has a history in Ayurvedic and traditional Chinese medicine for treatment of chronic diseases, including metabolic and cardiovascular diseases (CVD). This parallels a prevalence of age- and lifestyle-related diseases, especially CVD and type 2 diabetes (T2D), and associated mortality which has occurred in recent decades. While the chemical composition of turmeric is complex, curcuminoids and essential oils are known as two major groups that display bioactive properties. Curcumin, the most predominant curcuminoid, can modulate several cell signaling pathways involved in the etiology and pathogenesis of CVD, T2D, and related morbidities. Lesser bioactivities have been reported from other curcuminoids and essential oils. This review examines the chemical compositions of turmeric, and related bioactive constituents. A focus was placed on the cellular and molecular mechanisms that underlie the protective effects of turmeric and turmeric-derived compounds against diabetes and CVD, compiled from the findings obtained with cell-based and animal models. Evidence from clinical trials is also presented to identify potential preventative and therapeutic efficacies. Clinical studies with longer intervention durations and specific endpoints for assessing health outcomes are warranted in order to fully evaluate the long-term protective efficacy of turmeric.

Polyphenols Modulating Effects of PD-L1/PD-1 Checkpoint and EMT-Mediated PD-L1 Overexpression in Breast Cancer

Investigating dietary polyphenolic compounds as antitumor agents are rising due to the growing evidence of the close association between immunity and cancer. Cancer cells elude immune surveillance for enhancing their progression and metastasis utilizing various mechanisms. These mechanisms include the upregulation of programmed death-ligand 1 (PD-L1) expression and Epithelial-to-Mesenchymal Transition (EMT) cell phenotype activation. In addition to its role in stimulating normal embryonic development, EMT has been identified as a critical driver in various aspects of cancer pathology, including carcinogenesis, metastasis, and drug resistance. Furthermore, EMT conversion to another phenotype, Mesenchymal-to-Epithelial Transition (MET), is crucial in developing cancer metastasis. A central mechanism in the upregulation of PD-L1 expression in various cancer types is EMT signaling activation. In breast cancer (BC) cells, the upregulated level of PD-L1 has become a critical target in cancer therapy. Various signal transduction pathways are involved in EMT-mediated PD-L1 checkpoint overexpression. Three main groups are considered potential targets in EMT development; the effectors (E-cadherin and Vimentin), the regulators (Zeb, Twist, and Snail), and the inducers that include members of the transforming growth factor-beta (TGF-β). Meanwhile, the correlation between consuming flavonoid-rich food and the lower risk of cancers has been demonstrated. In BC, polyphenols were found to downregulate PD-L1 expression. This review highlights the effects of polyphenols on the EMT process by inhibiting mesenchymal proteins and upregulating the epithelial phenotype. This multifunctional mechanism could hold promises in the prevention and treating breast cancer.

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.

Luteolin ameliorates inflammation and Th1/Th2 imbalance via regulating the TLR4/NF-κB pathway in allergic rhinitis rats

OBJECTIVE

Luteolin has an anti-allergic effect but its mechanism is not clear. This study attempted to determine the mechanisms of luteolin in rhinitis.

METHODS

Allergic rhinitis rat model was established by ovalbumin (OVA) stimulation. Then, the rats were treated with normal saline, luteolin, or lipopolysaccharide (LPS) for 14 days. Nasal symptoms were scored; the histopathological changes of nasal mucosa were detected by hematoxylin-eosin staining. Serum levels of Th1 type cytokines (IFN-γ, IL-2), Th2 type cytokines (IL-4, IL-5, IL-13), and OVA-specific IgE (sIgE) were determined by ELISA. The expressions of Toll-like receptor 4 (TLR4) and p65 in nasal mucosa were detected by Western blot or immunohistochemistry.

RESULTS

Luteolin decreased symptom scores, specifically, the scores in control group, model group, model + 0.1 mg/kg luteolin, model + 1 mg/kg luteolin, and model + 10 mg/kg luteolin groups were 0.63 ± 0.52, 7.88 ± 0.83, 1.38 ± 0.52, 2.75 ± 0.46, and 5.00 ± 0.53, respectively. Luteolin ameliorated nasal mucosa inflammation by promoting the down-regulated levels of Th1 type cytokines, and suppressing the up-regulated levels of Th2 type cytokines, OVE-sIgE, TLR4, and p65. LPS further increased symptom scores, aggravated nasal mucosa inflammation, improved the unbalance of Th1/Th2 type cytokines, and lowered the expressions of OVE-sIgE, TLR4, and p65. Moreover, LPS reversed the effect of luteolin on allergic rhinitis rats.

CONCLUSION

Luteolin ameliorated inflammation and Th1/Th2 imbalance via regulating the TLR4/NF-κB pathway in allergic rhinitis rats. This study provided novel evidence that luteolin could be used as a candidate drug in allergic rhinitis treatment.

MicroRNA-29 mediates anti-inflammatory effects and alleviation of allergic responses and symptoms in mice with allergic rhinitis

BACKGROUND

To investigate the role of microRNA-29 (miR-29) in mice with allergic rhinitis (AR) and its underlying mechanism.

METHODS

AR model was established in BALB/c mice by intraperitoneal sensitization and intranasal challenge with ovalbumin (OVA). miRNA expression was examined in the nasal mucosa tissues of mice and patients with AR, and miRNA-29 was found to be downregulated. To unveil the role of miRNA-29 in AR, it was overexpressed in the nasal mucosa of AR mice by intranasal administration of miRNA-29 agomir. The symptoms of nasal rubbing and sneezing were recorded and evaluated. miR-29 expression, OVA-specific immunoglobulin E (IgE) concentration, pro-inflammatory cytokines levels, eosinophils number, and cleaved caspase-3 and CD276 expression were examined in nasal mucosa tissues and nasal lavage fluid (NALF) by qRT-PCR, ELISA, hematoxylin and eosin staining, western blotting, or immunohistochemistry, respectively. TUNEL assay was used to analyze nasal mucosa cells apoptosis.

RESULTS

Decreased expression of miR-29 was observed in AR, the symptoms of which were alleviated by overexpressing miR-29. In addition, overexpression of miR-29 markedly reduced the concentration of OVA-specific IgE, the levels of IL-4, IL-6, IL-10, and IFN-γ, the pathological alterations and eosinophils infiltration in the nasal mucosa. Furthermore, restoration of miR-29 expression reduced nasal mucosa cell apoptosis. Moreover, overexpression of miR-29 significantly attenuated CD276 mRNA and protein levels in nasal mucosa cells.

CONCLUSION

MiR-29 mediated antiallergic effects in OVA-induced AR mice by decreasing inflammatory response, probably through targeting CD276. MiRNA-29 may serve as a potential novel therapeutic target for the treatment of AR.

Combined effects of photobiomodulation and curcumin on mast cells and wound strength in wound healing of streptozotocin-induced diabetes in rats

We investigated the probable involvement of mast cell degranulation and their numbers in the remodeling step of wound healing in a diabetic ischemic skin wound model treated with photobiomodulation plus curcumin. A total of 108 adult male Wistar rats were randomized into one healthy control and five diabetic groups. Type I diabetes was inflicted in 90 of the 108 rats. After 1 month, an excisional wound was generated in each of the 108 rats. There were one healthy group (group 1) and five diabetic groups as follows: group 2 was the untreated diabetic control group and group 3 rats were treated with sesame oil. Rats in group 4 were treated with photobiomodulation (890 nm, 890 ± 10 nm, 80 Hz, 0.2 J/cm2) and those in group 5 received curcumin dissolved in sesame oil. Group 6 rats were treated with photobiomodulation and curcumin. We conducted stereological and tensiometric tests on days 4, 7, and 15 after treatment. The results indicated that photobiomodulation significantly improved wound strength in the diabetic rats and significantly decreased the total numbers of mast cells. The diabetic control group had significantly reduced tensiometric properties of the healing wounds and a significant increase in the total numbers of mast cells. Photobiomodulation significantly improved the healing process in diabetic animals and significantly decreased the total number of mast cells. The increased numbers of mast cells in the diabetic control group negatively affected tensiometric properties of the ischemic skin wound.

A reduced graphene oxide-β-cyclodextrin nanocomposite-based electrode for electrochemical detection of curcumin

In this study, a sensitive electrochemical sensor was fabricated based on a beta-cyclodextrin–reduced graphene oxide (β-CD–rGO) nanocomposite for measuring curcumin concentration.

The regulatory role of SFRP5/WNT5A axis in allergic rhinitis through inhibiting JNK pathway activation and lowering mucin generation in human nasal epithelial cells

Allergic rhinitis (AR) is tightly associated with type 2 inflammation. SFRP5 combined with WNT5A mainly inhibits chronic inflammatory response, atherosclerosis, and other metabolic disorders. However, the effect of SFRP5/WNT5A axis on recombinant human interleukin-13 (rhIL-13)-induced inflammation has not been studied. In this study, we aimed to investigate whether secreted frizzled-related protein 5 (SFRP5) could modulate the production of cytokines relevant to eosinophil infiltration and mucin secretion through blocking the activation of Wnt family 5A (WNT5A) signaling pathway. A mouse model of AR demonstrated low expression of SFRP5 and high expression of WNT5A, and indicated that the number of eosinophil and goblet cells was increased, concomitant with elevated IL-13, colony stimulating factor 2 (CSF2), chemokine ligand 11 (CCL11), Mucin 4, and Mucin 5AC levels. Furthermore, lentivirus-SFRP5 overexpression up-regulated the expression of SFRP5 but down-regulated WNT5A level, and inhibited the activation of JNK pathway via decreasing p-JNK1/2 (Thr183/Tyr185) and p-c-Jun (Ser73) protein expressions in rhIL-13-treated human nasal epithelial cells (HNEpCs). Noticeably, SFRP5 overexpression markedly reduced rhIL-13-induced inflammatory protein and mucin generation through lowered CSF2, CCL11, Mucin 4, as well as Mucin 5AC levels. Taken together, these findings confirmed the regulatory role of SFRP5/WNT5A axis in rhIL-13-mediated inflammatory response in HNEpCs.

Chlorogenic Acid Potentiates the Anti-Inflammatory Activity of Curcumin in LPS-Stimulated THP-1 Cells

The anti-inflammatory effects of curcumin are well documented. However, the bioavailability of curcumin is a major barrier to its biological efficacy. Low-dose combination of complimentary bioactives appears to be an attractive strategy for limiting barriers to efficacy of bioactive compounds. In this study, the anti-inflammatory potential of curcumin in combination with chlorogenic acid (CGA), was investigated using human THP-1 macrophages stimulated with lipopolysaccharide (LPS). Curcumin alone suppressed TNF-α production in a dose-dependent manner with a decrease in cell viability at higher doses. Although treatment with CGA alone had no effect on TNF-α production, it however enhanced cell viability and co-administration with curcumin at a 1:1 ratio caused a synergistic reduction in TNF-α production with no impact on cell viability. Furthermore, an qRT-PCR analysis of NF-κB pathway components and inflammatory biomarkers indicated that CGA alone was not effective in reducing the mRNA expression of any of the tested inflammatory marker genes, except TLR-4. However, co-administration of CGA with curcumin, potentiated the anti-inflammatory effects of curcumin. Curcumin and CGA together reduced the mRNA expression of pro-inflammatory cytokines [TNF-α (~88%) and IL-6 (~99%)], and COX-2 (~92%), possibly by suppression of NF-κB (~78%), IκB-β-kinase (~60%) and TLR-4 receptor (~72%) at the mRNA level. Overall, co-administration with CGA improved the inflammation-lowering effects of curcumin in THP-1 cells.

CCR3-shRNA promotes apoptosis and inhibits chemotaxis and degranulation of mouse mast cells

Mast cells (MCs) are the major effector cells of allergic rhinitis (AR). The present study aimed to investigate the effects of C-C chemokine receptor type 3 (CCR3) on the proliferation, apoptosis, chemotaxis and activated degranulation of mouse MCs. Mouse bone marrow-derived MCs were cultured in vitro, purified and identified using toluidine blue staining and flow cytometry. Three different CCR3-short hairpin (shRNA) lentiviral vectors were constructed and transfected into MCs, and the mRNA and protein expression levels of CCR3 were assessed by reverse transcription-quantitative PCR and western blotting. Proliferation and apoptosis of the MCs were measured using Cell Counting kit-8 (CCK-8) assays and flow cytometry, respectively. MC chemotaxis was assessed by Transwell assay and quantified using flow cytometry. The activation of MC degranulation was examined using ELISAs. The results demonstrated that MCs were appropriately isolated, and identified that CCR3-shRNA2 presented the higher knockdown effect among the three shRNAs tested. Following 96 h of transfection, the results of CCK-8 and flow cytometry assays demonstrated that CCR3-shRNA2 inhibited MC proliferation and promoted MC apoptosis. The results from the Transwell assay indicated that CCR3-shRNA2 restrained MC chemotaxis, whereas ELISA results demonstrated that CCR3-shRNA2 suppressed MC degranulation. In conclusion, CCR3-shRNA2 effectively downregulated CCR3 mRNA and protein expression levels in mouse MCs. In addition, CCR3-shRNA2 promoted MC apoptosis and suppressed the proliferation, chemotaxis and degranulation of mouse MCs, suggesting that CCR3-shRNA2 may serve as a therapeutic tool for the treatment of allergic rhinitis.

MicroRNA-345-5p acts as an anti-inflammatory regulator in experimental allergic rhinitis via the TLR4/NF-κB pathway

Allergic rhinitis (AR) is a common chronic condition characterized by inflammation of the nasal mucosa. The correlation of microRNAs (miRNAs) in AR has been highlighted particularly due to their roles in regulating inflammatory responses. The aim of this study was to explore the anti-inflammatory mechanism by which miR-345-5p regulates the toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) pathway in mice with AR. Initially, the putative miR-345-5p binding sites on the 3'untranslated region of TLR4 was predicted and verified. AR models were established using ovalbumin, after which the functional role of miR-345-5p in AR was determined using gain- and loss-of-function approaches. We found that miR-345-5p was poorly expressed in nasal mucosal tissues of mice with AR. Meanwhile, TLR4 expression and the TLR4/NF-κB pathway were identified to be promoted, which were then suppressed in the presence of overexpressed miR-345-5p. In addition, nasal epithelial cell apoptosis and fibrosis were inhibited in response to miR-345-5p overexpression and TLR4 silencing. Furthermore, miR-345-5p overexpression and TLR4 silencing were observed to decrease Th2 cells, expression of pro-inflammatory factors, but to increase Th1 cells and expression of anti-inflammatory factors. This study demonstrates an important role of miR-345-5p in alleviating the inflammatory response in mice with AR by inhibiting the TLR4/NF-κB pathway. Therefore, a better understanding of this process may aid in the development of novel therapeutic agents of AR.

Immune responses modulation by curcumin and allergen encapsulated into PLGA nanoparticles in mice model of rhinitis allergic through sublingual immunotherapy

The purpose of this study was the combination of curcumin and ovalbumin in free form or encapsulated into PLGA NPs (polylactic co-glycolic acid nanoparticles) to enhance their sublingual immunotherapy (SLIT) efficiency in mouse model of rhinitis allergic. PLGA NPs containing curcumin (CUR), ovalbumin (OVA) or both were prepared by emulsion-solvent evaporation method and characterized. After sensitization of BALB/C mice with ovalbumin, SLIT with free or encapsulated formulations was carried out and immunological profiles were evaluated. SLIT treatment with all synthesized PLGA formulations lead to significantly decreased total IgE. The combination immunotherapy in the present of free form of curcumin or ovalbumin with encapsulated forms of the another substance (P.OVA-CUR 10 and P.CUR 5-OVA), showed the highest level of IFN-γ:IL-4 compared to other target groups. On the other hands, a significant increasment was observed in this ratio between these optimal groups and treated group with subcutaneous administration of OVA as the most commonly used method for immunotherapy. The study of nasal lavage fluid (NALF) showed significant decreased levels of total and eosinophil cell count in the traeted nano-formulation groups. The histopathological results of NAL were also like normal with no cellular infiltration and no inflammation in the optimal formulations. Therefore, using curcumin and nanoparticles with allergen can be considerd as potential immune modulatory agents.

Activation of the Nrf2/HO-1 pathway by curcumin inhibits oxidative stress in human nasal fibroblasts exposed to urban particulate matter

BACKGROUND

Particulate matter (PM) can cause various negative acute and chronic diseases of the respiratory system, including the upper airways. Curcumin has been reported to have anti-inflammatory and anti-oxidative effects; therefore, we investigated the effects of curcumin on nasal fibroblasts exposed to urban PM (UPM).

METHODS

Samples of inferior turbinate tissue were obtained from six patients. Flow cytometry was used to assess the levels of reactive oxygen species (ROS) following the treatment of nasal fibroblasts with UPM and/or curcumin. We evaluated the effects of UPM and/or curcumin on the expression of phosphorylated ERK, Nrf2, HO-1, and SOD2 in fibroblasts by Western blotting.

RESULTS

When UPM was applied to nasal fibroblasts, ROS production was significantly increased in a dose-dependent manner. UPM-exposed fibroblasts caused the activation of ERK to increase HO-1 expression and decrease SOD2 expression. Treatment with curcumin reduced the UPM-mediated increase in ROS; this decrease in ROS occurred in a dose-dependent manner. The UPM-induced activation of ERK was inhibited by curcumin. Nrf2 production was also promoted to increase the expression of HO-1 and SOD2 by curcumin.

CONCLUSION

Curcumin reduced ROS production caused by UPM in human nasal fibroblasts in a dose-dependent manner, suggesting that curcumin has anti-oxidative effects and may be useful in the treatment of nasal diseases caused by UPM, such as allergic and chronic rhinitis.

Potential of phytochemicals as immune-regulatory compounds in atopic diseases: A review

Atopic diseases (atopic dermatitis, asthma and allergic rhinitis) affects a huge number of people around the world and their incidence rate is on rise. Atopic dermatitis (AD) is more prevalent in paediatric population which sensitizes an individual to develop allergic rhinitis and asthma later in life. The complex pathogenesis of these allergic diseases though involves numerous cellular signalling pathways but redox imbalance has been reported to be critical for induction/perpetuation of inflammatory process under such conditions. The realm of complementary and alternative medicine has gained greater attention because of the reported anti-oxidant/anti-inflammatory properties. Several case studies of treating atopic diseases with homeopathic remedies have provided positive results. Likewise, pre-clinical studies suggest that various natural compounds suppress allergic response via exhibiting their anti-oxidant potential. Despite the reported beneficial effects of phytochemicals in experimental model system, the clinical success has not been documented so far. It appears that poor absorption and bioavailability of natural compounds may be one of the reasons for realizing their full potential. The current paper throws light on impact of phytochemicals in the redox linked cellular and signalling pathways that may be critical in manifestation of atopic diseases. Further, an effort has been made to identify the gaps in the area so that future strategies could be evolved to exploit the medicinal value of various phytochemicals for an improved efficiency.

Effect of neuromedin U on allergic airway inflammation in an asthma model

Asthma is a major inflammatory airway disease with high incidence and mortality rates. The Global Initiative for Asthma released a report called ‘The Global Burden of Asthma’ in 2004. However, the specific pathogenesis of asthma remains unclear. An increasing number of studies have demonstrated that neuromedin U (NMU) plays a pleiotropic role in the pathogenesis of asthma. NMU is a highly structurally conserved neuropeptide that was first purified from porcine spinal cord and named for its contractile effect on the rat uterus. NMU amplifies type 2 innate lymphoid cell (ILC2)-driven allergic lung inflammation. The NMU receptors (NMURs), designated as NMUR1 and NMUR2, belong to the G protein-coupled receptor family. NMUR1 has also been found in immune cells, including ILC2s, mast cells and eosinophils. In view of the important roles of NMU in the pathogenesis of asthma, the present review evaluates the potential mechanisms underlying the impact of NMU on asthma and its association with asthma therapy.

Curcuminoids: Implication for inflammation and oxidative stress in cardiovascular diseases

It has been extensively verified that inflammation and oxidative stress play important roles in the pathogenesis of cardiovascular diseases (CVDs). Curcuminoids, from the plant Curcuma longa, have three major active ingredients, which include curcumin (curcumin I), demethoxycurcumin, and bisdemethoxycurcumin. Curcuminoids have been used in traditional medicine for CVDs' management and other comorbidities for centuries. Numerous studies had delineated their anti-inflammatory, antioxidative, and other medicinally relevant properties. Animal experiments and clinical trials have also demonstrated that turmeric and curcuminoids can effectively reduce atherosclerosis, cardiac hypertrophy, hypertension, ischemia/reperfusion injury, and diabetic cardiovascular complications. In this review, we introduce and summarize curcuminoids' molecular and biological significance, while focusing on their mechanistic anti-inflammatory/antioxidative involvements in CVDs and preventive effects against CVDs, and, finally, discuss relevant clinical applications.

Cellular and molecular mechanisms of curcumin in prevention and treatment of disease

Curcumin is a naturally occurring polyphenolic compound present in rhizome of Curcuma longa belonging to the family zingiberaceae. Growing experimental evidence revealed that curcumin exhibit multitarget biological implications signifying its crucial role in health and disease. The current review highlights the recent progress and mechanisms underlying the wide range of pharmacological effects of curcumin against numerous diseases like neuronal, cardiovascular, metabolic, kidney, endocrine, skin, respiratory, infectious, gastrointestinal diseases and cancer. The ability of curcumin to modulate the functions of multiple signal transductions are linked with attenuation of acute and chronic diseases. Numerous preclinical and clinical studies have revealed that curcumin modulates several molecules in cell signal transduction pathway including PI3K, Akt, mTOR, ERK5, AP-1, TGF-β, Wnt, β-catenin, Shh, PAK1, Rac1, STAT3, PPARγ, EBPα, NLRP3 inflammasome, p38MAPK, Nrf2, Notch-1, AMPK, TLR-4 and MyD-88. Curcumin has a potential to prevent and/or manage various diseases due to its anti-inflammatory, anti-oxidant and anti-apoptotic properties with an excellent safety profile. In contrast, the anti-cancer effects of curcumin are reflected due to induction of growth arrest and apoptosis in various premalignant and malignant cells. This review also carefully emphasized the pharmacokinetics of curcumin and its interaction with other drugs. Clinical studies have shown that curcumin is safe at the doses of 12 g/day but exhibits poor systemic bioavailability. The use of adjuvant like piperine, liposomal curcumin, curcumin nanoparticles and curcumin phospholipid complex has shown enhanced bioavailability and therapeutic potential. Further studies are warranted to prove the potential of curcumin against various ailments.

Effects of Boswellia Serrata Roxb. and Curcuma longa L. in an In Vitro Intestinal Inflammation Model Using Immune Cells and Caco-2

Inflammatory bowel diseases, which consist of chronic inflammatory conditions of the colon and the small intestine, are considered a global disease of our modern society. Recently, the interest toward the use of herbal therapies for the management of inflammatory bowel diseases has increased because of their effectiveness and favourable safety profile, compared to conventional drugs. Boswellia serrata Roxb. and Curcuma longa L. are amongst the most promising herbal drugs, however, their clinical use in inflammatory bowel diseases is limited and little is known on their mechanism of action. The aim of this work was to investigate the effects of two phytochemically characterized extracts of B. serrata and C. longa in an in vitro model of intestinal inflammation. Their impact on cytokine release and reactive oxygen species production, as well as the maintenance of the intestinal barrier function and on intestinal mucosa immune cells infiltration, has been evaluated. The extracts showed a good protective effect on the intestinal epithelium at 1 µg/mL, with TEER values increasing by approximately 1.5 fold, compared to LPS-stimulated cells. C. longa showed an anti-inflammatory mechanism of action, reducing IL-8, TNF-α and IL-6 production by approximately 30%, 25% and 40%, respectively, compared to the inflammatory stimuli. B. serrata action was linked to its antioxidant effect, with ROS production being reduced by 25%, compared to H₂O₂-stimulated Caco-2 cells. C. longa and B. serrata resulted to be promising agents for the management of inflammatory bowel diseases by modulating in vitro parameters which have been identified in the clinical conditions.

Inhibitory effects of bisdemethoxycurcumin on mast cell-mediated allergic diseases

Most allergic reactions are induced by mast cell activation. Mast cells play vital roles in the pathogenesis of allergic diseases. Bisdemethoxycurcumin (BDMC), a natural curcuminoid, has potential anti-allergic effects. Hence, we explored the effect of BDMC on mast cell-mediated allergic diseases. The study proved that BDMC suppresses β-hexosaminidase release, granule release, and membrane ruffling in monoclonal anti-2,4,6-dinitrophenyl-immunoglobulin (Ig) E/human serum albumin (DNP-IgE/HSA)-stimulated rat basophilic leukaemia cells (RBL-2H3 cells), and BDMC suppressed ovalbumin (OVA)-induced allergic rhinitis (AR) symptoms and OVA-specific IgE levels in AR mice. Furthermore, BDMC increased the survival of compound 48/80 anaphylaxis shock mice and elevated the decreased rectal temperature in OVA-induced active systemic anaphylaxis mice. These findings indicate that BDMC regulates the degranulation of mast cells, demonstrating its potential in the treatment of mast cell-induced allergic reactions.

Fungal-Host Interaction: Curcumin Modulates Proteolytic Enzyme Activity of Candida albicans and Inflammatory Host Response In Vitro

Current treatments for Candida albicans infection are limited due to the limited number of antifungal drugs available and the increase in antifungal resistance. Curcumin is used as a spice, food preservative, flavoring, and coloring agent that has been shown to have many pharmacological activities. Thus, this study evaluated the modulatory effects of curcumin on major virulence factors associated with the pathogenicity of C. albicans. The minimum inhibitory concentration (MIC) of curcumin against C. albicans (SC5314) was determined. Biofilm formation was quantified and the proteinase and phospholipase secretion was measured. The cytotoxicity was tested in oral fibroblast cells. A cocultured model was used to analyze the gene expression of proinflammatory cytokines (IL-1β, IL-1α, and IL-6) from host cells, as well SAP-1 and PLB-1 by RT-PCR. The MIC was between 6.25 and 12.5 µM, and the activity of proteinase enzyme was significantly decreased in biofilms treated with curcumin. However, proteinase gene expression was not downregulated after curcumin treatment. Furthermore, gene expressions of host inflammatory response, IL-1β and IL-1α, were significantly downregulated after exposure to curcumin. In conclusion, curcumin exhibited antifungal activity against C. albicans and modulated the proteolytic enzyme activities without downregulating the gene expression. In host inflammatory response, curcumin downregulated IL-1β and IL-1α gene expression.

Paeoniflorin inhibits mast cell-mediated allergic inflammation in allergic rhinitis

Paeoniflorin (PF), one of the main effective ingredients from the root of Paeonia lactiflora Pall., was reported to possess antitumor, anti-inflammatory, and antiallergic properties. However, the roles of PF in activated human mast cell line, HMC-1 cells, have not yet been elucidated. Thus, the aim of this study was to examine the antiallergic and anti-inflammatory effects of PF on phorbol-12-myristate 13-acetate plus calcium ionophore (PMACI)-induced human mast cells and to identify the mechanism responsible for these effects. Our results demonstrated that pretreatment with PF effectively attenuated PMACI-induced production of tumor necrosis factor-α and interleukin 1β in HMC-1 cells. In addition, PF significantly suppressed PMACI-induced histamine release and caspase-1 activation in HMC-1 cells. Furthermore, PF prevented the activation of nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways in activated HMC-1 cells. In conclusion, we showed for the first time that PF attenuated the mast cell-mediated allergic inflammatory response through suppressing the NF-κB and MAPK signaling pathways.

Efficacy of curcumin/turmeric on liver enzymes in patients with non-alcoholic fatty liver disease: A systematic review of randomized controlled trials

Background

Several studies reported that curcumin supplementation could improve non-alcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the efficacy of curcumin/turmeric supplementation on liver enzymes in patients with NAFLD.

Methods

PubMed, Scopus, Web of Science and Google Scholar were systematically searched until December 2017. We included randomized controlled trials (RCTs) which examined effect of curcumin/turmeric supplementation on NAFLD in adult participants. Main outcome was alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Potential risks of bias (ROB) were assessed by using Cochrane ROB tool.

Results

All included studies showed low ROB in most of item of Cochrane ROB tool. Meta-analysis of 4 randomized controlled trials including 228 subjects showed a trend toward significant reduction of ALT blood concentrations in subgroup with ≥1000 mg/day curcumin supplementation (–11.36 IU/L, 95% CI: –22.75 to 0.02; I²:51%). Meta-analysis showed a significant reduction of AST in studies with 8-weeks administration (–9.22 IU/L, 95% CI: –12.77 to –5.67; I²: 49%).

Conclusion

This review suggests that curcumin/turmeric might have a favorable effect on NAFLD in higher dosage. Further high-quality studies with large-scale and higher dosage are warranted.

Effect of artemisinin and neurectomy of pterygoid canal in ovalbumin-induced allergic rhinitis mouse model

Background

Allergic rhinitis (AR), characterized by sneezing, nasal itching and rhinorrhea, affects a large number of population. This study aimed to explore the effects of artemisinin alone or combined with neurectomy of pterygoid canal in ovalbumin-induced AR mouse model and illustrate the underlying mechanisms.

Methods

Allergic symptoms were evaluated to verify inhibitory effect of artemisinin alone or combined with neurectomy of pterygoid canal on AR. Serum levels of histamine, immunoglobulin E (IgE) and inflammatory factors TNF, INF-γ, IL-1β IL-10, IL-4 and IL-5 were measured by ELISA. The mRNA levels of TNF, INF-γ, IL-1β and IL-10 in local lymph nodes were measured by RT-qPCR. The total and phosphorylated levels of ERK and JNK were assessed by Western blot. CD4⁺CD25⁺Foxp3⁺ T (Treg) cells were analyzed by flow cytometry.

Results

Artemisinin significantly relieved the behavior symptoms of AR mice. The administration of artemisinin strikingly suppressed the expression of histamine, IgE and inflammatory factors. An increased Treg cell proportion and inhibited ERK phosphorylation were observed in artemisinin-treated groups as compared to those in the AR group. Moreover, artemisinin plus neurectomy of pterygoid almost abolished the behavioral score increase in AR mice.

Conclusions

These results indicated that artemisinin exhibited anti-allergic effect by inhibiting ERK activation and increasing Treg cell proportion, which subsequently decreased the expressions of allergic mediators. In addition, artemisinin combined with neurectomy of pterygoid showed better efficacy than artemisinin alone.

Electronic supplementary material

The online version of this article (10.1186/s13223-018-0249-6) contains supplementary material, which is available to authorized users.

Curcumin affects tracheal responsiveness and lung pathology in asthmatic rats

BACKGROUND

Curcumin has shown various pharmacological effects such as anti-inflammatory activities. In this study, the effects of curcumin on tracheal responsiveness and lung pathological features were evaluated in a rat model of asthma.

METHODS

Tracheal responsiveness and lung pathological features were evaluated in control rats (C), ovalbumin (OVA)-sensitized rats (as an animal model of asthma; A), A rats treated with curcumin (Cu, 0.15, 0.30, and 0.60 mg/ml) and dexamethasone (D, 1.25 μg/ml), (n = 8 in curcumin-treated groups and n = 6 in other groups). Curcumin and dexamethasone were added to animals' drinking water during the sensitization period.

RESULTS

Asthmatic group showed increased lung pathological score and tracheal responsiveness to methacholine and OVA compared to control group (p < 0.01 to p < 0.001). Pathological features including interstitial inflammation, interstitial fibrosis, bleeding, and emphysema as well as tracheal responsiveness to methacholine and OVA, were significantly decreased in treated groups with dexamethasone and all concentrations of curcumin compared to group A (p < 0.05 to p < 0.001). Epithelial damage was also significantly decreased in treated groups with the two higher concentrations of curcumin (p < 0.05 to p < 0.001).

CONCLUSION

Curcumin showed preventive effects on tracheal responsiveness and lung pathological features in asthmatic rats.

Glycyrrhizin attenuates histamine-mediated MUC5AC upregulation, inflammatory cytokine production, and aquaporin 5 downregulation through suppressing the NF-κB pathway in human nasal epithelial cells

Allergic rhinitis (AR) is a chronic respiratory inflammatory disease. Glycyrrhizin is a main bioactive component of the licorice root extract and exhibits anti-inflammatory activity. However, the role of glycyrrhizin in AR has not been studied. The aim of the present study was to investigate the effect of glycyrrhizin on histamine-induced human nasal epithelial cells (HNEpCs). Here, we found that glycyrrhizin (20 or 40 μM) inhibited histamine-induced the mRNA expression and secretion of mucin 5 subtype AC (MUC5AC), interleukin (IL)-6 and IL-8 in HNEpCs. The expression levels of aquaporin 5 (AQP5) and phosphorylated cyclic adenosine monophosphate-responsive element binding protein (p-CREB) were decreased by histamine in HNEpCs and increased in cells treated with glycyrrhizin. The glycyrrhizin treatment inhibited histamine-induced expressions of p-NF-κB p65 and p-IκBα in HNEpCs, indicating that glycyrrhizin inhibited the activation of NF-κB pathway in histamine-induced HNEpCs. In addition, inhibition of the NF-κB pathway exhibited the similar effect with glycyrrhizin on histamine-induced HNEpCs. In summary, the results showed that glycyrrhizin reversed the effect of histamine on MUC5AC expression, inflammatory cytokine production, and AQP5 expression in HNEpCs, and the NF-κB pathway was involved in the effect. Glycyrrhizin might be used for complementary and alternative therapeutics of AR.