Baicalein induces CD4(+)Foxp3(+) T cells and enhances intestinal barrier function in a mouse model of food allergy

Human milk oligosaccharides 2'-fucosyllactose and 3-fucosyllactose attenuate ovalbumin-induced food allergy through immunoregulation and gut microbiota modulation

The prebiotic properties of human milk oligosaccharides (HMOs) and emerging evidence of immunomodulatory effects suggest their potential therapeutic value in allergy management. 2'-Fucosyllactose (2'-FL) has been reported to alleviate food allergies, while the effect of other fucosylated HMOs on food allergy remains unclear. In this study, we assess the effect of two HMOs, 2'-FL and 3-fucosyllactose (3-FL), on symptomatology and immunological responses in an ovalbumin (OVA)-sensitized mouse model of food allergy as well as their influence on gut microbiota. The assessment of allergic symptoms, specific immunoglobulin E (IgE), and related gene expression levels in sensitized mice indicated that 3-FL was as effective as 2'-FL in alleviating food allergy. 2'-FL and 3-FL significantly decreased serum levels of OVA-specific IgE, mouse mast cell protease (mMCP-1) and IL-4 while increasing the levels of IFN-γ. Additionally, 2'-FL and 3-FL down-regulated gene expression of allergy-related cytokines in the small intestine and improved intestinal barrier damage. Furthermore, both 2'-FL and 3-FL treatment positively influenced the gut microbial profiles, in particular by enhancing the proportion of beneficial bacteria such as Lactobacillus and Bifidobacterium and decreasing the percentage of Turicibacter and Lachnospiraceae NK4A136 group, thereby modulating the immune system. Therefore, this study can provide insights into 2'-FL and 3-FL to alleviate OVA-induced allergy.

The effects of plant flavones on the membrane boundary potential and lipid packing stress

Here we have revealed the effects of different plant flavones on the physicochemical properties of model lipid membranes. We have demonstrated that baicalein increases the boundary potential of membranes composed of phosphatidylcholine, while wogonin does not affect it. Other flavones tested reduce membrane boundary potential, with this ability increasing among scutellarein, chrysin, apigenin, morin, fisetin, and luteolin. Molecular dynamics simulations demonstrate connection of alteration in boundary potential with the preferential orientation of intrinsic flavone dipole moments in membranes. We have also shown that flavones reduce the melting point of phosphatidylcholine, and this ability increases in the series of luteolin, morin, wogonin, scutellarein, apigenin, baicalein, chrysin, and fisetin. The introduction of baicalein, chrysin and fisetin also leads to a significant decrease in the sharpness of the lipid phase transition. We have hypothesized that the localization of flavones in the glycerol backbone or in the C1-C8 methylene region of lipid hydrocarbon chains leads to an increase in the area per lipid and, as a consequence, to an expansion of the lipid melting peak. Replacement of neutral phosphatidylcholine with negatively charged phosphatidylserine affects the membrane-modifying activity of flavones which given the externalization of phosphatidylserine on the surface of cancer cells may be crucial in the flavone anticancer effects.

Sulforaphane-mediated immune regulation through inhibition of NF-kB and MAPK signaling pathways in human dendritic cells

Inflammation and immune responses are intricately intertwined processes crucial for maintaining homeostasis and combating against pathogens. These processes involve complex signaling pathways, notably the Nuclear Factor kappa-light-chain-enhancer of activated B-cells (NF-κB) and Mitogen-Activated Protein Kinase (MAPK) pathways, which play crucial roles. Sulforaphane (SFN), a nutraceutic, has emerged as a potential regulator of NF-κB and MAPK signaling pathways, exhibiting anti-inflammatory properties. However, limited knowledge exists regarding SFN's effects on immune cell modulation. This study aimed to assess the immunomodulatory capacity of SFN pretreatment in human dendritic cells (DCs), followed by exposure to a chronic inflammatory environment induced by lipopolysaccharide. SFN pretreatment was found to inhibit the NF-κB and MAPK signaling pathways, resulting in phenotypic changes in DCs characterized by a slight reduction in the expression of surface markers, as well as a decrease of TNF-α/IL-10 ratio. Additionally, SFN pretreatment enhanced the proliferation of Treg-cells and promoted the production of IL-10 by B-cells before exposure to the chronic inflammatory environment. Furthermore, these changes in DCs were found to be influenced by the inhibition of NF-κB and MAPK pathways (specifically p38 MAPK and JNK), suggesting that these pathways may play a role in the regulation of the differentiation of adaptive immune responses (proliferation of T- and IL-10-producing regulatory-cells), prior to SFN pretreatment. Our findings suggest that SFN pretreatment may induce a regulatory response by inhibiting NF-κB and MAPK signaling pathways in an inflammatory environment. SFN could be considered a promising strategy for utilizing functional foods to protect against inflammation and develop immunoregulatory interventions.

Anti-ROS and NIR-II-Responsive Hyaluronic Acid Microneedle Loaded With Baicalin Nanoparticles for Treatment of Psoriasis

In this work, a natural medicine, baicalin, is designed for the treatment of psoriasis with the aid of hyaluronic acid (HA)-based MNs patches. This is also to improve the solubility of baicalin and increase its residence time in infected part, which is made into nanoparticles by complexation with humic acid and Eu2+. The baicalin nanoparticles loaded-MNs exhibit satisfactory rigidity, minimum injury, and controlled drug delivery. The anti-reactive oxygen species (anti-ROS) and anti-inflammatory action are verified by the effective scavenging oxygen and nitrogen radicals. In addition, the loading of baicalin nanoparticles brings remarkable photothermic effect to the MNs, enabling the device to release a controlled drug under near-infrared region II (NIR-II) laser irradiation. With the aid of NIR-II laser, the baicalin-mediated treatment of psoriasis is significantly improved by expediting radical scavenging and suppressing inflammation. The design of baicalin MNs provides a new idea for the treatment of chronic disease.

Baicalin ameliorates the gut barrier function and intestinal microbiota of broiler chickens

The deoxynivalenol (DON)-contaminated feeds can impair chicken gut barrier function, disturb the balance of the intestinal microbiota, decrease chicken growth performance and cause major economic loss. With the aim of investigating the ameliorating effects of baicalin on broiler intestinal barrier damage and gut microbiota dysbiosis induced by DON, a total of 150 Arbor Acres broilers are used in the present study. The morphological damage to the duodenum, jejunum, and ileum caused by DON is reversed by treatment with different doses of baicalin, and the expression of tight junction proteins (ZO-1, claudin-1, and occludin) is also significantly increased in the baicalin-treated groups. Moreover, the disturbance of the intestinal microbiota caused by DON-contaminated feed is altered by baicalin treatment. In particular, compared with those in the DON group, the relative abundances of Lactobacillus, Lachnoclostridium, Ruminiclostridium and other beneficial microbes in the baicalin-treated groups are significantly greater. However, the percentage of unclassified_f__Lachnospiraceae in the baicalin-treated groups is significantly decreased in the DON group. Overall, the current results demonstrate that different doses of baicalin can improve broiler intestinal barrier function and the ameliorating effects on broiler intestinal barrier damage may be related to modulations of the intestinal microbiota.

Modulation of the Immune Response to Allergies Using Alternative Functional Foods

Modulation of the allergic immune response through alternative therapies is a field of study that aims to address allergic reactions differently from traditional approaches. These therapies encompass the utilization of natural functional foods, which have been observed to exert an influence on the immune response, thus mitigating the severity of allergies. Indeed, some studies suggest that the incorporation of these nutraceuticals can regulate immune function, leading to a reduction in histamine release and subsequent alleviation of allergic symptoms. Moreover, certain herbs and dietary supplements, such as curcumin, are believed to possess anti-inflammatory properties, which may serve to moderate allergic responses. Although the results remain somewhat mixed and require further research, these alternative therapies exhibit the potential to impact the allergic immune response, thereby providing complementary options to conventional treatments. Therefore, in this review, we aim to provide an updated account of functional foods capable of modulating the immune response to allergies. In that sense, the review delves into functional foods sourced from plants (phytochemicals), animals, and marine algae. Emphasis is placed on their potential application in the treatment of allergic disorders. It also provides an overview of how these foods can be effectively utilized as functional foods. Additionally, it explores the molecular mechanisms and scientific validity of various bioactive natural compounds in the management of allergies.

Baicalein, a component of banxia xiexin decoction, alleviates CPT-11-induced gastrointestinal dysfunction by inhibiting ALOX15-mediated ferroptosis

Baicalein, one of the active ingredients of banxia xiexin decoction, has good therapeutic efficacy in treating diarrhea and improving gastrointestinal dysfunction. The role and mechanism of Baicalein on irinotecan (CPT-11)-induced gastrointestinal dysfunction are the focus of this study. Concretely, CPT-11 induced delayed diarrhea rat model and intestinal epithelial cell (IEC)-6 cell injury model with Baicalein treatment as needed. Colonic pathological changes were analyzed by hematoxylin-eosin staining, and inflammatory factor expressions in serum were determined by enzyme-linked immunosorbent assay. Immunohistochemistry and western blot were performed to quantify ferroptosis-related protein expressions. Thiobarbituric acid reactive substances (TBARS) kits and colorimetric assay kit were applied to detect lipid peroxidation levels and Fe2+ content, respectively. In vitro experiments also included quantitative real-time polymerase chain reaction, cell counting kit-8, and C11 BODIPY staining. CPT-11 induced aggravation of intestinal tissue damage, inflammatory factor release, Fe2+ accumulation, upregulation of lipid peroxidation and 15-Lipoxygenase (ALOX15) expression, and downregulation of glutathione peroxidase 4 (Gpx4) and SLC7A11 in vivo in rats; however, Baicalein dose-dependently reversed the effects of CPT-11. Baicalein elevated cell viability, reduced lipid peroxidation and Fe2+ accumulation, and elevated Gpx4 and SLC7A11 levels, whereas ALOX15 overexpression reversed the effects of Baicalein on a CPT-11-induced IEC-6 cell injury model. In conclusion, Baicalein plays a mitigating role in CPT-11-induced delayed diarrhea via ALOX15-mediated ferroptosis.

Dietary Polyphenols-Natural Bioactive Compounds with Potential for Preventing and Treating Some Allergic Conditions

In light of the constantly increasing prevalence of allergic diseases, changes in dietary patterns have been suggested as a plausible environmental explanation for the development and progression of these diseases. Nowadays, much attention has been paid to the development of dietary interventions using natural substances with anti-allergy activities. In this respect, dietary polyphenols have been studied extensively as one of the most prominent natural bioactive compounds with well-documented anti-inflammatory, antioxidant, and immunomodulatory properties. This review aims to discuss the mechanisms underlying the potential anti-allergic actions of polyphenols related to their ability to reduce protein allergenicity, regulate immune response, and gut microbiome modification; however, these issues need to be elucidated in detail. This paper reviews the current evidence from experimental and clinical studies confirming that various polyphenols such as quercetin, curcumin, resveratrol, catechins, and many others could attenuate allergic inflammation, alleviate the symptoms of food allergy, asthma, and allergic rhinitis, and prevent the development of allergic immune response. Conclusively, dietary polyphenols are endowed with great anti-allergic potential and therefore could be used either for preventive approaches or therapeutic interventions in relation to allergic diseases. Limitations in studying and widespread use of polyphenols as well as future research directions are also discussed.

Discovery of novel cGAS inhibitors based on natural flavonoids

Cyclic GMP-AMP synthase (cGAS) plays an important role in the inflammatory response. It has been reported that aberrant activation of cGAS is associated with a variety of immune-mediated inflammatory disorders. The development of small molecule inhibitors of cGAS has been considered as a promising therapeutic strategy for the diseases. Flavonoids, a typical class of natural products, are known for their anti-inflammatory activities. Although cGAS is closely associated with inflammation, the potential effects of natural flavonoid compounds on cGAS have been rarely studied. Therefore, we screened an in-house natural flavonoid library by pyrophosphatase (PPiase) coupling assay and identified novel cGAS inhibitors baicalein and baicalin. Subsequently, crystal structures of the two natural flavonoids in complex with human cGAS were determined, which provide mechanistic insight into the anti-inflammatory activities of baicalein and baicalin at the molecular level. After that, a virtual screening based on the crystal structures of baicalein and baicalin in complex with human cGAS was performed. As a result, compound C20 was identified to inhibit both human and mouse cGAS with IC50 values of 2.28 and 1.44 μM, respectively, and its detailed interactions with human cGAS were further revealed by the X-ray crystal structure determination. These results demonstrate the potential of natural products used as hits in drug discovery and provide valuable hints for further development of cGAS inhibitors.

Flavone and Hydroxyflavones Are Ligands That Bind the Orphan Nuclear Receptor 4A1 (NR4A1)

It was recently reported that the hydroxyflavones quercetin and kaempferol bind the orphan nuclear receptor 4A1 (NR4A1, Nur77) and act as antagonists in cancer cells and tumors, and they inhibit pro-oncogenic NR4A1-regulated genes and pathways. In this study, we investigated the interactions of flavone, six hydroxyflavones, seven dihydroxyflavones, three trihydroxyflavones, two tetrahydroxyflavones, and one pentahydroxyflavone with the ligand-binding domain (LBD) of NR4A1 using direct-binding fluorescence and an isothermal titration calorimetry (ITC) assays. Flavone and the hydroxyflavones bound NR4A1, and their KD values ranged from 0.36 µM for 3,5,7-trihydroxyflavone (galangin) to 45.8 µM for 3'-hydroxyflavone. KD values determined using ITC and KD values for most (15/20) of the hydroxyflavones were decreased compared to those obtained using the fluorescence assay. The results of binding, transactivation and receptor-ligand modeling assays showed that KD values, transactivation data and docking scores for these compounds are highly variable with respect to the number and position of the hydroxyl groups on the flavone backbone structure, suggesting that hydroxyflavones are selective NR4A1 modulators. Nevertheless, the data show that hydroxyflavone-based neutraceuticals are NR4A1 ligands and that some of these compounds can now be repurposed and used to target sub-populations of patients that overexpress NR4A1.

Promising Role of the Scutellaria baicalensis Root Hydroxyflavone-Baicalein in the Prevention and Treatment of Human Diseases

Plant roots, due to a high content of natural antioxidants for many years, have been used in herbal medicine. It has been documented that the extract of Baikal skullcap (Scutellaria baicalensis) has hepatoprotective, calming, antiallergic, and anti-inflammatory properties. Flavonoid compounds found in the extract, including baicalein, have strong antiradical activity, which improves overall health and increases feelings of well-being. Plant-derived bioactive compounds with antioxidant activity have for a long time been used as an alternative source of medicines to treat oxidative stress-related diseases. In this review, we summarized the latest reports on one of the most important aglycones with respect to the pharmacological activity and high content in Baikal skullcap, which is 5,6,7-trihydroxyflavone (baicalein).

Baicalein self-microemulsion based on drug-phospholipid complex for the alleviation of cytokine storm

Cytokine storm is a phenomenon whereby the overreaction of the human immune system leads to the release of inflammatory cytokines, which can lead to multiple organ dysfunction syndrome. At present, the existing drugs for the treatment of cytokine storm have limited efficacy and severe adverse effects. Here, we report a lymphatic targeting self-microemulsifying drug delivery system containing baicalein to effectively inhibit cytokine storm. Baicalein self-microemulsion with phospholipid complex as an intermediate carrier (BAPC-SME) prepared in this study could be spontaneously emulsified to form 12-nm oil-in-water nanoemulsion after administration. And then BAPC-SME underwent uptake by enterocyte through endocytosis mediated by lipid valve and clathrin, and had obvious characteristics of mesenteric lymph node targeting distribution. Oral administration of BAPC-SME could significantly inhibit the increase in plasma levels of 14 cytokines: TNF-α, IL-6, IFN-γ, MCP-1, IL-17A, IL-27, IL-1α, GM-CSF, MIG, IFN-β, IL-12, MIP-3α, IL-23, and RANTES in mice experiencing systemic cytokine storm. BAPC-SME could also significantly improve the pathological injury and inflammatory cell infiltration of lung tissue in mice experiencing local cytokine storm. This study does not only provide a new lymphatic targeted drug delivery strategy for the treatment of cytokine storm but also has great practical significance for the clinical development of baicalein self-microemulsion therapies for cytokine storm.

In Vitro Effect of Flavonoids on Basophils Degranulation and Intestinal Epithelial Barrier Damage Induced by ω-5 Gliadin-Derived Peptide

Flavonoids have antioxidant, anti-inflammatory and immunomodulatory properties, and may alleviate food allergic reactions and intestinal inflammation induced by ω-5 gliadin, a main allergen of wheat food allergy in children. In this study, a human basophil KU812 cell degranulation model and a Caco-2 monolayer cell model were constructed in vitro to evaluate the effects of four flavonoids on the allergenicity of ω-5 gliadin peptides and ω-5 gliadin peptide-induced barrier damage in Caco-2 intestinal epithelial monolayers. The results show that baicalein, luteolin, isorhamnetin and naringenin can significantly inhibit the degranulation of KU812 cells stimulated by ω-5 gliadin-derived peptide P4 and the release of IL-6 and TNF-α. In addition, the four flavonoids significantly inhibited the ω-5 gliadin-derived peptide P4 to induce the release of IL-6, IL-8 in Caco-2 cells, inhibited the release of zonulin, and significantly increase the expression of tight junction proteins Occludin and ZO-1 in the Caco-2 cell monolayer. In conclusion, baicalein, luteolin, isorhamnetin and naringenin inhibit degranulation stimulated by wheat allergen and enhance intestinal barrier functions, which supports the potential pharmaceutical application of the four flavonoids treatment for wheat food allergy.

Remodeling tumor microenvironment with natural products to overcome drug resistance

With cancer incidence rates continuing to increase and occurrence of resistance in drug treatment, there is a pressing demand to find safer and more effective anticancer strategy for cancer patients. Natural products, have the advantage of low toxicity and multiple action targets, are always used in the treatment of cancer prevention in early stage and cancer supplement in late stage. Tumor microenvironment is necessary for cancer cells to survive and progression, and immune activation is a vital means for the tumor microenvironment to eliminate cancer cells. A number of studies have found that various natural products could target and regulate immune cells such as T cells, macrophages, mast cells as well as inflammatory cytokines in the tumor microenvironment. Natural products tuning the tumor microenvironment via various mechanisms to activate the immune response have immeasurable potential for cancer immunotherapy. In this review, it highlights the research findings related to natural products regulating immune responses against cancer, especially reveals the possibility of utilizing natural products to remodel the tumor microenvironment to overcome drug resistance.

Reciprocal Interactions Between Regulatory T Cells and Intestinal Epithelial Cells

It has been well established that Foxp3+ regulatory T cells (Treg cells) play a crucial role for immune repression and tolerance, protecting the body from autoimmunity and inflammation. Previous studies indicate that intestinal Treg cells are one specialized population of Treg cells, distinct from those in other organ compartments, both functionally and phenotypically. Specific external and internal signals, particularly the presence of microbiota, shape these Treg cells to better cooperate with the gut ecosystem, controlling intestinal physiology. The integrity of intestinal epithelial barrier represents a key feature of gut immune tolerance, which can be regulated by multiple factors. Emerging evidence suggests that bidirectional interactions between gut epithelium and resident T cells significantly contribute to intestinal barrier function. Understanding how Treg cells regulate intestinal barrier integrity provides insights into immune tolerance-mediated mucosal homeostasis, which can further illuminate potential therapeutic strategies for treating inflammatory bowel disease and colon cancer.

Baicalein ameliorates ulcerative colitis by improving intestinal epithelial barrier via AhR/IL-22 pathway in ILC3s

Ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract, which is closely related to gut barrier dysfunction. Emerging evidence shows that interleukin-22 (IL-22) derived from group 3 innate lymphoid cells (ILC3s) confers benefits on intestinal barrier, and IL-22 expression is controlled by aryl hydrocarbon receptor (AhR). Previous studies show that baicalein protects the colon from inflammatory damage. In this study we elucidated the molecular mechanisms underlying the protective effect of baicalein on intestinal barrier function in colitis mice. Mice were administered baicalein (10, 20, 40 mg·kg-1·d-1, i.g.) for 10 days; the mice freely drank 3% dextran sulfate sodium (DSS) on D1-D7 to induce colitis. We showed that baicalein administration simultaneously ameliorated gut inflammation, decreased intestinal permeability, restored tight junctions of colons possibly via promoting AhR/IL-22 pathway. Co-administration of AhR antagonist CH223191 (10 mg/kg, i.p.) partially blocked the therapeutic effects of baicalein in colitis mice, whereas AhR agonist FICZ (1 μg, i.p.) ameliorated symptoms and gut barrier function in colitis mice. In a murine lymphocyte line MNK-3, baicalein (5-20 μM) dose-dependently increased the expression of AhR downstream target protein CYP1A1, and enhanced IL-22 production through facilitating AhR nuclear translocation, these effects were greatly diminished in shAhR-MNK3 cells, suggesting that baicalein induced IL-22 production in AhR-dependent manner. To further clarify that, we constructed an in vitro system consisting of MNK-3 and Caco-2 cells, in which MNK-3 cell supernatant treated with baicalein could decrease FITC-dextran permeability and promoted the expression of tight junction proteins ZO-1 and occluding in Caco-2 cells. In conclusion, this study demonstrates that baicalein ameliorates colitis by improving intestinal epithelial barrier via AhR/IL-22 pathway in ILC3s, thus providing a potential therapy for UC.

Amelioration of Ovalbumin-Induced Food Allergy in Mice by Targeted Rectal and Colonic Delivery of Cyanidin-3-O-Glucoside

Targeted rectal and colonic delivery is an effective strategy to exploit the biological functions of polyphenols. This work investigated the anti-food allergy (FA) activity of cyanidin-3-O-glucoside (C3G) delivered by enteric sodium alginate in vivo. The results showed that through targeted rectal and colonic delivery, the C3G showed better results in ameliorating clinical allergic symptoms, diarrhea, and serological indicators including ovalbumin-specific IgE, histamine, and mast cell protease-1. The C3G was more efficient in enhancing the intestinal epithelial barrier by up-regulating the tight junction protein expression and promoting secretory IgA and β-defensin secretion. The improved bioactivity in regulating T helper (Th)1/Th2 immune balance in the intestinal mucosa was also observed. Compared with the intestinal microbiota structure of the model group, targeted rectal and colonic delivery of C3G was able to bring the abundance of Bacteroidota and Firmicutes close to the levels found in normal mice. Furthermore, there was an evident increase in beneficial bacteria in the intestinal flora, such as Lactobacillus and Odoribacter, and a decrease in pathogenic bacteria like Helicobacter and Turicibacter. Therefore, the anti-FA activity of C3G could be increased via targeted rectal and colonic delivery, while the mechanism might be attributed to the regulation of intestinal microecological homeostasis.

Role of the dietary components in food allergy: A comprehensive review

Currently, the increasing incidence of food allergy is considered a major public health and food safety concern. Importantly, food-induced anaphylaxis is an acute, life-threatening, systemic reaction with varied clinical presentations and severity that results from the release of mediators from mast cells and basophils. Many factors are blamed for the increasing incidence of food allergy, including hygiene, microbiota (composition and diversity), inopportune complementary foods (a high-fat diet), and increasing processed food consumption. Studies have shown that different food components, including lipids, sugars, polyphenols, and vitamins, can modify the immunostimulating properties of allergenic proteins and change their bioavailability. Understanding the role of the food components in allergy might improve diagnosis, treatment, and prevention of food allergy. This review considers the role of the dietary components, including lipids, sugars, polyphenols, and vitamins, in the development of food allergy as well as results of mechanistic investigations in in vivo and in vitro models.

An ethnopharmacological review on the therapeutical properties of flavonoids and their mechanisms of actions: A comprehensive review based on up to date knowledge

Flavonoids -a class of low molecular weight secondary metabolites- are ubiquitous and cornucopia throughout the plant kingdom. Structurally, the main structure consists of C6-C3-C6 rings with different substitution patterns so that many sub-classes are obtained, for example: flavonols, flavonolignans, flavonoid glycosides, flavans, anthocyanidins, aurones, anthocyanidins, flavones, neoflavonoids, chalcones, isoflavones, flavones and flavanones. Flavonoids are evaluated to have drug like nature since they possess different therapeutic activities, and can act as cardioprotective, antiviral, antidiabetic, anti-inflammatory, antibacterial, anticancer, and also work against Alzheimer's disease and others. However, information on the relationship between their structure and biological activity is scarce. Therefore, the present review tries to summarize all the therapeutic activities of flavonoids, their mechanisms of action and the structure activity relationship.

•

Latest updated ethnopharmacological review of the therapeutic effects of flavonoids.

•

Flavonoids are attracting attention because of their therapeutic properties.

•

Flavonoids are valuable candidates for drug development against many dangerous diseases.

•

This overview summarizes the most important therapeutic effect and mechanism of action of flavonoids.

•

General knowledge about the structure activity relationship of flavonoids is summarized.

•

Substitution of chemical groups in the structure of flavonoids can significantly change their biological and chemical properties.

•

The chemical properties of the basic flavonoid structure should be considered in a drug-based structural program.

Identifying gene network patterns and associated cellular immune responses in children with or without nut allergy

Background

Although evidence suggests that the immune system plays a key role in the pathophysiology of nut allergy, the precise immunological mechanisms of nut allergy have not been systematically investigated. The aim of the present study was to identify gene network patterns and associated cellular immune responses in children with or without nut allergy.

Methods

Transcriptome profiling of whole blood cells was compared between children with and without nut allergy. Three genes were selected to be validated on a larger cohort of samples (n = 86) by reverse transcription-polymerase chain reactions (RT-qPCR). The composition of immune cells was inferred from the transcriptomic data using the CIBERSORTx algorithm. A co-expression network was constructed employing weighted gene co-expression network analysis (WGCNA) on the top 5000 most variable transcripts. The modules were interrogated with pathway analysis tools (InnateDB) and correlated with clinical phenotypes and cellular immune responses.

Results

Proportions of neutrophils were positively correlated and CD4⁺ T-cells and regulatory T-cells (Tregs) were negatively correlated with modules of nut allergy. We also identified 2 upregulated genes, namely Interferon Induced With Helicase C Domain 1 (IFIH1), DNA damage-regulated autophagy modulator 1 (DRAM1) and a downregulated gene Zinc Finger Protein 512B (ZNF512B) as hub genes for nut allergy. Further pathway analysis showed enrichment of type 1 interferon signalling in nut allergy.

Conclusions

Our findings suggest that upregulation of type 1 interferon signalling and neutrophil responses and downregulation of CD4⁺ T-cells and Tregs are features of the pathogenesis of nut allergy.

Clinical Efficacy of Adjuvant Treatment of Primary Nephrotic Syndrome in Pediatric Patients with Chinese Medicine

OBJECTIVE

Current study aimed to investigate the benefits of adjuvant therapy with traditional Chinese medicine on the pediatric primary nephrotic syndrome.

METHODS

A total of 455 patients with PNS admitted to our hospital from January 2010 to January 2019 were divided into the traditional Chinese medicine group (n = 217) and the control group (n = 238). The control group received conventional Western medical treatment, and the traditional Chinese medicine group was treated with traditional Chinese medicine supplemented with Western medical treatment. The differences in remission rate, recurrence rate, and recurrence-free survival between the two groups were evaluated.

RESULTS

The differences in clinical parameters between the two groups were not statistically significant. Compared with the control group, adjuvant treatment with traditional Chinese medicine increased the clinical remission rate (p=0.037), decreased the relapse rate (p=0.015), prolonged relapse-free survival (p ≤ 0.01), and was an independent protective factor for relapse-free survival in children with PNS (HR = 0.55, 95% CI 0.49-0.63, p ≤ 0.01). In a subgroup analysis of the traditional Chinese medicine formulations, Yuebi Jiazhu Tang, Ganlu Xiaodu Dan, and Yupingfeng granules significantly reduced the risk of recurrence in children (p ≤ 0.01, p ≤ 0.01, p=0.003).

CONCLUSION

Adjuvant treatment of pediatric primary nephrotic syndrome with traditional Chinese medicine could benefit the children.

Analysis of the active components and mechanism of Shufeng Jiedu capsule against COVID-19 based on network pharmacology and molecular docking

This study investigates the active components and mechanism of Shufeng Jiedu Capsules (SFJDC) against novel coronavirus through network pharmacology and molecular docking.The TCMSP, TCMID, and BATMAN-TCM databases were used to retrieve the components of SFJDC. The active components were screened by ADME (absorption, distribution, metabolism, and excretion) parameters, and identified by Pubchem, Chemical Book, and ChemDraw softwares. The molecular docking ligands were constructed. SARS Coronavirus-2 Major Protease (SARS-CoV-2-Mpro) and angiotension converting enzyme 2 (ACE2) were used as molecular docking receptors. AutoDock software was used for molecular docking. Cytoscape 3.7.1 software was used to generate an herbs-active components-targets network. Gene Ontology gene function and Kyoto Encyclopedia of Genes and Genomes signal pathway analysis were performed by DAVID data.A total of 1244 components were identified from SFJDC, and 210 active components were obtained. Among them, 97 active components were used as docking ligands to dock with SARS-CoV-2-Mpro and ACE2. There were 48 components with good binding activity to SARS-CoV-2-Mpro. Ten active components (including 7-Acetoxy-2-methylisoflavone, Kaempferol, Quercetin, Baicalein, Glabrene, Glucobrassicin, Isoglycyrol, Wogonin, Petunidin, and Luteolin) combined with SARS-CoV-2-Mpro and ACE2 simultaneously. Among them, Kaempferol, Wogonin, and Baicalein showed higher binding activity. The herbs-active components-targets network contained 7 herbs, 10 active components, and 225 targets. The 225 target targets were involved in 653 biological processes of Gene Ontology analysis and 130 signal pathways (false discovery rate ≤ 0.01) of Kyoto Encyclopedia of Genes and Genomes analysis.The active components of SFJDC (such as Kaempferol, Wogonin, and Baicalein) may combine with ACE2 and act on multiple signaling pathways and targets to exert therapeutic effect on novel coronavirus.

An overview of pharmacological activities of baicalin and its aglycone baicalein: New insights into molecular mechanisms and signaling pathways

The flavonoids, baicalin, and its aglycone baicalein possess multi-fold therapeutic properties and are mainly found in the roots of Oroxylum indicum (L.) Kurz and Scutellaria baicalensis Georgi. These flavonoids have been reported to possess various pharmacological properties, including antibacterial, antiviral, anticancer, anticonvulsant, anti-oxidant, hepatoprotective, and neuroprotective effects. The pharmacological properties of baicalin and baicalein are due to their abilities to scavenge reactive oxygen species (ROS) and interaction with various signaling molecules associated with apoptosis, inflammation, autophagy, cell cycle, mitochondrial dynamics, and cytoprotection. In this review, we summarized the molecular mechanisms underlying the chemopreventive and chemotherapeutic applications of baicalin and baicalein in the treatment of cancer and inflammatory diseases. In addition, the preventive effects of baicalin and baicalein on mitochondrial dynamics and functions were highlighted with a particular emphasis on their anti-oxidative and cytoprotective properties. The current review highlights could be useful for future prospective studies to further improve the pharmacological applications of baicalein and baicalin. These studies should define the threshold for optimal drug exposure, dose optimization and focus on therapeutic drug monitoring, objective disease markers, and baicalin/baicalein drug levels.

Effect of Lactiplantibacillus plantarum HM-22 on immunoregulation and intestinal microbiota in α-lactalbumin-induced allergic mice

Milk protein is one of the eight major allergens, and α-lactalbumin (α-LA) is one of the major allergens of bovine milk protein. Our previous studies found that Lactiplantibacillus plantarum HM-22 (L. plantarum HM-22) showed a good gastrointestinal survival rate and intestinal colonization. To investigate the effect of L. plantarum HM-22 on intestinal inflammation and intestinal microbiota in α-LA-induced allergic mice, in this study, L. plantarum HM-22 at low and high doses was intragastrically administered to α-LA-induced allergic mice for 5 weeks. The results showed that L. plantarum HM-22 significantly relieved the weight loss and organ index of α-LA-induced allergic mice (p < 0.05). L. plantarum HM-22 increased the levels of interleukin-10 (IL-10), interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) in the serum of α-LA-induced allergic mice and decreased the levels of total immunoglobulin E (IgE) and the proinflammatory factor interleukin-4 (IL-4) (p < 0.05). The crypt structure of the colon tissues of α-LA-induced allergic mice changed, goblet cells decreased, and the phenomenon of a large number of inflammatory corpuscles that appeared was improved and alleviated with the intervention of L. plantarum HM-22 by hematoxylin-eosin (HE) staining. Western blot analysis showed that L. plantarum HM-22 significantly increased the expression of occludin and claudin-1 in the colon of α-LA-induced allergic mice and decreased the expression of the inflammatory proteins p65 and IκBα (p < 0.05). The intestinal microbiota of mice in each group was determined by 16S rRNA amplicon sequencing, and the results showed that intervention with L. plantarum HM-22 improved the intestinal microbes of α-LA-induced allergic mice. Spearman's correlation analysis revealed the correlation between intestinal microbiota changes and the α-LA-induced allergy-related index. This study provides a theoretical basis for probiotics to prevent allergies by changing the intestinal microbiota.

Caloric restriction alleviates radiation injuries in a sex-dependent fashion

Safe and effective regimens are still needed given the risk of radiation toxicity from iatrogenic irradiation. The gut microbiota plays an important role in radiation damage. Diet has emerged as a key determinant of the intestinal microbiome signature and function. In this report, we investigated whether a 30% caloric restriction (CR) diet may ameliorate radiation enteritis and hematopoietic toxicity. Experimental mice were either fed ad libitum (AL) or subjected to CR preconditioning for 10 days and then exposed to total body irradiation (TBI) or total abdominal irradiation (TAI). Gross examinations showed that short-term CR pretreatment restored hematogenic organs and improved the intestinal architecture in both male and female mice. Intriguingly, CR preconditioning mitigated radiation-induced systemic and enteric inflammation in female mice, while gut barrier function improved in irradiated males. 16S rRNA high-throughput sequencing showed that the frequency of pro-inflammatory microbes, including Helicobacter and Desulfovibrionaceae, was reduced in female mice after 10 days of CR preconditioning, while an enrichment of short-chain fatty acid (SCFA)-producing bacteria, such as Faecalibaculum, Clostridiales, and Lactobacillus, was observed in males. Using fecal microbiota transplantation (FMT) or antibiotic administration to alter the gut microbiota counteracted the short-term CR-elicited radiation tolerance of both male and female mice, further indicating that the radioprotection of a 30% CR diet depends on altering the gut microbiota. Together, our findings provide new insights into CR in clinical applications and indicate that a short-term CR diet prior to radiation modulates sex-specific gut microbiota configurations, protecting male and female mice against the side effects caused by radiation challenge.

Baicalein, Baicalin, and Wogonin: Protective Effects against Ischemia-Induced Neurodegeneration in the Brain and Retina

Ischemia is a common pathological condition present in many neurodegenerative diseases, including ischemic stroke, retinal vascular occlusion, diabetic retinopathy, and glaucoma, threatening the sight and lives of millions of people globally. Ischemia can trigger excessive oxidative stress, inflammation, and vascular dysfunction, leading to the disruption of tissue homeostasis and, ultimately, cell death. Current therapies are very limited and have a narrow time window for effective treatment. Thus, there is an urgent need to develop more effective therapeutic options for ischemia-induced neural injuries. With emerging reports on the pharmacological properties of natural flavonoids, these compounds present potent antioxidative, anti-inflammatory, and antiapoptotic agents for the treatment of ischemic insults. Three major active flavonoids, baicalein, baicalin, and wogonin, have been extracted from Scutellaria baicalensis Georgi (S. baicalensis); all of which are reported to have low cytotoxicity. They have been demonstrated to exert promising pharmacological capabilities in preventing cell and tissue damage. This review focuses on the therapeutic potentials of these flavonoids against ischemia-induced neurotoxicity and damage in the brain and retina. The bioactivity and bioavailability of baicalein, baicalin, and wogonin are also discussed. It is with hope that the therapeutic potential of these flavonoids can be utilized and developed as natural treatments for ischemia-induced injuries of the central nervous system (CNS).

Oral Mucosa as a Potential Site for Diagnosis and Treatment of Allergic and Autoimmune Diseases

Most prevalent food allergies during early childhood are caused by foods with a high allergenic protein content, such as milk, egg, nuts, or fish. In older subjects, some respiratory allergies progressively lead to food-induced allergic reactions, which can be severe, such as urticaria or asthma. Oral mucosa remodeling has been recently proven to be a feature of severe allergic phenotypes and autoimmune diseases. This remodeling process includes epithelial barrier disruption and the release of inflammatory signals. Although little is known about the immune processes taking place in the oral mucosa, there are a few reports describing the oral mucosa-associated immune system. In this review, we will provide an overview of the recent knowledge about the role of the oral mucosa in food-induced allergic reactions, as well as in severe respiratory allergies or food-induced autoimmune diseases, such as celiac disease.

Edible and Herbal Plants for the Prevention and Management of COVID-19

Background: The outbreak of the pandemic coronavirus disease 2019 (COVID-19) has now become a global pandemic spreading throughout the world. Unfortunately, due to the high infectiousness of the novel β-coronavirus, it is very likely to become an ordinary epidemic. The development of dietary supplements and functional foods might provide a strategy for the prevention and management of COVID-19.

Scope and Approach: A great diversity of potential edible and medicinal plants and/or natural compounds showed potential benefits in managing SARS, which may also combat COVID-19. Moreover, many plants and compounds have currently been proposed to be protective against COVID-19. This information is based on data-driven approaches and computational chemical biology techniques. In this study, we review promising candidates of edible and medicinal plants for the prevention and management of COVID-19. We primarily focus on analyzing their underlying mechanisms. We aim to identify dietary supplements and functional foods that assist in managing this epidemic.

Key findings and Conclusion: We infer that acetoside, glyasperin, isorhamnetin, and several flavonoid compounds may prevent and/or be effective in managing COVID-19 by targeting the viral infection, reducing the host cytokine storm, regulating the immune response, and providing organ protection. These bioactive dietary components (used either alone or in combination) might assist in the development of dietary supplements or functional foods for managing COVID-19.

Xiao-Yin-Fang Therapy Alleviates Psoriasis-like Skin Inflammation Through Suppressing γδT17 Cell Polarization

Psoriasis is an immune-mediated chronic inflammatory skin disease primarily mediated by the activation of interleukin (IL)-17-producing T cells. Traditional Chinese Medicine (TCM) represents one of the most effective complementary and alternative medicine (CAM) agents for psoriasis, which provides treasured sources for the development of anti-psoriasis medications. Xiao-Yin-Fang (XYF) is an empirically developed TCM formula that has been used to treat psoriasis patients in Shanghai Changhai Hospital for over three decades. Imiquimod (IMQ)-induced psoriasis-like dermatitis mouse model was utilized to investigate the therapeutic effects of XYF by the assessment of disease severity and skin thickness. Flow cytometric assay was performed to explore the influence of XYF on skin-related immunocytes, primarily T cells. And, RNA sequencing analysis was employed to determine the alternation in gene expression upon XYF therapy. We discovered that XYF alleviated psoriasis-like skin inflammation mainly through suppressing dermal and draining lymph-node IL-17-producing γδT (γδT17) cell polarization. Moreover, XYF therapy ameliorated the relapse of psoriasis-like dermatitis and prohibited dermal γδT cell reactivation. Transcriptional analysis suggested that XYF might regulate various inflammatory signaling pathways and metabolic processes. In conclusion, our results clarified the therapeutic efficacy and inner mechanism of XYF therapy in psoriasis, which might promote its clinical application in psoriasis patients and facilitate the development of novel anti-psoriasis drugs based on the bioactive components of XYF.

The Use of Chinese Skullcap (Scutellaria baicalensis) and Its Extracts for Sustainable Animal Production

Simple Summary

With the increasing pressure to address the problems of bacterial resistance and drug residues, medicinal herbs are gradually taking a more important role in animal production. Scutellaria baicalensis is a common and widely used Chinese medicinal herb. The main bioactive compounds in the plant are baicalein and baicalin. These compounds have many biological functions including anti-oxidation, antipyretic, analgesic, anti-inflammatory, antiallergic, antimicrobial, immunomodulatory, and antitumor effects. S. baicalensis and its extracts can effectively promote animal growth, improve the production performance of dairy cows, reduce the stress and inflammatory response, and have effective therapeutic effects on diseases caused by bacteria, viruses, and other pathogenic microorganisms. This paper summarizes the biological function of S. baicalensis and its application in sustainable animal production to provide a reference for future application of S. baicalensis and other medicinal herbs in animal production and disease treatment.

Abstract

Drugs have been widely adopted in animal production. However, drug residues and bacterial resistance are a worldwide issue, and thus the most important organizations (FAO, USDA, EU, and EFSA) have limited or banned the use of some drugs and the use of antibiotics as growth promoters. Natural products such as medicinal herbs are unlikely to cause bacterial resistance and have no chemical residues. With these advantages, medicinal herbs have long been used to treat animal diseases and improve animal performance. In recent years, there has been an increasing interest in the study of medicinal herbs. S. baicalensis is a herb with a high medicinal value. The main active compounds are baicalin and baicalein. They may act as antipyretic, analgesic, anti-inflammatory, antiallergenic, antimicrobial, and antitumor agents. They also possess characteristics of being safe, purely natural, and not prone to drug resistance. S. baicalensis and its extracts can effectively promote the production performance of livestock and treat many animal diseases, such as mastitis. In this review, we summarize the active compounds, biological functions, and applications of S. baicalensis in the production of livestock and provide a guideline for the application of natural medicines in the production and treatment of diseases.

l-Arabinose Attenuates Gliadin-Induced Food Allergy via Regulation of Th1/Th2 Balance and Upregulation of Regulatory T Cells in Mice

Gliadins are the main cause of wheat allergies, and the prevalence of gliadin allergy has increased in many countries. l-Arabinose, a kind of plant-specific five-carbon aldose, possesses beneficial effects on food allergy to gliadins. This study investigated the antiallergic activities and underlying mechanisms of l-arabinose in a wheat gliadin-sensitized mouse model. BALB/c mice were sensitized to gliadin by intraperitoneal injections with gliadin followed by being given a gliadin challenge. l-arabinose-treated mice exhibited a marked reduction in the productions of total immunoglobulin E (IgE), gliadin-specific IgE, gliadin-specific IgG1, and histamine, with an increase in IgG2a level as compared with gliadin-sensitized mice. Beside that, a significant decrease in Th2-related cytokine level, IL-4, and an increase in Th1-related cytokine level, IFN-γ, in the serum and splenocytes were observed after treatment with l-arabinose. l-Arabinose treatment also improved the imbalance of Th1/Th2 immune response on the basis of the expression levels of related cytokines and key transcription factors in the small intestine and spleen of sensitized mice. In addition, gliadin-induced intestinal barrier impairment was blocked by l-arabinose treatment via regulation of TJ proteins and suppression of p38 MAPK and p65 NF-κB inflammation signaling pathways. Notably, the results confirmed that l-arabinose treatment increased CD4⁺ Foxp3⁺ T cell populations and Treg-related factors associated with increased expression of IL-2 and activation of STAT5 in gliadin-sensitized mice. In conclusion, l-arabinose attenuated the gliadin-induced allergic symptoms via maintenance of Th1/Th2 immune balance and regulation of Treg cells in a gliadin-induced mouse model, suggesting l-arabinose could be used as a promising agent to alleviate gliadin allergy.

Piper nigrum extract attenuates food allergy by decreasing Th2 cell response and regulating the Th17/Treg balance

Piper nigrum is extensively utilized because of its antioxidation, antiallergic, antitumor, antiinflammatory, antidiarrhea, and gastrointestinal protection. We attempted to indicate whether the Piper nigrum extract (PNE) could alleviate ovalbumin (OVA)-induced food allergy, and to explore its potential mechanism. An OVA-induced food allergy mouse model was established, and different concentrations of PNE were administrated. Symptoms of food allergy, levels of immunoglobulin E (IgE), mucosal mast cell protease-1 (mMCP-1), and intestine pathological changes were assessed. Additionally, the expressions of T helper (Th) 2, Th17 and regulatory T (Treg)-associated cytokines and the proportion of Th17 and Treg cells in CD4⁺ T cells were measured. We found PNE attenuated symptoms of food allergy and decreased the levels of IgE and mMCP-1. In PNE group, the infiltration degree of inflammatory cells was ameliorated and the villi of small intestine were more complete. Moreover, the expressions of Th2 and Th17 cell-associated cytokines were down-regulated by PNE pretreatment, while the levels of Treg cell-associated cytokines were up-regulated. PNE decreased the number of Th17 cells, while increased the Tregs cells. PNE treatment dose-dependently improved the Th17/Treg balance. PNE plays a protective role in OVA-induced food allergy through inhibiting Th2 cell response and regulating the Th17/Treg balance.

Flavonoids: structure-function and mechanisms of action and opportunities for drug development

Flavonoids are polyphenolic phytochemicals produced in fruits, nuts and vegetables and dietary consumption of these structurally diverse compounds is associated with multiple health benefits including increased lifespan, decreased cardiovascular problems and low rates of metabolic diseases. Preclinical studies with individual flavonoids demonstrate that these compounds exhibit anti-inflammatory and anticancer activities and they enhance the immune system. Their effectiveness in both chemoprevention and chemotherapy is associated with their targeting of multiple genes/pathways including nuclear receptors, the aryl hydrocarbon receptor (AhR), kinases, receptor tyrosine kinases and G protein-coupled receptors. However, despite the remarkable preclinical activities of flavonoids, their clinical applications have been limited and this is due, in part, to problems in drug delivery and poor bioavailability and these problems are being addressed. Further improvements that will expand clinical applications of flavonoids include mechanism-based precision medicine approaches which will identify critical mechanisms of action of individual flavonoids with optimal activities that can be used in combination therapies.

The Aryl Hydrocarbon Receptor in Chronic Kidney Disease: Friend or Foe?

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that promotes cell responses to small molecules derived from the diet, microorganisms, metabolism and pollutants. The AhR signal regulates many basic cellular processes, including cell cycle progression, adhesion, migration, apoptosis and cell proliferation. Many studies have shown that AhR is associated with chronic kidney disease (CKD) and its complications. This article reviews the current knowledge about the role of AhR in CKD, showing that AhR mediates CKD complications, including cardiovascular disease, anemia, bone disorders, cognitive dysfunction and malnutrition, and that it influences drug metabolism in individuals with CKD. AhR enhances the intestinal barrier function to reduce the harmful effects of uremic toxins. Therefore, understanding the complex roles of AhR during CKD is important to be able to target this transcription factor safely and effectively for CKD prevention and treatment.

The main bioactive compounds of Scutellaria baicalensis Georgi. for alleviation of inflammatory cytokines: A comprehensive review

Scutellaria baicalensis Georgi., a plant used in traditional Chinese medicine, has multiple biological activities, including anti-inflammatory, antiviral, antitumor, antioxidant, and antibacterial effects, and can be used to treat respiratory tract infections, pneumonia, colitis, hepatitis, and allergic diseases. The main active substances of S. baicalensis, baicalein, baicalin, wogonin, wogonoside, and oroxylin A, can act directly on immune cells such as lymphocytes, macrophages, mast cells, dendritic cells, monocytes, and neutrophils, and inhibit the production of the inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α, and other inflammatory mediators such as nitric oxide, prostaglandins, leukotrienes, and reactive oxygen species. The molecular mechanisms underlying the immunomodulatory and anti-inflammatory effects of the active compounds of S. baicalensis include downregulation of toll-like receptors, activation of the Nrf2 and PPAR signaling pathways, and inhibition of the nuclear thioredoxin system and inflammation-associated pathways such as those of MAPK, Akt, NFκB, and JAK-STAT. Given that in addition to the downregulation of cytokine production, the active constituents of S. baicalensis also have antiviral and antibacterial effects, they may be more promising candidate therapeutics for the prevention of infection-related cytokine storms than are drugs having only antimicrobial or anti-inflammatory activities.

Baicalein Restores the Balance of Th17/Treg Cells via Aryl Hydrocarbon Receptor to Attenuate Colitis

As one of the ligands of aryl hydrocarbon receptor (AhR), baicalein, isolated from Scutellaria baicalensis Georgi, has been proved to exert potential therapeutic effects on ulcerative colitis (UC), but its therapeutic mechanism remains obscure. Authentically, ulcerative colitis can be alleviated by regulating the differentiation of naïve CD4⁺ T cells via AhR activation. So, our study planned to prove the hypothesis that baicalein protected mice against UC by regulating the balance of Th17/Treg cells via AhR activation. Immunofluorescence and western blot results showed that baicalein could promote AhR activation and induce it to transfer to the nucleus. We further determined the effect of baicalein on naïve CD4⁺ T cell differentiation in vitro by magnetic cell separation and drug intervention. The results showed that baicalein could promote Treg cell differentiation by activating AhR. In vivo study, UC mice were established by free drinking of dextran sulfate sodium (DSS) for 7 days and then were orally administrated by baicalein (10, 20, and 40 mg/kg), TCDD (AhR agonist), and CH223191 (antagonist). The results demonstrated that baicalein improved the symptoms of UC mice, regulated the balance of Th17/Treg cells, and restored the balance of proinflammatory cytokines such as IL-17, IL-6, and TNF-α; anti-inflammatory cytokines such as IL-10 and TGF-β; and epithelial protective cytokine IL-22 in UC mice, and these effects were related to AhR. Taken together, our research found that baicalein might be a potential drug for UC via regulating Treg cell differentiation and maintaining immune homeostasis and attempted to shed a light on the pivotal role of AhR in these effects.

Research Progress of the Antiviral Bioactivities of Natural Flavonoids

Flavonoids are now considered as an indispensable component in a variety of nutraceutical and pharmaceutical applications. Most recent researches have focused on the health aspects of flavonoids for humans. Especially, different flavonoids have been investigated for their potential antiviral activities, and several natural flavonoids exhibited significant antiviral properties both in vitro and in vivo. This review provides a survey of the literature regarding the evidence for antiviral bioactivities of natural flavonoids, highlights the cellular and molecular mechanisms of natural flavonoids on viruses, and presents the details of most reported flavonoids. Meanwhile, future perspectives on therapeutic applications of flavonoids against viral infections were discussed.

Resveratrol reduces obesity in high-fat diet-fed mice via modulating the composition and metabolic function of the gut microbiota

Resveratrol (RSV) is a natural polyphenol with anti-obesity effects. However, the mechanisms of anti-obesity remain unclear due to its low bioavailability. Recent evidence demonstrates that gut microbiota plays a key role in obesity. This spurred us to investigate whether the anti-obesity effects of RSV are related to modulations in the gut microbiota and metabolic functions. Here, RSV significantly improved metabolic phenotype and intestinal oxidative stress in the high-fat diet (HFD)-fed mice. A multi-omics approach was used to systematically profile the microbial signatures at both the phylogenetic and functional levels using 16S rRNA gene sequencing and metagenome. At the phylogenetic level, RSV treatment significantly modulated the gut microbiota composition in HFD-fed mice, characterized with increased Blautia abundance and decreased Desulfovibrio and Lachnospiraceae_NK4A136_group abundance. At the functional level, RSV significantly decreased the enrichment of pathways linked to host metabolic disease and increased the enrichment of pathways involved in the generation of small metabolites. Besides, the fecal microbiota transplantation experiment showed anti-obesity and microbiota-modulating effects similar to those observed in the oral RSV-feeding experiment. Furthermore, metabolomic analysis and antibiotic treatment verified that 4-hydroxyphenylacetic acid (4-HPA) and 3-hydroxyphenylpropionic acid (3-HPP) were the two gut metabolites of RSV, which contribute to improving lipid metabolism in vitro. Moreover, the content of 4-HPA and 3-HPP exhibited strong correlation with the intestinal oxidative state. We concluded that the RSV-mediated alteration of gut microbiota, related gut metabolites and redox state of the intestinal environment contributed to prevention of metabolic syndrome in HFD-fed mice.

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

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

Resveratrol-induced gut microbiota reduces obesity in high-fat diet-fed mice

OBJECTIVE

Resveratrol (RSV) is a natural polyphenol with putative anti-obesity effects; however, its mechanisms of action remain unclear due to its low bioavailability. Microbial functions in the physiology result from the microbiota-host coevolution has profoundly affected host metabolism. Here, we sought to determine how beneficial microbiome caused by RSV interventions affects antiobesity.

METHODS

C57BL/6J mice were fed either standard diet (SD) or RSV (300 mg/kg/day) diet for 16 weeks. The composition of the gut microbiota was assessed by analyzing 16S rRNA gene sequences. Then, transplant the RSV-microbiota to high-fat diet (HFD)-fed mice (HFD-RSVT) to explore the function of microbiota. Body weight and food intake were monitored. Markers of lipid metabolism, inflammation, gut microbiota compostion, and intestinal barrier were determined.

RESULTS

Mice treated with RSV shows a remarkable alteration in microbiota composition compared with that of SD-fed mice and is characterized by an enrichment of Bacteroides, Lachnospiraceae_NK4A136_group, Blautia, Lachnoclostridium, Parabacteroides, and Ruminiclostridium_9, collectively referred to as RSV-microbiota. We further explored whether RSV-microbiota has anti-obesity functions. Transplantation of the RSV-microbiota to high-fat diet (HFD)-fed mice (HFD-RSVT) was sufficient to decrease their weight gain and increase their insulin sensitivity. Moreover, RSV-microbiota was able to modulate lipid metabolism, stimulate the development of beige adipocytes in WAT, reduce inflammation and improve intestinal barrier function.

CONCLUSIONS

Our study demonstrates that RSV-induced microbiota plays a key role in controlling obesity development and brings new insights to a potential therapy based on host-microbe interactions.

Silkworm dropping extract regulates food allergy symptoms via inhibition of Th2-related responses in an ovalbumin-induced food allergy model

BACKGROUND

Silkworm droppings have long been used in traditional medicine to remedy allergic itching, palsy, blood circulation problems, and arthritis in Asian countries. To investigate the anti-allergic effect of silkworm dropping extract (SDE) and its mechanism, we used a mouse model of food allergy induced by ovalbumin (OVA).

RESULTS

SDE ameliorated the symptoms of OVA-induced food allergies, and the levels of T helper 2 (Th2)-related cytokines [such as interleukin (IL)-4, IL-5, IL-10, and IL-13] were found to be significantly decreased in both the spleen and mesenteric lymph nodes by SDE. Furthermore, SDE treatment directly inhibited OVA permeation, IL-4 production, and degranulation of mast cells; in contrast, immunoglobulin E (IgE) production from B cells was not affected.

CONCLUSION

These results suggest that SDE has potential anti-allergic activities, and SDE may be useful in the treatment/prevention of allergic disorders such as food allergies, serving as therapeutic agents. © 2019 Society of Chemical Industry.

Baicalein Mitigates Radiation-Induced Enteritis by Improving Endothelial Dysfunction

Background and Aims: Radiation-induced intestinal injury occurred in application of radiotherapy for abdominal and pelvic cancers or in nuclear accidents. Radiation-induced enteritis may be considered an ideal model of gastrointestinal inflammation. The endothelium is a crucial component of inflammation, and the endothelial dysfunction following radiation exposure induces the intestinal proinflammatory response and progression of radiation enteritis. Baicalein (5,6,7-trihydroxyflavonoid) is a flavonoid from Scutellaria baicalensis used in oriental herbal medicine. Baicalein has been found to have multiple beneficial properties including antioxidant, anti-inflammatory, anti-allergic, and anti-cancer activities. Here, we investigated the therapeutic effects of baicalein on endothelial dysfunction in radiation-induced intestinal inflammation. Materials and Methods: We performed histological analysis, bacterial translocation, and intestinal permeability assays and also assessed infiltration of leukocytes and inflammatory cytokine expression using a mouse model of radiation-induced enteritis. In addition, to investigate the effect of baicalein in endothelial dysfunction, we analyzed endothelial-derived adherent molecules in human umbilical vein endothelial cells (HUVECs) and irradiated intestinal tissue. Results: Histological damage such as shortening of villi length and impaired intestinal crypt function was observed in the radiation-induced enteritis mouse model. Intestinal damage was attenuated in baicalein-treated groups with improvement of intestinal barrier function. Baicalein inhibited the expression of radiation-induced adherent molecules in HUVECs and intestine of irradiated mouse and decreased leukocyte infiltration in the radiation-induced enteritis. Conclusions: Baicalein could accelerate crypt regeneration via recovery of endothelial damage. Therefore, baicalein has a therapeutic effect on radiation-induced intestinal inflammation by attenuating endothelial damage.

Anti-inflammatory effects of flavonoids

Inflammation plays a key role in diseases such as diabetes, asthma, cardiovascular diseases and cancer. Diet can influence different stages of inflammation and can have an important impact on several inflammatory diseases. Increasing scientific evidence has shown that polyphenolic compounds, such as flavonoids, which are found in fruits, vegetables, legumes, or cocoa, can have anti-inflammatory properties. Recent studies have demonstrated that flavonoids can inhibit regulatory enzymes or transcription factors important for controlling mediators involved in inflammation. Flavonoids are also known as potent antioxidants with the potential to attenuate tissue damage or fibrosis. Consequently, numerous studies in vitro and in animal models have found that flavonoids have the potential to inhibit the onset and development of inflammatory diseases. In the present review, we focused in flavonoids, the most abundant polyphenols in the diet, to give an overview of the most recent scientific knowledge about their impact on different inflammatory diseases.

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

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

Polyphenols and Tryptophan Metabolites Activate the Aryl Hydrocarbon Receptor in an in vitro Model of Colonic Fermentation

Scope

Many dietary phytochemicals have been reported to promote gut health. Specific dietary phytochemicals, such as luteolin, as well as specific microbial metabolites of tryptophan are ligands of the aryl hydrocarbon receptor (AhR), which plays a role in immunity and homeostasis of the gut barrier. Here, the fate of luteolin during colonic fermentation and the contribution of tryptophan metabolites to AhR activity in different parts of the colon are investigated.

Methods and results

Several polyphenols are screened for AhR activation and oregano, containing the ligand luteolin, is added to batch cultures of human microbiota from the distal colon. Luteolin is rapidly metabolized, with no measurable increase in AhR activity. In the second experiment, using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME), not all luteolin is metabolized in the ascending colon, but disappear rapidly in the transverse colon. The greatest AhR activity is due to microbiota‐derived metabolites of tryptophan, particularly in the descending colon.

Conclusions

Luteolin in food is rapidly metabolized in the transverse colon. Tryptophan metabolism by the microbiota in the colon contributes substantially to the pool of lumen metabolites that can activate the AhR.

A murine model of atopic dermatitis can be generated by painting the dorsal skin with hapten twice 14 days apart

Drug development involves pharmacometric experiments in animals. Such experiments should limit animal pain and stress. Conventional murine models of atopic dermatitis (AD) used in drug development are generated by weekly painting of hapten on dorsal skin for 5 weeks. The present study aimed to develop a protocol that involves less animal distress. The experiments focused on serum total IgE levels, which are a marker of AD. The conventional protocol induced ever rising IgE levels. Experiments with extended intervals between sensitizations showed that IgE peaked ~5 days after the second sensitization, after which it returned to the control level within 12-19 days. An additional third sensitization on day 28 further increased the serum IgE level. In the 4-5 days after the second sensitization, the dorsal skin exhibited typical AD-like lesions with edema, scabs, epithelial-cell hypertrophy, marked mast-cell and lymphocyte infiltration of dermis, and increased IL-4, IL-6, IL-10, IL-1β, IL-17A, IFN-γ and TNF-α expression. Thus, two 2,4-dinitrofluorobenzene sensitizations yield a murine AD model in less than 20 days. This study shows that animal model protocols used in drug development can be fine-tuned so that they remain effective yet cause animals less stress and pain.