Honokiol targeting ankyrin repeat domain of TRPV4 ameliorates endothelial permeability in mice inflammatory bowel disease induced by DSS.

ETHNOPHARMACOLOGICAL RELEVANCE: As a classic traditional Chinese medicine, Magnolia officinalis (M. officinalis) is widely used in digestive diseases. It has rich gastrointestinal activity including inflammatory bowel disease (IBD) treatment, but the mechanism is not clear. AIM OF THE STUDY: In recent years, there has been a growing interest in investigating the regulatory effects of herbal compounds on transient receptor potential (TRP) channel proteins. Transient receptor potential vanilloid 4 (TRPV4), a subtype involved in endothelial permeability regulation, was discussed as the target of M. officinalis in the treatment of IBD in the study. Based on the targeting effect of TRPV4, this study investigated the active ingredients and mechanism of M. officinalis extract in treating IBD. MATERIALS AND METHODS: To reveal the connection between the active ingredients in M. officinalis and TRPV4, a bioactivity-guided high performance liquid chromatography system coupled with mass spectrometry identification was utilized to screen for TRPV4 antagonists. TRPV4 siRNA knockdown experiment was employed to validate the significance of TRPV4 as a crucial target in regulating endothelial permeability by honokiol (HON). The interaction of the active ingredient representing HON with TRPV4 was confirmed by molecular docking, fluorescence-based thermal shift and live cell calcium imaging experiments. The potential binding sites and inhibitory mechanisms of HON in TRPV4 were analyzed by molecular dynamics simulation and microscale thermophoresis. The therapeutic effect of HON based on TRPV4 was discussed in DSS-IBD mice. RESULTS: Our finding elucidated that the inhibitory activity of M. officinalis against TRPV4 is primarily attributed to HON analogues. The knockdown of TRPV4 expression significantly impaired the calcium regulation and permeability protection in endothelial cells. The mechanism study revealed that HON specifically targets the Q239 residue located in the ankyrin repeat domain of TRPV4, and competitively inhibits channel opening with adenosine triphosphate (ATP) binding. The immunofluorescence assay demonstrated that the administration of HON enhances the expression and location of VE-Cadherin to protect the endothelial barrier and attenuates immune cell infiltration. CONCLUSIONS: The finding suggested that HON alleviates IBD by improving endothelial permeability through TRPV4. The discovery provides valuable insights into the potential therapeutic strategy of active natural products for alleviating IBD.

Dietary purple potato supplement attenuates DSS-induced colitis in mice: impact on mitochondrial function.

Inflammatory bowel disease (IBD) is a condition characterized by disrupted intestinal barrier function, abnormal immune response, and mucosal structure loss. This study evaluated the beneficial role of purple potato (PP) supplementation against IBD symptoms using a murine model of dextran sulfate sodium (DSS)-induced colitis, and further explored the underlying mechanisms. Six-week-old C57BL/6J male mice were randomized into two groups and fed a standard rodent diet with or without 10% PP powder for 7 weeks. At the 5th week of dietary supplements, mice in each group were further divided into two subgroups and were either induced with or without 2.5% DSS induction for 7 days, followed by 7 days of recovery. Data showed that PP supplementation ameliorated the disease activity index in DSS-treated mice and reversed the colonic structure loss, mucosal damage, macrophage infiltration, and pro-inflammatory cytokine secretion induced by DSS in the colonic tissue. PP supplementation also restored the levels of tight junction proteins and caudal type homeobox 2 in DSS-treated mice. Furthermore, dietary PP enhanced peroxisome proliferator-activated receptor-γ coactivator-1α signaling pathway, mitochondrial biogenesis, mitochondrial proteostasis, and protein-folding capacity. In summary, dietary PP ameliorated DSS-induced colitis and improved gut structures and barrier function, which was associated with improved mitochondrial function. These results support further investigation of PP as a potential dietary intervention for IBD.

Iron chelation and supplementation: A comparison in the management of inflammatory bowel disease using drosophila.

AIMS: Inflammatory Bowel Disease (IBD) is associated with systemic iron deficiency and has been managed with iron supplements which cause adverse side effects. Conversely, some reports highlight iron depletion to ameliorate IBD. The underlying intestinal response and comparative benefit of iron depletion and supplementation in IBD is unknown. The aims of this work were to characterize and compare the effects of iron supplementation and iron depletion in IBD. MAIN METHODS: IBD was induced in Drosophila melanogaster using 3 % dextran sodium sulfate (DSS) in diet for 7 days. Using this model, we investigated the impacts of acute iron depletion (using bathophenanthroline disulfonate, BPS) and supplementation (using ferrous sulphate, FS), before and after IBD induction, on gut iron homeostasis, cell death, gut permeability, inflammation, antioxidant defence, antimicrobial response and several fly phenotypes. KEY FINDINGS: DSS decreased fly mass (p < 0.001), increased gut permeability (p < 0.001) and shortened lifespan (p = 0.035) compared to control. The DSS-fed flies also showed significantly elevated lipid peroxidation (p < 0.001), and the upregulated expression of apoptotic marker- drice (p < 0.001), tight junction protein - bbg (p < 0.001), antimicrobial peptide - dpta (p = 0.002) and proinflammatory cytokine - upd2 (p < 0.001). BPS significantly (p < 0.05) increased fly mass and lifespan, decreased gut permeability, decreased lipid peroxidation and decreased levels of drice, bbg, dpta and upd2 in IBD flies. This iron chelation (using BPS) showed better protection from DSS-induced IBD than iron supplementation (using FS). Preventive and curative interventions, by BPS or FS, also differed in outcomes. SIGNIFICANCE: This may inform precise management strategies aimed at tackling IBD and its recurrence.

Cationic fructan-based pH and intestinal flora dual stimulation nanoparticle with berberine for targeted therapy of IBD.

Inflammatory bowel disease (IBD) can cause intestinal microbial imbalance and aggravate intestinal inflammation. Mixed fructan is more easily fermented by colonic microorganisms and can be used as colonic drug delivery materials. Here, we constructed a mixed fructan based nanoparticle with dual targeted stimulation of pH and intestinal flora to effectively deliver berberine for the treatment of ulcerative colitis (UC). The complex of fructan based nanoparticle and berberine (BBRNPs) significantly ameliorated the inflammatory response of sodium dextran sulfate (DSS)-induced colitis in mice by inhibiting the activation of NF-κB/STAT-3 pathway and increasing tight junction protein expression in vivo. Importantly, BBRNPs improved the responsiveness of colitis microbiome and effectively regulated the relative homeostasis of harmful flora Enterobacteriaceae and Escherichia-shigolla, and beneficial flora Ruminococcaceae and Akkermansiaceae. This study provides a promising strategy for the effective treatment of UC and expands the application of branched fructan in pharmaceutics.

Effects of Huzhangoside C on Dextran Sodium Sulfate-Stimulated Colitis in Mice.

Chronic inflammation is a major risk factor for cancer. Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract, ultimately leading to a breakdown of intestinal barrier function. Clematis florida var. plena is a folk prescription used to treat inflammation and rheumatism in She pharmacy. The bioactivity of C. florida var. plena is primarily due to triterpene saponins. Huzhangoside C (HZ) is an active component of C. florida var. plena. In this study, the anti-inflammatory effect of HZ on a mouse colitis model induced by dextran sulfate sodium (DSS) was investigated. Result indicated a notable reduction in body weight loss and colon length shortening in HZ-mediated mice compared to DSS-stimulated control mice. Furthermore, inflammatory signaling mechanisms involving interleukin-6 and tumor necrosis factor-α were suppressed in HZ-treated mice. HZ treatment significantly suppressed the expression of nuclear factor kappa B (NF-κB), STAT3, and iNOS in colon tissue. After HZ treatment, malondialdehyde and nitric oxide levels were significantly decreased, while Nrf-2, superoxide dismutase, and glutathione expression levels were notably improved. The result indicated that HZ could activate the Nrf-2 signal cascade, inhibit the expression of NF-κB, eNOS, and STAT3, and enhance the intestinal barrier function of DSS stimulated ulcerative colitis intestinal injury. The results suggest that HZ is potential anti-inflammatory agent for treating IBD.

Mechanisms and regulation of defensins in host defense.

As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.

Garlic-derived exosome-like nanovesicles alleviate dextran sulphate sodium-induced mouse colitis via the TLR4/MyD88/NF-κB pathway and gut microbiota modulation.

Plant-derived exosome-like nanovesicles play an important role in transferring their biological cargos to recipient cells. The effect of garlic-derived exosome-like nanovesicles (GENs) against inflammatory bowel disease (IBD) remains unknown. This study aimed to investigate the effect of GENs on dextran sulphate sodium (DSS)-induced colitis in mice. A comprehensive analysis of bioactive components in GENs was performed. Data showed that GENs contained 26 lipids, 61 proteins and 127 known microRNAs (miRNAs). Han-miR3630-5p in GENs could bind to the 3' untranslated region of toll-like receptor 4 (TLR4), which led to the inhibition of TLR4 expression. Besides, GENs significantly up-regulated the expression of barrier-related proteins and inhibited the overproduction of pro-inflammatory cytokines in LPS-induced Caco-2 cells. As a result, pretreatment with GENs at 100 mg kg-1 efficiently ameliorated the inflammatory bowel behavior, intestinal histological pathological damage, and tight junction protein dysfunction induced by DSS in the colon tissue. Intake of GENs significantly down-regulated the expressions of TLR4, myeloid differentiation primary response gene 88 (MyD88), and nuclear factor kappa-B (NF-κB), which suppressed the downstream cascades and led to less secretion of pro-inflammatory cytokines induced by DSS. Furthermore, pretreatment with GENs altered the gut microbiota profile of colitis mice by recovering the relative abundance of Lachnospiraceae and reducing the relative abundance of Helicobacter. Totally, GENs had potential to protect the colon against DSS-induced damage through inhibiting the TLR4/MyD88/NF-κB signaling pathway and regulating gut microbiota. This study clarified the role of miRNAs of GENs in anti-colitis and proved that GENs had a potential application for IBD prevention.

Gut Protective Effect from D-Methionine or Butyric Acid against DSS and Carrageenan-Induced Ulcerative Colitis.

Microbiome dysbiosis resulting in altered metabolite profiles may be associated with certain diseases, including inflammatory bowel diseases (IBD), which are characterized by active intestinal inflammation. Several studies have indicated the beneficial anti-inflammatory effect of metabolites from gut microbiota, such as short-chain fatty acids (SCFAs) and/or D-amino acids in IBD therapy, through orally administered dietary supplements. In the present study, the potential gut protective effects of d-methionine (D-Met) and/or butyric acid (BA) have been investigated in an IBD mouse model. We have also built an IBD mouse model, which was cost-effectively induced with low molecular weight DSS and kappa-carrageenan. Our findings revealed that D-Met and/or BA supplementation resulted in the attenuation of the disease condition as well as the suppression of several inflammation-related gene expressions in the IBD mouse model. The data shown here may suggest a promising therapeutic potential for improving symptoms of gut inflammation with an impact on IBD therapy. However, molecular metabolisms need to be further explored.

Oral pectin/oligochitosan microspheres for colon-specific controlled release of quercetin to treat inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic, life quality-reducing disease with no cures available yet. To develop an effective medication suitable for long-term use is an urgent but unmet need. Quercetin (QT) is a natural dietary flavonoid with good safety and multifaceted pharmacological activities against inflammation. However, orally administrated quercetin yields unproductive outcomes for IBD treatment because of its poor solubility and extensive metabolism in the gastrointestinal tract. In this work, a colon-targeted QT delivery system (termed COS-CaP-QT) was developed, of which the pectin (PEC)/Ca2+ microspheres were prepared and then crosslinked by oligochitosan (COS). The drug release profile of COS-CaP-QT was pH-dependent and colon microenvironment-responsive, and COS-CaP-QT showed preferential distribution in the colon. The mechanism study showed that QT triggered the Notch pathway to regulate the proliferation of T helper 2 (Th2) cells and group 3 innate lymphoid cells (ILC3s) and the inflammatory microenvironment was remodeled. The in vivo therapeutic results revealed that COS-CaP-QT could relieve the colitis symptoms and maintain the colon length and intestinal barrier integrity.

LACC1: A critical involvement in macrophage immunometabolism.

Laccase domain-containing 1 (LACC1) protein is an enzyme highly expressed in inflammatory macrophages, and studies have shown that it has a key role in diseases such as inflammatory bowel disease, arthritis, and microbial infections. Therefore, in this review, we focus on LACC1-mediated catalysis. In detail, LACC1 converts l-CITrulline (l-CIT) to l-ORNithine (l-ORN) and isocyanic acid in mice and humans and acts as a bridge between proinflammatory nitric oxide synthase (NOS2) and polyamine immunometabolism, thus exerting anti-inflammatory and antibacterial effects. Considering the actions of LACC1, targeting LACC1 may be a potent therapeutic avenue for inflammation-related diseases and microbial infection diseases.

Gut Microbial Metabolite Butyrate and Its Therapeutic Role in Inflammatory Bowel Disease: A Literature Review.

Background and objective: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic inflammatory disorder characterized by aberrant immune responses and compromised barrier function in the gastrointestinal tract. IBD is associated with altered gut microbiota and their metabolites in the colon. Butyrate, a gut microbial metabolite, plays a crucial role in regulating immune function, epithelial barrier function, and intestinal homeostasis. In this review, we aim to present an overview of butyrate synthesis and metabolism and the mechanism of action of butyrate in maintaining intestinal homeostasis and to discuss the therapeutic implications of butyrate in IBD. Methods: We searched the literature up to March 2023 through PubMed, Web of Science, and other sources using search terms such as butyrate, inflammation, IBD, Crohn's disease, and ulcerative colitis. Clinical studies in patients and preclinical studies in rodent models of IBD were included in the summary of the therapeutic implications of butyrate. Results: Research in the last two decades has shown the beneficial effects of butyrate on gut immune function and epithelial barrier function. Most of the preclinical and clinical studies have shown the positive effect of butyrate oral supplements in reducing inflammation and maintaining remission in colitis animal models and IBD patients. However, butyrate enema showed mixed effects. Butyrogenic diets, including germinated barley foodstuff and oat bran, are found to increase fecal butyrate concentrations and reduce the disease activity index in both animal models and IBD patients. Conclusions: The current literature suggests that butyrate is a potential add-on therapy to reduce inflammation and maintain IBD remission. Further clinical studies are needed to determine if butyrate administration alone is an effective therapeutic treatment for IBD.

Targeting the gut-microbiota-brain axis in irritable bowel disease to improve cognitive function - recent knowledge and emerging therapeutic opportunities.

The brain-gut axis forms a bidirectional communication system between the gastrointestinal (GI) tract and cognitive brain areas. Disturbances to this system in disease states such as inflammatory bowel disease have consequences for neuronal activity and subsequent cognitive function. The gut-microbiota-brain axis refers to the communication between gut-resident bacteria and the brain. This circuits exists to detect gut microorganisms and relay information to specific areas of the central nervous system (CNS) that in turn, regulate gut physiology. Changes in both the stability and diversity of the gut microbiota have been implicated in several neuronal disorders, including depression, autism spectrum disorder Parkinson's disease, Alzheimer's disease and multiple sclerosis. Correcting this imbalance with medicinal herbs, the metabolic products of dysregulated bacteria and probiotics have shown hope for the treatment of these neuronal disorders. In this review, we focus on recent advances in our understanding of the intricate connections between the gut-microbiota and the brain. We discuss the contribution of gut microbiota to neuronal disorders and the tangible links between diseases of the GI tract with cognitive function and behaviour. In this regard, we focus on irritable bowel syndrome (IBS) given its strong links to brain function and anxiety disorders. This adds to the growing body of evidence supporting targeted therapeutic strategies to modulate the gut microbiota for the treatment of brain/mental-health-related disease.

Radix Panacis quinquefolii Extract Ameliorates Inflammatory Bowel Disease through Inhibiting Inflammation.

OBJECTIVE: To investigate the anti-inflammatory activity of Radix Panacis quinguefolii root extract (RPQE) and its therapeutic effects on inflammatory bowel disease (IBD). METHODS: The 72-hour post-fertilization zebrafish was used to generate the local and systematic inflammation models through tail-amputation and lipopolysaccharide (LPS)-induction (100 µ g/mL), respectively. The Tg(zlyz:EGFP) zebrafish was induced with 75 µ g/mL 2,4,6-trinitrobenzene sulfonic acid (TNBS) for establishing the IBD model. The tail-amputated, LPS-, and TNBS-induced models were subjected to RPQE (ethanol fraction, 10-20 µ g/mL) administration for 12 and 24 h, respectively. Anti-inflammatory activity of RPQE was evaluated by detecting migration and aggregation of leukocytes and expression of inflammation-related genes. Meanwhile, TNBS-induced fish were immersed in 0.2% (W/V) calcein for 1.5 h and RPQE for 12 h before photographing to analyze the intestinal efflux efficiency (IEE). Moreover, the expression of inflammation-related genes in these fish was detected by quantitative polymerase chain reaction. RESULTS: Subject to RPQE administration, the migration and aggregation of leukocytes were significantly alleviated in 3 zebrafish models (P<0.01). Herein, RPQE ameliorated TNBS-induced IBD with respect to a significantly reduced number of leukocytes, improved IEE, and inhibited gene expression of pro-inflammatory factors (P<0.05 or P<0.01). CONCLUSION: RPQE exhibited therapeutic effects on IBD by inhibiting inflammation.

Auricularia polytricha and Flammulina velutipes reduce liver injury in DSS-induced Inflammatory Bowel Disease by improving inflammation, oxidative stress, and apoptosis through the regulation of TLR4/NF-κB signaling pathways.

Auricularia polytricha and Flammulina velutipes are two dietary mushrooms mostly consumed in China and known for their traditional use on gastric ulceration and to boost bowel movement. Considering the gut-liver axis, which has been recognized for its role in the autoimmune modulation, and the implications of the intestinal barrier in the pathogenesis of liver diseases that remain unclear, the therapeutic effects of A. polytricha (APE) and F. velutipes (FVE) on inflammatory bowel disease (IBD)-induced liver injury in mice was investigated as well as their potential mechanism via the signaling pathways they could involve. 3% DSS was administered to the mice in drinking water, to induce ulcerative colitis, followed by oral administration of APE and FVE. The biochemical, oxidative stress and inflammatory parameters, mRNA and protein expressions were assessed. The results revealed that DSS-induced liver histopathological changes were ameliorated by APE and FVE treatment. APE and FVE administration also improved the ALT and AST activity as well as the pro-inflammatory cytokines and oxidative factors. Data also showed that, in addition to their regulation of tight junctions' disruption, APE and FVE attenuated genes and proteins expression involved in apoptosis, lipid metabolism, and bile acid homeostasis via inhibiting TLR4/NF-κB and caspase signaling pathways and stimulating Keap1/Nrf2 signaling pathways. In conclusion, APE and FVE regulated liver injury on DSS-induced ulcerative colitis by alleviating inflammation, oxidative stress, and apoptosis, suggesting that they could be used as therapeutic alternatives against liver diseases in addition to their functions as dietary supplements.

Novel Horizons in Postbiotics: Lactobacillaceae Extracellular Vesicles and Their Applications in Health and Disease.

Lactobacillus probiotics contained in dietary supplements or functional foods are well-known for their beneficial properties exerted on host health and diverse pathological situations. Their capacity to improve inflammatory bowel disease (IBD) and regulate the immune system is especially remarkable. Although bacteria-host interactions have been thought to occur directly, the key role that extracellular vesicles (EVs) derived from probiotics play on this point is being unveiled. EVs are lipid bilayer-enclosed particles that carry a wide range of cargo compounds and act in different signalling pathways. Notably, these EVs have been recently proposed as a safe alternative to the utilisation of live bacteria since they can avoid the possible risks that probiotics may entail in vulnerable cases such as immunocompromised patients. Therefore, this review aims to give an updated overview of the existing knowledge about EVs from different Lactobacillus strains, their mechanisms and effects in host health and different pathological conditions. All of the information collected suggests that EVs could be considered as potential tools for the development of future novel therapeutic approaches.

Anti-Inflammatory Activity of an In Vitro Digested Anthocyanin-Rich Extract on Intestinal Epithelial Cells Exposed to TNF-α.

BACKGROUND: The consumption of foods rich in anthocyanins (ACN) have been associated with beneficial properties in chronic inflammatory disorders such as intestinal bowel diseases (IBD). These effects were attributed not only to a direct antioxidant mechanism but also to the modulation of cell redox-dependent signaling. However, ACN bioavailability is low for their poor stability in the digestive tract, so ACN gastrointestinal digestion should be considered. METHODS: To have a more realistic knowledge of the effects of ACN, we performed an in vitro simulated gastrointestinal digestion of an ACN-rich purified and standardized bilberry and blackcurrant extract (BBE), followed by an evaluation of ACN composition modification (HPLC-DAD and pH differential method) and antioxidant activity (FRAP assay). Then, we studied the effects of BBE gastrointestinal extract on Caco-2 exposed to TNF-α. RESULTS: The results confirmed the high instability of ACN in the mild alkaline environment of the small intestine (17% recovery index). However, the digested BBE maintained part of its bioactivity. Additionally, BBE gastrointestinal extract inhibited the TNF-α-induced NF-κB pathway in Caco-2 and activated the Nrf2 pathway. CONCLUSIONS: Although ACN stability is affected by gastrointestinal digestion, the anti-inflammatory and antioxidant activity of digested extracts were confirmed; thus, the loss of ACN can probably be counterweighed by their metabolites. Then, ACN introduced by diet or food supplements could represent an approach for IBD prevention.

Soluble Protein Hydrolysate Ameliorates Gastrointestinal Inflammation and Injury in 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Colitis in Mice.

Inflammatory bowel diseases (IBD) are chronic, recurring gastrointestinal diseases that severely impair health and quality of life. Although therapeutic options have significantly expanded in recent years, there is no effective therapy for a complete and permanent cure for IBD. Well tolerated dietary interventions to improve gastrointestinal health in IBD would be a welcome advance especially with anticipated favorable tolerability and affordability. Soluble protein hydrolysate (SPH) is produced by the enzymatic hydrolysis of commercial food industry salmon offcuts (consisting of the head, backbone and skin) and contains a multitude of bioactive peptides including those with anti-oxidant properties. This study aimed to investigate whether SPH ameliorates gastrointestinal injury in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis model. Mice were randomly assigned to four groups: Control (no colitis), Colitis, Colitis/CP (with control peptide treatment), and Colitis/SPH (with SPH treatment). Colitis was induced by cutaneous sensitization with 1% TNBS on day -8 followed by 2.5% TNBS enema challenge on day 0. Control peptides and SPH were provided to the mice in the Colitis/CP or Colitis/SPH group respectively by drinking water at the final concentration of 2% w/v daily from day -10 to day 4. Then, the colon was harvested on day 4 and examined macro- and microscopically. Relevant measures included disease activity index (DAI), colon histology injury, immune cells infiltration, pro- and anti-inflammatory cytokines and anti-oxidative gene expression. It was found that SPH treatment decreased the DAI score and colon tissue injury when compared to the colitis-only and CP groups. The protective mechanisms of SPH were associated with reduced infiltration of CD4+ T, CD8+ T and B220+ B lymphocytes but not macrophages, downregulated pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-6), and upregulated anti-inflammatory cytokines (transforming growth factor-ß1 and interleukin-10) in the colon tissue. Moreover, the upregulation of anti-oxidative genes, including ferritin heavy chain 1, heme oxygenase 1, NAD(P)H quinone oxidoreductase 1, and superoxide dismutase 1, in the colons of colitis/SPH group was observed compared with the control peptide treatment group. In conclusion, the protective mechanism of SPH is associated with anti-inflammatory and anti-oxidative effects as demonstrated herein in an established mice model of colitis. Clinical studies with SPH as a potential functional food for the prevention or as an adjuvant therapy in IBD may add an effective and targeted diet-based approach to IBD management in the future.

XA pH-Responsive and Colitis-Targeted Nanoparticle Loaded with Shikonin for the Oral Treatment of Inflammatory Bowel Disease in Mice.

Epidemiology shows that more than 6.8 million people in the world are influenced by inflammatory bowel disease (IBD) each year. IBD is a refractory inflammatory disease, and the disease mainly affects the colon. Shikonin (SK) was originally extracted from traditional Chinese medicine "Zicao" (with an English name Lithospermum erythrorhizon) and found to inhibit inflammation, regulate immunity, and be involved in healing wounds. Herein, we used chitosan (CS), hyaluronic acid (HA), and pH-responsive polymer Eudragits S100 (ES100) to design SK-loaded ES100/HA/CS nanoparticles (SK@SAC) as an oral delivery system to treat the colitis mice. Particle size of SK@SAC was 190.3 nm and drug loading efficiency was 6.6%. SAC nanoparticles accumulated in RAW264.7 macrophages and exhibited colitis-targeted ability by increasing the local drug concentration as well as reducing nonspecific distribution after oral gavage. In TNBS-induced IBD mice, SK@SAC treatment had significant therapeutic effects, regulated of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß) and anti-inflammatory cytokines (IL-10 and TGF-ß), and also inhibited COX-2 and iNOS activity. SK@SAC also increased tight junction protein ZO-1 and occludin to some extent. These promising results showed that this novel oral SK-loaded nanoparticle drug delivery system for targeted treatment provides a new strategy for the management of IBD.

Qingchang Wenzhong Decoction Alleviates DSS-Induced Inflammatory Bowel Disease by Inhibiting M1 Macrophage Polarization In Vitro and In Vivo.

Background: An imbalance of macrophage M1/M2 polarization significantly influences the pathogenesis of inflammatory bowel disease. Qingchang Wenzhong decoction (QCWZD) has a proven therapeutic effect on patients with inflammatory bowel disease (IBD) and can significantly inhibit the inflammatory response in mice with colitis. However, its effect on macrophages during IBD treatment remains nebulous. Aim of the Study. Explore the mechanism underlying QCWZD effects in a dextran sulfate sodium (DSS)-induced colitis mouse model in vivo and RAW264.7 cell in vitro by observing macrophage polarization dynamics. Methods: The main active components of QCWZD were determined using high-performance liquid chromatography. Surface marker expression on M1-type macrophages was analyzed using flow cytometry and immunofluorescence. The effect on inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) released by M1 type macrophages was determined using ELSA and RT-PCR. The expression of key proteins in the JAK2/STAT3 signaling pathway was analyzed using western blotting. QCWZD cytotoxicity in macrophages was measured using CCK8 and Annexin V-FITC/PI assays. Results: The main active components of QCWZD were berberine chloride, coptisine chloride, epiberberine chloride, gallic acid, ginsenoside Rg1, ginsenoside Rb1, indigo, indirubin, notoginsenoside R1, palmatine chloride, and 6-curcumin. QCWZD markedly alleviated DSS-induced colitis in mice, as revealed by the rescued weight loss and disease activity index, attenuated the colonic shortening and mucosal injury associated with the inhibition of M1 macrophage polarization and expression of related cytokines, such as IL-6 and TNF-α, in vivo and in vitro. Furthermore, QCWZD decreased the iNOS, JAK2, and STAT3 levels in vivo and in vitro, regulating the JAK2/STAT3 signaling pathway. Conclusion: QCWZD administration improves intestinal inflammation by inhibiting M1 macrophage polarization. The JAK2/STAT3 signaling pathway may mediate the effects of QCWZD on M1 macrophage polarization in colitis treatment. This study presents a novel macrophage-mediated therapeutic strategy for the treatment of IBD.

LACC1 bridges NOS2 and polyamine metabolism in inflammatory macrophages.

The mammalian immune system uses various pattern recognition receptors to recognize invaders and host damage and transmits this information to downstream immunometabolic signalling outcomes. Laccase domain-containing 1 (LACC1) protein is an enzyme highly expressed in inflammatory macrophages and serves a central regulatory role in multiple inflammatory diseases such as inflammatory bowel diseases, arthritis and clearance of microbial infection1-4. However, the biochemical roles required for LACC1 functions remain largely undefined. Here we elucidated a shared biochemical function of LACC1 in mice and humans, converting L-citrulline to L-ornithine (L-Orn) and isocyanic acid and serving as a bridge between proinflammatory nitric oxide synthase (NOS2) and polyamine immunometabolism. We validated the genetic and mechanistic connections among NOS2, LACC1 and ornithine decarboxylase 1 (ODC1) in mouse models and bone marrow-derived macrophages infected by Salmonella enterica Typhimurium. Strikingly, LACC1 phenotypes required upstream NOS2 and downstream ODC1, and Lacc1-/- chemical complementation with its product L-Orn significantly restored wild-type activities. Our findings illuminate a previously unidentified pathway in inflammatory macrophages, explain why its deficiency may contribute to human inflammatory diseases and suggest that L-Orn could serve as a nutraceutical to ameliorate LACC1-associated immunological dysfunctions such as arthritis or inflammatory bowel disease.