Modulation of NLRP3 Inflammasome Attenuated Inflammatory Response Associated to Diarrhea-Predominant Irritable Bowel Syndrome

Nanoscale Liposomes Co-Loaded with Irinotecan Hydrochloride and Thalidomide for Colorectal Cancer Synergistic Therapy

Irinotecan hydrochloride (CPT-11) is one of the first-line drugs used in the clinical treatment of colorectal cancer (CRC). However, the concomitant adverse effect of delayed diarrhea has hindered its clinical use. CPT-11 combined with Thalidomide (THA) therapy is considered a palliative strategy. To optimize the synergistic treatment of CPT-11 and THA, co-loaded liposomes are constructed using cholesterol, lecithin, and 1, 2-Distearoyl-sn-glycero-3-phosphoethanolamine-Poly(ethylene glycol) (DSPE-PEG) as the "immune and gut microbiota regulator." The co-loaded liposomes, which possess good stability, are prepared by the solvent injection method. After the treatment with the co-loaded liposomes, tumor growth in CRC-bearing mice is significantly inhibited. In particular, the co-loaded liposomes demonstrate favorable diarrhea-relieving effects through the modulation of inflammatory cytokines and gut microbiota. These findings suggest that the co-loaded liposomes have great potential as a combined drug-delivery platform for CRC therapy.

The Role and the Regulation of NLRP3 Inflammasome in Irritable Bowel Syndrome: A Narrative Review

Irritable bowel syndrome (IBS) is a chronic disorder of the gastrointestinal tract. Its pathogenesis involves multiple factors, including visceral hypersensitivity and immune activation. NLRP3 inflammasome is part of the nucleotide-binding oligomerization domain-like receptor (NLR) family, a crucial component of the innate immune system. Preclinical studies have demonstrated that inhibiting NLRP3 reduces visceral sensitivity and IBS symptoms, like abdominal pain, and diarrhea, suggesting that targeting the NLRP3 might represent a novel therapeutic approach for IBS. This review aims to assess the NLRP3 inhibitors (tranilast, β-hydroxybutyrate, Chang-Kang-fang, paeoniflorin, coptisine, BAY 11-7082, and Bifidobacterium longum), highlighting the signaling pathways, and their potential role in IBS symptoms management was assessed. Although premature, knowledge of the action of synthetic small molecules, phytochemicals, organic compounds, and probiotics might make NLRP3 a new therapeutic target in the quiver of physicians' therapeutic choices for IBS symptoms management.

Inflammasomes in Intestinal Disease: Mechanisms of Activation and Therapeutic Strategies

NOD-like receptors (NLRs) are a family of cytosolic pattern recognition receptors (PRRs) implicated in the innate immune sensing of pathogens and damage signals. NLRs act as sensors in multi-protein complexes called inflammasomes. Inflammasome activity is necessary for the maintenance of intestinal homeostasis, although their aberrant activation contributes to the pathogenesis of several gastrointestinal diseases. In this review, we summarize the main features of the predominant types of inflammasomes involved in gastrointestinal immune responses and their implications in intestinal disease, including Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), celiac disease, and Colorectal Cancer (CRC). In addition, we report therapeutic discoveries that target the inflammasome pathway, highlighting promising novel therapeutic strategies in the treatment of intestinal diseases. Collectively, our understanding of the mechanisms of intestinal inflammasome activation and their interactions with other immune pathways appear to be not fully elucidated. Moreover, the clinical relevance of the efficacy of inflammasome inhibitors has not been evaluated. Despite these limitations, a greater understanding of the effectiveness, specificity, and reliability of pharmacological and natural inhibitors that target inflammasome components could be an opportunity to develop new therapeutic options for the treatment of intestinal disease.

Chang-Kang-Fang alleviates diarrhea predominant irritable bowel syndrome (IBS-D) through inhibiting TLR4/NF-κB/NLRP3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Chang-Kang-Fang (CKF), originated from traditional Chinese medicine (TCM) formulas, has been utilized to treat diarrhea predominant irritable bowel syndrome (IBS-D) based on clinical experience. However, the underlying mechanism of CKF for treating IBS-D remains unclear and need further clarification.

AIM OF THE STUDY

The objective of this present investigation was to validate the efficacy of CKF on IBS-D model rats and to uncover its potential mechanism for the treatment of IBS-D.

MATERIALS AND METHODS

We first established the IBS-D rat model through neonatal maternal separation (NMS) in combination with restraint stress (RS) and the administration of senna decoction via gavage. To confirm the therapeutic effect of CKF on treating IBS-D, abdominal withdrawal reflex (AWR) scores, the quantity of fecal pellets, and the fecal water content (FWC) were measured to evaluate the influence of CKF on visceral hypersensitivity and the severity of diarrhea symptom after the intragastric administration of CKF for 14 days. Subsequently, enzyme linked immunosorbent assay (ELISA) was applied to assess the effect of CKF on neuropeptides substance P (SP) and 5-hydroxytryptamine (5-HT), as well as inflammatory cytokines in serum and in intestinal tissues. Further, colonic pathological changes, the amount of colonic mast cells, and the expression level of occludin in rat colon tissues, were investigated by hematoxylin-eosin (HE) staining, toluidine blue staining, and immunohistochemistry, respectively. To explore the underlying mechanisms, alterations in colonic RNA transcriptomics for the normal, model, and CKF treatment groups were assessed using RNA sequencing (RNA-Seq). Subsequently, quantitative real-time polymerase chain reaction (qRT-PCR), Western blot (WB), and immunofluorescence (IF) assays were applied to validate the effect of CKF on predicted pathways in vivo and in vitro. In addition, to elucidate the potential active compounds in CKF, 11 representative components found in CKF were selected, and their anti-inflammation potentials were evaluated using LPS-treated RAW264.7 cell models.

RESULTS

CKF treatment significantly reduced the number of fecal pellets, attenuated visceral hypersensitivity, and decreased 5-HT and SP concentrations in serum and colon tissues, along with a reduction in colonic mast cell counts, correlating with improved symptoms in IBS-D rats. Meanwhile, CKF treatment reduced the colonic inflammatory cell infiltration, lowered the levels of IL-6, TNF-α, and IL-1β in serum and colon tissues, and increased the occludin protein expression in colon tissues to improve inflammatory response and colonic barrier function. RNA-Seq, in conjugation with our previous network pharmacology analysis, indicated that CKF might mitigate the symptoms of IBS-D rats by inhibiting the Toll like receptor 4/Nuclear factor kappa-B/NLR family pyrin domain-containing protein 3 (TLR4/NF-κB/NLRP3) pathway, which was confirmed by WB, IF, and qRT-PCR experiments in vivo and in vitro. Furthermore, coptisine, berberine, hyperoside, epicatechin, and gallic acid present in CKF emerged as potential active components for treating IBS-D, as they demonstrated in vitro anti-inflammatory effects.

CONCLUSION

Our findings demonstrate that CKF effectively improves the symptoms of IBS-D rats, potentially through the inhibition of the TLR4/NF-κB/NLRP3 pathway. Moreover, this study unveils the potential bioactive components in CKF that could be applied in the treatment of IBS-D.

Network pharmacology and experimental validation to explore the mechanism of Changji'an formula against irritable bowel syndrome with predominant diarrhea

Changji'an Formula (CJAF) is a Chinese herbal compound, which is effective against irritable bowel syndrome with predominant diarrhea (IBS-D) in clinic. However, the molecular mechanism has not been well defined. In the current study, the potential targets and signaling pathways of CJAF against IBS-D were predicted using network pharmacology analysis. The pharmacological mechanisms of CJAF against IBS-D and the potential mechanism were validated by using an IBS-D mouse model induced by enema with trinitrobenzene-sulfonic acid (TNBS) plus with restraint stress and further intervened with CJAF. A total of 232 active compounds of CJAF were obtained, a total of 397 potential targets for the active ingredients were retrieved and a total of 219 common targets were obtained as the potential targets of CJAF against IBS-D. GO and KEGG enrichment analyses showed that multiple targets were enriched and could be experimentally validated in a mouse model of IBS-D. The mechanisms were mainly converged on the immune and inflammatory pathways, especially the NF-κB, TNF and IL-17 signaling pathway, which were closely involved in the treatment of CJAF against IBS-D. Animal experiment showed that CJAF alleviated visceral hypersensitivity and diarrhea symptom of IBS-D. CJAF also restored the histological and ultrastructure damage of IBS-D. The result of Western blot showed that CJAF upregulated colonic tight junction proteins of ZO-1, Occludin and Claudin-1. Further results demonstrated that CJAF inhibited the protein expression of NF-κB/NLRP3 inflammasome pathway targets and downregulated proinflammatory mediators of IL-1β, IL-18, TNF-α. In conclusion, CJAF could effectively reduce inflammatory response and alleviate visceral hypersensitivity as well as diarrhea symptom of IBS-D by inhibiting the NF-κB/NLRP3 signaling pathway. This study not only reveals the mechanism of CJAF against IBS-D, but also provides a novel therapeutic strategy for IBS-D.

Tranilast alleviates visceral hypersensitivity and colonic hyperpermeability by suppressing NLRP3 inflammasome activation in irritable bowel syndrome rat models

Visceral hypersensitivity resulting from compromised gut barrier with activated immune system is a key feature of irritable bowel syndrome (IBS). Corticotropin-releasing factor (CRF) and Toll-like receptor 4 (TLR4) activate proinflammatory cytokine signaling to induce these changes, which is one of the mechanisms of IBS. As activation of the NLRP3 inflammasome by lipopolysaccharide (LPS) or TLR4 leads to release interleukin (IL)-1β, the NLRP3 inflammasome may be involved in the pathophysiology of IBS. Tranilast, an anti-allergic drug has been demonstrated to inhibit the NLRP3 inflammasome, and we evaluated the impact of tranilast on visceral hypersensitivity and colonic hyperpermeability induced by LPS or CRF (IBS rat model). Visceral pain threshold caused by colonic balloon distention was measured by monitoring abdominal muscle contractions electrophysiologically. Colonic permeability was determined by quantifying the absorbed Evans blue within the colonic tissue. Colonic protein levels of NLRP3 and IL-1β were assessed by immunoblot or ELISA. Intragastric administration of tranilast (20-200 mg/kg) for 3 days inhibited LPS (1 mg/kg)-induced visceral hypersensitivity and colonic hyperpermeability in a dose-dependent manner. Simultaneously, tranilast also abolished these alterations induced by CRF (50 µg/kg). LPS increased colonic protein levels of NLRP3 and IL-1β, and tranilast inhibited these changes. β-hydroxy butyrate, an NLRP3 inhibitor, also abolished visceral hypersensitivity and colonic hyperpermeability caused by LPS. In contrast, IL-1β induced similar GI alterations to LPS, which were not modified by tranilast. In conclusion, tranilast improved visceral pain and colonic barrier by suppression of the NLRP3 inflammasome in IBS rat models. Tranilast may be useful for IBS treating.

The impact of the microbiota-gut-brain axis on endometriosis-associated symptoms: mechanisms and opportunities for personalised management strategies

Endometriosis is a chronic inflammatory condition affecting one in 10 women and those assigned female at birth, defined by the presence of endometrial-like tissue outside the uterus. It is commonly associated with pain, infertility, and mood disorders, and often comorbid with other chronic pain conditions, such as irritable bowel syndrome. Recent research has identified a key role for the microbiota-gut-brain axis in health and a range of inflammatory and neurological disorders, prompting an exploration of its potential mechanistic role in endometriosis. Increased awareness of the impact of the gut microbiota within the patient community, combined with the often-detrimental side effects of current therapies, has motivated many to utilise self-management strategies, such as dietary modification and supplements, despite a lack of robust clinical evidence. Current research has characterised the gut microbiota in endometriosis patients and animal models. However, small cohorts and differing methodology has resulted in little consensus in the data. In this narrative review, we summarise research studies that have investigated the role of gut microbiota and their metabolic products in the development and progression of endometriosis lesions, before summarising insights from research into co-morbid conditions and discussing the reported impact of self-management strategies on symptoms of endometriosis. Finally, we suggest ways in which this promising field of research could be expanded to explore the role of specific bacteria, improve access to 'microbial' phenotyping, and to develop personalised patient advice for reduction of symptoms such as chronic pain and bloating.

Glucocorticoid receptor-mediated Nr1d1 chromatin circadian misalignment in stress-induced irritable bowel syndrome

Stress-elevated glucocorticoids cause circadian disturbances and gut-brain axis (GBA) disorders, including irritable bowel syndrome (IBS). We hypothesized that the glucocorticoid receptor (GR/NR3C1) might cause chromatin circadian misalignment in the colon epithelium. We observed significantly decreased core circadian gene Nr1d1 in water avoidance stressed (WAS) BALB/c colon epithelium, like in IBS patients. WAS decreased GR binding at the Nr1d1 promoter E-box (enhancer box), and GR could suppress Nr1d1 via this site. Stress also altered GR binding at the E-box sites along the Ikzf3-Nr1d1 chromatin and remodeled circadian chromatin 3D structures, including Ikzf3-Nr1d1 super-enhancer, Dbp, and Npas2. Intestinal deletion of Nr3c1 specifically abolished these stress-induced transcriptional alternations relevant to IBS phenotypes in BALB/c mice. GR mediated Ikzf3-Nr1d1 chromatin disease related circadian misalignment in stress-induced IBS animal model. This animal model dataset suggests that regulatory SNPs of human IKZF3-NR1D1 transcription through conserved chromatin looping have translational potential based on the GR-mediated circadian-stress crosstalk.

MicroRNA-29b-3p promotes intestinal permeability in IBS-D via targeting TRAF3 to regulate the NF-κB-MLCK signaling pathway

Irritable bowel syndrome with predominant diarrhea (IBS-D) is characterized by increased intestinal permeability. Previous studies have shown that the microRNA-29 gene is involved in the regulation of intestinal permeability in patients with IBS-D. NF-κB was proved to play a key role in inflammatory response of intestine and resultant disruption of tight junction integrity, whose activity could be inhibited by TNF Receptor-Associated Factor 3 (TRAF3). However, the exact mechanism that induces increased intestinal permeability in IBS-D patients has not been clarified. In this study, we found that microRNA-29b‑3p (miR-29b-3p) was significantly upregulated, while TRAF3 was decreased and the NF-κB-MLCK pathway was activated within the colonic tissue of IBS-D patients. Subsequently, we confirmed the targeting relationship between miR-29b-3p and TRAF3 through a double-luciferase reporter assay. Lentivirus transfection of NCM460 cells with miR-29b-3p-overexpressing and -silencing vectors demonstrated that the expression of TRAF3 was negatively correlated with the level of miR-29b-3p. The NF-κB/MLCK pathway was activated in the miR-29b-3p-overexpressing group and inhibited to some extent in the miR-29b-3p-silencing group. Results in WT and miR-29 knockout mice showed that miR-29b-3p levels were increased, TRAF3 levels were decreased, and the NF-κB/MLCK signaling was activated in the WT IBS-D group as compared with the WT control group. The protein levels of TRAF3 and TJs in the miR-29b-/- IBS-D group were partially recovered and NF-κB/MLCK pathway indicators were, to a certain extent, decreased as compared with the WT IBS-D group. These results suggested that miR-29b-3p deletion enhances the TRAF3 level in IBS-D mice and alleviates the high intestinal permeability. In brief, through the analysis of intestinal tissue samples from IBS-D patients and miR-29b-/- IBS-D mice, we showed that miR-29b-3p is involved in the pathogenesis of intestinal hyperpermeability in IBS-D via targeting TRAF3 to regulate the NF-κB-MLCK signaling pathway.

Neuroprotective effects of GSK-343 in an in vivo model of MPTP-induced nigrostriatal degeneration

Parkinson's disease (PD) is characterized by the degeneration of dopaminergic nigrostriatal neurons, which causes disabling motor disorders. Scientific findings support the role of epigenetics mechanism in the development and progression of many neurodegenerative diseases, including PD. In this field, some studies highlighted an upregulation of Enhancer of zeste homolog 2 (EZH2) in the brains of PD patients, indicating the possible pathogenic role of this methyltransferase in PD. The aim of this study was to evaluate the neuroprotective effects of GSK-343, an EZH2 inhibitor, in an in vivo model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic degeneration. Specifically, nigrostriatal degeneration was induced by MPTP intraperitoneal injection. GSK-343 was administered intraperitoneally daily at doses of 1 mg/kg, 5 mg/kg and 10 mg/kg, mice were killed 7 days after MPTP injection. Our results demonstrated that GSK-343 treatment significantly improved behavioral deficits and reduced the alteration of PD hallmarks. Furthermore, GSK-343 administration significantly attenuated the neuroinflammatory state through the modulation of canonical and non-canonical NF-κB/IκBα pathway as well as the cytokines expression and glia activation, also reducing the apoptosis process. In conclusion, the obtained results provide further evidence that epigenetic mechanisms play a pathogenic role in PD demonstrating that the inhibition of EZH2, mediated by GSK-343, could be considered a valuable pharmacological strategy for PD.

Therapeutic Potential of BAY-117082, a Selective NLRP3 Inflammasome Inhibitor, on Metastatic Evolution in Human Oral Squamous Cell Carcinoma (OSCC)

Oral squamous cell carcinoma (OSCC) is a commonly occurring head and neck cancer and it is characterized by a high metastasis grade. The aim of this study was to evaluate for the first time the effect of BAY-117082, a selective NLRP3 inflammasome inhibitor, in an in vivo orthotopic model of OSCC and its role in the invasiveness and metastasis processes in neighbor organs such as lymph node, lung, and spleen tissues. Our results demonstrated that BAY-117082 treatment, at doses of 2.5 mg/kg and 5 mg/kg, was able to significantly reduce the presence of microscopic tumor islands and nuclear pleomorphism in tongue tissues and modulate the NLRP3 inflammasome pathway activation in tongue tissues, as well as in metastatic organs such as lung and spleen. Additionally, BAY-117082 treatment modulated the epithelial-mesenchymal transition (EMT) process in tongue tissue as well as in metastatic organs such as lymph node, lung, and spleen, also reducing the expression of matrix metalloproteinases (MMPs), particularly MMP2 and MMP9, markers of cell invasion and migration. In conclusion, the obtained data demonstrated that BAY-117082 at doses of 2.5 mg/kg and 5 mg/kg were able to reduce the tongue tumor area as well as the degree of metastasis in lymph node, lung, and spleen tissues through the NLRP3 inflammasome pathway inhibition.

Evaluation of two laboratory model methods for diarrheal irritable bowel syndrome

BACKGROUND

Diarrheal irritable bowel syndrome (IBS-D) is a common chronic functional gastrointestinal disorder, and the underlying pathogenic mechanism is still unclear. Animal models that mimic the pathological state of IBS-D patients were constructed to provide a reference for later drug research and model development.

METHODS

The IBS-D model was induced using restraint stress and chemical stimulation (rhubarb), and rats were divided into normal control group (NC), chemically stimulated group (CS), and restraint stress group (RS). Visceral motility responses to Colorectal Balloon Dilation (CRD) were measured by Abdominal Withdrawal Reflex (AWR); evaluation of faecal properties and water content; determination of colonic tissue tight junction (TJ) mRNA expression by RT-PCR; measurement of inflammatory cytokines by ELISA; and intestinal flora and short chain fatty acids.

RESULTS

Compared to NC group, CS and RS group rats showed increased intestinal sensitivity and Bristol stool score, significant diarrheal symptoms and weight loss. Mucin 2, ZO-1, OCLN, CLDN4 mRNA expression was reduced and the intestinal mucosal barrier function was diminished. In addition, the levels of inflammatory factors IL-1β, IL-6, IL-8, IL-10 and TNF-α increased, the abundance and diversity of intestinal flora decreased, the content of beneficial bacteria such as Bifidobacteria decreased, and SCFAs such as acetic acid, propionic acid and butyric acid decreased to different degrees. Although, no significant difference was observed for any molecular and inflammatory marker, but compared to CS group, RS group had less water in the stool, higher visceral sensitivity, and higher relative abundance of beneficial intestinal bacteria such as Actinobacteria.

CONCLUSION

In conclusion, restraint stress combined with chemical stimulation can mimic the pathological state of diarrhoea symptoms, visceral hypersensitivity, reduced intestinal mucosal barrier permeability, immune regulatory dysfunction and dysbiosis in IBS-D patients. However, herbs with antibacterial effects such as rhubarb and senna, for example, are not suitable as the first choice for chemical stimulation, as they may lead to a decrease in harmful bacteria and an increase in beneficial bacteria in the intestinal fraction and do not perfectly mimic the imbalanced state of intestinal flora in IBS-D patients, while restraint stress may be a key factor in modelling.

Paeoniflorin alleviates inflammatory response in IBS-D mouse model via downregulation of the NLRP3 inflammasome pathway with involvement of miR-29a

Paeoniflorin has been traditionally used to treat pain and immunologic derangement in China. However, its detailed mechanism remains to be illuminated. We investigated the mechanism by which paeoniflorin alleviates the inflammatory response in a mouse model of irritable bowel syndrome with predominant diarrhea (IBS-D). C57BL/6 wild type (WT) and miR-29a knockout (KO) mice were randomly divided into control, model, rifaximin, and paeoniflorin groups (n = 7). IBS-D model was induced by single intracolonic instillation of 0.1 mL trinitro-benzene-sulfonic acid (TNBS, 50 mg/mL) combined with restraint stress for seven consecutive days. The treatment groups received rifaximin (100 mg/kg) and paeoniflorin (50 mg/kg) via intragastric administration for seven days, respectively. The results showed that the fecal water content, fecal pellet output, visceral sensitivity, and histopathological score after paeoniflorin treatment were lower than those of the model group in both WT and miR-29a KO mice (P < 0.05). In both lineage mice, damage was observed in the colon tissues of model group, while paeoniflorin treatment partially ameliorated the tissue damage. Serum levels of DAO, DLA, IL-1β, IL-18, TNF-α, and MPO were decreased after paeoniflorin treatment (P < 0.05), with miR-29a KO mice in a lower level compared with that of WT mice. RT-PCR showed that the relative expression of miR-29a, NF-κB (p65), NLRP3, ASC, caspase-1, IL-1β, and TNF-α was downregulated while NKRF was upregulated after paeoniflorin treatment (P < 0.05). Immunohistochemistry showed that intestinal epithelial protein levels of NLRP3, ASC, and caspase-1 decreased while those of Claudin-1 and ZO-1 increased in the paeoniflorin treatment group (P < 0.05). In general, compared with WT mice, NLRP3 inflammasome pathway targets was in much lower expression level than miR-29a KO mice. In conclusion, paeoniflorin could inhibit abnormal activation of the NLRP3 inflammasome pathway by inhibiting miR-29a in IBS-D, thereby relieving the inflammatory response of the intestinal mucosa and reconstructing the intestinal epithelial barrier.

Coptisine attenuates post‑infectious IBS via Nrf2‑dependent inhibition of the NLPR3 inflammasome

Inhibition of the activation of the NLR family pyrin domain‑containing 3 (NLRP3) inflammasome has previously been reported to confer protection against post‑infectious irritable bowel syndrome (PI‑IBS). Coptisine, the second most abundant isoquinoline alkaloid in Coptis chinensis, can inhibit NLRP3 inflammasome activation; however, whether coptisine exhibits protective effects against PI‑IBS remains unclear. In the present study, coptisine significantly reduced gastrointestinal motility and abdominal withdrawal reflex scores in a PI‑IBS rat model that was induced using intragastric administration of Trichinella spiralis larvae. Coptisine treatment significantly decreased the protein levels of oxidative stress markers, 4‑hydroxynonenal, protein carbonyl and 8‑hydroxy‑2'deoxyguanosine, and proinflammatory cytokines, TNF‑α, IL‑1β and IL‑18 in the colon of PI‑IBS rats. Moreover, coptisine treatment significantly increased nuclear factor erythroid 2‑related factor 2 (Nrf2) nuclear translocation and heme oxygenase‑1 protein expression levels, while significantly downregulating the protein expression levels of NLRP3, apoptosis‑associated speck‑like protein containing a CARD and caspase‑1 in the colons of PI‑IBS rats. It is important to note that the anti‑inflammatory effects of coptisine were blocked by the Nrf2 inhibitor ML385. In summary, the present study indicated that coptisine potentially attenuated PI‑IBS in rats via Nrf2‑dependent inhibition of the NLPR3 inflammasome.

Intrarectal Capsazepine Administration Modulates Colonic Mucosal Health in Mice

Antagonism of transient receptor potential vanniloid-1 (TRPV1) and desensitization of transient receptor potential ankyrin-1 (TRPA1) nociceptors alleviate inflammatory bowel diseases (IBD)-associated chronic pain. However, there is limited literature available about their role in regulating the mucosal layer, its interaction with host physiology, and luminal microbial community. The present study focuses on the effects’ intra rectal administration of capsazepine (modulator of TRPA1/TRPV1 expressing peptidergic sensory neurons) on colonic mucus production and gut health. We performed histological analysis, gut permeability alteration, gene expression changes, metabolite profiling, and gut microbial abundance in the ileum, colon, and cecum content of these animals. Intra rectal administration of capsazepine modulates TRPA1/TRPV1-positive nociceptors (behavioral pain assays) and resulted in damaged mucosal lining, increased gut permeability, and altered transcriptional profile of genes for goblet cell markers, mucus regulation, immune response, and tight junction proteins. The damage to mucosal lining prevented its role in enterosyne (short chain fatty acids) actions. These results suggest that caution must be exercised before employing TRPA1/TRPV1 modulation as a therapeutic option to alleviate pain caused due to IBD.

Ulva pertusa, a Marine Green Alga, Attenuates DNBS-Induced Colitis Damage via NF-κB/Nrf2/SIRT1 Signaling Pathways

Inflammatory bowel diseases (IBD) including Crohn's disease (CD) and ulcerative colitis (UC) represent gastrointestinal (GI) disorders associated with varied responses to microbial and environmental agents. Natural compounds have been suggested as a valid approach to the management of various GI diseases, particularly the green alga Ulva pertusa, belonging to the Ulvaceae family, which showed powerful biological properties. Here, we aimed to evaluate the effect and the mechanism of Ulva pertusa treatments in a murine model of DNBS-induced colitis. Colitis was induced by DNBS intrarectal installation (4 mg in 100 μL of 50% ethanol), while Ulva pertusa treatments (doses of 10, 50 and 100 mg/kg) were administered orally daily. Ulva pertusa, at the higher doses of 50 and 100 mg/kg, significantly reduced tissue damage DNBS-induced and the consequent inflammatory cascade via NF-κB inhibition. Furthermore, we demonstrated, for the first time, Ulva pertusa action on the SIRT1/Nrf2 axis, enhancing antioxidant response and the modulation of the apoptosis pathway colitis-induced, regulating the expression of p53, Bax, Bcl-2, and Caspases. Taken together, Ulva pertusa could be considered a valid approach for counteracting and blocking the progression of IBDs through modulation of the NF-κB/SIRT1/Nrf2 axis.

Evaluation of a Gel Containing a Propionibacterium Extract in an In Vivo Model of Wound Healing

Inappropriate wound healing (WH) management can cause significant comorbidities, especially in patients affected by chronic and metabolic diseases, such as diabetes. WH involves several different, partially overlapping processes, including hemostasis, inflammation, cell proliferation, and remodeling. Oxidative stress in WH contributes to WH impairment because of the overexpression of radical oxygen species (ROS) and nitrogen species (RNS). This study aimed to evaluate the in vitro antioxidative action of a gel containing a Propionibacterium extract (Emorsan® Gel) and assess its skin re-epithelialization properties in a mouse model of WH. The scavenging effects of the bacterial extract were assessed in vitro through the ABTS and DPPH assays and in L-929 murine fibroblasts. The effects of the Emorsan® Gel were studied in vivo in a murine model of WH. After WH induction, mice were treated daily with vehicle or Emorsan® Gel for 6 or 12 days. According to the in vitro tests, the Propionibacterium extract exerted an inhibitory effect on ROS and RNS, consequently leading to the reduction in malondialdehyde (MDA) and nitrite levels. Before proceeding with the in vivo study, the Emorsan® Gel was verified to be unabsorbed. Therefore, the observed effects could be ascribed to a local action. The results obtained in vivo showed that through local reduction of oxidative stress and inflammation (IL-1β, TNF-α), the Emorsan® Gel significantly reduced the infiltration of mast cells into the injured wound, leading to the amelioration of symptoms such as itch and skin irritation. Therefore, the Emorsan® Gel improved the speed and percentage of wound area closure by improving the tissue remodeling process, prompting vascular–endothelial growth factor (VEGF) and transforming growth factor (TGF)- β production and reducing the expression of adhesion molecules. Emorsan® Gel, by its ability to inhibit free radicals, could reduce local inflammation and oxidative stress, thus enhancing the speed of wound healing.

A Combination of Mediterranean and Low-FODMAP Diets for Managing IBS Symptoms? Ask Your Gut!

Among other factors, food intolerance is cardinal in triggering irritable bowel syndrome (IBS) symptoms in a significant percentage of patients. As a result, specific dietary patterns are the first-line therapeutic approach. The low-FODMAP diet (LFD) is gaining ground as the most well-documented diet intervention that significantly reduces IBS symptoms. Though the LFD improves symptoms, the diet’s impact on intestinal low-grade inflammation, one of the cardinal mechanisms contributing to symptom development, remains doubtful. On the other hand, the Mediterranean diet (MedDiet) is recommended for chronic low-grade inflammation-related diseases because of its anti-inflammatory properties, derived predominantly from olive oil and phenolic compounds. Thus far, the role of a modified LFD, enriched with the MedDiet’s anti-inflammatory components, has not been evaluated in IBS patients. This review aims to examine the hypothesis of a potential combination of the immunomodulatory effects of the MedDiet with the LFD to improve IBS symptoms.

Efficacy of a Product Containing Xyloglucan and Pea Protein on Intestinal Barrier Function in a Partial Restraint Stress Animal Model

Functional abdominal bloating and distension (FABD) are common and frequent symptoms in patients with pre-existing gastrointestinal (GI) disorders. FABD is characterized by recurrent abdominal fullness and bloating. The pathophysiology of FABD is still unclear. However, the plausible mechanisms involved are small intestinal bacterial overgrowth (SIBO), imbalance of gut microbiota, visceral hypersensitivity, intestinal permeability alteration, and disruption of intestinal barrier function. Thus, the creation of a barrier on the wall of the intestine could represent an alternative therapeutic strategy to prevent FABD. This study aimed to investigate the effect of two natural substances, Xyloglucan (XG) and Pea-protein (PP), known for their mucosal-protective properties, in an in vivo model of Partial restraint-stress (PRS). Our results showed that the pre-treatment with a product containing XG and PP in stressed-rats was able to reduce the number of abdominal contractions and visceral hypersensitivity. Moreover, XG and PP were able to reduce intestinal permeability alteration, restoring tight-junctions (TJs) expression and decreased the lactulose–mannitol ratio, a quantitative marker used to measure intestinal permeability, compared to PRS-group. In conclusion, the data obtained revealed that the product containing XG and PP was able to restore the normal intestinal-barrier function; therefore, it could be considered a therapeutic strategy to manage FABD.

An Integrated Gut Microbiota and Network Pharmacology Study on Fuzi-Lizhong Pill for Treating Diarrhea-Predominant Irritable Bowel Syndrome

Diarrhea-predominant irritable bowel syndrome (IBS-D) is one of the most common chronic functional gastrointestinal diseases with limited treatments. Gut microbiota play an important role in chronic gastrointestinal diseases. In traditional Chinese medicine (TCM), Spleen-Yang deficiency (SYD) is one of the root causes of IBS-D. Fuzi-Lizhong pill (FLZP) is well known for its powerful capacity for treating SYD and has a good clinical effect on IBS-D. However, the mechanism of FLZP on the gut microbiota of IBS-D has not been fully clarified. Our present study aimed to reveal the mechanism of FLZP regulating gut microbiota of IBS-D. The body mass, CCK, MTL, and Bristol fecal character score were used to verify the establishment of the IBS-D model. IL-6, TNF, IL-1β, and IFN-γ were crucial targets screened by network pharmacology and preliminarily verified by ELISA. Eighteen gut microbiota were important for the treatment of IBS-D with FLZP. Bacteroidetes, Blautia, Turicibacter, and Ruminococcus_torques_group were the crucial gut microbiota that FLZP inhibits persistent systemic inflammation in the IBS-D model. Lactobacillus is the crucial gut microbiota that FLZP renovates intestinal immune barrier in the IBS-D model. In summary, FLZP can affect bacterial diversity and community structures in the host and regulate inflammation and immune system to treat IBS-D.

Beneficial effect of KYP-2047, a propyl-oligopeptidase inhibitor, on oral squamous cell carcinoma

Oral squamous cell-carcinoma (OSCC) is a common cancer which arises from the alveolar ridge, buccal mucosa, and tongue. Among OSCC, the incidence of tongue squamous cell-carcinoma (TSCC) is growing all over the world. Oral carcinogenesis has been linked to genetic mutations, chromosomal aberrations and viral factors. Apoptosis and angiogenesis play a key role in the development of oral cancer. Therefore, it is very important discover new therapeutic strategies to counteract oral cancer progression. This study aimed to investigate the effect of KYP-2047 in an in vitro model of TSCC and in vivo CAL27-xenograft model. Our results demonstrated that KYP-2047 was able to reduce TSCCs cell viability at the concentrations of 50 μM and 100 μM. Additionally, KYP-2047 was able to increase Bax, Bad and caspase-3 expression, whereas Bcl-2 and p53 expression were reduced. Moreover, KYP-2047 significantly reduced vascular-endothelial-growth-factor (VEGF) and endothelial-nitric-oxide-synthase (eNOS) expression. In the vivo xenograft model, KYP-2047 at doses of 1 and 5 mg/kg significantly reduced tumor burden and tumor weight, decreasing also angiogenesis markers VEGF and eNOS. Moreover, KYP-2047 increased Bax and reduced Bcl2 expressions. Thus, KYP-2047 could represent a potential therapeutic treatment to counteract tongue oral-cancer growth, thanks its abilities to modulate angiogenesis and apoptosis pathways.

NLRP3 Inflammasome Inhibitor BAY-117082 Reduces Oral Squamous Cell Carcinoma Progression

Oral cancer is one of the most common human malignancies, and its incidence is increasing worldwide. In particular, oral squamous cell carcinoma (OSCC) is characterized by high rates of proliferation, invasiveness, and metastasis. Currently, standard treatment for OSCC includes surgical removal, chemotherapy, and radiotherapy; however, the survival rate of patients with OSCC remains low, thus new therapies are needed. It has been proven that excessive NLRP3 inflammasome activation and apoptosis alteration may contribute to oral cancer progression. This study aimed to investigate the effect of BAY-117082, an NLRP3 inflammasome inhibitor, in an in vitro and in vivo xenograft model of oral cancer. In vitro results revealed that BAY-117082 at concentrations of 5, 10, and 30 µM was able to reduce OSCC cell viability. BAY-117082 at higher concentrations significantly reduced NLRP3, ASC, caspase-1, IL-1β, and IL-18 expression. Moreover, Bax, Bad, and p53 expression were increased, whereas Bcl-2 expression was reduced. Furthermore, the in vivo study demonstrated that BAY-117082 at doses of 2.5 and 5 mg/kg significantly decreased subcutaneous tumor mass, and also reduced NLRP3 inflammasome pathway activation. Therefore, based on these results, the use of BAY-117082 could be considered a promising strategy to counteract oral cancer progression, thanks its ability to modulate the NLRP3 inflammasome and apoptosis pathways.

Inflammasome Signaling Regulates the Microbial-Neuroimmune Axis and Visceral Pain in Mice

Interactions between the intestinal microbiota, immune system and nervous system are essential for homeostasis in the gut. Inflammasomes contribute to innate immunity and brain–gut interactions, but their role in microbiota–neuro–immune interactions is not clear. Therefore, we investigated the effect of the inflammasome on visceral pain and local and systemic neuroimmune responses after antibiotic-induced changes to the microbiota. Wild-type (WT) and caspase-1/11 deficient (Casp1 KO) mice were orally treated for 2 weeks with an antibiotic cocktail (Abx, Bacitracin A and Neomycin), followed by quantification of representative fecal commensals (by qPCR), cecal short chain fatty acids (by HPLC), pathways implicated in the gut–neuro-immune axis (by RT-qPCR, immunofluorescence staining, and flow cytometry) in addition to capsaicin-induced visceral pain responses. Abx-treatment in WT-mice resulted in an increase in colonic macrophages, central neuro-immune interactions, colonic inflammasome and nociceptive receptor gene expression and a reduction in capsaicin-induced visceral pain. In contrast, these responses were attenuated in Abx-treated Casp1 KO mice. Collectively, the data indicate an important role for the inflammasome pathway in functional and inflammatory gastrointestinal conditions where pain and alterations in microbiota composition are prominent.