Berberine improves intestinal epithelial tight junctions by upregulating A20 expression in IBS-D mice

Berberine mitigates diclofenac-induced intestinal mucosal mechanical barrier dysfunction through the restoration of autophagy by inhibiting exosome-mediated lncRNA H19

Small intestine damage caused by diclofenac is called diclofenac enteropathy. Berberine (BBR), a class of isoquinoline alkaloids derived from Berberis vulgaris and Phellodendron amurense, is widely used in intestinal diseases. The present study evaluated the protective effect of BBR on the intestinal mucosal mechanical barrier in diclofenac enteropathy and its possible action mechanism. The in vitro animal experiment revealed that BBR downregulated the expression of long non-coding RNA H19 (lncRNA H19) in the small intestine and exosomes. In the co-culture experiment involving exosomes and intestinal epithelial cell-6 (IEC-6) cells, the results of qRT-PCR, western blotting, and immunofluorescence assays demonstrated that the elevated expression of lncRNA H19 in the small intestine, conveyed via exosomes derived from the diclofenac group, suppressed the expression levels of autophagy-associated protein 5 (Atg 5) and light chain 3 (LC 3), as well as and the tight junction (TJ) proteins zonula occludens-1 (ZO-1), claudin-1, and occluding, relative to the control group. BBR treatment attenuated exosomal lncRNA H19 levels, upregulated the expression of Atg5 and LC3 expression, enhanced TJ protein expression, and increased the light chain 3 (LC3)-II/LC3-I ratio. These findings significantly elucidated that BBR promoted the restoration of autophagy in IECs by inhibiting exosomal lncRNA H19, thereby mitigating the impairment of the intestinal mucosal mechanical barrier function in diclofenac enteropathy. The process involving exosomal lncRNA H19 regulating autophagy, thereby affecting the intestinal mucosal mechanical barrier, offers a novel perspective for the application of BBR in the treatment of diclofenac enteropathy.

The Possible Synergistic Pharmacological Effect of an Oral Berberine (BBR) and Curcumin (CUR) Complementary Therapy Alleviates Symptoms of Irritable Bowel Syndrome (IBS): Results from a Real-Life, Routine Clinical Practice Settings-Based Study

Irritable bowel syndrome (IBS) is a prevalent chronic functional gastrointestinal disorder, characterised by recurrent abdominal discomfort and altered bowel movements. IBS cause a significantly negative impact on quality of life (QoL). Growing pharmacological evidence suggests that berberine (BBR) and curcumin (CUR) may mitigate IBS symptoms through multiple complementary synergistic mechanisms, resulting in the attenuation of intestinal inflammation and regulation of bowel motility and gut functions. In the present observational study conducted under real-life routine clinical practice settings, 146 patients diagnosed with IBS were enrolled by general practitioner clinics and pharmacies in Belgium. For the first time, this study assessed the potential synergistic pharmacological effect of a combined oral BBR/CUR supplement (Enterofytol® PLUS, containing 200 mg BBR and 49 mg CUR) (two tablets daily for 2 months), serving as complementary therapy in the management of IBS. Following the 2-month supplementation, significant improvements were observed in the patients' IBS severity index (IBSSI) (47.5%) and all the primary IBS symptoms, such as abdominal discomfort (47.2%), distension (48.0%), intestinal transit (46.8%), and QoL (48.1%) (all p < 0.0001). The improvement in the patients' IBSSI was independent of age, sex, and IBS sub-types. The patients' weekly maximum stool passage frequency decreased significantly (p < 0.0001), and the stool status normalized (p < 0.0001). The patients' need for concomitant conventional IBS treatment decreased notably: antispasmodics by 64.0% and antidiarrhoeals by 64.6%. Minor adverse effects were reported by a small proportion (7.1%) of patients, mostly gastrointestinal. The majority (93.1%) experienced symptom improvement or resolution, with a high satisfaction rate (82.6%) and willingness to continue the supplementation (79.0%). These findings support the potential synergistic pharmacological role of BBR and CUR in IBS, and their co-supplementation may alleviate IBS symptoms and improve QoL.

Berberine Enhances Intestinal Mucosal Barrier Function by Promoting Vitamin D Receptor Activity

OBJECTIVE

To evaluate if berberine can act on vitamin D receptors (VDR) and thereby regulate the expression of tight junction proteins (TJPs) in irritable bowel syndrame-diarrhea-predominant (IBS-D) rats.

METHODS

The newborn rats were induced into IBS-D rat model via neonatal maternal separation combined with acetic acid chemical stimulation. After modeling, the model was evaluated and rats were divided into the control group and berberine treatment groups (0.85, 1.7 and 3.4 mg/kg, once a day for 2 weeks). The distal colon was obtained and colonic epithelial cells (CECs) were isolated and cultured after IBS-D model evaluation. The vitamin D receptor response element (VDRE) reporter gene was determined in the CECs of IBS-D rats to analyze the effect of berberine on the VDRE promoter. VDR overexpression or silencing technology was used to analyze whether VDR plays a role in promoting intestinal barrier repair, and to determine which region of VDR plays a role in berberine-regulated intestinal TJPs.

RESULTS

The IBS-D rat model was successfully constructed and the symptoms were improved by berberine in a dose-dependent manner (P<0.05). The activity of VDRE promoter was also effectively promoted by berberine (P<0.05). Berberine increased the expression of TJPs in IBS-D CECs (P<0.05). VDR expression was significantly increased after transfection of different domains of VDR when compared to normal control and basic plasmid groups (all P<0.05). RT-qPCR and Western blot results showed that compared with the blank group, expressions of occludin and zonula occludens-1 were significantly higher in VDR containing groups (all P<0.05). Berberine plus pCMV-Myc-VDR-N group exerted the highest expression levels of occludin and zonula occludens-1 (P<0.05).

CONCLUSION

Berberine enhances intestinal mucosal barrier function of IBS-D rats by promoting VDR activity, and the main site of action is the N-terminal region of VDR.

Modulation of the vitamin D receptor by traditional Chinese medicines and bioactive compounds: potential therapeutic applications in VDR-dependent diseases

The Vitamin D receptor (VDR) is a crucial nuclear receptor that plays a vital role in various physiological functions. To a larger extent, the genomic effects of VDR maintain general wellbeing, and its modulation holds implications for multiple diseases. Current evidence regarding using vitamin D or its synthetic analogs to treat non-communicable diseases is insufficient, though observational studies suggest potential benefits. Traditional Chinese medicines (TCMs) and bioactive compounds derived from natural sources have garnered increasing attention. Interestingly, TCM formulae and TCM-derived bioactive compounds have shown promise in modulating VDR activities. This review explores the intriguing potential of TCM and bioactive compounds in modulating VDR activity. We first emphasize the latest information on the genetic expression, function, and structure of VDR, providing a comprehensive understanding of this crucial receptor. Following this, we review several TCM formulae and herbs known to influence VDR alongside the mechanisms underpinning their action. Similarly, we also discuss TCM-based bioactive compounds that target VDR, offering insights into their roles and modes of action.

Decellularized small intestine scaffolds: a potential xenograft for restoration of intestinal perforation

Small intestine perforation is a serious medical condition that requires immediate medical attention. The traditional course of treatment entails resection followed by anastomosis; however, it has complications such as small bowel syndrome (SBS), anastomotic leakage, and fistula formation. Here, a novel strategy is demonstrated, that utilizes the xenogeneic, decellularized goat small intestine as a patch for small intestine regeneration in cases of intestinal perforation. The goat small intestine scaffold underwent sodium dodecyl sulfate decellularization, which revealed consistent, quick, and effective decellularization. Decellularization contributed the least amount of extracellular matrix degradation while maintaining the intestinal architecture. By implanting the decellularized goat small intestine scaffolds (DGSIS) on the chorioallantoic membrane (CAM), no discernible loss of angiogenesis was seen in the CAM region, and this enabled the DGSIS to be evaluated for biocompatibility in ovo. The DGSIS was then xeno-transplanted as a patch on a small intestine perforation rat model. After 30 days post transplant, barium salt used as contrast gastrointestinal X-ray imaging revealed no leakage or obstruction in the small intestine. Histology, scanning electron microscopy, and immunohistochemistry assisted in analyzing the engraftment of host cells into the xeno patch. The xeno-patch expressed high levels of E-cadherin, α-smooth muscle actin (α-SMA), Occludin, Zonnula occluden (ZO-1), Ki 67, and Na+/K+-ATPase. The xeno-patch was consequently recellularized and incorporated into the host without causing an inflammatory reaction. As an outcome, decellularized goat small intestine was employed as a xenograft and could be suitable for regeneration of the perforated small intestine.

Cell-cell communications: new insights into targeting efficacy of phytochemical adjuvants on tight junctions and pathophysiology of various malignancies

Cancer is a cellular impairment disorder characterized by the loss of cell cycle regulation leading to aberrant cell proliferation. Cell-cell communication plays a crucial role in cell signaling which is highly disrupted in various malignancies. Tight junctions (TJs) are major proteins that regulate the proper communication, and the dysregulation of TJ proteins makes these tumor cells more aggressive, leading to tumor invasion and metastasis. Hence targeting TJs might be a novel insight towards addressing these highly invasive, metastatic tumors. Due to the prohibitive costs of treatments, side effects, and development of resistance, herbal medications comprising bioactive ingredients have become more popular for various human ailments. Unfortunately, the importance of natural compounds has significantly reduced due to the development of modern synthetic techniques to formulate drugs. However, the pharmaceutical industry that adopts chemistry-based drug development in combination with high throughput synthesis have not resulted in the expected drug productivity. Hence, the focus was shifted back to natural compounds in search of novel drugs with advanced technology to isolate the biologically active compound from the natural ones. The current review delivers the importance of TJ regulation, promoting it through phytochemicals to target malignant tumor cells.

Natural Products: A Dependable Source of Therapeutic Alternatives for Inflammatory Bowel Disease through Regulation of Tight Junctions

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), can affect the entire gastrointestinal tract and mucosal layer and lead to intestinal damage and intestinal dysfunction. IBD is an inflammatory disease of the gastrointestinal tract that significantly impacts public health development. Monoclonal antibodies and other synthetic medications are currently used to treat IBD, but they are suspected of producing serious side effects and causing a number of other problems with long-term use. Numerous in vitro and in vivo studies have shown that organic macromolecules from plants and animals have an alleviating effect on IBD-related problems, and many of them are also capable of altering enzymatic function, reducing oxidative stress, and inhibiting the production of cytokines and release of proinflammatory transcriptional factors. Thus, in this paper, the natural products with potential anti-IBD activities and their mechanism of action were reviewed, with a focus on the protective effects of natural products on intestinal barrier integrity and the regulation of tight junction protein expression and remodeling. In conclusion, the insights provided in the present review will be useful for further exploration and development of natural products for the treatment of IBD.

Modulating AHR function offers exciting therapeutic potential in gut immunity and inflammation

Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a classical exogenous synthetic ligand of AHR that has significant immunotoxic effects. Activation of AHR has beneficial effects on intestinal immune responses, but inactivation or overactivation of AHR can lead to intestinal immune dysregulation and even intestinal diseases. Sustained potent activation of AHR by TCDD results in impairment of the intestinal epithelial barrier. However, currently, AHR research has been more focused on elucidating physiologic AHR function than on dioxin toxicity. The appropriate level of AHR activation plays a role in maintaining gut health and protecting against intestinal inflammation. Therefore, AHR offers a crucial target to modulate intestinal immunity and inflammation. Herein, we summarize our current understanding of the relationship between AHR and intestinal immunity, the ways in which AHR affects intestinal immunity and inflammation, the effects of AHR activity on intestinal immunity and inflammation, and the effect of dietary habits on intestinal health through AHR. Finally, we discuss the therapeutic role of AHR in maintaining gut homeostasis and relieving inflammation.

The protective effects of electroacupuncture on intestinal barrier lesions in IBS and UC model

Irritable bowel syndrome (IBS) and ulcerative colitis (UC) are two intestinal diseases with different pathological changes. Electroacupuncture (EA) at Zusanli (ST36) on both IBS and UC is widely used in clinic practice. But it is unclear whether acupuncture at one acupoint can treat two different intestinal diseases at different layers of intestinal barrier. To address this question, we explored three intestinal barrier lesions in IBS and UC mice with the aid of transcriptome data analysis and studied the efficacy of EA at ST36 on them. The transcriptome data analysis showed that both UC and IBS had disrupted intestinal barrier in various layers. And both UC and IBS had epithelial barrier lesions with reduction of ZO-1, Occludin and Claudin-1, while UC rather than IBS had the destruction of the mucus barrier with less MUC2 expression. As to the vascular barrier, UC showed a higher CD31 level and mesenteric blood flow reduction, while IBS showed a lower PV-1 level. EA at ST36 can significantly improve the above lesions of intestinal barrier of IBS and UC. Our results gave more details about the comprehensive protective effect of EA for UC and IBS. We guess the effect of acupuncture may be a kind of homeostasis regulation.

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.

Oleuropein Prevents OVA-Induced Food Allergy in Mice by Enhancing the Intestinal Epithelial Barrier and Remodeling the Intestinal Flora

SCOPE

This study assesses whether oleuropein prevents ovalbumin (OVA)-induced food allergy (FA) and investigates the underlying mechanisms.

METHODS AND RESULTS

A Balb/c FA mouse model is established and maintained for 7 weeks. The subjects are administered OVA by oral gavage to induce FA and supplemented with different oleuropein doses (1.00-20.00 mg kg^-1 per day) to evaluate its preventative efficacy. The results indicate that oleuropein effectively alleviates OVA-induced allergy symptoms and promotes temperature elevation in sensitized mice. The secretion of serology-specific OVA-immunoglobulin (Ig)E, OVA-IgG, and histamine is inhibited in the sensitized mice. Oleuropein dramatically upregulates the expression of intestinal tight junction (TJ) proteins, regenerating gene (Reg) IIIγ, and interleukin (IL)-22, enhancing the physical and biochemical barrier function of the intestinal epithelium. Additionally, oleuropein improves the immune homeostasis of the intestinal epithelium by affecting the function of mucosal mast cells and regulatory T (Treg) cells. The disordered intestinal flora of the sensitized mice also improves after oleuropein administration.

CONCLUSIONS

These findings suggest that oleuropein prevents FA by enhancing intestinal epithelial barrier function and improving immune homeostasis and intestinal flora in sensitized mice. Therefore, diets rich in oleuropein should be recommended for people with FA.

Protective effect of berberine against LPS-induced injury in the intestine: a review

Sepsis is a systemic inflammatory condition caused by an unbalanced immunological response to infection, which affects numerous organs, including the intestines. Lipopolysaccharide (LPS; also known as endotoxin), a substance found in Gram-negative bacteria, plays a major role in sepsis and is mostly responsible for the disease's morbidity and mortality. Berberine is an isoquinoline alkaloid found in a variety of plant species that has anti-inflammatory properties. For many years, berberine has been used to treat intestinal inflammation and infection. Berberine has been reported to reduce LPS-induced intestinal damage. The potential pathways through which berberine protects against LPS-induced intestinal damage by inhibiting NF-κB, suppressing MAPK, modulating ApoM/S1P pathway, inhibiting COX-2, modulating Wnt/Beta-Catenin signaling pathway, and/or increasing ZIP14 expression are reviewed.Abbreviations: LPS, lipopolysaccharide; TLR, Toll-like receptor; MD-2, myeloid differentiation factor 2; CD14, cluster of differentiation 14; LBP, lipopolysaccharide-binding protein; MYD88, myeloid differentiation primary response 88; NF-κB, nuclear factor kappa light-chain enhancer of activated B cells; MAPK, mitogen-activated protein kinase; IL, interleukin; TNFα, tumor necrosis factor-alpha; Caco-2, cyanocobalamin uptake by human colon adenocarcinoma cell line; MLCK, myosin light-chain kinase; TJ, tight junction; IκBα, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha; IBS, irritable bowel syndrome; ERK, extracellular signal-regulated kinase; JNK, c-Jun N-terminal kinase (JNK; GVB, gut-vascular barrier; ApoM, apolipoprotein M; S1P, sphingosine-1-phosphate; VE-cadherin, vascular endothelial cadherin; AJ, adherens junction; PV1, plasmalemma vesicle-associated protein-1; HDL, high-density lipoprotein; Wnt, wingless-related integration site; Fzd, 7-span transmembrane protein Frizzled; LRP, low-density lipoprotein receptor-related protein; TEER, transendothelial/transepithelial electrical resistance; COX-2, cyclooxygenase-2; iNOS, inducible nitric oxide synthase; IGF, insulin-like growth factor; IGFBP, insulin-like growth factor-binding protein; ZIP, Zrt-Irt-like protein; PPAR, peroxisome proliferator-activated receptors; p-PPAR, phosphorylated-peroxisome proliferator-activated receptors; ATF, activating transcription factors; SOD, superoxide dismutase; GSH-Px, glutathione peroxidase; SARA, subacute ruminal acidosis; IPEC-J2, porcine intestinal epithelial cells; ALI, acute lung injury; ARDS, acute respiratory distress syndrome.

Maintenance of Intestinal Homeostasis in Diarrhea-Predominant Irritable Bowel Syndrome by Electroacupuncture Through Submucosal Enteric Glial Cell-Derived S-Nitrosoglutathione

Objective: To determine whether electroacupuncture (EA) maintains intestinal homeostasis in diarrhea-predominant irritable bowel syndrome (IBS-D) rats by repairing intestinal barrier function through enteric glial cell (EGC)-derived S-nitrosoglutathione (GSNO).

Methods: Sprague–Dawley rats were randomly divided into a control group (n = 10) and an IBS-D group (n = 20). These rats received senna solution by gavage and chronic unpredictable mild stress for 14 days and were further divided into a model group (n = 10) and an EA group (n = 10). Rats in the EA group were electroacupunctured at ST25 (Tianshu), ST36 (Zusanli), and LR3 (Taichong) for 20 min every day for 14 days. The abdominal withdrawal reflex (AWR), the percentage of time spent in open arms (OT%) in the elevated plus maze test, and the diarrhea index (DI) were measured. Histopathological examination was performed to evaluate the pathological features of the colon after sacrificing the rats. Transmission electron microscopy was used to observe the EGC in the muscle and submucosal layers. Enzyme-linked immunosorbent assay was performed to detect GSNO expression in the colon. Double immunofluorescence labeling was used to detect the colocalized GFAP and GSNO expressions in the muscle and submucosal layers. Plasma FITC-dextran was used to measure intestinal permeability, whereas western blot was used to detect ZO-1 and occludin expressions in the colon.

Results: OT% and ZO-1 and occludin expressions were significantly lower than those of the control group, whereas AWR scores, DI, GSNO expression in the colon, colocalized GFAP and GSNO expressions in the submucosal layer, and intestinal permeability were significantly higher than those of the control group. Structural EGC abnormalities were observed in the model group. After EA treatment, OT% and ZO-1 and occludin expressions increased significantly, whereas AWR scores, DI, GSNO expression, colocalized GFAP and GSNO expressions in the submucosal layer, and intestinal permeability decreased significantly. The EGC structure was then restored to its normal state.

Conclusion: EA treatment downregulates the submucosal EGC–derived GSNO expressions, repairs the intestinal barrier by upregulating the ZO-1 and occludin expression, and improves IBS-D symptoms, including visceral hypersensitivity, anxiety, and diarrhea, suggesting a potential role for EGC-derived GSNO in the regulation of intestinal homeostasis in IBS-D rats.

Anti-Hyperglycemic Agents in the Adjuvant Treatment of Sepsis: Improving Intestinal Barrier Function

Intestinal barrier injury and hyperglycemia are common in patients with sepsis. Bacteria translocation and systemic inflammatory response caused by intestinal barrier injury play a significant role in sepsis occurrence and deterioration, while hyperglycemia is linked to adverse outcomes in sepsis. Previous studies have shown that hyperglycemia is an independent risk factor for intestinal barrier injury. Concurrently, increasing evidence has indicated that some anti-hyperglycemic agents not only improve intestinal barrier function but are also beneficial in managing sepsis-induced organ dysfunction. Therefore, we assume that these agents can block or reduce the severity of sepsis by improving intestinal barrier function. Accordingly, we explicated the connection between sepsis, intestinal barrier, and hyperglycemia, overviewed the evidence on improving intestinal barrier function and alleviating sepsis-induced organ dysfunction by anti-hyperglycemic agents (eg, metformin, peroxisome proliferators activated receptor-γ agonists, berberine, and curcumin), and summarized some common characteristics of these agents to provide a new perspective in the adjuvant treatment of sepsis.

Ameliorative Effects of Humulus japonicus Extract and Polysaccharide-Rich Extract of Phragmites rhizoma in Rats with Gastrointestinal Dysfunctions Induced by Water Avoidance Stress

Chronic stress can cause the gastrointestinal disorders characterized by an altered bowel movement and abdominal pain. Studies have shown that Humulus japonicus extract (HJE) has anti-inflammatory and antidiarrheal effects, and Phragmites rhizoma extract (PEP) has antioxidative and antistress effects. The present study aimed to investigate the possible effects of HJE and PEP in rat models with stress-induced gastrointestinal dysfunctions. The rats were exposed to water avoidance stress (WAS, 1 h/day) for 10 days to induce gastrointestinal disorders. We found that WAS significantly increased fecal pellet output during 1 h stress, gastric emptying, colonic contractility, and permeability compared to the normal rats. Pretreatment with HJE and PEP (0.25 and 0.5 mL/kg, both administered separately) improved the increased gastric emptying and colonic contractility induced by electrical field stimulation, acetylcholine, and serotonin and also alleviated the increased colonic permeability. HJE and PEP also increased the claudin-1 and occludin expressions, reduced by WAS. WAS increased the concentration of TNF-α and TBARS and reduced FRAP. HJE and PEP recovered these effects. HJE and PEP improved the gastrointestinal disorders induced by WAS by upregulating the tight junction protein, possibly acting on cholinergic and serotonergic receptors to abolish the colonic hypercontractility and hyperpermeability and degradation of inflammatory cytokines via an antioxidant effect.

The Role of lncRNAs in Regulating the Intestinal Mucosal Mechanical Barrier

lncRNA is a transcript that is more than 200 bp in length. Currently, evidence has shown that lncRNA is of great significance in cell activity, involved in epigenetics, gene transcription, chromatin regulation, etc. The existence of an intestinal mucosal mechanical barrier hinders the invasion of pathogenic bacteria and toxins, maintaining the stability of the intestinal environment. Serious destruction or dysfunction of the mechanical barrier often leads to intestinal diseases. This review first summarizes the ability of lncRNAs to regulate the intestinal mucosal mechanical barrier. We then discussed how lncRNAs participate in various intestinal diseases by regulating the intestinal mucosal mechanical barrier. Finally, we envision its potential as a new marker for diagnosing and treating intestinal inflammatory diseases.

Mechanism of QingHuaZhiXie Prescription Regulating TLR4-IECs Pathway in the Intervention of Diarrhea Predominant Irritable Bowel Syndrome

To investigate the effect and mechanism of QingHuaZhiXie prescription on diarrhea predominant irritable bowel syndrome (D-IBS), animal models of rats were used in this study. 48 rats were randomly divided into 6 groups, containing one control group, one animal model group (D-IBS group), and four drug intervention groups (low, medium, and high dosage of QingHuaZhiXie prescription and trimebutine maleate intervention group). Abdominal withdrawal reflex (AWR) and Bristol stool form scale were recorded; the expression levels of inflammatory factors (TNF-α and IFN-γ), pathway proteins TLR4, MyD88, NF-κB, and key proteins of tight junction between intestinal epithelial cells (IECs) were detected; the microstructure of intestinal mucosal was observed by hematoxylin and eosin (H&E) staining; MPO activity was detected with immunohistochemical analysis to reflect the inflammation of tissues. Results show that QingHuaZhiXie prescription reduced diarrhea index and intestinal hypersensitivity and intestinal tissue integrity after intervention. MPO activity in QingHuaZhiXie prescription-treated rats was significantly lower relative to their model group. The expression levels of inflammatory factors and TLR4/MyD88/NF-κB pathway proteins were repressed, and the protein levels of occludin and claudin-1 increased. Meanwhile, this study also found that the remission effect of QingHuaZhiXie prescription on D-IBS increased with its dosage increase. Hence, as a therapeutic prescription for D-IBS, QingHuaZhiXie prescription could relieve D-IBS symptoms through balancing the inflammatory factors expression by inhibiting the TLR4/MyD88/NF-κB pathway and maintaining the function and structure of IECs by improving the protein levels of JAM, occludin, claudin-1, and ZO-1.

Berberine improves intestinal barrier function and reduces inflammation, immunosuppression, and oxidative stress by regulating the NF-κB/MAPK signaling pathway in deoxynivalenol-challenged piglets

The aim of this study was to evaluate the effect of berberine (BBR) on the intestinal health of piglets exposed to deoxynivalenol (DON). A total of 180 weaned piglets were randomly allotted to 1 of 3 treatment groups with 10 replication pens per treatment and 6 piglets per pen. The treatments were basal diet, basal diet +4 mg/kg DON, and basal diet +4 mg/kg DON +40 mg/kg BBR. The experiment lasted for 21 d. BBR improved the growth performance of DON-challenged piglets. BBR could inhibit DON-induced intestinal injury by increasing the expression of serum antioxidant enzymes and T cell surface antigens and reducing the release of proinflammatory cytokines in the small intestine. BBR significantly increased the protein expression levels of zonula occludens 1 (ZO-1), Occludin and Claudin-1 in the ileal and jejunal mucosa and increased the morphological parameters of the jejunum. Moreover, we found that BBR significantly reduced the DON-induced gene and protein expression levels of ERK, JNK, and NF-κB in the jejunum and ileum. In conclusion, BBR can regulate DON-induced intestinal injury, immunosuppression and oxidative stress by regulating the NF-κB and MAPK signaling pathways and ultimately maintain the intestinal health of piglets.

Sinapic Acid Alleviated Inflammation-Induced Intestinal Epithelial Barrier Dysfunction in Lipopolysaccharide- (LPS-) Treated Caco-2 Cells

The integrity and permeability of the intestinal epithelial barrier are important indicators of intestinal health. Impaired intestinal epithelial barrier function and increased intestinal permeability are closely linked to the onset and progression of various intestinal diseases. Sinapic acid (SA) is a phenolic acid that has anti-inflammatory, antihyperglycemic, and antioxidant activities; meanwhile, it is also effective in the protection of inflammatory bowel disease (IBD), but the specific mechanisms remain unclear. Here, we evaluated the anti-inflammatory of SA and investigated its potential therapeutic activity in LPS-induced intestinal epithelial barrier and tight junction (TJ) protein dysfunction. SA improved cell viability; attenuated epithelial permeability; restored the protein and mRNA expression of claudin-1, ZO-1, and occludin; and reversed the redistribution of the ZO-1 and claudin-1 proteins in LPS-treated Caco-2 cells. Moreover, SA reduced the inflammatory response by downregulating the activation of the TLR4/NF-κB pathway and attenuated LPS-induced intestinal barrier dysfunction by decreasing the activation of the MLCK/MLC pathway. This study demonstrated that SA has strong anti-inflammatory activity and can alleviate the occurrence of high intercellular permeability in Caco-2 cells exposed to LPS.

Wild plants used by the Lhoba people in Douyu Village, characterized by high mountains and valleys, in southeastern Tibet, China

BACKGROUND

Douyu Village, inhabited by the Lhoba people, is situated within the Eastern Himalayas, in southeastern Tibet, China. The village is located among high mountains and valleys, which feature complex terrain with cold and dry climates and distinctive vegetation types and species. The Lhoba people in this village are isolated from other groups in China. The Lhoba people have lived in this village since the 15th century and mainly depended on gathering, hunting, and swidden agriculture before the 1960s. Because they have a long history and live under extreme climatic, geographical, and ecological conditions, the Lhoba people in Douyu Village may have unique traditional knowledge about wild plants. Thus, this research aims to record the traditional botanical knowledge of the Lhoba people in Douyu.

METHODS

An ethnobotanical study was conducted on the Lhoba people in Douyu Village in Longzi County, Tibet, China. Semi-structured interviews and group discussions with informed consent were used in the study. We interviewed 41 informants (14 key informants) between 18 and 75 years of age. All information was collected, organized, and compiled into "use reports" for quantitative analysis. The informant consensus factor (ICF) was used to determine the homogeneity of the informants' knowledge of medicinal plants, while the cultural importance index (CI) was used to estimate the cultural importance of shared species.

RESULTS

A total of 91 wild species (90 vascular plants and 1 fungus) belonging to 71 genera and 39 families utilized by the Lhoba people in Douyu were documented. Of these species, Pimpinella xizangense and Wikstroemia lungtzeensis are endemic to Longzi County, while Sinopodophyllum hexandrum and Paeonia ludlowii are endangered species in China. All habitats, from the field vegetation at the valley bottoms to the alpine shrubland and meadows, were used for plant collection, and the numbers of species of plants collected from the various vegetation types (except for fields) decreased with increasing altitude. Our study found that 55 species are edible plants and fungi, 29 species are medicinal plants, and 38 species are used for other purposes. Medicinal plants are used for 11 categories of diseases, among which diseases of blood-forming organs (ICF = 0.96) and gastrointestinal diseases (ICF = 0.95) exhibited the highest ICF values. Based on the CI values, the most important plants in this study area are Berberis xanthophloea, B. kongboensis, Sinopodophyllum hexandrum, Vicatia thibetica, and Hippophae rhamnoides subsp. gyantsensis. Moreover, a comparison of the wild plants used by Lhoba ethnic groups in three counties in China showed significant differences among these regions.

CONCLUSIONS

Our study demonstrates that the wild plants utilized by the Lhoba people in Douyu Village are highly diverse, at 90 plant and one fungal species, which reflects not only the number of species but also their diversified functions. The extreme climatic, geographical, and ecological conditions of Douyu within the high mountains and valleys of the Eastern Himalayas potentially affect the Lhoba people's culture, including plant utilization practices, and contribute to the rich diversity of the wild plants used by the local people.

Association between serum TNF-α and sarcopenia in liver cirrhosis

Background/Aims

Sarcopenia is an independent prognostic factor of liver cirrhosis (LC). However, the association between LC-related systemic inflammation and sarcopenia is unclear.

Methods

Sprague-Dawley rats were treated with thioacetamide (TAA) or saline as a control. Rifaximin was administered to TAA-induced LC rats. Enzyme-linked immunosorbent assay was performed to measure inflammatory mediators in rat serum. RT-PCR was performed to measure the molecular expression in tissues. Hematoxylin and eosin (H&E) staining and immunohistochemistry were performed to investigate tissue pathology. Serum tumor necrosis factor-α levels, liver stiffness (LS), and the L3 skeletal muscle index (L3SMI) were measured in 60 patients with chronic liver disease.

Results

LC and sarcopenia were successfully induced by TAA. Serum TNF-α levels were increased in LC rats and correlated with myostatin expression, muscle weight, and myofiber diameter. The expression of intestinal occludin and zona occludens-1 was reduced in LC rats and associated with serum TNF-α levels and sarcopenia. In patients with LS ≥7 kPa or sarcopenia, serum TNF-α levels were significantly increased, which was also confirmed when we raised the LS cutoff to 10 kPa. The L3SMI was inversely correlated with serum TNF-α levels in patients with LS ≥7 kPa. TNF-α was reduced by rifaximin, which might have resulted in reduced expression of muscular MuRF1 and myostatin and improvements in myofiber diameters within muscle tissues.

Conclusions

These results suggest that serum TNF-α is associated with LC-related sarcopenia. Rifaximin might be effective in reducing serum TNF-α levels and improving sarcopenia in LC, but these results need to be validated in future studies.

Puerarin from Pueraria lobata alleviates the symptoms of irritable bowel syndrome-diarrhea

As a functional bowel disorder, irritable bowel syndrome (IBS), especially IBS-diarrhea (IBS-D), affects approximately 9-20% of the population worldwide. Classical treatments for IBS usually result in some side effects and intestinal microbial disorders, which inhibit the clinical effects. Natural edible medicines with beneficial effects and few side effects have received more attention in recent years. Puerarin is the main active ingredient in pueraria and has been used in China to treat splenasthenic diarrhea and as a natural food in folk medicine for hundreds of years. However, there have been no reports of using puerarin in the treatment of IBS-D, and the underlying mechanism is also still unclear. In this study, a comprehensive model that could reflect the symptoms of IBS-D was established by combining neonatal maternal separation (NMS) and adult colonic acetic acid stimulation (ACAAS) in rats. The results showed that puerarin could reverse the abdominal pain and diarrhea in IBS-D rats. The therapeutic effect was realized by regulating the richness of the gut microbiota to maintain the stabilization of the intestinal micro-ecology. Furthermore, the possible mechanism might be related to the activity of the hypothalamic-pituitary-adrenal (HPA) axis by the suppressed expression of corticotropin-releasing hormone receptor (CRF) 1. At the same time, intestinal function was improved by enhancing the proliferation of colonic epithelial cells by upregulating the expression of p-ERK/ERK and by repairing the colonic mucus barrier by upregulating occludin expression. All these results suggest that puerarin could exert excellent therapeutic effects on IBS-D.

LncRNA H19 as a Competing Endogenous RNA to Regulate AQP Expression in the Intestinal Barrier of IBS-D Patients

Objective

The study aimed to investigate the role of Long non-coding RNA (LncRNA) H19 in the pathogenesis of Diarrhea Irritable Bowel Syndrome (IBS-D), and further to the regulatory effect of LncRNA H19 on AQP1, 3 in the intestinal mucosa of IBS-D patients, so as to seek a new way to elucidate the mechanism of IBS in clinic.

Methods

The levels of LncRNA H19, AQP1, and AQP3 were detected in colonic tissues of IBS-D patients, compared with that in healthy controls. Through RNA gene interference and activation methods, small activating RNA (saRNA) and small interfering (siRNA) were transfered into Caco-2 cells in vitro experiment, and sub-group for two control group, siH19 empty vector group, siH19 interference group, overexpression H19 vector group, and overexpression H19 empty vector group. Quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot were applied to evaluate the expression levels of LncRNA H19 and the amount of AQP1 and AQP3 protein expression, respectively.

Results

Compared with healthy volunteers, the levels of LncRNA H19, AQP1, and AQP3 in the colonic mucosa of IBS-D patients were significantly decreased (P < 0.05). The results in vitro transfection experiment revealed that the level of LncRNA H19 in the siH19 interference group was significantly declined (P < 0.05), while there was a remarkable increase in the overexpression H19 vector group (P < 0.05), compared with the corresponding control groups. The expression of AQP1 and AQP3 in Caco-2 cells was of positive correlation with the level of LncRNA H19.

Conclusion

That the down-regulation of LncRNA H19 resulted in the expression changes of AQP1 and AQP3 may play an important role in the occurrence and development of IBS-D.

The Aging Bowel Dysfunction and Elderly Vulnerability towards COVID-19 Infection

Severe acute respiratory syndrome coronavirus 2, primarily a respiratory tract virus, also affects the enteric organs. The most affected sector of the community are the retirement and nursing home elderly residents. Along their life the senescent gastrointestinal functions are deteriorating and failing to fully execute their digestive, absorptive, mucosal barriers, and immune protective duties. Adding the decreased motility, increased intestinal permeability, dysbiosis, morbid chronic disease background, the consumed polypharmacy enteric adverse effects to the presence of the SARS-CoV-2 host receptor along the intestinal tracts put the basis for the current hypothesis. It is hypothesized that the disadvantages and failures of the aging enteric tract contribute to the elderly morbidity and mortality during the current new coronavirus pandemic. In a more optimistic look, several nutraceuticals can prevent or restore the dysfunctional intestinal barrier functions, mainly in the elderly and potentially in those who are SARS-CoV-2 infected.

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

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a multifactorial chronic gastrointestinal disorder characterized by inflammation and immune response. In this context, NLRP3 over-activation is associated with a breakdown of enteric-immune balance related to IBS-D. The aim of this study was to evaluate the effect of the inflammasome inhibitor, BAY 11-7082, in a rat model of IBS-D. Syndrome was induced by intracolonic instillation of 1 mL 4% acetic acid at 8 cm proximal to the anus for 30 s and sacrificed 2 weeks after IBS-D induction. BAY 11-7082 (10 and 30 mg/kg) was administered daily by oral gavage. The results obtained showed that the treatment with BAY 11-7082 (30 mg/kg) significantly reduced tissue injury characterized by edema, neutrophil infiltration, and loss of colon structure. We demonstrated that BAY 11-7082 treatment inhibited NLRP3 inflammasome activation and NF-kB translocation, reducing inflammatory mediators. Moreover, treatment with BAY 11-7082 restored tight junction alteration following IBS-D induction and reduced the restraint stress. Taken together, our data demonstrate that IBS-D induced NLRP3 inflammasome pathway activation, accompanied by the production of proinflammatory response. The modulation of the inflammosome pathway with BAY 11-7082 inhibitor significantly reduced pathological signs of IBS-D, therefore, can be considered a valuable strategy to reduce the development of IBS-D.

Perspective: Prospects for Nutraceutical Support of Intestinal Barrier Function

Impairment of intestinal barrier function is linked to certain pathologies and to aging, and can be a cause of bacterial infections, systemic and hepatic inflammation, food allergies, and autoimmune disorders. The formation and maintenance of intestinal tight junctions is supported by glucagon-like peptide-2 (GLP-2), which via insulin-like growth factor I activity boosts phosphoinositide 3-kinase/Akt/mammalian target of rapamycin complex 1 (PI3K/Akt/mTORC1) signaling in enterocytes. 5'-AMP-activated protein kinase (AMPK) activity as well as estrogen receptor-β (ERβ) activity are also protective in this regard. Conversely, activation of mitogen-activated protein kinases (MAPKs) and cellular Src (c-Src) under inflammatory conditions can induce dissociation of tight junctions. Hence, nutraceuticals that promote GLP-2 secretion from L cells-effective pre/probiotics, glycine, and glutamine-as well as diets rich in soluble fiber or resistant starch, can support intestinal barrier function. AMPK activators-notably berberine and the butyric acid produced by health-promoting microflora-are also beneficial in this regard, as are soy isoflavones, which function as selective agonists for ERβ. The adverse impact of MAPK and c-Src overactivation on the intestinal barrier can be combatted with various antioxidant measures, including phycocyanobilin, phase 2-inducer nutraceuticals, and N-acetylcysteine. These considerations suggest that rationally designed functional foods or complex supplementation programs could have clinical potential for supporting and restoring healthful intestinal barrier function.

How Dysregulated Ion Channels and Transporters Take a Hand in Esophageal, Liver, and Colorectal Cancer

Over the last two decades, the understanding of how dysregulated ion channels and transporters are involved in carcinogenesis and tumor growth and progression, including invasiveness and metastasis, has been increasing exponentially. The present review specifies virtually all ion channels and transporters whose faulty expression or regulation contributes to esophageal, hepatocellular, and colorectal cancer. The variety reaches from Ca²⁺, K⁺, Na⁺, and Cl^- channels over divalent metal transporters, Na⁺ or Cl^- coupled Ca²⁺, HCO₃^- and H⁺ exchangers to monocarboxylate carriers and organic anion and cation transporters. In several cases, the underlying mechanisms by which these ion channels/transporters are interwoven with malignancies have been fully or at least partially unveiled. Ca²⁺, Akt/NF-κB, and Ca²⁺- or pH-dependent Wnt/β-catenin signaling emerge as cross points through which ion channels/transporters interfere with gene expression, modulate cell proliferation, trigger epithelial-to-mesenchymal transition, and promote cell motility and metastasis. Also miRs, lncRNAs, and DNA methylation represent potential links between the misexpression of genes encoding for ion channels/transporters, their malfunctioning, and cancer. The knowledge of all these molecular interactions has provided the basis for therapeutic strategies and approaches, some of which will be broached in this review.

Synergistic Effect of Berberine-Based Chinese Medicine Assembled Nanostructures on Diarrhea-Predominant Irritable Bowel Syndrome In Vivo

Diarrhea-predominant irritable bowel syndrome (IBS-D) is one common chronic functional disease of the digestive system with limited treatments. The microbiota–gut–brain axis (MGBA) has a central function in the pathogeny of IBS-D, which includes the participation of many various factors, such as brain-gut peptides (BGPs), immune inflammation, and intestinal flora. Inspired by the drug combination in traditional Chinese medicine (TCM), our previous study discovered that berberine (BBR) and baicalin (BA) could form natural self-assemblies as BA-BBR nanoparticles (BA-BBR NPs) and showed synergistic effects against IBS-D. Here, we investigated the synergistic effects of BA-BBR NPs on IBS-D model mice induced by chronic restraint stress plus Senna alexandrina Mill decoction with the influence on MGBA. BA-BBR NPs showed the best therapeutic effect on improving visceral hypersensitivity and diarrhea on IBS-D model mice, compared with BBR, BA, and BA/BBR mixture. Furthermore, BA-BBR NPs significantly (P<0.05) reduced the levels of 5-hydroxytryptamine (5-HT), vasoactive intestinal polypeptide (VIP) and choline acety transferase (CHAT) in colon tissues or of serum from BGPs; it lowered the expressions of the nuclear factor kappa-B (NF-κB) in colon tissues and changed the levels of basophil granulocyte (BASO) and leukomonocyte (LYMPH) in whole blood from immune inflammation; it altered the intestinal flora of Bacteroidia, Deferribacteres, Verrucomicrobia, Candidatus_Saccharibacteria, and Cyanobacteria from intestinal flora. In conclusion, BA-BBR NPs, after forming the natural self-assembly between BBR and BA, promoted the synergistic effect on IBS-D mice than the sum of BBR and BA effects, based to the formation of self-assemblies rather than the simple mixing. It further proved that synergistic effect of BA-BBR NPs on IBS-D mice might be related to BGPs, immune inflammation, and intestinal flora from three important interrelated components of MGBA. This study will provide a novel idea for the interpretation of TCM compatibility theory and provide the basis for BA-BBR NPs as a medicinal plant-derived natural and efficient nanomaterial for clinical use.