Rebamipide promotes healing of colonic ulceration through enhanced epithelial restitution

Immunological Regulation of Gut-Tropic Immune Cells by Extracellular Vesicles

The remarkable diversity of lymphocytes, essential components of the immune system, serves as an ingenious mechanism for maximizing the efficient utilization of limited host defense resources. While cell adhesion molecules, notably in gut-tropic T cells, play a central role in this mechanism, the counterbalancing molecular details have remained elusive. Conversely, we've uncovered the molecular pathways enabling extracellular vesicles secreted by lymphocytes to reach the gut's mucosal tissues, facilitating immunological regulation. This discovery sheds light on immune fine-tuning, offering insights into immune regulation mechanisms.

Further insights into the impact of rebamipide on gentamicin-induced nephrotoxicity in rats: modulation of SIRT1 and β-catenin/cyclin D1 pathways

Gentamicin (GM) is an effective antibiotic administered to treat acute Gram-negative infections. Nevertheless, its clinical application is limited due to nephrotoxicity. Therefore, our research aimed to investigate the potential renoprotective impact of rebamipide (RBM), a gastroprotective drug, on GM-induced kidney damage in rats, as well as putative nephroprotective pathways. RBM was orally administered (100 mg/kg/d for 14 d) commencing 7 d before the administration of GM (100 mg/kg/d, intraperitoneally). Nephrotoxicity was elucidated, and the silent information regulator 1 (SIRT1) and β-catenin/cyclin D1 pathways were assessed. GM induced a significant elevation in the serum levels of creatinine, blood urea nitrogen (BUN), and kidney injury molecule-1 (KIM-1), as well as the relative kidney index. In addition, GM increased lipid peroxidation and lowered total antioxidant capacity (TAC) level and superoxide dismutase (SOD) activity. GM administration also demonstrated a significant amplification in tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), nuclear factor-κappa B p65 (NF-κB p65), p38 mitogen-activated protein kinase (p38 MAPK), and caspase-3 kidney levels, as well as B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 ratio. Notably, RBM treatment amended all these changes induced by GM. Furthermore, the potential role of SIRT1 and β-catenin-dependent signaling pathways in GM-induced renal injury was assessed. Our findings showed that GM-treated rats demonstrated a substantial decrease in SIRT1, nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) along with an increase in β-catenin, forkhead box O-3a (FOXO-3a), and cyclin D1 protein expressions. RMB treatment markedly attenuated the deterioration caused by GM on these pathways. Additionally, RBM alleviated the GM-induced deleterious kidney tissue histopathology. In conclusion, our findings have verified that RBM can halt GM-induced renal injury by partly modulating SIRT1 and β-catenin pathways.

Efficacy and safety of 1% and 2% rebamipide clear solution in dry eye disease: a multicenter randomized trial

BACKGROUND

To evaluate the efficacy of 1% and 2% rebamipide clear solution in the treatment of dry eye disease (DED).

METHODS

Two hundred twenty patients with DED were randomly assigned to one of three groups: the 1% rebamipide, 2% rebamipide, or placebo (eye drops containing the same ingredients, except for the active components). Each eye drop was instilled four times daily for 12 weeks. Changes in tear film break-up time (TBUT), corneal and conjunctival staining score, Schirmer 1 test, and the Ocular Surface Disease Index (OSDI) from baseline to 12-week visit between the study groups were compared for efficacy assessment.

RESULTS

The mean age of study patients was 43.8±14.2 years. The 1% and 2% rebamipide groups showed greater improvement in TBUT (1.99±1.87 and 2.02±2.21 s) at 12 weeks from baseline than the placebo group (1.25±2.93 s). The 2% rebamipide group showed greater improvement in the corneal staining score (- 3.15±2.00) at 12 weeks from baseline than the placebo group (- 2.85±1.80). The 1% and 2% rebamipide groups showed improvement in Schirmer 1 test (1.27±3.86 and 1.50±4.14 mm) at 12 weeks of treatment, but not the placebo group (0.55±2.99 mm). Both the rebamipide groups and the placebo group showed significantly improved OSDI after treatment for 12 weeks; however, there was no significant difference among the three groups.

CONCLUSIONS

1% and 2% rebamipide clear solutions are an effective therapeutic option for improving TBUT and tear volume, and stabilizing the corneal staining score in DED.

The effect of rebamipide on non-steroidal anti-inflammatory drug-induced gastro-enteropathy: a multi-center, randomized pilot study

BACKGROUND/AIMS

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly-used medications, and ailments such as arthritis or heart disease, require long-term use of these drugs, which can induce gastroenteropathy with bleeding and ulcers. This study investigated the associations between efficacy, safety, and gastrointestinal symptoms linked to rebamipide and proton pump inhibitor administration in patients requiring long-term NSAID use.

METHODS

This study was a multi-center, randomized, open-labeled, pilot design.

RESULTS

Thirty-three patients were included. Of these, 15 were included in the study group and 18 were in the control group. NSAID-induced gastric ulcers, which were the primary outcome of this study, did not occur in either the study or control group. Changes in the number of small bowel erosions and ulcers were -0.6 ± 3.06 in the study group and 1.33 ± 4.71 in the control group. The number of subjects with mucosal breaks (defined as multiple erosions and/or ulcers) was three (20%) in the study group and six (40%) in the control group (p = 0.427). No serious adverse events occurred in either group. However, dyspepsia and skin rashes occurred in six patients (31.58%) in the study group and 13 (65%) in the control group (p = 0.036).

CONCLUSION

Although statistically significant differences were not generated, possibly as a result of the small sample size, mucosal breaks observed via capsule endoscopy revealed that rebamipide was likely to be more effective than lansoprazole in preventing small intestine damage caused by NSAIDs. Furthermore, fewer side-effects emerged with rebamipide.

Erosive and ulcerative lesions of the digestive tract: optimization of diagnosis and management tactics

Erosive and ulcerative lesions of the digestive tract are one of the most pressing problems in the clinic of internal diseases due to the extremely widespread prevalence, the presence of severe complications, often fatal, diagnostic difficulties due to the presence of a large number of asymptomatic pathologies and difficulties in the rational choice of therapy. Particularly noteworthy is the data that during the global pandemic of Covid-19 infection, it is capable, quite often, of causing the development of erosive and ulcerative lesions of the gastrointestinal tract. In this regard, it seems important to use drugs that can not only prevent the occurrence of erosive and ulcerative lesions and strictures throughout the gastrointestinal tract, but also effectively achieve epithelialization of injuries to the mucous membrane of the oral cavity, esophagus, stomach, small and large intestine. One of them is Rebamipid-CZ, which has a fairly high safety and efficacy profile. It seems important to consider the issues of optimizing the prevention and treatment of erosive and ulcerative lesions of various parts of the gastrointestinal tract of various etiologies, taking into account the possibility of using rebamipide both as part of complex therapy and in isolation.

Functional gastrointestinal disorders. Overlap syndrome Clinical guidelines of the Russian Scientific Medical Society of Internal Medicine and Gastroenterological Scientific Society of Russia

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Computational drug repositioning of atorvastatin for ulcerative colitis

OBJECTIVE

Ulcerative colitis (UC) is a chronic inflammatory disorder with limited effective therapeutic options for long-term treatment and disease maintenance. We hypothesized that a multi-cohort analysis of independent cohorts representing real-world heterogeneity of UC would identify a robust transcriptomic signature to improve identification of FDA-approved drugs that can be repurposed to treat patients with UC.

MATERIALS AND METHODS

We performed a multi-cohort analysis of 272 colon biopsy transcriptome samples across 11 publicly available datasets to identify a robust UC disease gene signature. We compared the gene signature to in vitro transcriptomic profiles induced by 781 FDA-approved drugs to identify potential drug targets. We used a retrospective cohort study design modeled after a target trial to evaluate the protective effect of predicted drugs on colectomy risk in patients with UC from the Stanford Research Repository (STARR) database and Optum Clinformatics DataMart.

RESULTS

Atorvastatin treatment had the highest inverse-correlation with the UC gene signature among non-oncolytic FDA-approved therapies. In both STARR (n = 827) and Optum (n = 7821), atorvastatin intake was significantly associated with a decreased risk of colectomy, a marker of treatment-refractory disease, compared to patients prescribed a comparator drug (STARR: HR = 0.47, P = .03; Optum: HR = 0.66, P = .03), irrespective of age and length of atorvastatin treatment.

DISCUSSION & CONCLUSION

These findings suggest that atorvastatin may serve as a novel therapeutic option for ameliorating disease in patients with UC. Importantly, we provide a systematic framework for integrating publicly available heterogeneous molecular data with clinical data at a large scale to repurpose existing FDA-approved drugs for a wide range of human diseases.

PDE9 Inhibitor PF-04447943 Attenuates DSS-Induced Colitis by Suppressing Oxidative Stress, Inflammation, and Regulating T-Cell Polarization

Ulcerative colitis (UC) is a form of inflammatory bowel disease, which manifests as irritation or swelling and sores in the large intestine in a relapsing and remitting manner. In a dextran sulfate sodium sulfate (DSS)-induced UC model in female mice, we found that the levels of cyclic guanosine monophosphate (cGMP) are reduced, while the expression of phosphodiesterase 9A (PDE9A) is highest among all phosphodiesterase (PDEs). Since PDE9 has the highest affinity toward cGMP, we evaluated the selective PDE9 inhibitor PF-04447943 (PF) as a potential candidate for UC treatment. PF has been extensively studies in cognitive function and in sickle cell disease, but not in models for inflammatory bowel disease (IBD). Therefore, we used female C57BL/6 mice treated with 3% DSS alone or co-treated with PF or sulfasalazine (SASP) to study the body weight, colon length, histopathology, and measure superoxide dismutase (SOD), malondialdehyde (MDA), and cGMP level, as well as cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-17 (IL-17), interleukin-12/23 (IL-12/23), interleukin-10 (IL-10), and pathways including nuclear factor kappa B (NF-κB), signal transducer and activator of transcription 3 (STAT3), and inflammasome activation. In addition, the number of dendritic cells (DC) and regulatory T cells (Treg cell) was assessed in the spleen, lymph node, and colon using flow cytometry. DSS reduced the number of goblet cells, decreased colon lengths and body weights, all of them were attenuated by PF treatment. It also suppressed the elevated level of inflammatory cytokines and increased level the anti-inflammatory cytokine, IL-10. PF treatment also reduced the DSS-induced inflammation by suppressing oxidative stress, NF-κB, STAT3, and inflammasome activation, by upregulating nuclear factor erythroid 2-related factor 2 (Nrf-2) and its downstream proteins via extracellular signal-regulated kinase (ERK) phosphorylation. Importantly, PF reversed imbalance in Treg/T helper 17 cells (Th17) cells ratio, possibly by regulating dendritic cells and Treg developmental process. In summary, this study shows the protective effect of a PDE9A inhibitor in ulcerative colitis by suppressing oxidative stress and inflammation as well as reversing the Treg/Th17 cells imbalance.

Rectal administration of carbon monoxide inhibits the development of intestinal inflammation and promotes intestinal wound healing via the activation of the Rho-kinase pathway in rats

The inhalation of carbon monoxide (CO) gas and the administration of CO-releasing molecules were shown to inhibit the development of intestinal inflammation in a murine colitis model. However, it remains unclear whether CO promotes intestinal wound healing. Herein, we aimed to evaluate the therapeutic effects of the topical application of CO-saturated saline enemas on intestinal inflammation and elucidate the underlying mechanism. Acute colitis was induced with trinitrobenzene sulfonic acid (TNBS) in male Wistar rats. A CO-saturated solution was prepared via bubbling 50% CO gas into saline and was rectally administrated twice a day after colitis induction; rats were sacrificed 3 or 7 days after induction for the study of the acute or healing phases, respectively. The distal colon was isolated, and ulcerated lesions were measured. In vitro wound healing assays were also employed to determine the mechanism underlying rat intestinal epithelial cell restitution after CO treatment. CO solution rectal administration ameliorated acute TNBS-induced colonic ulceration and accelerated ulcer healing without elevating serum CO levels. The increase in thiobarbituric acid-reactive substances and myeloperoxidase activity after induction of acute TNBS colitis was also significantly inhibited after CO treatment. Moreover, the wound healing assays revealed that the CO-saturated medium enhanced rat intestinal epithelial cell migration via the activation of Rho-kinase. In addition, the activation of Rho-kinase in response to CO treatment was confirmed in the inflamed colonic tissue. Therefore, the rectal administration of a CO-saturated solution protects the intestinal mucosa from inflammation and accelerates colonic ulcer healing through enhanced epithelial cell restitution. CO may thus represent a novel therapeutic agent for the treatment of inflammatory bowel disease.

[Rebamipide: evidence base for use in gastroenterology]

Rebamipide is a cytoprotective drug that has been used in practical gastroenterology for 30 years. This article summarizes the main results of the most relevant clinical studies of rebamipide in diseases of various parts of the gastrointestinal tract, including the esophagus, stomach, small and large intestine.

Pharmacological and clinical feature of rebamipide: new therapeutic targets

Rebamipide is a cytoprotector developed in Japan where it has been successfully used for the treatment of stomach diseases for 30 years. Initially discovered effects of the drug included the induction of prostaglandins and the elimination of free oxygen radicals. Recent studies discovered new therapeutic targets of the drug, its new forms that made possible using rebamipid for the treatment of such diseases as NSAID enteropathy, ulcerative colitis, radiation colitis, pouchitis, enteropathy with impaired membrane digestion. It is used in endoscopy, ophthalmology, chemotherapy, rheumatology. The aim of this review is to present current information about the pharmacological and clinical feature of rebamipide and to study its therapeutic potential.

Rebamipide-loaded chitosan nanoparticles accelerate prostatic wound healing by inhibiting M1 macrophage-mediated inflammation via the NF-κB signaling pathway

A large proportion of benign prostatic hyperplasia (BPH) patients suffer from lower urinary tract symptoms after surgery due to the presence of prostatic urothelium wounds. Rebamipide (RBM) exerts wound healing promotion and anti-inflammatory effects on various tissues, including the urothelium. However, intravesical administration of RBM is hindered due to its low solubility and resulting unsustainable drug concentrations in the bladder. In this study, RBM-loaded chitosan nanoparticles (RBM/CTS NPs) were prepared using the ionic cross-linking method. Physicochemical characteristics and the wound healing promotion effect, as well as in vitro influence on macrophages were evaluated. The results show that RBM/CTS NPs are spherical with uniform size distribution, while slower and sustained in vitro release of RBM is presented. In vivo, faster wound healing and improved re-epithelialization progress were observed after treatment with RBM/CTS NPs in a model of thulium laser resection of the prostate (TmLRP). The degree of local inflammatory response decreased, as confirmed by decreasing numbers of pro-inflammatory M1 phenotype macrophages and levels of IL-1β, IL-6, IL-12 and TNF-α in the urine of canines. We also found that RBM/CTS NPs suppress macrophage M1 polarization induced by lipopolysaccharide and interferon-γ and inhibit the activation of the NF-κB signaling pathway. Therefore, as a novel therapeutic strategy, intravesical administration of RBM/CTS NPs can effectively avoid drug intolerance and drug wastage, accelerating the postoperative wound repairing of the prostatic urethra by suppressing macrophage M1 phenotype polarization.

Partially hydrolyzed guar gum enhances colonic epithelial wound healing via activation of RhoA and ERK1/2

BACKGROUND AND AIMS

Healing of the intestinal mucosal epithelium was found to be a critical factor in the treatment of inflammatory bowel disease (IBD). In this study, we provide further evidence that partially hydrolyzed dietary fiber (PHGG) enhances colonic epithelial cell wound healing, and partially characterize the mechanism that governs this process.

MATERIALS AND METHODS

Young adult mouse colonic (YAMC) epithelial cells were scraped with a 10 μl micro-pipette tip to denude a round of the monolayer and were incubated with PHGG. The area of cell migration was measured using Image J software. Meanwhile, Rho activation assays were utilized to monitor Rho activation levels. To assess in vivo effects, C57B6 mice were treated with DSS for 7 days and then provided food supplemented with PHGG for 8 days.

RESULTS

YAMC cells treated with PHGG exhibited significantly enhanced wound healing compared to the control cells; however, this enhancement was inhibited by both Y-27632 (RhoA inhibitor) and U0126 (ERK1/2 inhibitor). Likewise, there was a PHGG-dependent increase in F-actin accumulation and Rho kinase activity that was blocked by U0126. Meanwhile, PHGG-dependent ERK1/2 activity was not inhibited by Y-27632. In the DSS-induced mouse colitis model, animals that received food supplemented with PHGG exhibited significant recovery of the colonic mucosa.

CONCLUSIONS

In this study, we demonstrate that PHGG promotes colonic epithelial cell wound healing via activation of RhoA, which occurs downstream of ERK1/2 activation. These findings indicate that PHGG could be utilized as a therapeutic agent for patients with intestinal mucosal damage such as those with IBD.

Suppression of epithelial restitution using an inhibitor against Rho-associated coiled-coil containing protein kinase aggravates colitis through reduced epithelial expression of A-kinase anchor protein 13

In the gastrointestinal tract, the immediate healing response to mucosal damage is critical to sustain mucosal homeostasis. The migration of surrounding epithelial cells to cover the denuded area without proliferation is termed restitution, followed by early reparation of the damage. In this study, we determined the role of A-kinase anchor protein 13 (AKAP13) in mice with dextran sulphate sodium (DSS)-induced colitis upon mucosal injury and restitution, and investigated whether inhibition of Rho-associated coiled-coil containing protein kinase (ROCK), downstream effector of AKAP13, affects these mucosal responses. BALB/c mice were challenged with 4% or 2% DSS in their drinking water for up to 8 or 16days, respectively. During this period, mice received subcutaneous injections of fasudil hydrochloride hydrate (FH, 10mg/kg, twice per day), an inhibitor of phosphorylation of ROCK. In immunohistochemistry, AKAP13 was highly expressed in the mucosal epithelium prior to DSS-induced mucosal injury, and also expressed in ulcer-covering non-proliferative epithelium, which corresponded to restituted epithelial cells. Coadministration of FH increased serum amyloid A levels and histopathological scores for mucosal injury, as compared with the DSS group. The effects were associated with a decrease in gene expression of Akap13 in the mucosal tissue and the inhibition of restitution rata (the length of restituted epithelial cells per ulcer). These results suggested that AKAP13 and ROCK are involved in mucosal response at early injury and restitution during healing in DSS-induced colitis in mice.

Do Cyclosporine A, an IL-1 Receptor Antagonist, Uridine Triphosphate, Rebamipide, and/or Bimatoprost Regulate Human Meibomian Gland Epithelial Cells?

PURPOSE

Researchers have hypothesized that treatment with cyclosporine A (CyA), interleukin-1 receptor antagonists (IL-1RA; e.g., anakinra), P2Y2 receptor agonists (e.g., uridine triphosphate; UTP), and rebamipide may alleviate human meibomian gland dysfunction (MGD) and/or dry eye disease. Investigators have also proposed that prostaglandin analogues (e.g., bimatoprost) may induce MGD. Our goal was to determine whether these compounds directly influence human meibomian gland epithelial cell (HMGEC) function.

METHODS

Multiple concentrations of each compound were tested for effects on immortalized (I) HMGEC morphology and survival. Nontoxic dosages were used for our studies. Immortalized HMGEC were cultured in the presence of vehicle, CyA, IL-1RA, UTP, rebamipide, or bimatoprost for up to 6 days in various media. Experiments included positive controls for proliferation (epidermal growth factor and bovine pituitary extract), differentiation (azithromycin), and signaling pathway activation (insulin-like growth factor 1). Cells were analyzed for neutral lipid staining, lysosome accumulation, lipid composition, and phosphatidylinositol-3-kinase/Akt (AKT), phosphorylation.

RESULTS

Our findings demonstrate that CyA, IL-1RA, UTP, rebamipide, and bimatoprost had no effect on the proliferation; neutral lipid content; lysosome number; or levels of free cholesterol, triglycerides, or phospholipids in IHMGECs. Cylosporine A, IL-1RA, rebamipide, and bimatoprost significantly reduced the phosphorylation of AKT, as compared to control. Of interest, tested doses of CyA above 8 nM killed the IHMGECs.

CONCLUSIONS

Our results show that CyA, IL-1RA, UTP, rebamipide, and bimatoprost do not influence the proliferation or differentiation of IHMGEC. However, with the exception of UTP, these compounds do decrease the activity of the AKT signaling pathway, which is known to promote cell survival.

A Novel Role of Spred2 in the Colonic Epithelial Cell Homeostasis and Inflammation

Rapid and adequate mucosal healing is important for a remission of ulcerative colitis (UC) patients. Here, we examined whether Spred2, a member of the Sprouty-related EVH1-domain-containing proteins that inhibit the Ras/Raf/ERK pathway, plays a role in colonic mucosal homeostasis and inflammation by using Spred2 knockout (KO) mice. We first detected increased epithelial cell proliferation and cadherin 1 expression in the colon of naïve Spred2 KO mice compared to wild-type mice. Interestingly, Spred2 KO mice were resistant to dextran sulfate sodium (DSS)-induced acute colitis as indicated by lower levels of body weight loss and disease activity index. Histologically, epithelial cell injury and inflammation were milder in the colonic mucosa of Spred2 KO mice on day 3 and almost undetectable by day 8. Experiments with bone chimeric mice indicated that Spred2-deficiency in non-hematopoietic cells was responsible for the reduced sensitivity to DSS. Finally, Spred2 KO mice developed significantly fewer tumors in response to azoxymethane plus DSS. Taken together, our results demonstrate, for the first time, that Spred2 plays an important role in the regulation of colonic epithelial cell proliferation and inflammation by potentially down-regulating the activation of ERK. Thus, Spred2 may be a new therapeutic target for the treatment of UC.

Combination of proton pump inhibitor and rebamipide, a free radical scavenger, promotes artificial ulcer healing after endoscopic submucosal dissection with dissection size >40 mm

In our previous study, the healing effect of proton pump inhibitor plus rebamipide for endoscopic submucosal dissection-related artificial ulcer smaller than 40 mm showed statistical significance. However, such effect of the combination was not yet clear for ulcers with dissected diameter more than 40 mm. The aim of this present study was to resolve this problem under sufficient statistical power, with adequate sample size. We conducted a randomized controlled study. Either the proton pump inhibitor mono-therapy or the combination therapy was prescribed for 28 days after endoscopic submucosal dissection. Eighty-seven patients were eligible for outcome evaluation. Combination therapy was significantly superior to mono-therapy, 27.8% vs 0% reached healing stage (scar stage) in cases with ulcers of dissection diameter more than 40 mm. In conclusion, the combination therapy with rebamipide was favorable regimen in patients with larger artificial ulcer after endoscopic submucosal dissection.