Rebamipide activates genes encoding angiogenic growth factors and Cox2 and stimulates angiogenesis: a key to its ulcer healing action?

Rebamipide and Derivatives are Potent, Selective Inhibitors of Histidine Phosphatase Activity of the Suppressor of T Cell Receptor Signaling Proteins

The suppressor of T cell receptor signaling (Sts) proteins are negative regulators of immune signaling. Genetic inactivation of these proteins leads to significant resistance to infection. From a 590,000 compound high-throughput screen, we identified the 2-(1H)-quinolinone derivative, rebamipide, as a putative inhibitor of Sts phosphatase activity. Rebamipide, and a small library of derivatives, are competitive, selective inhibitors of Sts-1 with IC50 values from low to submicromolar. SAR analysis indicates that the quinolinone, the acid, and the amide moieties are all essential for activity. A crystal structure confirmed the SAR and reveals key interactions between this class of compound and the protein. Although rebamipide has poor cell permeability, we demonstrated that a liposomal preparation can inactivate the phosphatase activity of Sts-1 in cells. These studies demonstrate that Sts-1 enzyme activity can be pharmacologically inactivated and provide foundational tools and insights for the development of immune-enhancing therapies that target the Sts proteins.

Rebamipide for the Improvement of Gastric Atrophy and Intestinal Metaplasia: A Prospective, Randomized, Pilot Study

BACKGROUND

The presence of atrophic gastritis (AG) and intestinal metaplasia (IM) is associated with an increased risk of gastric cancer (GC). Thus, the development of new strategies to improve AG/IM is essential for reducing the incidence of GC.

AIMS

We aimed to evaluate the efficacy of rebamipide for improving AG/IM.

METHODS

This was a prospective, randomized, pilot study from a single tertiary referral center. Fifty-three (rebamipide, n = 34 vs. placebo, n = 19) patients, who underwent endoscopic resection for gastric dysplasia or early GC, were analyzed. We obtained tissue samples from the antrum and corpus of the stomach, at the time of screening and 1-year later. The histologic grading of inflammation was performed by histopathologists RESULTS: The AG grade in the antrum improved significantly after rebamipide treatment (pre-administration, 1.870 ± 0.932 vs. post-administration, 1.430 ± 0.986; P = 0.013). Additionally, the severity of IM in the antrum was significantly improved (pre-administration, 1.750 ± 0.963 vs. post-administration, 1.370 ± 1.032; P = 0.038). The rebamipide subgroup analysis revealed that patients with no Helicobacter pylori (HP) infection showed significant improvements in AG in the antrum (pre-administration, 1.880 ± 1.040 vs. post-administration, 1.250 ± 0.894; P = 0.028) and IM in antrum (pre-administration, 1.840 ± 1.012 vs. post-administration, 1.180 ± 0.912; P = 0.020).

CONCLUSIONS

This study demonstrated that the administration of rebamipide improves AG and IM in the antrum, especially in patients with HP non-infection (KCT0001915).

Food intolerances and the small intestine

The article presents an analysis of the literature on food intolerance (FS) associated with the presence in the diet of fermentable oligodimosaccharides and polyols FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols), histamine and food additives. The relationship between FS and insufficient activity of enzymes of the small intestine mucosa, in particular, in patients with irritable bowel syndrome, is discussed. FS often noted in them forces them to strictly adhere to the elimination diet and significantly impair the quality of life due to dissatisfaction with the results of treatment. Analysis of the literature has confirmed in many patients with irritable bowel syndrome an etiotropic relationship with poor food tolerance and dictates the need for randomized studies to further study the pathogenetic mechanisms of increasing food tolerance under the influence of cytoprotective therapy.

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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Biopharmaceutical characterization of rebamipide: The role of mucus binding in regional-dependent intestinal permeability

In this study, we aimed to elucidate biopharmaceutical characteristics of the anti-ulcer drug rebamipide, with special emphasis on the influence of gastrointestinal (GI) mucus on rebamipide segmental-dependent permeability and absorption. Experimental studies and physiologically-based pharmacokinetic (GastroPlus^TM) simulations were used to elucidate segmental-dependent absorption and pharmacokinetic (PK) profile, accounting for various drug properties, including solubility/dissolution limitations, regional-dependent drug affinity to mucus and membrane permeability, as well as physiological factors such as regional-pH differences along the intestine, thickness and types of mucus, transit time and surface areas. Low permeability and extensive binding to GI mucus were the key modeling features, and accounting for these resulted in good fitting between the predicted and in-vivo PK profiles, validating the ability of the model to pinpoint the underlying mechanisms of rebamipide limited oral bioavailability. Furthermore, the simulations indicated regional-dependent intestinal permeability of rebamipide, with absorption rank order of jejunum>ileum>duodenum>colon, mainly attributable to segmental mucus differences. Food effect simulations indicated somewhat decreased rebamipide absorption in the fed state, in corroboration with previous reports. Since this anti-ulcer drug is currently examined for additional indications, this work provides important input for future development of rebamipide.

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.

A Multicenter, Randomized, Controlled Trial of Rebamipide Plus Lansoprazole for the Treatment of Postendoscopic Submucosal Dissection Ulcers

To evaluate the healing efficacy of rebamipide and lansoprazole combination therapy with lansoprazole alone for endoscopic submucosal dissection (ESD)–induced ulcers and clarify the ulcer healing-associated factors.

Rebamipide increases the disaccharidases activity in patients with enteropathy with impaired membrane digestion. Pilot study

AIM

To evaluate the effectiveness of enteroprotector Rebamipide in the treatment of enteropathy with impaired membrane digestion (EIMD).

MATERIALS AND METHODS

We examined 102 patients aged 18 to 50 years (41 men and 61 women) with clinical signs of irritable bowel syndrome (n=65), functional diarrhea (n=33), and functional constipation (n=4) according to Rome IV criteria (2016). The activities of glucoamylase (GA), maltase, sucrase and lactase were determined by Dahlquist-Trinder method in duodenal biopsies obtained during esophagogastroduodenoscopy. The control group consisted of 20 healthy people aged 23-47. They showed following average enzyme activity: lactase - 42±13 ng glucose on 1 mg of tissue per minute, GA - 509±176, maltase - 1735±446, sucrase - 136±35 ng glucose on 1 mg of tissue per minute. These numbers were taken as the norm.

RESULTS

The activity of the disaccharidases was reduced in 89.2% out of 102 patients, and they were diagnosed with EIMD. Thirteen patients with EIMD were recommended to maintain the FODMAP diet and take enteroprotector Rebamipide 100 mg 3 times a day for 12 weeks. After 3 months 11 patients reported decreased or no flatulence, abdominal pain, stool disorder; 2 patients reported no change. The activity of GA increased to an average of 149±82 (by 78%, p=0.016), maltase - to 864±472 (by 131%, p=0.0019), sucrase - 63±35 (by 95%, p=0.0041) and lactase - 10±8 ng glucose on 1 mg of tissue per minute. The activity of lactase did not change.

CONCLUSION

We discovered a previously unknown phenomenon of the disaccharidases activity increase in duodenal mucosa and improved carbohydrates tolerance in the patients with EIMD taking Rebamipide in the dose 300 mg/day for 12 weeks.

Comorbidities in clinical practice. Algorithms for diagnostics and treatment

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Role of mucoprotective agents in endoscopic submucosal dissection-derived ulcers: A systematic review

BACKGROUND

Currently, it is still unclear whether adding a mucoprotective agent to a proton pump inhibitor (PPI) results in better outcomes compared with using a PPI alone in patients with post-gastric endoscopic submucosal dissection (ESD) ulcers. This study aimed to examine the efficacy of PPI alone versus combination treatment in healing of post-gastric ESD ulcers, as well as on delayed bleeding and amount of blood transfused.

METHODS

A systematic search of MEDLINE, EMBASE, Cochrane, and ISI Web of knowledge databases, up until May 2017, for randomized trials comparing PPI alone versus PPI plus a mucoprotective drug in achieving ulcer healing in patients undergoing gastric ESD was performed. The primary outcome is scarring stage on endoscopic assessment at 4 or 8 weeks after gastric ESD.

RESULTS

From an initial 3071 citations, eight articles (n = 953 lesions from 934 patients) were analyzed. Patients receiving combination treatment achieved a scarring stage significantly more often than those on a PPIs alone at 4 or 8 weeks after ESD, (risk ratio = 1.36, 95% CI; 1.06-1.75). No study reported amount of blood transfused. There were no significant between treatment-group differences in terms of delayed bleeding (risk ratio = 0.58, 95% CI; 0.17-1.99). Neither location of ulcer nor Helicobacter pylori infection was related to ulcer scarring stage.

CONCLUSION

The limited evidences suggested combination treatment may be more effective in accelerating the process of ulcer healing in patients undergoing gastric ESD than the use of PPI alone, but does not appear to alter delayed bleeding risk.

Rebamipide solution: a novel submucosal injection material to promote healing speed and healing quality of ulcers induced by endoscopic submucosal dissection

BACKGROUND AND AIMS

Rebamipide is administered perorally to protect the gastric mucosa. We assessed the efficacy and safety of a novel rebamipide solution as a submucosal injection material for endoscopic submucosal dissection (ESD) using an in vivo porcine model.

METHODS

An endoscopist blinded to the test agents performed ESDs of hypothetical 30 mm lesions using a 2% rebamipide solution at 2 sites (rebamipide group) and a saline solution at 2 other sites (control group) in the stomachs of 8 pigs. The technical outcomes were compared between the 2 groups. The gastric ulcer stages were evaluated by endoscopy once weekly for 4 weeks after the ESD to determine the healing score (1-6). The pigs were killed at 1 week (n = 2), 2 weeks (n = 2), and 4 weeks (n = 4) after the ESD for pathologic evaluation of ESD-induced ulcers and scarring.

RESULTS

There were no significant differences in any of the technical outcomes between the 2 groups, and no adverse events related to the ESD in any of the animals. The healing score was significantly higher in the rebamipide group than in the control group at 2 weeks (P = .027), 3 weeks (P = .034), and 4 weeks (P = .012). In the histopathologic assessment, fibrosis was significantly less extensive in the rebamipide group than in the control group at 2 weeks (P = .02) and 4 weeks (P = .04).

CONCLUSIONS

The rebamipide solution appeared to promote both the speed and quality of healing of ESD-induced ulcers by suppressing fibrosis.

Implementation of Quality by Design for Formulation of Rebamipide Gastro-retentive Tablet

The purpose of the present study was to develop a rebamipide (RBM) gastro-retentive (GR) tablet by implementing quality by design (QbD). RBM GR tablets were prepared using a sublimation method. Quality target product profile (QTPP) and critical quality attributes (CQAs) of the RBM GR tablets were defined according to the preliminary studies. Factors affecting the CQAs were prioritized using failure mode and effects analysis (FMEA). Design space and optimum formulation were established through a mixture design. The validity of the design space was confirmed using runs within the area. The QTPP of the RBM GR tablets was the orally administered GR tablet containing 300 mg of RBM taken once daily. Based on the QTPP, dissolution rate, tablet friability, and floating property were chosen as CQAs. According to the risk assessment, the amount of sustained-release agent, sublimating material, and diluent showed high-risk priority number (RPN) values above 40. Based on the RPN, these factors were further investigated using mixture design methodology. Design space of formulations was depicted as an overlaid contour plot and the optimum formulation to satisfy the desired responses was obtained by determining the expected value of each response. The similarity factor (f2) of the release profile between predicted response and experimental response was 89.463, suggesting that two release profiles are similar. The validity of the design space was also confirmed. Consequently, we were able to develop the RBM GR tablets by implementing the QbD concept. These results provide useful information for development of tablet formulations using the QbD.

New opportunities for the prevention of gastric cancer

The approvals and provisions of the Management of Helicobacter pylori infection-the Maastricht V/ Florence Consensus Report and those of the Kyoto Global Consensus Conference on H. pylori-associated gastritis, concerning with the primary and secondary prevention of gastric cancer (GC), unambiguously suggest that H. pylori infection is the most important risk factor of GC. Accordingly, the basis for the primary and secondary prevention of GC is the optimization of H. pylori eradication therapy. The clear direct relationship of the risk of GC to the severity and extent of atrophic gastritis, intestinal metaplasia and dysplasia and no reversal of intestinal metaplasia and dysplasia in the presence of H. pylori eradication presume that gastroprotective agents should be used for primary and secondary prevention. Experimental and clinical findings can lead to the conclusion that rebamipide is a highly effective and safe agent for the primary and secondary prevention of GC in patients with and without H. pylori infection, by optimizing anti-Helicobacter therapy, its anti-inflammatory effect and ability to restore the cellular structure of the gastric epithelium.

The solid state of rebamipide: preparation, characterization, and dissolution

Rebamipide is marketed as a peptic ulcer agent under the trade name Mucosta(R). The objective of this work was to investigate the existence of polymorphs and pseudopolymorphs of rebamipide. Two crystal forms of rebamipide were isolated by recrystallization and characterized by differential thermal analysis (DTA), thermogravimetric analysis (TG), powder X-ray diffractometry, infrared spectrometry, and nuclear magnetic resonance. The DTA curve of Form 1 showed one endothermic peak at 305.2 °C, and that of Form 2 showed one endothermic peak at 307.3 °C. The TG curve of Form 1 showed a single weight loss at 305.2 °C, which corresponded to melting. The TG curve of Form 2 also showed a single weight loss at 307.3 °C, which corresponded to melting. The melting point of Form 2 was higher than that of Form 1. In the dissolution studies in pH 6.8 buffer at 37 ± 0.5 °C, the two crystal forms showed no significant differences in dissolution. After 3 months of storage at 0, 52, and 95% RH, the two crystal forms were not transformed. After milling with a Specamill for 2 h, the two crystal forms were not transformed.

Effect of topical rebamipide on conjunctival goblet cell recovery after vitrectomy

In vitro and in vivo experiments have shown that topical rebamipide will increase the number of goblet cells in the bulbar conjunctiva. The purpose of this study was to determine whether topical rebamipide will enhance the recovery of conjunctival goblet cells that were damaged during vitrectomy. Forty patients who underwent vitrectomy surgery were studied. The 40 patients consisted of 20 with diabetes mellitus (DM) and 20 patients without DM. They were randomized in a 1:1 ratio into groups that were treated or not treated with topical 2% rebamipide after the surgery. Impression cytology was performed at the end of surgery and at 14 days after the surgery. The mean goblet cell density of each specimen was determined by averaging the total number of goblet cells obtained from three consecutive high magnification microscopic images. In patients without DM, the mean goblet cell density at 14 days after the vitrectomy was significantly higher in eyes with topical rebemipide than in eyes without rebemipide (P < 0.01). In patients with DM, a similar tendency was observed but the difference was not significant (P = 0.09). These results suggest that topical rebamipide can be helpful in patients with globlet cell damage that occur during and after vitrectomy.

Rebamipide suppresses mite-induced asthmatic responses in NC/Nga mice

Allergic asthma caused by continuous allergen exposure evokes allergen-specific Th2 responses and is characterized by chronic airway inflammation and hyperresponsiveness. A previous report showed that rebamipide improved asthmatic symptoms in an ovalbumin/trypsin mice model. However, it is still unclear how rebamipide exerts its effects in asthma. In this study, rebamipide improved the asthmatic responses induced by mite exposure in NC/Nga mice, revealing the mechanism of this therapeutic effect. Rebamipide suppressed the infiltration of eosinophils into the airways and lung as well as attenuating the production of reactive oxygen species in tissues. In addition to these anti-inflammatory effects, rebamipide inhibited the production of IL-33, a member of the IL-1 family that drives the subsequent production of Th2-associated cytokines. These observations identify the point where rebamipide exerts its suppressive action on asthma and suggest that rebamipide has therapeutic potential in preventing mite-induced asthma.

Rebamipide delivered by brushite cement enhances osteoblast and macrophage proliferation

Many of the bioactive agents capable of stimulating osseous regeneration, such as bone morphogenetic protein-2 (BMP-2) or prostaglandin E2 (PGE2), are limited by rapid degradation, a short bioactive half-life at the target site in vivo, or are prohibitively expensive to obtain in large quantities. Rebamipide, an amino acid modified hydroxylquinoline, can alter the expression of key mediators of bone anabolism, cyclo-oxygenase 2 (COX-2), BMP-2 and vascular endothelial growth factor (VEGF), in diverse cell types such as mucosal and endothelial cells or chondrocytes. The present study investigates whether Rebamipide enhances proliferation and differentiation of osteoblasts when delivered from brushite cement. The reactive oxygen species (ROS) quenching ability of Rebampide was tested in macrophages as a measure of bioactivity following drug release incubation times, up to 14 days. Rebamipide release from brushite occurs via non-fickian diffusion, with a rapid linear release of 9.70% ± 0.37% of drug per day for the first 5 days, and an average of 0.5%-1% per day thereafter for 30 days. Rebamipide slows the initial and final cement setting time by up to 3 and 1 minute, respectively, but does not significantly reduce the mechanical strength below 4% (weight percentage). Pre-osteoblast proliferation increases by 24% upon exposure to 0.4 uM Rebamipide, and by up to 73% when Rebamipide is delivered via brushite cement. Low doses of Rebamipide do not adversely affect peak alkaline phosphatase activity in differentiating pre-osteoblasts. Rebamipide weakly stimulates proliferation in macrophages at low concentrations (118 ± 7.4% at 1 uM), and quenches ROS by 40-60%. This is the first investigation of Rebamipide in osteoblasts.

An update on dry eye disease molecular treatment: advances in drug pipelines

INTRODUCTION

Dry eye disease is a common disorder provoking changes in tear film and ocular surface. Untreated dry eye could cause ocular infections, corneal ulcer and blindness. Only a few drugs are authorized so far for the treatment of dry eye disease and the possibilities of evolution in this sector are immense. Consequently, a significant number of new potential solutions are under development or placed in the pharmaceutical pipeline, promising better results and lesser side effects.

AREAS COVERED

In this article, the corresponding literature and recent Phase III clinical trial data and the corresponding literature, for dry eye disease treatment are reviewed, revealing the new strategic movements in drug pipelines.

EXPERT OPINION

From the clinical trial results, the advancement in tear substitutes and secretagogues in addressing specific deficiencies of tear components even though not resolving the underlying conditions of the disease is evident. The vast majority of new compounds under development are anti-inflammatories, steroids, non-steroids and antibiotics; however, there are also some novel lubricating drops and mucin-tear secretagogues. A future aggressive therapy for dry eye, depending on the severity of the symptoms, would include combinations of soft steroids, anti-inflammatories, such as cyclosporine A, with the addition of the new polyvalent mucin and tear secretagogues.

Efficacy and safety of proton pump inhibitors (PPIs) plus rebamipide for endoscopic submucosal dissection-induced ulcers: a meta-analysis

OBJECTIVE

To compare the efficacy of proton pump inhibitors (PPIs) with rebamipide versus PPIs alone for the treatment of ulcers after endoscopic submucosal dissection (ESD).

METHODS

PubMed, Web of Science, Medline, Embase, the Cochrane Central Register of Controlled Trials and China Naitonal Knowledge Infrastructure were searched up to the end of October 2013 in order to identify all randomized controlled trials reporting the effects of PPIs plus rebamipide on healing ulcers after ESD. The outcome measurement was complete ulcer healing.

RESULTS

A total of six studies involving 724 patients were included. The pooled data suggested a significantly higher rate of ulcer healing after endoscopic therapy among patients treated with PPIs plus rebamipide than among those treated with PPIs alone [odds ratio (OR)=2.40, 95% confidence interval (CI): 1.68-3.44]. The subgroup analysis showed PPI plus rebamipide therapy to be more effective in healing ESD-induced ulcers than treatment with PPIs alone after both four (OR=2.22, 95%CI: 1.53-3.24) and eight weeks of treatment (OR=3.19, 95%CI: 1.22-8.31). In addition, the combination therapy was found to be significantly more effective than the use of PPIs alone for all ESD ulcers greater than 20 mm in size (OR=4.77, 95%CI: 2.22-10.26). There were no significant differences between the treatment groups with regard to ulcer location (low, middle or upper stomach) or the presence of absence of H. pylori infection. No serious adverse events were observed in either group.

CONCLUSION

The results of this meta-analysis suggest that treatment with PPIs plus rebamipide is superior to PPI monotherapy for healing ESD-induced ulcers over four weeks, particularly large ulcers. However, more well-designed trials are needed to confirm these findings.

Pharmacokinetic interactions between rebamipide and selected nonsteroidal anti-inflammatory drugs in rats

Nonsteroidal anti-inflammatory drugs (NSAIDs) cause gastrointestinal and renal side effects. Rebamipide is a mucoprotective agent that reduces gastrointenstinal side effects when administered concomitantly with NSAIDs. In this study, we investigated the pharmacokinetic drug interactions of rebamipide with two selected NSAIDs, celecoxib or diclofenac. Rats were randomly divided into five groups. Two groups received placebo and three groups were administered rebamipide (30 mg/kg) orally twice daily for two days. On day 3, the animals treated with placebo received celecoxib (40 mg/kg) or diclofenac (10mg/kg) and rats receiving rebamipide were administerd rebamipide followed by a single dose of placebo, celecoxib, or diclofenac. To investigate drug protein interactions, blank rat plasma was spiked with known concentrations of rebamipide, diclofenac plus rebamipide, or celecoxib plus rebamipide then dialyzed through a Rapid Equilibrium Dialysis device. AUC (139.70±24.97 μg h/mL), Cmax (42.99±2.98 μg/mL), and CLoral (0.08±0.02 L/h/kg) values of diclofenac in diclofenac plus rebamipide group altered when compared to those of diclofenac treated groups. Treatment with rebamipide showed no significant change in pharmacokinetic parameters of celecoxib treated rats. Cmax (7.80±1.22 μg/mL), AUC (56.46±7.30 μg h/mL), Vd/F (7.55±1.37 L/kg), and CLoral (0.58±0.09 L/h/kg) of rebamipide were significantly altered when diclofenac was co-administered with rebamipide. Pharmacokinetic parameters of rebamipide plus celecoxib group were not significantly different from those of rebamipide group. Plasma protein binding was not affected by concomitant administration of another drug. These results indicate alteration of pharmacokinetic parameters of both rebamipide and diclofenac when co-administered and cannot be explained by a variation in plasma protein binding.

The effect of polaprezinc on gastric mucosal protection in rats with ethanol-induced gastric mucosal damage: comparison study with rebamipide

AIMS

Polaprezinc (PZ), which consists of l-carnosine and zinc, is widely used to treat gastric ulcers. We compared the effects of PZ with those of rebamipide (RM) on the expression of inflammatory cytokines, antioxidants, growth factors, and heat shock proteins (HSP) in a rat model.

MAIN METHODS

Seventy Sprague-Dawley rats were randomly assigned to test groups according to the dose of PZ at 5, 10, or 30 mg/kg or RM at 10, 30, or 100 mg/kg. Next, we obtained ulcer indices from rats with ethanol-induced gastric mucosal damage. Western blot analysis was used to evaluate the expression of various target proteins.

KEY FINDINGS

Pathological ulcer indices in the PZ and RM groups were significantly lower than those in the control group. The levels of inflammatory cytokines (interleukin 1β [IL-1β], IL-6, IL-8, and tumor necrosis factor α) decreased, whereas the levels of platelet-derived growth factor-B, vascular endothelial growth factor, and nerve growth factor significantly increased after PZ administration. Furthermore, the expression of antioxidants (superoxide dismutase 1 [SOD-1], SOD-2, heme oxygenase-1, glutathione S-transferase, peroxidredoxin-1, and peroxidredoxin-5) was significantly higher in the PZ group, and the levels of HSP 90, 70, 60, 47, 27, and 10 significantly increased with an increase in PZ dose.

SIGNIFICANCE

In a rat model of ethanol-induced gastric mucosal damage, PZ administration ameliorated ethanol-induced mucosal injury and showed protective effects on the mucosa by reducing the levels of inflammatory cytokines and increasing the expression of antioxidant enzymes and growth factors. Furthermore, PZ showed cytoprotective effects by increasing the HSP levels.

The efficacy of rebamipide add-on therapy in arthritic patients with COX-2 selective inhibitor-related gastrointestinal events: a prospective, randomized, open-label blinded-endpoint pilot study by the GLORIA study group

OBJECTIVE

We aimed to confirm the effect of combined treatment with celecoxib and rebamipide would be more effective than celecoxib alone for prevention of upper gastrointestinal (GI) events.

METHODS

Patients with rheumatoid arthritis, osteoarthritis, and low back pain were enrolled in this study. Patients were randomized to two groups: a monotherapy group (100 mg celecoxib twice daily) and a combination therapy group (add on 100 mg of rebamipide three times a day). The GI mucosal injury was evaluated by endoscopic examination before treatment and at 3 months. The primary endpoint was to evaluate the preventive effect of the combination therapy group for GI events, endoscopic upper GI ulcers and intolerable GI symptoms, compared with the monotherapy group.

RESULTS

Seventy-five patients were enrolled. Sixty-five patients were analyzed (16 males, 49 females; mean age: 67 ± 13 years). The prevalence of upper GI events, five of endoscopic GI ulcers and one of intolerable GI symptoms, were 6/34 (17.6%) in the monotherapy group and 0/31 in the combination therapy group, p = 0.0252.

CONCLUSIONS

The combination therapy group was more effective than the monotherapy group for prevention of upper GI events in this study. Rebamipide might be a candidate for an option to prevent COX-2 selective inhibitor-induced upper GI events.

Resolution of persistent corneal erosion after administration of topical rebamipide

Rebamipide is an antiulcer agent used to treat gastric ulcer and gastritis. Biological effects of rebamipide include cytoprotection, wound healing, and anti-inflammatory properties that are known to be universal for a variety of tissues in addition to gastrointestinal mucosa. The therapeutic effects of rebamipide eye drops are due to its ability to increase corneal and conjunctival mucin-like substances and improve corneal and conjunctival injury in vivo. In this paper, we report a case of Sjögren’s syndrome with complete disappearance of corneal erosion after administration of rebamipide eye drops. This was observed even though corneal erosion had not improved for 6 months after punctal occlusion surgery. The patient was a 33-year-old female, diagnosed with Sjögren’s syndrome by a salivary gland biopsy. The corneal and conjunctival surfaces were filled with dense erosions, which did not improve with topical drugs. Punctal plugs were applied several times; however, the plugs were repeatedly shed. All four puncta of both eyelids were surgically occluded, and both corneal and conjunctival erosion was clearly improved. However, the erosion in the inferior cornea of both eyes had not improved for 6 months after surgery. We used the newly approved topical rebamipide for treatment of this patient. The corneal erosion gradually improved and completely disappeared 4 weeks after administration of the drug. Dry eye sensation disappeared at the same time. Both membrane-associated mucin and secreted mucin in the ocular surface are thought to be essential for maintenance of the tear film. Induction of mucin from ocular surface epithelium could be an effective treatment in cases of dry eye caused by mucin deficiency. Through its various mechanisms, rebamipide improves ocular surface conditions. To our knowledge, this is the first clinical case report using rebamipide ophthalmic solution. This drug may provide a novel approach to treat drying diseases of the eye.

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.

Can rebamipide and proton pump inhibitor combination therapy promote the healing of endoscopic submucosal dissection-induced ulcers? A randomized, prospective, multicenter study

BACKGROUND

There has been no consensus regarding the optimal treatment durations and drug regimens in patients with endoscopic submucosal dissection (ESD)-induced ulcers.

OBJECTIVE

To assess the efficacy of proton pump inhibitor (PPI) and rebamipide combination therapy compared with PPI monotherapy for ESD-induced ulcer healing.

DESIGN

Randomized, prospective, controlled study; clinical trial.

SETTING

Five hospitals in a University Medical Center group in Korea.

PATIENTS

This study involved 290 adults (309 lesions) who underwent ESD for gastric adenoma or early gastric cancer.

INTERVENTION

PPI and rebamipide combination therapy.

MAIN OUTCOME MEASUREMENTS

The ulcer healing rate at 4 weeks after ESD.

RESULTS

The ulcer healing rates at 4 weeks after ESD in the PPI and rebamipide combination therapy group were significantly higher than those in the PPI alone group, both in the full analysis (94.9% vs 89.9%; P < .0001) and in the per-protocol analysis (94.5% vs 91.2%; P = .020). This combination therapy was an independent predictive factor for a high ulcer healing rate (adjusted odds ratio [OR] 5.572; 95% confidence interval [CI], 2.615-11.876; P = .014). Additionally, the combination therapy group exhibited a higher quality of ulcer healing than the PPI monotherapy group (reviewer 1: P = .027; OR 1.949; 95% CI, 1.077-3.527; reviewer 2: P = .027; OR 1.933; 95% CI, 1.074-3.481).

LIMITATIONS

Open-label study.

CONCLUSION

PPI and rebamipide combination therapy had a superior 4-week ESD-induced ulcer healing rate and quality of ulcer healing compared with PPI monotherapy. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01167101.).

Contributing factors to gastric ulcer healing after endoscopic submucosal dissection including the promoting effect of rebamipide

BACKGROUND

The healing process for artificial ulcers resulting from endoscopic submucosal dissection (ESD) for gastric cancer is not understood.

AIM

To clarify factors that promote healing and the additional healing effects of rebamipide, we conducted a randomized controlled trial to compare proton pump inhibitor (PPI) and combination PPI plus rebamipide treatments.

METHODS

One hundred and seventy patients with early gastric cancers that had undergone ESD were enrolled. Follow-up endoscopy was scheduled at 4-6 weeks after ESD. We assessed marginal healing and basal healing independently by endoscopic observation. Marginal healing was determined by a regenerating epithelium and/or converging folds around the periphery of the ulcer. Basal healing was declared when the ulcer was covered by white coat thinning such that basal granulation could be seen. The sizes of the artificial ulcers were divided into normal size (area <1,200 mm(2)) or large size (area ≥ 1,200 mm(2)).

RESULTS

Initial ulcer size and duration after ESD were significantly correlated with both marginal and basal healing rates by univariate analysis. The marginal healing rate of antral lesions was higher than that of body lesions. Multivariate analysis showed a large-sized ulcer was the only significant predictor of delayed healing, with delayed healing defined as no observed marginal or basal healing (p < 0.0001). Subgroup analysis for the effect of rebamipide on large-sized ulcers showed a significantly higher rate of basal healing in the combination PPI and rebamipide group (p = 0.015).

CONCLUSIONS

Healing in ESD-induced ulcers was dependent on the initial ulcer size. In large-sized ulcers, rebamipide promotes basal healing.

Transcriptome Analysis for Cytoprotective Actions of Rebamipide against Indomethacin-Induced Gastric Mucosal Injury in Rats

We have reported that rebamipide, a gastroprotective drug, suppresses indomethacin-induced gastric mucosal injury in humans and rats. However, the mechanisms of the cytoprotective actions of rebamipide have not been fully addressed. In the present study, we determined mRNA expression profile of the gastric mucosa treated with indomethacin in rats, and investigated the cytoprotective effects of rebamipide against indomethacin-induced injury with a high-density oligonucleotide array (Rat Toxicology U34 GeneChip array). Gastric epithelial cells were obtained by laser-assisted microdissection. Data analysis was performed with a GeneChip Operating Software, GeneSpring software 7.0, and Ingenuity Pathway Analysis. Among 1,031 probes, the expression of 160 probes (15.5%) showed at least 2.0-fold up-regulation (158 probes) and down-regulation (2 probes) 2 h after indomethacin administration in comparison with the vehicle-treated rats. The pathway analysis of the up-regulated 123 probes identified the network with a highly significant score, which consisted of known clusters of cell death, cancer, and endocrine system disorders. We succeeded in listing 10 genes that were up-regulated by the treatment with indomethacin and that were down-regulated by rebamipide, including growth arrest and DNA damage-induced 45α. In conclusion, we demonstrated that cell death, especially apoptosis, pathway is involved in the pathogenesis of indomethacin-induced gastric mucosal injury, and that inhibition of apoptosis-related genes is possibly important for the cytoprotective effect of rebamipide against this injury.

A randomized controlled trial of rebamipide plus rabeprazole for the healing of artificial ulcers after endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) is an increasingly common technique for the resection of early gastric cancers. Although 8 weeks of treatment with a proton pump inhibitor (PPI) reportedly heals most patients with ESD-derived artificial ulcers, it does not heal those with severe atrophic gastritis, for whom there is little data. This study examined whether healing rates of the latter especially were improved by the addition of the non-PPI mucosal healing agent rebamipide after ESD.

METHODS

Patients were randomly assigned to two treatment groups for 8 weeks following ESD: patients in the PPI group received daily rabeprazole alone (20 mg), whereas those in the combination group received daily rabeprazole (20 mg) and rebamipide (300 mg). At the primary endpoint (56 days after ESD) we determined the proportion of patients in whom ulcers had healed to scar-stage (S-stage, complete healing). A pre-specified subgroup analysis examined ulcer healing in patients with severe atrophic gastritis.

RESULTS

Overall, progression to S-stage occurred in 54.8% in the PPI group, and 86.7% in the combination group (odds ratio 5.3, 95% confidence interval 1.50-19.02, p = 0.006). Among those patients with severe atrophic gastritis, healing to S-stage occurred in 30.0% in the PPI group, and in 92.9% in the combination group (odds ratio 30.3, 95% confidence interval 2.63-348.91, p = 0.0023).

CONCLUSION

Treatment with a PPI plus rebamipide improved healing rates at 8 weeks for patients with ESD-derived artificial ulcer, and appeared to be particularly effective for patients with severe atrophic gastritis.

Management of recurrence of symptoms of gastroesophageal reflux disease: synergistic effect of rebamipide with 15 mg lansoprazole

BACKGROUND

Proton pump inhibitors (PPIs) are effective in healing reflux esophagitis and relieving the symptoms of gastroesophageal reflux disease (GERD). Prevention of recurrence of symptoms has become a therapeutic aim in patients with these conditions.

AIMS

We investigated the effects of rebamipide, a mucosal protective anti-ulcer agent, on recurrence of reflux symptoms during PPI maintenance therapy.

METHODS

Patients with esophagitis of Los Angeles classification A or B were treated with PPIs for 8 weeks. Patients with relief of symptoms were enrolled for further study. Forty-one patients were randomized to maintenance therapy with 15 mg of lansoprazole daily or 15 mg of lansoprazole and 300 mg rebamipide daily, and recurrence of symptoms was monitored over 12 months. In some patients, concentration of rebamipide and interleukin(IL)-8 expression in the esophageal mucosa were estimated.

RESULTS

During the 12-month period, 11/20 patients (52.4%) taking lansoprazole 15 mg daily suffered recurrence of symptoms, compared to 4/20 patients (20%) treated with lansoprazole 15 mg and rebamipide 300 mg daily (P < 0.05). Rebamipide was detected in the esophageal mucosa 90-180 min after oral administration. IL-8 mRNA expression in the esophageal mucosa of patients with rebamipide was significantly decreased compared with that of patients without rebamipide.

CONCLUSIONS

Combination therapy with rebamipide and lansoprazole appears to be highly effective in preventing recurrence of symptoms during long-term maintenance treatment for GERD.

Rebamipide may be comparable to H2 receptor antagonist in healing iatrogenic gastric ulcers created by endoscopic mucosal resection: a prospective randomized pilot study

Endoscopic mucosal resection (EMR) results in the formation of iatrogenic gastric ulcers and the optimal treatments for such ulcers are still unclear. We aimed to evaluate the efficacy of rebamipide in the management of EMR-induced ulcers by comparing it with an H(2) receptor antagonist. After EMR, patients were randomly assigned into either rebamipide or famotidine groups. All patients received a one-week lansoprazole 30 mg q.d. therapy followed by three-week famotidine (20 mg b.i.d.) or rebamipide (100 mg t.i.d.) therapy. Four weeks after the treatments, ulcer sizes, stages, bleeding rates, and ulcer-related symptoms were compared using endoscopy and a questionnaire. A total of 63 patients were enrolled in this study. Finally, 51 patients were analyzed, 26 in rebamipide and 25 in famotidine group. Baseline characteristics were not significantly different between the two groups. Four weeks after EMR, the two groups were comparable in terms of ulcer reduction ratio (P=0.297), and ulcer stage (P=1.000). Moreover, no difference was observed with regard to ulcer-related symptoms, drug compliance, adverse drug event rates, and bleeding rates. Our data suggest that rebamipide is not inferior to famotidine in healing iatrogenic gastric ulcers, and could be a therapeutic option in the treatment of such ulcers.

Clinical trial: rebamipide promotes gastric ulcer healing by proton pump inhibitor after endoscopic submucosal dissection--a randomized controlled study

BACKGROUND

Endoscopic submucosal dissection (ESD) is useful for treating gastric tumors. Several trials have shown the efficacy of 4 or 8 weeks of proton pump inhibitor (PPI) administration for post-ESD ulcers. However, if the size of the post-ESD ulcer is larger than predicted, PPI administration alone might not be sufficient for the ulcer to heal within 4 weeks. We examined the efficacy of a combination therapy of PPI and rebamipide, a mucosal-protective antiulcer drug, on the acceleration of post-ESD ulcer healing.

METHODS

Patients were randomly assigned to either the PPI and rebamipide therapy or the PPI alone. Sixty-two consecutive patients with gastric tumors gave informed consent for enrolling in the study. In all cases, the estimated size of the post-ESD ulcer was larger than 20 mm. Oral administration of the drug was started on the 2nd day post-ESD and continued to the 28th day.

RESULTS

All patients received the assigned pharmaceuticals and adhered well to the treatment regimen for 28 days. The endpoint ulcers reached S1 (scar stage) in 11/31 (36%) patients in the PPI-only group and in 21/31 (68%) in the combination group (P = 0.010).

CONCLUSIONS

The combination of PPI plus rebamipide was more effective than the PPI alone for treating ulcers larger than 20 mm within 4 weeks after ESD.

Successful treatment for pouchitis with rebamipide refractory to a combination of metronidazole (MNZ) and ciprofloxacin (CFX)

A 35-year-old male who had undergone proctocolectomy and ileo-anal pouch surgery (IPAA) because of ulcerative colitis presented with worsening diarrhea and hematochezia. Pouchitis was diagnosed, and he was prescribed with metronidazole (MNZ) and a betamethasone enema. However, his condition did not remarkably improve despite these strategies. Endoscopy revealed ulceration and inflammation in the ileal pouch together with contact bleeding and mucous discharge. He underwent granulocytapheresis (G-CAP) and was prescribed anal 5-aminosalicylic acid (5-ASA) and oral prednisolone. Oral azathioprine (AZA) and a combination of MNZ and ciprofloxacin (CFX) did not result in any improvement. He was then treated with rebamipide enemas twice daily for 8 weeks without additional drug therapy. Two weeks thereafter, stool frequency started to decrease, fecal hemoglobin became negative, and his symptoms gradually improved. Endoscopic findings after the rebamipide therapy showed that the ulcers in the ileal pouch had mostly healed without obvious inflammation and bleeding. Rebamipide was thus maintained throughout the therapeutic period and for 13 months of follow-up. Rebamipide effectively treated severe pouchitis that was refractory to intensive conventional medication including antibiotics and corticosteroids.

Significance of ERK nitration in portal hypertensive gastropathy and its therapeutic implications

Portal hypertensive (PHT) gastric mucosa increases susceptibility to injury and delayed mucosal healing. It is possible that nitration of ERK by peroxynitrite might alter MAPK (ERK) signaling in PHT gastric mucosa, leading to delayed mucosal healing, since excessive nitric oxide production is implicated in PHT gastric mucosa and MAPK (ERK) signaling induces cell proliferation and leads to gastric mucosal healing in response to injury. Portal hypertension was produced by staged portal vein ligation, and sham-operation (SO) rats served as controls. Lipid peroxide (LPO) and nitrotyrosine increased significantly in PHT gastric mucosa compared with SO rats. ERK activation was impaired in PHT gastric mucosa in response to ethanol injury, whereas no significant difference in the phosphorylation of MEK, an upstream molecule of ERK, was seen between the two groups. The nitration of ERK by peroxynitrite, as detected by the coimmunoprecipitation of ERK and nitrotyrosine, was significantly enhanced in PHT gastric mucosa. Administration of rebamipide, a gastroprotective drug that acts as an oxygen-derived free radical scavenger, significantly decreased LPO and nitrotyrosine as well as the nitration of ERK by peroxynitrite in PHT gastric mucosa, therefore normalizing ERK activation and restoring the gastric mucosal healing response to ethanol injury. Enhanced nitration of ERK by peroxynitrite is involved in the impaired MAPK (ERK) signaling in PHT gastric mucosa. These findings demonstrate a new molecular mechanism in which PHT gastric mucosa is predisposed to injury and impaired healing.

Anti-inflammatory effects of rebamipide according to Helicobacter pylori status in patients with chronic erosive gastritis: a randomized sucralfate-controlled multicenter trial in China-STARS study

The aim of the study was to investigate the effects of rebamipide on symptom, histology, endogenous prostaglandin, and mucosal oxygen free radicals in chronic erosive gastritis (CEG) patients by using sucralfate as a control. The trial also examined whether Helicobacter pylori infection would affect rebamipide-induced protection. A total of 453 endoscopy-confirmed CEG patients from 11 hospitals in China were enrolled in the study. They randomly received either rebamipide (100 mg t.i.d) or sucralfate (1.0 t.i.d) for 8 weeks with a ratio of 3:1. Per-protocol analysis (n = 415) showed the accumulated symptom score in the rebamipide group dropped from 5.54 +/- 0.97 to 0.80 +/- 0.47 after 8 weeks (P < 0.001 versus control). The endoscopic inflammation score in rebamipide group also decreased from 2.65 +/- 0.09 to 0.60 +/- 0.10, which showed better effects than sucralfate. It was shown a significant improvement (P < 0.01) in prostaglandin E2 (PGE(2)) contents in rebamipide-treated subjects mucosa (225.4 +/- 18.3 pg/g versus 266.7 +/- 14.7 pg/g) compared with that in sucralfate group after 8 weeks of treatment. Malondialdehyde (MDA) contents were significantly depressed both in the trial and control group. When Helicobacter pylori infection was considered, no statistically difference was found in the effect of rebamipide on either symptom or inflammation scores. In conclusion, Rebamipide demonstrated a stronger suppressive effect on the mucosal inflammation in chronic erosive gastritis than sucralfate. The gastroprotection induced by rebamipide is not influenced by H. pylori infection, which indicates its usage in the treatment of H. pylori-associated CEG.

Prophylactic effect of rebamipide on aspirin-induced gastric lesions and disruption of tight junctional protein zonula occludens-1 distribution

Aspirin and nonsteroidal anti-inflammatory agents are known to induce gastroduodenal complications such as ulcer, bleeding, and dyspepsia. In this study, we examined the prophylactic effect of rebamipide, an anti-ulcer agent with free-radical scavenging and anti-inflammatory effect, on acidified aspirin-induced gastric mucosal injury in rats. In addition, we investigated the mucosal barrier functions disrupted by aspirin. Oral administration of acidified aspirin resulted in linear hemorrhagic erosions with increasing myeloperoxidase activity and thiobarbituric acid-reactive substance concentrations in the gastric mucosa. Rebamipide suppressed these acidified aspirin-induced gastric lesions and inflammatory changes significantly, and its protective effect was more potent in the case of repeated (twice daily for 3 days) treatment than single treatment before aspirin administration. Immunostaining of zonula occludens (ZO)-1, one of the tight junctional proteins, was strengthened in rat gastric mucosa after repeated administration of rebamipide. In addition, aspirin induced the increasing transport of fluorescine isothiocyanate-labeled dextrans with localized disruption and decreased expression of ZO-1 protein on rat gastric mucosal cell line RGM-1. Rebamipide effectively prevented aspirin-induced permeability changes and disruption of ZO-1 distribution. These results suggest that rebamipide protects against aspirin-induced gastric mucosal lesions by preserving gastric epithelial cell-to cell integrity in addition to the anti-inflammatory effects.

Rebamipide, a gastro-protective and anti-inflammatory drug, promotes gastric ulcer healing following eradication therapy for Helicobacter pylori in a Japanese population: a randomized, double-blind, placebo-controlled trial

BACKGROUND

One week of Helicobacter pylori eradication therapy is insufficient for healing of gastric ulcers. We examined the efficacy of rebamipide in gastric ulcer healing following 1 week of eradication therapy in a randomized, double-blind, placebo-controlled trial.

METHODS

Patients with H. pylori-positive gastric ulcer were enrolled and received 1 week of eradication therapy, followed by 100 mg of rebamipide or placebo for 7 weeks. The primary end point was the gastric ulcer healing rate.

RESULTS

Of the 309 patients entered in the trial, 301 completed H. pylori eradication therapy; 154 patients took rebamipide, and 147 took placebo. The healing rate in the rebamipide group was higher than that in the placebo group in the per-protocol analysis-80.0% (104/130) versus 66.1% (82/124) [95% confidence interval (CI), 3.1-24.7; P = 0.013)-and in a full analysis-70.1% (108/154) versus 60.5% (89/147) (95% CI, -1.1 to 20.3; P = 0.080).

CONCLUSIONS

Compared with placebo, rebamipide significantly promoted gastric ulcer healing following 1 week of eradication therapy.

Successful treatment of severe pouchitis with rebamipide refractory to antibiotics and corticosteroids: A case report

The antibiotics, metronidazole and ciprofloxacin, are the first-line treatment for pouchitis. Patients who do not respond to antibiotics or conventional medications represent a major challenge to therapy. In this report, we have described a successful treatment of severe refractory pouchitis with a novel agent, rebamipide, known to promote epithelial cell regeneration and angiogenesis. A 27-year-old male with ileo-anal pouch surgery presented with worsening anal pain, diarrhea, and abdominal pain. The patient was diagnosed to have pouchitis and was given metronidazole together with betamethasone enema (3.95 mg/dose). However, despite this intensive therapy, the patient did not improve. On endoscopy, ulceration and inflammation were seen in the ileal pouch together with contact bleeding and mucous discharge. The patient was treated with rebamipide enema (150 mg/dose) twice a day for 8 wk without additional drug therapy. Two weeks after the rebamipide therapy, stool frequency started to decrease and fecal hemoglobin became negative at the 4^th wk. At the end of the therapy, endoscopy revealed that ulcers in the ileal pouch had healed with no obvious inflammation. The effect of rebamipide enema was dramatic and was maintained throughout the 11-mo follow-up. The patient continued to be in remission. No adverse effects were observed during the treatment or the follow-up period. The sustained response seen in this case with severe and refractory pouchitis indicates that agents, which promote epithelial cell growth, angiogenesis and mucosal tissue regeneration, are potential therapeutic agents for the treatment of refractory colorectal lesions.

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Insulin promotes sinusoidal endothelial cell proliferation mediated by upregulation of vascular endothelial growth factor in regenerating rat liver after partial hepatectomy

AIM: To determine whether insulin could promote sinusoidal endothelial cell (SEC) proliferation mediated by upregulation of vascular endothelial growth factor (VEGF) in regenerating rat liver after partial hepatectomy (PHx).

METHODS: Adult male Sprague-Dawley rats undergoing 70% PHx were injected with insulin (300 MU/kg) or saline via the tail veins every 8 h after surgery for 7 d and killed at 0, 24, 48, 72, 96, 120, 144, and 168 h after surgery. Proliferation of both hepatocytes and SECs was monitored by evaluating the proliferating cell nuclear antigen (PCNA) labeling index (LI). The expression of VEGF protein was evaluated by immunohistochemistry. The mRNA expressions of VEGF and its receptors Flt-1 and Flk-1 were evaluated by semi-quantitative reverse transcription-PCR.

RESULTS: Insulin markedly increased the expression of VEGF mRNA between 24 and 120 h after hepatectomy compared to controls. Similarly, insulin significantly increased the expression of Flt-1 between 24 and 96 h. However, insulin had no significant effect on Flk-1. Furthermore, the immunohistochemical staining revealed that expression of VEGF protein increased in the insulin groups. Insulin significantly increased the PCNA LI of hepatocytes and SECs compared to controls.

CONCLUSION: Exogenous insulin may promote SEC proliferation with an enhanced expression of VEGF and its receptor Flt-1 inregenerating rat liver after PHx.

Rebamipide enemas-new effective treatment for patients with corticosteroid dependent or resistant ulcerative colitis

In this study we investigated the effect of rebamipide enema in patients with steroid-resistant and/or dependent ulcerative colitis. Rebamipide enemas were administered twice daily for a 12-week period; this treatment was further continued longer in patients who requested this. Disease activity index as reflecting the clinical condition and endoscopic index with histological grading were determined before and after the treatment period. Nine of 11 (81.8%) patients on 12-week treatment with rebamipide approved and were classified as colitis in remission. Moreover, seven of 11 patients requested long-term medication, the longest medication term being 80 weeks. These results medicated that rebamipide enemas may be effective in patients with steroid-resistant and/or dependent ulcerative colitis.

Gastro-protective agent rebamipide induces cyclooxygenease-2 (COX-2) in gastric epithelial cells

Cyclooxyngease-2 (COX-2) is a key enzyme in prostaglandin (PG) synthesis, and COX-2 induction plays an important role in the healing of gastric ulceration. Rebamipide is a gastro-protective agent and attenuates the activity of neutrophils. A number of reports have shown that rebamipide treatment increases PG production in the gastric mucosa {in vivo}. Although its clinical significance in ulcer healing has been demonstrated, {in vitro} evidence remains to be accumulated. Non-transformed rat gastric mucosal cells (RGM1 cells) were stimulated with rebamipide. RT-PCR and Western blot analysis revealed time and dose-dependent transcriptional and translational stimulation of COX-2. PGE(2) was also produced dose-dependently. However, marked COX-2 induction by rebamipide was transient and lasted less than 24 hr. COX-1 expression was unaltered by rebamipide. Reporter assay results confirmed the stimulation of Cox-2 promoter activity by rebamipide. In conclusion, this study provides {in vitro} evidence that rebamipide transcriptionally induces COX-2 and supports the rationale for its clinical use.

15th anniversary of rebamipide: looking ahead to the new mechanisms and new applications

Rebamipide, a gastro-protective drug, was developed in Japan for the treatment of peptic ulcer disease. It was proven superior to the former same category drug cetraxate in a randomized, controlled, double-blind, comparative clinical study in 1989. Rebamipide's mechanisms of actions are different from anti-secretory drugs; it accelerates and improves the quality of ulcer healing and reduces ulcer recurrence rate. Numerous studies have been conducted to explain the mechanisms responsible for these actions, 37 papers were published by 1998. Major properties of rebamipide include: stimulation of prostaglandin and mucus glycoprotein synthesis, inhibition of reactive oxygen species, inflammatory cytokines and chemokines, and inhibition of neutrophils activation. Since 1998, 107 papers were published, clarifying further effects of rebamipide on cyclooxygenase-2, prostaglandin E receptors, growth factors (i.e., HGF, EGF, and VEGF), heat-shock proteins, nitric oxide, adhesion molecules, neutrophils, and Helicobacter pylori- and NSAID-related pathology. Moreover, inhibitory action of rebamipide on gastric cancer growth has also been shown. In this issue we reviewed recent advances in understanding of rebamipide's mechanism of action and its newest clinical applications.

Rebamipide reduces delay in gastric ulcer healing in cyclooxygenase-2-deficient mice

Rebamipide is an antiulcer drug capable of various actions including the induction of cyclooxygenase-2 (COX-2). In this study, we investigated the effect of rebamipide on gastric ulcer healing in COX-2-deficient mice. Wild-type (N=34) and COX-2-deficient mice (N=28) with gastric ulcers were administered 30 mg/kg of rebamipide or the vehicle. Ulcerous tissues were subjected to measurements of ulcer size, immunohistochemical staining of CD31 (an endothelial cell marker), and mRNA levels. COX-2 deficiency delayed ulcer healing and inhibited angiogenesis and bFGF mRNA expression in the granulation tissue. In wild-type mice, rebamipide accelerated ulcer healing and increased COX-2 mRNA expression. In COX-2-deficient mice, rebamipide prevented delayed ulcer healing and reversed the inhibition in angiogenesis and bFGF mRNA expression. The effect of rebamipide on the enhancement of ulcer healing, angiogenesis, and induction of bFGF expression was more prominent in wild-type mice than in COX-2-deficient mice. In conclusion, rebamipide may accelerate gastric ulcer healing through both COX-2-dependent and COX-2-independent mechanisms.