Effects of 12-sulfodehydroabietic acid monosodium salt (TA-2711), a new anti-ulcer agent, on gastric secretion and experimental ulcers in rats

The effect of sequential therapy with lansoprazole and ecabet sodium in treating iatrogenic gastric ulcer after endoscopic submucosal dissection: a randomized prospective study

OBJECTIVE

Ecabet sodium (ES) is a new non-systemic anti-ulcer agent belonging to the category of gastroprotective agents. In this study we aimed to compare the efficacy of a combination therapy with lansoprazole (LS) followed by ES with LS alone in treating endoscopic submucosal dissection (ESD)-induced iatrogenic gastric ulcers.

METHODS

Patients diagnosed with gastric adenomas or early gastric cancer were randomly divided into either the LS group (30 mg once daily for 4 weeks; n = 45) or the LS + ES group (LS 30 mg once daily for one week followed by ES 1500 mg twice daily for 3 weeks; n = 45). Four weeks after ESD, a follow-up endoscopy was conducted to evaluate the proportions of ulcer reduction and ulcer stages in the two groups.

RESULTS

In all, 79 patients were included in the final analyses. Both treatment modalities were well-tolerated in most patients, with a drug compliance of over 80%. There were no significant differences between the two groups in terms of the proportions of ulcer reduction (0.9503 ± 0.1215 in the LS group vs 0.9192 ± 0.0700 in the LS + ES group, P = 0.169) or ulcer stage (P = 0.446). The prevalence of adverse events related to drugs and bleeding were also similar between the two groups.

CONCLUSION

Sequential therapy with LS + ES is as effective as LS alone against ESD-induced gastric ulcers.

Efficacy of ecabet sodium enema on intractable rectal ulcer after piecemeal endoscopic mucosal resection for rectal tumor

We describe a case with rectal bleeding from a rectal ulcer after endoscopic mucosal resection (EMR), successfully treated with an ecabet sodium (ES) enema. A 44-year-old woman with a laterally spreading rectal tumor of a granular type, 60 mm in diameter, underwent piecemeal EMR. After the EMR, she suffered from rectal bleeding on several occasions over a period of 1 month. Although she was repeatedly treated with thermocoagulation by a heater probe to stop the bleeding, a rectal ulcer with visible vessels still remained at the resected site. Because the rectal ulcer was considered to be intractable, an ES enema was used twice a day (1.5 g) for 2 weeks, which improved rectal bleeding. Colonoscopic findings revealed that the ulcer improved with mucosal healing after the ES enema treatment. This represents the first report of an ES enema treatment in a patient with a rectal ulcer after EMR. Further studies are needed to determine the effectiveness and safety of using an ES enema in patients with EMR-related refractory colorectal ulcers.

Effects of ecabet sodium on acute mixed reflux esophagitis in rats

OBJECTIVE

Ecabet sodium (ENa) is a drug that repairs epithelial cells in the digestive tract via selective adhesion to damaged tissue. While the principal cause of reflux esophagitis is gastroesophageal acid reflux, the involvement of duodenal juice has also been identified as an important factor. This study aimed to explore the effect of ENa in an acute mixed reflux esophagitis (AMRE) rat model.

MATERIAL AND METHODS

Eight-week-old male Wistar rats were used to prepare an AMRE model. There were four experimental groups: Group A (sham-operated rats), Group B (AMRE rats), Group C (AMRE rats dosed with ENa at 10 mg/kg), and Group D (AMRE rats dosed with ENa at 30 mg/kg). All rats were assessed for incidence of macroscopic esophageal lesions, esophagitis index, and pathological findings. Amylase activity, bile acid concentration in the digestive fluid retained in the esophagogastric lumen and ENa concentration in the esophageal mucosa were determined.

RESULTS

The incidence of esophagitis was 0% for Group A, 100% for Group B, 40% for Group C, and 20% for Group D. It was significantly lower for Groups C and D relative to Group B. The median esophagitis index was 0 for Group A, 58.2 for Group B, 0 for Group C, and 0 for Group D, and it was significantly lower for Groups C and D relative to Group B. The histological severity grade of esophagitis in Groups C and D was significantly less than that in Group B.

CONCLUSION

Treatment with ENa inhibited the development of AMRE in rats.

Essential role of pepsin in pathogenesis of acid reflux esophagitis in rats

Pepsin, a protease activated by gastric acid, is a component of the refluxate, yet the role of pepsin in the pathogenesis of reflux esophagitis has not been well studied. In the present study, we examined the effect of pepstatin, a specific inhibitor of pepsin, on acid reflux esophagitis. Acid reflux esophagitis was induced in rats by ligating both the pylorus and the forestomach for 3 or 4 hr. Pepstatin, ecabet Na (the anti-ulcer drug), and L-glutamine were administered intragastrically after the ligation. Pepstatin or ecabet Na, given intragastrically, significantly prevented esophageal lesions, even though they did not affect basal acid secretion in pylorus-ligated rats. Pepstatin significantly inhibited pepsin activity in vivo and in vitro, while ecabet Na inhibited this activity in vitro. By contrast, L-glutamine given intragastrically aggravated the lesions in a dose-dependent manner, but even in the presence of L-glutamine the development of esophageal lesions was totally prevented by coadministration of pepstatin or ecabet Na. L-Glutamine increased the pH of gastric contents to approximately 2.0, the optimal pH for the proteolytic activity of pepsin in vitro. In addition, intragastric administration of exogenous pepsin worsened the severity of esophageal damage. These results suggest that pepstatin is highly effective against acid reflux esophagitis, without influencing acid secretion, while L-glutamine aggravated these lesions by increasing the pepsin activity by shifting the intraluminal pH to the optimal pH range for proteolytic action. It is assumed that pepsin plays a major pathogenic role in the development of acid reflux esophagitis.

Efficacy of ecabet sodium for Helicobacter pylori eradication triple therapy in comparison with a lansoprazole-based regimen

BACKGROUND

The cytoprotective agent, ecabet sodium, inhibits urease activity and growth of Helicobacter pylori.

AIM

To evaluate the efficacy and safety of ecabet sodium-based eradication of H. pylori infection, compared with a lansoprazole-based regimen, in a randomized multicentre study.

SUBJECTS AND METHODS

A total of 120 H. pylori-positive patients were assigned to one of two treatment regimens for 2 weeks: ecabet sodium 1 g b.d., amoxicillin 500 mg t.d.s. and clarithromycin 400 mg b.d. (EAC: 60 patients); or lansoprazole 30 mg (o.m.) with the same antimicrobial agents (LAC: 60 patients). Cure of infection was assessed by a 13C-urea breath test 1 month after completion of treatment.

RESULTS

One patient in the EAC group and two in the LAC group did not complete therapy because of an adverse event, and three did not undergo the 13C-urea breath test. Cure rates for the intention-to-treat, all-patients-treated and per protocol analysis in the EAC group were 85%, 86% and 88%, respectively, whereas those in the LAC group were 85%, 88% and 91%. There were no significant differences in cure rate or adverse events between the two regimens.

CONCLUSIONS

Ecabet sodium in combination with amoxicillin and clarithromycin is as effective as lansoprazole-based eradication therapy for H. pylori.

Effect of ecabet sodium enema on mildly to moderately active ulcerative proctosigmoiditis: an open-label study

OBJECTIVES

Ecabet sodium (ES), a nonabsorbable antigastric ulcer agent, has been shown to adhere to the region of an ulcer. It topically enhances gastric mucosal defensive factors such as the endogenous prostaglandins, capsaicin-sensitive sensory nerves, nitric oxide, and mucin. All of these mucosal defensive factors play an important role in maintaining the mucosal integrity of the colon and rectum. Therefore, we investigated the effect of ES in patients with mildly to moderately active ulcerative proctosigmoiditis.

METHODS

In an open-label study, seven patients with mildly to moderately active ulcerative colitis (UC) who had an inflamed mucosa in the rectum and/or sigmoid and were resistant to 4-wk topical and systemic standard treatment were treated with an ES enema b.i.d. for 14 days. The enema consisted of ES (1 g) and tepid water (20 or 50 ml). These patients were assessed by the Clinical Activity Index, colonoscopically, and histologically before and after the ES therapy. The ES therapy was started after obtaining informed consent from the patients.

RESULTS

Six of the seven patients responded to therapy and achieved clinical, endoscopic, and histological remissions. One patient was withdrawn because of increased stool frequency. All six patients who completed the study showed a significant change in the mean Clinical Activity Index score from 5.3+/-1.4 (mean +/- SD) to 0.5+/-0.8 (p < 0.05), in the colonoscopic score from 3.0+/-0.9 to 0.8+/-0.4 (p < 0.05), and in the histological score from 2.7+/-0.5 to 0.5+/-0.6 (p < 0.05), and achieved remission at the end of the study. There were no side effects attributable to the ES therapy. Five of the six patients are still in clinical remission after a median follow-up period of 5 months.

CONCLUSIONS

The ES enemas proved to be a safe and potentially useful adjuvant therapy currently available for treating patients with mildly to moderately active ulcerative proctosigmoiditis. A controlled study is necessary to confirm our results.

High-dose ecabet sodium improves the eradication rate of helicobacter pylori in dual therapy with lansoprazole and amoxicillin

AIM

The additive effect of ecabet sodium in combination with dual therapy on Helicobacter pylori eradication was evaluated.

METHODS

H. pylori-positive chronic gastritis patients were randomly assigned to one of the following three groups and medicated for 2 weeks. Group LA: dual therapy (lansoprazole 30 mg o.d. plus amoxicillin 750 mg b.d.). Group LA1E: dual therapy plus ecabet sodium (1 g b.d.). Group LA2E: dual therapy plus ecabet sodium (2 g b.d.). Patients were evaluated 4 weeks after the cessation of treatment by culture and 13C-urea breath test.

RESULTS

Seventy-one patients (mean age, 56.6 years; range, 26-79 years; 40 males, 31 females) were enrolled in this prospective, single-blind study, and 68 completed the protocol. The eradication rates per protocol patient were 43% in group LA, 62% in group LA1E, and 79% in group LA2E, and those on the intention-to-treat basis were 42% in group LA, 57% in group LA1E and 79% in group LA2E. The eradication rate in group LA2E was significantly higher than group LA (P=0.032 in per protocol, P=0.022 in intention-to-treat). Adverse effects were observed in 10 patients in this study. There were no severe adverse effects caused by ecabet sodium.

CONCLUSION

High-dose ecabet sodium increases eradication rates of H. pylori in dual therapy with lansoprazole and amoxicillin.

Ecabet sodium, a novel locally-acting anti-ulcer agent, protects the integrity of the gastric mucosal gel layer from pepsin-induced disruption in the rat

BACKGROUND

Ecabet sodium, a novel non-systemic anti-ulcer agent, possesses high affinity to gastric adherent mucus, which plays an important role in the protection of the gastric epithelium against acid and pepsin.

AIM

To assess the effect of ecabet on pepsin-induced degradation of the structure of the mucus gel layer.

METHODS

Everted sacs of rat stomach were incubated in HCl solution containing pepsin with or without ecabet. Pepsin-induced release of the cleaved peptides and hexosamine from the sacs was determined. Changes in the molecular size of glycoproteins in the adherent mucus (using gel filtration methods) and in the morphology of the epithelium (using both light and scanning electron microscopy) were also examined.

RESULTS

Ecabet reduced the pepsin-induced release of peptides and hexosamine, depending on its content in the adherent mucus. Pepsin treatment partially lowered the molecular weight of native glycoproteins in the adherent mucus, caused exfoliation of the epithelial cells, and degraded the network-like ultrastructure of the mucus layer, giving it a lumpy, globular appearance. Ecabet prevented both the pepsin-induced molecular size shift in mucus glycoproteins, and morphological alteration of the epithelium, including ultrastructural derangement of the mucus gel layer.

CONCLUSION

Ecabet protects the polymeric structure of mucus glycoproteins from proteolytic degradation by pepsin, and thus maintains integrity of the gastric mucus gel layer.

Gefarnate increases PAS positive cell density in rabbit conjunctiva

AIMS

The effects of three drugs for the treatment of gastritis and gastric ulcer--gefarnate, ecabet sodium, and troxipide--on periodic acid Schiff (PAS) positive cell density in rabbit conjunctiva in vivo were investigated.

METHODS

Eye drops containing gefarnate (0.1%, 1%), ecabet sodium (0.1%, 1%), or troxipide (0.1%, 1%) were instilled in both eyes of rabbits, six times a day for 7 days. On the eighth day, filter paper was gently pressed on the bulbar and palpebral conjunctiva, and impression cytology was performed with PAS staining. Three points in each specimen were selected randomly, and PAS stained cells were counted.

RESULTS

The instillation of gefarnate increased PAS positive cell density significantly at the concentration of 1% (p < 0.05). In contrast, instillation of ecabet sodium or troxipide failed to change PAS positive cell density.

CONCLUSIONS

These results demonstrated that gefarnate stimulates PAS positive cell density in rabbit conjunctiva.

Prospective evaluation of a new anti-ulcer agent, ecabet sodium, for the treatment of Helicobacter pylori infection

BACKGROUND

A new anti-ulcer agent, ecabet sodium, is active against Helicobacter pylori.

AIM

To assess the efficacy of ecabet sodium for the eradication of H. pylori in patients with gastroduodenal diseases.

METHODS

In a prospective, randomized and controlled study, patients infected with H. pylori were assigned to one of the following two groups: group LA, who received lansoprazole 30 mg o.d. + amoxycillin 500 mg q.d.s. after meals for 2 weeks, and group LAE, who received lansoprazole 30 mg o.d. + amoxycillin 500 mg q.d.s. + ecabet sodium 1000 mg b.d. after meals for 2 weeks. H. pylori status was determined before and at least 4 weeks after the therapy by rapid urease test, histology and a urea breath test.

RESULTS

Of 101 patients (mean age 53 years, range 17-77 years, M/F: 68/33) enrolled in the study, 97 patients completed the protocol. Four patients were withdrawn because of diarrhoea (three from group LA) and skin rash (one from group LAE). The eradication of H. pylori was achieved in 28/48 (58%) patients in group LA and 38/49 (78%) patients in group LAE. The rate of eradication of H. pylori produced by the LAE treatment was significantly higher than that produced by the LA treatment. Side-effects appeared in two patients (malaise 1, skin rash 1) in group LAE and in seven patients (diarrhoea 6, dizziness 1) in group LA. These side effects disappeared spontaneously with cessation of the treatment.

CONCLUSIONS

Ecabet sodium in combination with lansoprazole and amoxycillin increased the rate of eradication of H. pylori. Ecabet sodium appeared to reduce the incidence of diarrhoea as a side-effect of the dual LA therapy.

Ecabet sodium, a locally acting antiulcer drug, inhibits urease activity of Helicobacter pylori

In order to clarify the mechanism of the anti-Helicobacter pylori action of ecabet sodium (ecabet), a locally acting antiulcer drug, we evaluated the effects of ecabet on H. pylori urease activity in vitro. H. pylori was cultured and a crude preparation of urease was made. Urea-dependent survival of H. pylori at acid pH was significantly inhibited by ecabet. The urease activity of intact cells and a crude enzyme preparation from H. pylori had two pH optima: pH 4.5-5.0 and 8.0. Ecabet (1-4 mg/ml) concentration dependently inhibited the urease activity of both preparations at pH 5.0, but there was no inhibition at pH 8.0. The enzyme activity was inhibited by ecabet gradually and was not restored by dilution, in contrast to the inhibition elicited by benzohydroxamic acid, a specific and reversible urease inhibitor. These results suggest that irreversible inhibition of H. pylori urease activity contributes to the anti-H. pylori action of ecabet.

Gefarnate stimulates secretion of mucin-like glycoproteins by corneal epithelium in vitro and protects corneal epithelium from desiccation in vivo

The effect of drugs for gastritis and gastric ulcer (ecabet sodium, gefarnate, teprenone, and troxipide) on the secretion of mucin-like glycoproteins from rat cornea were investigated in vitro and on a short-term, rabbit dry eye model in vivo. For the studies in vitro, cultured rat cornea sections (3 mm diameter) were incubated with radiolabeled sodium sulfate, rinsed, and then incubated for 30 min in the presence of one of the drugs. The culture media were reacted with Dolichos biflorus agglutinate (DBA)-lectin, and the radioactivity of DBA-bound mucin-like glycoproteins was measured. A cytotoxicity assay confirmed that mucin-like glycoproteins had not leaked from damaged cells. For studies in vivo, eye drop vehicle or drops containing gefarnate were instilled in the eyes of nine anesthetized rabbits, and then the eyes were kept open with specula for two hours. These rabbits and two control rabbits not subjected to ocular drying were killed, and their eyes were enucleated and stained with methylene blue. Corneal epithelial damage from desiccation was evaluated based on the extent of methylene blue staining. Among the four kinds of drugs for gastritis and gastric ulcers, only gefarnate significantly increased the mucin-like glycoprotein secretion from cultured rat corneas in vitro; this stimulatory effect of gefarnate was dose-dependent. In vivo, the instillation of gefarnate reduced corneal epithelial damage from desiccation in a dose-dependent fashion. These results suggest that gefarnate reduces desiccation of corneal epithelium, perhaps by stimulating secretion of mucin-like glycoproteins from corneal epithelium.

Bacterial activity of a new antiulcer agent, ecabet sodium, against Helicobacter pylori under acidic conditions

Helicobacter pylori NCTC 11637, which is nonviable at pH 3.0, became viable after addition of 10 mM urea owing to ammonia production by urease. In a buffer supplemented with urea, ecabet sodium decreased both the production of ammonia and the number of viable cells of H. pylori NCTC 11637 and changed the bacteria from the bacilliform to the horseshoe or doughnut shape in a concentration-dependent manner. In particular, ecabet sodium (2 and 4 mg/ml) decreased the number of viable cells below the control level. Benzohydroxamic acid, a urease inhibitor, also caused a decrease in ammonia production accompanied by a decrease in the number of viable cells and changed the morphological form at pH 3.0, but the number of viable cells was not lowered below the control level. In buffers at various pHs without urea, ecabet sodium showed a concentration-dependent bactericidal effect on H. pylori at pHs 4.0 and 5.0 but not at pHs 6.0 and 7.0 while benzohydroxamic acid caused only a slight decrease in the number of viable cells at pH 4.0. These results suggest that ecabet sodium has strong bactericidal activity in addition to its urease-inhibiting activity under acidic conditions.

Relationship between gastroprotective effect of locally acting antiulcer agent ecabet sodium and its binding to gastric mucosa in rats. Comparison with sucralfate

The present study was designed to examine the relationship between the gastroprotective efficacy of the locally acting antiulcer drug ecabet sodium (ecabet) against ethanol-induced gastric lesions and the amount of the drug bound to the mucosa in comparison with sucralfate in rats. Oral administration of ecabet (25-100 mg/kg) and sucralfate (25-400 mg/kg) dose dependently prevented the formation of ethanol-induced gastric lesions, and dose dependently increased the amount of each drug bound to the gastric mucosa. Pretreatment with the antisecretory agent cimetidine (200 mg/kg, per os) significantly reduced the gastroprotective effect of sucralfate in proportion to a decrease in its binding to the mucosa. The same pretreatment tended to reduce both gastroprotection by ecabet and its binding to the mucosa. In an in vitro study using an everted stomach sac, the binding of sucralfate to the mucosa was more markedly decreased than that of ecabet on increasing the pH. These findings indicate that ecabet and sucralfate protect the gastric mucosa against ethanol in proportion to the amount of each drug bound to the gastric mucosa and that the binding of these drugs to the mucosa is under the influence of intraluminal pH. However, the gastroprotective effect of ecabet seems to be less dependent on intraluminal acidity than that of sucralfate.

SUT-8701, a cholecystokinin analog, prevents the cholinergic degeneration in the rat cerebral cortex following basal forebrain lesioning

SUT-8701 is a cholecystokinin octapeptide (CCK8) analog and a more lipophilic peptide than CCK8. We previously demonstrated that intra-ventricularly administered CCK8 protected against the degeneration of the cholinergic neurons in the cortex of the nucleus basalis magnocellularis (nbm)-lesioned rat. We determined whether SUT-8701 and CCK8 have the ability to protect against cholinergic degeneration in the cerebral cortex of nbm-lesioned rats. Systemically administered SUT-8701 (0.1-1 micrograms/day/animal, s.c.) preserved choline acetyltransferase activity and K(+)-evoked acetylcholine release in nbm-lesioned rats. SUT-8701 was more potent than CCK8. However, SUT-8701 was much less potent than CCK8 in satiety action. The affinity of SUT-8701 to the cholecystokinin (CCK) receptors assessed by using [125I]-CCK8 was almost the same as that of CCK8 in the mouse cerebral cortex, but was 107 times less than that of CCK8 in guinea pig pancreas. These results suggest that SUT-8701 may be effective in slowing down the degenerative processes in Alzheimer's disease by preserving the integrity of cholinergic neurons in the nucleus basalis.

Pharmacological isolation and characterization of NMDA receptor-mediated synaptic potential in the dentate gyrus of rat hippocampal slices

We attempted to observe the dentate gyrus field potential evoked by low-frequency stimulation of the perforant path in Mg(2+)-free medium and identify the N-methyl-D-aspartate (NMDA) receptor-mediated synaptic potential using rat hippocampal slices. When perfusing solution was changed from normal medium (1.3 mM Mg2+) to Mg(2+)-free medium, the evoked potential was greatly increased and secondary population spikes appeared following a primary population spike. The evoked potential recorded in Mg(2+)-free medium was only partly blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), a non-NMDA receptor antagonist. The CNQX-resistant component of the evoked potential in Mg(2+)-free medium was completely abolished by 30 microM DL-2-amino-5-phosphonovalerate, a NMDA receptor antagonist, indicating that the NMDA receptor-mediated synaptic response can be isolated by masking the non-NMDA receptor-mediated component of the evoked potential under the Mg(2+)-free condition. The isolated NMDA receptor-mediated synaptic potential was also blocked by 7-chlorokynurenate, an antagonist at the glycine site of the NMDA receptor, and restored by the concomitant presence of glycine. Observation of pharmacologically isolated NMDA receptor-mediated synaptic potential is a simple and good method for studying the direct effects of drugs on NMDA receptor-mediated responses.