Effect Of Ebrotidine Research Articles

Involvement of interleukin-4 in down-regulation of endothelin-1 during gastric ulcer healing: Effect of ebrotidine

Aims: Healing gastric mucosal injury implies an orderly involvement of the signaling molecules that exert their influence on the processes leading to the restoration of the mucosal integrity. In this study, we investigated the effect of antiulcer agent, ebrotidine, on the course of events during gastric ulcer healing by analyzing the expression of interleukin-4 (IL-4), endothelin-1 (ET-1), tumor necrosis factor-a (TNF-a), and the mucosal activity of caspase-3, and constitutive (cNOS) and inducible (NOS-2) nitric oxide synthase.Methods: Rats with experimentally induced chronic gastric ulcers were administered twice daily for 14 days with either ebrotidine at 100 mg/kg or vehicle, and at different stages of treatment their stomachs were used for macroscopic and biochemical assessments.Results: The ulcer onset was characterized by a massive epithelial apoptosis associated with a significant increase in caspase-3, NOS-2, TNF-a and ET-1, and a decline in the mucosal expression of cNOS and IL-4. The healing was reflected in a rapid recovery in IL-4, decrease in apoptosis, caspase-3, TNF-a, ET-1 and NOS-2, and a slow recovery in cNOS, and the process was accelerated in the ebrotidine-treated group. In the absence of ebrotidine the expression of IL-4 returned to the level of normal mucosa by the seventh day of healing, and that of ET-1 and TNF-a by the fourteenth day. An accelerated ulcer healing (7 days) with ebrotidine treatment was associated with IL-4 recovery by the fourth day, ET-1 by the seventh day, and TNF-a and cNOS by the 10th day. However, in both groups of animals the apoptotic DNA fragmentation rate, and the expression of caspase-3 and NOS-2 remained significantly elevated even after the ulcer healed.Conclusions: Our findings suggest that a drop in the mucosal expression of IL-4 at the ulcer onset causes dysregulation of ET-1 production, induction of TNF-a and triggers the apoptotic events that affect the efficiency of the repair process. Ebrotidine, by eliciting rapid recovery in IL-4, is capable of suppression the mucosal apoptotic events and accelerate the ulcer healing.

Effect of ebrotidine on Helicobacter pylori lipopolysaccharide-induced up-regulation of endothelin-1 in gastric mucosa

Helicobacter pylori is recognized as a primary etiologic factor in the development of gastric disease. We applied the animal model of H. pylori lipopolysaccharide-induced acute gastritis to study the effect of the anti-ulcer agent, ebrotidine, on the course of mucosal inflammatory responses by analyzing over a period of 10 days the extent of epithelial cell apoptosis and the mucosal expression of endothelin-1 (ET-1), tumor necrosis factor α (TNFα), and the activity of constitutive (cNOS) and inducible (NOS-2) nitric oxide synthase. Rats, pretreated twice daily for 3 days with ebrotidine at 100 mg/kg or the vehicle, were subjected to intragastric application of H. pylori lipopolysaccharide at 50 µg/animal, and after 2, 4, and 10 additional days on the drug or vehicle regimen their mucosal tissue was used for histological and biochemical assessment. In the absence of ebrotidine, H. pylori lipopolysaccharide elicited within 2 days extensive mucosal inflammation accompanied by a significant increase in epithelial cell apoptosis (13.5-fold) and the mucosal expression of TNFα (11.7-fold), NOS-2 (9.3-fold), and ET-1 (2.9-fold), while cNOS activity showed a 5.5-fold decrease. The extent of mucosal inflammatory involvement reached a maximum by the 4th day and showed a decline by the 10th day. This was reflected in a marked reduction in epithelial cell apoptosis, a decrease in the mucosal expression of ET-1, TNFα and NOS-2, and the recovery in cNOS activity. Treatment with ebrotidine caused a reduction in the extent of mucosal inflammatory involvement elicited by the lipopolysaccharide and this effect of ebrotidine was reflected at the end of a 10 day period in a 61.3% reduction in inflammation, and a decrease in apoptosis (83%), TNFα (51.8%), ET-1 (27.6%) and NOS-2 (62.9%), while the expression of cNOS increased by 78.6%. The findings indicate that an increase in the ET-1 level elicited by H. pylori lipopolysaccharide, combined with a decline in cNOS, trigger the induction of TNFα which propagates the inflammatory process. We also show that ebrotidine is capable of suppressing the H. pylori-induced gastric mucosal inflammatory responses.

Induction of Tumor Necrosis Factor-α and Apoptosis in Gastric Mucosal Injury by Indomethacin: Effect of Omeprazole and Ebrotidine

Background: The gastric injury associated with nonsteroidal anti-inflammatory drug (NSAID) therapy has been linked to the detrimental effects of the agents on the processes of prostaglandin generation, leukocyte adherence, superoxides production, and mucosal cell proliferation. In the present study we investigated the expression of tumor necrosis factor-α (TNF-α) and epithelial cell apoptosis during indomethacin-induced gastric mucosal injury and evaluated the effect of two antiulcer agents on this process. Methods: The experiments were carried out with groups of rats subjected to intragastric pretreatment with 40 mg/kg omeprazole, 100 mg/kg ebrotidine, or vehicle, followed 30 min later by an intragastric dose of indomethacin at 60 mg/kg. After 2 h the animals were killed, and the gastric mucosal tissue used for macroscopic damage assessment, quantitation of TNF-α expression, and the assay of epithelial cell apoptosis. Results: In the absence of antiulcer drugs, indomethacin caused extensive multiple hemorrhagic lesions accompanied by a 47% increase in mucosal expression of TNF-α and a dramatic (300-fold) enhancement in gastric epithelial cell apoptosis. Pretreatment with a proton pump inhibitor, omeprazole, produced only marginal (6–8%) reduction in the extent of mucosal damage caused by indomethacin, whereas the mucosal expression of TNF-α decreased by 15% and the apoptotic DNA fragmentation by 10–13%. In contrast, the H2-receptor antagonist ebrotidine, also known for its gastroprotective effects, not only successfully prevented (98.3%) the enhancement in mucosal TNF-α expression caused by indomethacin but also caused a 54% reduction in the epithelial cell apoptosis. These effects of ebrotidine were, furthermore, reflected in a 90.2% prevention in the gastric mucosal damage. Conclusions: Our findings provide new insights into the mechanism of gastric injury caused by NSAIDs and show that ebrotidine protection against indomethacin-induced mucosal damage occurs through the inhibition of epithelial celt apoptosis triggered by the enhancement in the mucosal TNF-α expression. Our data also show that omeprazole does not possess antiapoptotic properties.

Susceptibility of growth factors to degradation by Helicobacter pylori protease: effect of ebrotidine and sucralfate.

In this study, we investigated the susceptibility of the growth factors (EGF, bFGF, TGF beta and PDGF) to degradation by the protease elaborated by H. pylori and assessed the effect of antiulcer agents, ebrotidine and sucralfate, on this enzymatic action of the bacterium. The colonies of H. pylori were washed with saline, filtered to retain the bacteria, and the filtrate used as an enzyme source. The assays revealed that while EGF and beta FGF showed only marginal (5-7%) susceptibility to H. pylori protease, a 61.7% degradation occurred with PDGF and 62.3% with TGF beta. Introduction of ebrotidine or sucralfate to the assay system led to the reduction in the rate of growth factors degradation, which at 50 micrograms/ml ebrotidine reached the value of 85.1% for PDGF and 88.6% for TGF beta, while with sucralfate the optimal inhibition of PDGF (79.6%) and TGF beta (82.7%) degradation occurred at 200 micrograms/ml. The results demonstrate that PDGF and TGF beta are susceptible to H. pylori degradation and that antiulcer agents, ebrotidine and sucralfate are capable of counteracting this effect.

Inhibition of gastric mucosal mucin receptor by H. pylori lipopolysaccharide: Effect of ebrotidine

1. 1. H. pylori infection causes the loss of mucus coat continuity and its patchy appearance. Here, we present evidence that the bacterium, through its cell wall lipopolysaccharide, disrupts the interaction between mucin and its mucosal receptor, and that ebrotidine is capable of counteracting this process. 2. 2. The receptor for mucin, isolated from the solubilized gastric epithelial cell membrane by affinity chromatography on Sepharose-bound wheat germ agglutinin, displayed a molecular weight of 97 kDa and exhibited specific affinity towards mucin-coated surface. 3. 3. The mucin binding to the receptor was susceptible to the inhibitin by H. pylori lipopolysaccharide and reached a maximum of 91%. This effect of the lipopolysaccharide was counteracted by ebrotidine, which caused a dose-dependent relief of the lipopolysaccharide inhibitory effect with maximum restoration in mucin-receptor binding of 51% at 60 μl/ml ebrotidine. 4. 4. The results show that H. pylori, through its lipopolysaccharide, is capable of disrupting the integrity of mucus perimeter of gastric mucosal defense and that antiulcer agent, ebrotidine, counteracts this untoward effect.

Effect of ebrotidine on several enteroendoceine cell populations in rodent gastric mucosa

Effect of ebrotidine on several enteroendoceine cell populations in rodent gastric mucosa

Effect of ebrotidine on the density of antral G‐cells in the gastric mucosa in the rat

Two groups of male rats were treated orally for 60 days with ebrotidine and cimetidine, used as reference standard, respectively. The dose used of both drugs was 500 mg/kg. A third group, used as control, received 10 ml/kg of an aqueous agar suspension. After receiving the last dose, the animals were killed by inhalation of CO2 in a sealed chamber and the stomachs were removed for histological preparation. The purpose of this study was to count antral G-cells throughout the gastric mucosa by light microscope. A PAP system-associated antigastrin immunohistochemical method was used for cell identification. Cell density, with respect to their location in the gastric mucosa and the treatments given, was calculated using image analysis techniques. The results showed that ebrotidine did not cause any significant differences in the density of the population of these cells compared with the control group, while cimetidine induced a significant proliferation of antral G-cells.

Effect of ebrotidine on H. pylori urease activity

Effect of ebrotidine on H. pylori urease activity

Inhibition of gastric mucosal mucin receptor by H. pylori LPS: Effect of ebrotidine: [formula omitted], J. Piotrowski, V.L.N. Murty and A. Slomiany. Res. Ctr., UMDNJ, Newark, NJ 07103

Inhibition of gastric mucosal mucin receptor by H. pylori LPS: Effect of ebrotidine: [formula omitted], J. Piotrowski, V.L.N. Murty and A. Slomiany. Res. Ctr., UMDNJ, Newark, NJ 07103

Effect of ebrotidine on the synthesis and secretion of gastric sulfomucin

1. 1. The effect of a new antiulcer agent, ebrotidine, on the synthesis and secretion of sulfomucin in gastric mucosa was investigated. Rat gastric mucosal segments were incubated in DMEM containing [ 3H]proline, [ 3H]glucosamine and [ 35S]Na 2SO 4 as markers for mucin synthesis, glycosylation and sulfation, in the presence of 0–150 μM ebrotidine. 2. 2. The drug, while showing no discernible effect on the apomucin synthesis, evoked a dose-dependent increase in mucin glycosylation and sulfation, which at 100 μM ebrotidine, attained its maximum of 2.4 and 2.7-fold stimulation, respectively. 3. 3. The analysis of mucin secretory responses revealed that ebrotidine caused a concentration-dependent enhancement in sulfomucin secretion which attained its maximum increase of 3.3-fold at 100–120 μM ebrotidine. Furthermore, the sulfomucin elaborated in the presence of ebrotidine exhibited a higher content of a large molecular-weight mucus glycoprotein form, the assembly of which is intimately associated with the sulfation event. 4. 4. The results suggest that the ability of ebrotidine to enhance gastric sulfomucin synthesis and secretion may play an important role in the gastroprotective mechanism of action of this agent.

Ebrotidine effect on the proteolytic and lipolytic activities of Helicobacter pylori

1. 1. The effect of ebrotidine, a new antiulcer agent, on the activity of mucus degrading of protease and lipase enzymes elaborated by Helicobacter pylori was investigated. 2. 2. In the absence of ebrotidine, the H. pylori protease caused extensive degradation of gastric mucus protein, while free fatty acids, glycerol mono-oleate and lysophosphatidylcholine were produced by the action of H. pylori lipase and phospholipase A enzymes. 3. 3. Introduction of ebrotidine to the incubation system led to the reduction in the rate of mucus protein and lipid degradation. The rate of proteolysis inhibition was proportional to ebrotidine concentration up to 35 μg/ml at which point, a 57% reduction in mucus degradation was obtained, while the maximum inhibition of phospholipase A (96%) and lipase (93%) activities occurred at ebrotidine concentration of 60 μg/ml. 4. 4. The results indicate that ebrotidine is capable of counteracting the mucolytic activity of H. pylori towards protein and lipid constituents of gastric mucus layer.