Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038358 (gastric ulcer)
 5,179 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aims of our experiments were to clear up the possible correlations between the free radical mechanisms and the gastric cytoprotection of beta-carotene on HCl-induced gastric mucosal lesions. The beta-carotene was intragastrically given in doses of 1 and 10 mg/kg and 30 min. later 1 ml 0.6 N HCl was given to provoke the mucosal damage. After 1, 5, 15, 30 and 60 min. the animals were sacrificed. The number and severity of gastric mucosal lesions were calculated. The superoxide dismutase (SOD), glutathion peroxidase (GPX), catalase (CAT) activity and the malondialdehyde (MDA) and reduced glutathion (GSH) contents were determined from the gastric mucosa of rats. It was found that 1. beta-carotene was able to reduce the number and severity of ulcers only after 30 min.; 2. the CAT activity was decreased at 60 min. by carotene; 3. the GPX activity became dissimilar in the different groups after 15 min; 4. the changes of GSH were found to be similar ones; 5. the SOD activity was lower during the cyto-protection; 6. the MDA level remained practically unchanged. It has been concluded that 1. the free radicals are the consequences of the development of gastric ulcer and cytoprotection; 2. the scavenger character of beta-carotene is involved in its cytoprotective effect.
 ...
PMID:The free radical mechanisms in beta-carotene induced gastric cytoprotection in HCl model. 259 22

Diethyldithiocarbamate (DDC), an inhibitor of Cu,Zn-superoxide dismutase (SOD), at a dose of 500 mg/kg or aminotriazole (AT), an inhibitor of catalase, at a dose of 2,000 mg/kg reduced slightly gastric mucosal SOD activity, did not change gastric mucosal blood flow (GMBF), and did not cause gastric ulcers. However, when both DDC and AT were administered together, gastric mucosal SOD activity and GMBF remarkably decreased, and gastric ulcers appeared. Moreover, the administration of SOD attenuated gastric ulcer induced by DDC plus AT. These results suggested that SOD may play an important role in the gastric mucosal defense mechanisms against active oxygen species.
 ...
PMID:Gastric mucosal protection and superoxide dismutase. 284 84

Biopsy specimens of human gastric mucosa of patients with gastric complaints and subjected to endoscopic examination were cultured microaerobically, and Campylobacter pyloridis was detected in 46 out of 80 cases (57.5%). The organism was found in 13 out of 22 patients with gastritis, 11 out of 16 with gastric ulcer scar, 7 out of 16 with gastric ulcer, 3 out of 9 with gastric polyp, 4 out of 5 with gastric carcinoma, 2 out of 2 with esophagus carcinoma, and 6 out of 9 with other gastric diseases. The isolates were identified as C. pyloridis, demonstrating its characteristic features such as positive for oxidase and catalase, negative for reduction of nitrite and nitrate, positive for urease, no growth at 25 C, growth at 37 C, not tolerant to 1% glycine, and resistant to nalidixic acid. Positive alkaline phosphatase activity was considered as an additional feature characteristic for the strains of C. pyloridis. The major cellular fatty acids were tetradecanoic acid and 19-carbon-cyclopropane acid. This pattern is unique among Campylobacter species. The survival of the organism for a longer period than 60 min at pH 2.5 indicates its significant resistance to acidic environment.
 ...
PMID:Isolation of Campylobacter pyloridis from human gastric mucosa and characterization of the isolates. 343 27

The pathogenesis of gastric mucosal injury is still poorly understood. Recent reports implicate redox active metals and reactive oxygen species as mediators of gastric damage induced by ethanol or non-steroidal anti-inflammatory drugs. Attempts were made therefore to prevent gastric injury using chelators and the antioxidant enzymes catalase and superoxide dismutase. These attempts, at best, would only detoxify extracellular reactive species, such as those produced by activated circulating granulocytes and macrophages. This study utilises another strategy by pre-emption of both intra and extracellular reactive species using radical-radical annihilation reactions and by detoxifying redox active transition metals. Nitroxide, stable free radicals were shown to enter mucous cells, protect against the ethanol induced damage, and prevent gastric lesions induced by aspirin, indomethacin, 25% NaCl, or 0.6 N HCl. These findings confirm that gastric mucosal damage from the above agents is mediated by free radicals and, moreover, introduce a prototypical agent within a potential new class of gastric ulcer preventing drugs.
 ...
PMID:A novel antiulcerogenic stable radical prevents gastric mucosal lesions in rats. 795 22

We investigated the role of xanthine oxidase-derived oxygen radicals in the development of endothelin-1-induced gastric ulcer. Mucosal lipid peroxidation showed a peak 24 h after injection, while gastric mucosal haemodynamics were fully restored 26 h after endothelin-1 injection. Allopurinol and oxypurinol, but not superoxide dismutase or catalase, protected the gastric mucosa 24 h after endothelin-1 injection. Oxypurinol antagonized both the vasoconstrictor effect of endothelin-1 and the decrease in gastric ATP. All treatments on the second day after endothelin-1 injection significantly reduced gastric mucosal damage. Xanthine oxidase-derived oxygen radicals contributed largely to the exacerbation but they did not mediate the onset of endothelin-1-induced gastric ulcer. Pretreatment with probucol (500 mg/kg, p.o.) also protected the gastric mucosa from endothelin-1-induced mucosal injury by its antioxidant activity. Oxypurinol was gastroprotective through its vasoactive and energy saving actions. The haemodynamic background of endothelin-1-induced gastric ulcer consists of long lasting ischaemia and subsequent "reperfusion" which may be responsible for the late burst of oxygen radicals.
 ...
PMID:Oxygen radicals mediate the final exacerbation of endothelin-1-induced gastric ulcer in rat. 1117 71

The objective of the present study is to delineate the mechanism of oxidative damage in human gastric ulcerated mucosa despite the presence of some antioxidant enzymes. We report for the first time the critical role of an endogenous peroxidase, a major H(2)O(2) metabolizing enzyme, in controlling oxidative damage in gastric mucosa. Human gastric mucosa contains a highly active peroxidase in addition to the myeloperoxidase contributed by neutrophil. In both non-Helicobacter pylori (H. pylori)- and H. pylori-mediated gastric ulcer, when myeloperoxidase level increases due to neutrophil accumulation, gastric peroxidase (GPO) level decreases significantly. Moreover, gastric ulcer is associated with oxidative damage of the mucosa as evidenced by significant increase in lipid peroxidation, protein oxidation, and thiol depletion indicating accumulation of reactive oxygen metabolites (ROM). Mucosal total superoxide dismutase (Mn and Cu-Zn SOD) level also decreases significantly leading to increased accumulation of O(2)(*-). To investigate the plausible ROM-mediated inactivation of the GPO during ulceration, the enzyme was partially purified from the mucosa. When exposed to an in vitro ROM generating system, using Cu(2+), ascorbate, and H(2)O(2,) the enzyme gets inactivated, which is dependent on Cu(2+), ascorbate, or H(2)O(2). Insensitivity to SOD excludes inactivation by O(2)(*-). However, complete protection by catalase indicates that H(2)O(2) is essential for inactivation. Sensitivity to EDTA and hydroxyl radical *OH) scavengers indicates that GPO is inactivated most probably by *OH generated from H(2)O(2). We propose that GPO is inactivated in vivo by ROM generated by activated neutrophil. This leads to further accumulation of endogenous H(2)O(2) to cause more oxidative damage to aggravate the ulcer.
 ...
PMID:Critical role of an endogenous gastric peroxidase in controlling oxidative damage in H. pylori-mediated and nonmediated gastric ulcer. 1193 99

Aralia elata Seemann is an edible mountain vegetable in Korea containing saponin, alkaloid, palmitic acid, linoleic acid, methyl eicosanoate and hexacosol, and is known to manifest an effect on cardiac infarction, gastric ulcer, colitis, and enervation. This study has examined the effects of Aralia elata Seemann ethanol extract on antioxidant enzyme systems and lipid metabolism in rats along with benzo(a)pyrene (B(a)P) administration. Rats were divided into four groups: control (C), an extract fed group (CE), a B(a)P fed group (CB), and a B(a)P and extract fed group (CBE). The ethanol extracts of Aralia elata Seemann (50 mg/kg body weight) were fed to the rats for 4 weeks by stomach tubing. Extract administration increased the antioxidant activities of glutathione sulfur transferase (GST). Total superoxide dismutase (SOD) and Cu,Zn-SOD activities were stimulated. Catalase activities were increased by 50% with extract feeding. Cu,Zn-SOD was greatly enhanced from 0.10 unit to 0.18 unit and catalase activity also was increased. Serum alpha-tocopherol was markedly increased by the extracts. The ethanol fraction of Aralia elata Seemann decreased total serum cholesterol. However, serum HDL-cholesterol was increased by 35% (p<0.05). The results indicate that Aralia elata Seemann exerts antioxidant and strong hypocholesterolemic and hypolipidemic effects in vivo with the administration of B(a)P.
 ...
PMID:Ethanol fraction of Aralia elata Seemann enhances antioxidant activity and lowers serum lipids in rats when administered with benzo(a)pyrene. 1451 64

Reactive oxygen species (ROS) are reportedly associated with gastric ulcer. We previously reported the use of an in vivo 300-MHz electron spin resonance (ESR) spectroscopy/nitroxyl probe technique to detect *OH generation in the stomachs of rats with gastric ulcers induced by NH4OH. However, this is an acute ulcer model, and the relationship between in vivo ROS generation and lesion formation remains to be clarified. To address this question, the same technique was applied to a sub-acute water immersion restraint (WIR) model. A nitroxyl probe that was less membrane-permeable was orally administered to WIR-treated rats, and the spectra in the gastric region were obtained by in vivo ESR spectroscopy. The signal intensity of the orally administered probe was clearly changed in the WIR group, but no change occurred in the control group. Both enhanced signal decay and neutrophil infiltration into mucosa were observed 2h after WIR with little formation of any mucosal lesions. The enhanced signal decay was caused by *OH generation, based on the finding that the decay was suppressed by mannitol, desferrioxamine and catalase. Intravenous treatment with either anti-neutrophil antibody or allopurinol also suppressed the enhanced signal decay, and allopurinol depressed neutrophil infiltration into the mucosa. In rats treated with WIR for 6 h, lesion formation was suppressed by 50% with all antioxidants used in this experiment except anti-neutrophil antibody. These findings suggest that *OH, which is generated in the stomach via the hypoxanthine/xanthine oxidase system upon neutrophil infiltrated into the mucosa, induces mucosal lesion formation, but that it accounts for only half the cause of lesion formation.
 ...
PMID:Non-invasive analysis of reactive oxygen species generated in rats with water immersion restraint-induced gastric lesions using in vivo electron spin resonance spectroscopy. 1510 8

The effect of 50% ethanolic extract of Utleria salicifolia (USE) was assessed in different acute and chronic gastric ulcer models in rats. USE, 50-200 mg/kg administered orally, twice daily for 5 days showed dose-dependent ulcer protective effect in pylorus ligation (14.48-51.03% protection, P < 0.5 to P < 0.01), aspirin (28.80-56.52% protection, P < 0.5 to P < 0.001), ethanol (13.22-60.74% protection, P < 0.5 to P < 0.001), cold-restraint stress (21.22-77.14% protection, P < 0.05 to P < 0.001), and acetic acid (20.0-84.37% protection, P < 0.5 to P < 0.001)-induced acute and chronic ulcers. USE also significantly (P < 0.001) reduced the ulcer incidence (50 and 10%) and severity (67.83 and 91.34% protection) of duodenal ulcer, induced by cysteamine. Besides USE offered protection (53.52 and 60.58%) against ethanol-induced depletion of gastric wall mucus. However, USE reduced the ulcer index with significant decrease in plasma corticosterone (25.53 and 39.52% protection, P < 0.1 and P < 0.05), lipid peroxidation (18.75 and 47.92% protection, P < 0.01 and P < 0.001), superoxide dismutase (15.80 and 26.61% protection, P < 0.05 and P < 0.001) and increased in catalase (28.42 and 71.0% protection, P < 0.05 and P < 0.001) activity, respectively. Preliminary phytochemical screening of the USE gave the positive test for steroids, alkaloids, terpenoids, saponins and tannins. The HPTLC studies in the toluene: ethyl acetate: formic acid and the densitometric scanning at 254 nm gave three major spots with area corresponding to 28.16, 17.17, and 13.79% at 0.69, 0.78, and 0.88 R(f) values, respectively. The results indicate that USE possesses antiulcer activity.
 ...
PMID:Antiulcer activity of Utleria salicifolia rhizome extract. 1512 Apr 46

Usnea longissima, a medicinal lichen of Anatolia (Turkey), is used in the treatment of gastric ulcer in local folk medicine. In this paper, the gastroprotective effect of usnic acid (UA) isolated from Usnea longissima was investigated in the indomethacin-induced gastric ulcers in rats at doses of 25, 50, 100 and 200 mg/kg body weight. The gastric lesions were significantly reduced by all doses of UA as compared with the indomethacin (25 mg/kg body weight) treated group. In the stomach tissues of treated animals, the in vivo antioxidant levels were evaluated. The administration of indomethacin caused a significant decrease in the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH), and an increase in the lipid peroxidation (LPO) level (p < 0.05). The administration of all doses of UA reversed the trend, inducing a significant increase of SOD, GSH and GPx levels and a reduction in LPO level in tissues. However, catalase (CAT), glutathione reductase (GR) and myeloperoxidase (MPx) activities, increased by indomethacin, were found to be lower in the UA- and ranitidine-treated groups. The gastric mucosal constitutive NO synthase (cNOS) and inducible NO synthase (iNOS) activities were also investigated in tissues of UA- (100 mg/kg), ranitidine- (50 mg/kg) and indomethacin-treated rat groups. The administration of UA and ranitidine increased the cNOS activity and lowered the iNOS activity as compared with indomethacin-treated group. These results suggest that the gastroprotective effect of UA can be attributed to its reducing effect on the oxidative damage and neutrophil infiltration in tissues.
 ...
PMID:Gastroprotective and antioxidant effects of usnic acid on indomethacin-induced gastric ulcer in rats. 1616 75


1 2 3 4 5 6 7 8 9 10 Next >>