The effect of induction of endogenous CO by heme-oxygenase inducer, hemin versus heme-oxygenase blocker, zinc mesoporphyrin on gastric secretion and ulceration under different conditions in adult male albino rats

Although its role and importance is less well studied, carbon monoxide (CO) has been identified as the second gasotransmitter in the GI tract. This study was performed to investigate the effect of modifying the endogenous CO production by altering heme oxygenase (HO) activity either by induction through hemin administration or inhibition by zinc mesoporphyrin administration on gastric secretion and ulceration induced by either cold restraint stress (CRS) or indomethacin (IND) treatment in adult male albino rats. Our results revealed that hemin significantly increased HO-1 levels with an increase in carboxyhemoglobin (COHb) level while zinc mesoporphyrin significantly decreased HO-1 levels with a decrease in COHb level in all groups. Hemin pretreatment significantly attenuated the gastric mucosal lesions induced by CRS and IND administration, which was accompanied by significant reduction in free and total acidity of gastric secretion, decreased proteolytic activity and marked attenuation of lipid peroxidation inspite of decreased NO and PGE2 levels. On the other hand, Inhibition of HO-1 activity by zinc mesoporphyrin prevented most of the effects caused by hemin administration except for its similar reduction in gastric mucosal NO and PGE2 levels. On conclusion, Hemin exerts a protective effect against CRS and IND-induced gastric ulcers possibly via inducing HO-1 and increasing endogenous production of CO (Tab. 2, Fig. 4, Ref. 75).

The selective ASIC3 inhibitor APETx2 alleviates gastric mucosal lesion in the rat

This study aimed to assess the in vivo efficacy of acid sensing ion channel 3 (ASIC3) inhibitor APETx2 to alleviate acute gastric mucosal lesion (AGML) in a rat model. Thirty-six male Wistar rats were divided randomly into three groups: control group, water immersion restraint stress (WIRS) group, and APETx2 treatment group (n = 12). AGML was induced by WIRS for 6 h, and 25 microg/kg APETx2 was injected intraperitoneally before the onset of stress. Intragastric pH, ulcer index (UI) and gastric histopathological changes were measured, ASIC3 expression in thoracic dorsal root ganglia (DRG) neurons was examined by immunohistochemistry, PCR and Western blot analysis. Compared with control group, WIRS group showed obvious gastric injury with increased UI score, decreased intragastric pH and increased ASIC3 expression in DRG neurons (p < 0.05). APETx2 treatment before WIRS significantly alleviated gastric mucosal injury, decreased UI score, decreased gastric acidity and reduced ASIC3 expression in thoracic DRG neurons (p < 0.05). In conclusion, ASIC3 expression in DRG neurons projecting to the stomach is positively correlated with gastric mucosal lesion and acidosis in WIRS model. ASIC3 inhibitor APETx2 could improve gastric acidosis and alleviate AGML.

Anti-ulcerogenic Lignans from Taxus baccata L

Four lignan type compounds, lariciresinol, taxiresinol, isolariciresinol and 3-demethyl-isolariciresinol, were isolated from the heartwood of Taxus baccata L. (Taxaceae) growing in Turkey through chromatographic techniques. In vivo anti-ulcerogenic potency of these compounds was investigated on ethanol-induced ulcerogenesis model in rats at two different doses, 50 and 100 mg/kg. All compounds were shown to possess significant anti-ulcerogenic activity at both doses. However, the effect of taxiresinol was the most prominent.

Antiulcerogenic Activity of Crude Extract, Fractions and Populnoic Acid Isolated from Austroplenckia populnea (Celastraceae)

Many plant crude extracts and their isolated compounds are the most attractive sources of new drugs and show promising results for the treatment of gastric ulcers. Austroplenckia populnea is commonly known as “marmelinho-do campo, mangabeira-brava, mangabarana and vime” and it has been used in folk medicine as anti-dysenteric and anti-rheumatic. Powdered bark wood (3.25 kg) was macerated with aqueous ethanol (96%) and the extract was concentrated under reduced pressure to yield 406 g of crude hydralcoholic extract. The hydralcoholic extract was suspended in aqueous methanol and partitioned with hexane, chloroform and ethyl acetate (EtOAc) in sequence, yielding 8.0 g, 9.5 g and 98.17 g of crude extracts, respectively. Chromatography of the hexane extract over a silica gel column led to the isolation of the triterpene populnoic acid. The oral administration of hydralcoholic, hexane, chloroform and EtOAc extracts (200 mg/kg) decreased the ulcer lesion index (ULI) by 83.15%, 46.87%, 32.2%, 68.12%, respectively. Oral administration of populnoic acid (100 mg/ kg) diminished the ULI by 55.29%. All the obtained results were significant in comparison with the negative control, with exception of the chloroform extract.

Suppressive Effect of Astaxanthin Isolated from theXanthophyllomyces dendrorhousMutant on Ethanol-Induced Gastric Mucosal Injury in Rats

Ethanol has been found to induce ulcerative gastric lesion in humans. The present study investigated the in vivo protective effect of astaxanthin isolated from the Xanthophyllomyces dendrorhous mutant against ethanol-induced gastric mucosal injury in rats. The rats were treated with 80% ethanol for 3 d after pretreatment with two doses of astaxanthin (5 and 25 mg/kg of body weight respectively) for 3 d, while the control rats received only 80% ethanol for 3 d. The oral administration of astaxanthin (5 and 25 mg/kg of body weight) showed significant protection against ethanol-induced gastric lesion and inhibited elevation of the lipid peroxide level in gastric mucosa. In addition, pretreatment with astaxanthin resulted in a significant increase in the activities of radical scavenging enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. A histologic examination clearly indicated that the acute gastric mucosal lesion induced by ethanol nearly disappeared after pretreatment with astaxanthin.

Protective effects of Croton campestris A. St-Hill in different ulcer models in rodents: evidence for the involvement of nitric oxide and prostaglandins

ETHNOPHARMACOLOGICAL RELEVANCE

Croton campestris A. St.-Hill., popularly known as "velame do campo", is a species native from savannah area of Northeast Brazil, which is used by traditional communities in folk medicine for a variety of health problems, especially detoxification, inflammation and gastritis. The present study investigates the possible gastric antiulcer activity of Croton campestris root extract (CCRE) and mechanisms of action underlying this effect.

MATERIALS AND METHODS

Gastric lesions were induced in mice by ethanol, acidified ethanol and indomethacin. CCRE was previously administered orally in doses ranging from 50 to 750 mg/kg. Stomach lesions were measured. The involvement of Nitric Oxide (NO), prostaglandins (PGEs), ATP-dependent K+ channel and adrenergic receptor was investigated through specific inhibitors.

RESULTS

CCRE produced significant antiulcer activity against absolute ethanol, acidified ethanol and indomethacin induced gastric lesions. The pretreatment with L-NAME (10 mg/kg, p.o.), an inhibitor of nitric oxide synthesis and indomethacin (10 mg/kg, s.c.), an inhibitor of prostaglandin production, reversed the antiulcer action of CCRE.

CONCLUSION

Taking together, these results suggest that the antiulcer activity of CCRE is dependent of NO and prostaglandin pathways possibly due to its ability to stimulate the synthesis of NO, and activation of endogenous prostaglandin production. Therefore, the use of CCRE in traditional Brazilian medicine against gastric disorders has a scientific basis.

Sodium alginate ameliorates indomethacin-induced gastrointestinal mucosal injury via inhibiting translocation in rats

AIM: To investigate the effects of sodium alginate (AL-Na) on indomethacin-induced small intestinal lesions in rats.

METHODS: Gastric injury was assessed by measuring ulcerated legions 4 h after indomethacin (25 mg/kg) administration. Small intestinal injury was assessed by measuring ulcerated legions 24 h after indomethacin (10 mg/kg) administration. AL-Na and rebamipide were orally administered. Myeloperoxidase activity in the stomach and intestine were measured. Microvascular permeability, superoxide dismutase content, glutathione peroxidase activity, catalase activity, red blood cell count, white blood cell count, mucin content and enterobacterial count in the small intestine were measured.

RESULTS: AL-Na significantly reduced indomethacin-induced ulcer size and myeloperoxidase activity in the stomach and small intestine. AL-Na prevented increases in microvascular permeability, superoxide dismutase content, glutathione peroxidase activity and catalase activity in small intestinal injury induced by indomethacin. AL-Na also prevented decreases in red blood cells and white blood cells in small intestinal injury induced by indomethacin. Moreover, AL-Na suppressed mucin depletion by indomethacin and inhibited infiltration of enterobacteria into the small intestine.

CONCLUSION: These results indicate that AL-Na ameliorates non-steroidal anti-inflammatory drug-induced small intestinal enteritis via bacterial translocation.

[Gastroprotective effect of honey and bee pollen]

The effect of honey and pollen for an experimental gastric ulcer in rats by electromyography was investigated Okabe ulcer by applying the 100% acetic acid in the gastric serosa was simulated. Honey and pollen prevent the development of painful gastric motility, which confirms its gastroprotective action.

[Effects of 2-(2-hydroxyphenoxy) acetyl-L-prolinate sodium on antioxidant defense system of the gastric mucosa of rats under conditions of stress action]

We investigated the preventive effect of low molecular weight organic compound 2-(2-hydroxyphenoxy) acetyl-L-prolinat sodium on erosive and ulcerative lesions in the gastric mucosa caused by stress. It was established that prophylactic administration of this substance to rats at a dose of 1 mg/kg reduced the lesion area by 56.7%. 2-(2-hydroxyphenoxy) acetyl-L-prolinat sodium efficiently restored the impaired pro-/antioxidative balance in the gastric mucosa of rats under stress: the content of diene conjugates was reduced by 1.24 times, TBA-active products reduced by 1.31 times, Schiff's bases reduced by 1.28 times. This effect was accompanied by increased activities of the superoxide dismutase, catalase and of glutathione system.

Cytoprotective effect of American ginseng in a rat ethanol gastric ulcer model

Panax quinquefolium L. (American Ginseng, AG) is one of the most popular herbal medicines in the World. We aimed to investigate whether chronic (28-day) supplementation with AG could protect against ethanol-induced ulcer in gastric tissue. Furthermore, we investigated the possible molecular mechanisms leading to AG-mediated gastric mucosal protection. We randomized 32 male Wistar rats into four groups for treatment (n = 8 per group): supplementation with water (vehicle) and low-dose (AG-1X), medium-dose (AG-2X) and high-dose (AG-5X) AG at 0, 250, 500, and 1250 mg/kg, respectively. In the first experiment, animals were fed vehicle or AG treatments for 4 weeks. At day 29, 75% ethanol was given orally to each animal at 10 mL/kg to induce gastric ulceration for 2 h. In a second experiment, animals were pretreated orally with each treatment for 1 hr before a single oral administration of ethanol (70%, 10 mL/kg). Trend analysis revealed that AG treatments inhibited ethanol-induced gastric mucosal damage. AG supplementation dose-dependently decreased the pro-inflammatory levels of interleukin 1β and cyclooxygenase 2 and the expression of pro-apoptotic proteins tBid, cytochrome C, and caspases-9 and -3 and increased the levels of anti-apoptotic proteins Bcl-2, Bcl-xL and p-Bad. AG could have pharmacological potential for treating gastric ulcer.

Anti-ulcerogenic mechanism of magnesium in indomethacin induced gastric ulcer in rats

The gastric mucosa is continuously exposed to various agents like food condiments, spices, alcohol, acids and drugs, some of which are implicated in the pathogenesis of gastric ulcer. Magnesium compounds commonly used as laxatives and antacids have been reported to prevent ulcer formation but the mechanisms underlying this potential is unknown. This study therefore seeks to evaluate the gastro-protective mechanism of magnesium in the stomach through its effect on the parietal and mucus cells. Thirty-six male albino rats divided into 6 groups of 6 rats each were used. Group 1 was control, Group 2 was ulcer induced and untreated, Group 3 was treated with 500mg/kg b.w magnesium alone, Group 4 was pre-treated with 500mg/kg b.w magnesium before inducing ulcer, Group 5 was pre-treated with 500mg/kg b.w magnesium and 20mg/kg omeprazole 4 hours before inducing ulcer, Group 6 was treated with 20mg/kg omeprazole 4 hours before inducing ulcer. Animals were sacrificed 6 hours after ulcer induction and their stomachs were removed for ulcer scoring and histological analysis. A significant reduction was observed in the ulcer scoring of magnesium pre-treated ulcerated rats (9.4±0.8) compared with ulcerated untreated (20.8±0.9) groups. Parietal cell count of magnesium pre treated ulcerated group significantly decreased (169.7±18.9) compared with ulcerated untreated group (310.5±34.7). Mucous cell count of magnesium pre-treated ulcerated group (264.6±8.3) significantly increased compared with ulcerated untreated group (170.0±17.7). This study shows that magnesium possesses anti-ulcerogenic properties due to its ability to reduce the number of parietal cell and increase mucous cell counts.

Anti-secretory and cyto-protective effects of peganine hydrochloride isolated from the seeds of Peganum harmala on gastric ulcers

Gastroprotective mechanism of peganine hydrochloride isolated from Peganum harmala seeds was investigated. Peganine hydrochloride was evaluated against cold restraint (CRU), aspirin (AS), alcohol (AL) and pyloric ligation (PL) induced gastric ulcer models in rats. Potential anti-ulcer activity of peganine was observed against CRU (50.0%), AS (58.5%), AL (89.41%) and PL (62.50%) induced ulcer models. The reference drug omeprazole (10mg/kg, p.o.) showed 77.45% protection against CRU, 49.97% against AS and 69.42% against PL model. Sucralfate, another reference drug (500mg/kg, p.o.) showed 62.50% protection in AL induced ulcer model. Peganine significantly reduced free acidity (33.38%), total acidity (38.09%) and upregulated mucin secretion by 67.91%, respectively. Further, peagnine significantly inhibited H(+) K(+)-ATPase activity in vitro with IC50 of 73.47μg/ml as compared to the IC50 value of omeprazole (30.24μg/ml) confirming its anti-secretory activity.

Gastroprotective effects of the essential oil of Hyptis crenata Pohl ex Benth. on gastric ulcer models

ETHNOPHARMACOLOGICAL RELEVANCE

Hyptis crenata Pohl ex Benth (Lamiaceae), popularly known as "hortelã-brava" or "hortelã do campo", is widely distributed in the northeast of Brazil. In Brazil, the leaves of this plant have been used in traditional medicine for the treatment of gastrointestinal disturbances, including gastric ulcers. In an attempt to experimentally validate this claimed antiulcerogenic activity, the gastroprotective effects of the essential oil extracted from the leaves of the Hyptis crenata Pohl ex Benth (EOHc) were evaluated in recognized gastric ulcer models in mice.

MATERIALS AND METHODS

EOHc was obtained by hydrodistillation and analyzed using gas chromatography-mass spectrometry (GC-MS). Swiss male mice (25-30g) were used for the studies. The gastric ulcers were induced by oral administration of absolute ethanol or indomethacin 45min after oral pretreatment with EOHc, vehicle and positive control drugs. One hour after the ulcerative challenges, the stomachs were removed and the area of the lesions was measured. The volume, pH and total acidity of the gastric secretions were determined using the pylorus ligature model. The gastrointestinal motility was measured using gastric emptying and intestinal transit. The ethanol-induced gastric mucus depletion and lipid peroxidation were also analyzed.

RESULTS

Our findings are as follows: A significant inhibition of gastric lesions induced by absolute ethanol was observed in the mice pre-treated with EOHc, at a dose of 30 and 100 and 300mg/kg (5.56±1.51, 2.88±0.82 and 1.71±0.54mm(2), respectively) compared to control group (118.03±35.4mm(2)). Also, EOHc (300mg/kg) produced a gastroprotective effect against the gastric lesions induced by indomethacin (16.07±4.68mm(2)) compared to control group (38.64±6.1mm(2)). EOHc pretreatment produced a reduction in the ethanol-induced lipid peroxidation from 3.9±0.22 to 2.4±0.1μmol/mg tissue (EOHc-300mg/kg and control group, respectively). We also observed that EOHc pretreatment decreased the gastric emptying, but did not alter the intestinal transit ratio, ethanol-induced depletion of the gastric wall mucus or secretion parameters (volume, pH and [H(+)]).

CONCLUSION

Our data indicate that EOHc exerts a gastroprotective effect, indicated by its significant inhibition of gastric lesions in ethanol- and indomethacin-induced ulcer models, which may be associated with its accelerating effect on gastric emptying and reduction in oxidative damages. Our data suggest a potential therapeutic application for EOHc in the treatment of gastric ulcers.

Co-prescription of gastroprotective agents and their efficacy in elderly patients taking nonsteroidal anti-inflammatory drugs: a systematic review of observational studies

BACKGROUND & AIMS

Guidelines recommend prescribing gastroprotective agents (proton pump inhibitors, misoprostol) to older patients (primarily ≥65 years old) taking nonsteroidal anti-inflammatory drugs (NSAIDs) to prevent gastrointestinal ulcers. Older individuals are underrepresented in clinical trials of these agents. We systematically reviewed evidence from observational studies on the use of gastroprotective agents in elderly patients and their ability to prevent NSAID-related ulcers in this population.

METHODS

We performed a systematic search of Embase and MEDLINE and identified 23 observational studies that focused on elderly patients and reported data on co-prescription of gastroprotective agents and NSAIDs and/or the effectiveness of the agents in preventing gastrointestinal events in NSAID users. We collected data on rates of co-prescription and NSAID-related gastrointestinal events in patients with and without gastroprotection.

RESULTS

A median of 24% (range, 10%-69%) of elderly patients taking NSAIDs received a co-prescription for gastroprotective agents; this percentage was only slightly higher in the oldest age groups. All studies of efficacy showed a positive effect of gastroprotection. However, the adjusted results were not suitable for synthesis, and the 5 studies reporting unadjusted results were too heterogeneous for meta-analysis (I(2) = 97%). The studies differed in outcomes, definitions of co-prescription, and differences in baseline risk factors between patients with and without gastroprotection. None of the studies assessed adverse effects of gastroprotective agents. The 2 cost-effectiveness studies reached opposing conclusions.

CONCLUSIONS

In a systematic review, the observational evidence for the efficacy of gastroprotective agents in preventing NSAID-associated gastrointestinal events was in agreement with results of randomized controlled trials. However, because of heterogeneity of included studies, it is not clear what the effect would be if more patients were treated, or at what age gastroprotection should be recommended. We offer suggestions to facilitate comparison with other work and address the questions of risk and benefit in relation to age.

Pyranocycloartobiloxanthone A, a novel gastroprotective compound from Artocarpus obtusus Jarret, against ethanol-induced acute gastric ulcer in vivo

Pyranocycloartobiloxanthone A (PA), a xanthone derived from the Artocarpus obtusus Jarret, belongs to the Moraceae family which is native to the tropical forest of Malaysia. In this study, the efficacy of PA as a gastroprotective compound was examined against ethanol-induced ulcer model in rats. The rats were pretreated with PA and subsequently exposed to acute gastric lesions induced by absolute ethanol. The ulcer index, gastric juice acidity, mucus content, histological analysis, glutathione (GSH) levels, malondialdehyde level (MDA), nitric oxide (NO) and non-protein sulfhydryl group (NP-SH) contents were evaluated in vivo. The activities of PA as anti-Helicobacter pylori, cyclooxygenase-2 (COX-2) inhibitor and free radical scavenger were also investigated in vitro. The results showed that the oral administration of PA protects gastric mucosa from ethanol-induced gastric lesions. PA pretreatment significantly (p<0.05) restored the depleted GSH, NP-SH and NO levels in the gastric homogenate. Moreover, PA significantly (p<0.05) reduced the elevated MDA level due to ethanol administration. The gastroprotective effect of PA was associated with an over expression of HSP70 and suppression of Bax proteins in the ulcerated tissue. In addition, PA exhibited a potent FRAP value and significant COX-2 inhibition. It also showed a significant minimum inhibitory concentration (MIC) against H. pylori bacterium. The efficacy of PA was accomplished safely without the presence of any toxicological parameters. The results of the present study indicate that the gastroprotective effect of PA might contribute to the antioxidant and anti-inflammatory properties as well as the anti-apoptotic mechanism and antibacterial action against Helicobacter pylori.

Gastric antisecretory and antiulcer activity of bovine hemoglobin

AIM: To investigate gastric antisecretory and gastroprotective activity of bovine hemoglobin (B-Hb) in rats.

METHODS: Adult Albino-Wistar rats were divided into groups of 6 animals each. B-Hb in doses of 100, 300 and 900 mg/kg body weight was tested for gastric acid secretion and antiulcer activity. Gastric secretions were measured 6 h after pylorus ligation in rats pretreated with B-Hb. The acidity was measured by titrating gastric contents against 0.01 mol/L NaOH to pH 7. Indomethacin ulcers were produced by oral administration of 30 mg/kg bw in the rats pretreated with B-Hb one hour before indomethacin. Six hours after indomethacin stomach removed and ulcer index was recorded. Ethanol ulcer were produced by 1 mL of ethanol in the rats pretreated with B-Hb 30 min before the ethanol. One hour after ethanol stomach were cut open to score ulcers. Histological examination and analysis of gastric wall mucus, non-protein sulfhydryl groups (NP-SH), and myeloperoxidase (MPO) were carried in gastric tissue following ethanol administration.

RESULTS: In control rats pylorus ligation for 6 h resulted in the accumulation of 8.1 ± 0.61 mL of gastric secretion. The treatment of the rats with 100, 300 and 900 mg/kg of B-Hb produced a significant decrease in the volume of gastric secretion 5.6 ± 0.63, 5.5 ± 0.75 and 4.7 ± 0.58 mL respectively as compared to the control group [analysis of variance (ANOVA) F = 4.77, P < 0.05]. The lesion area in the control group was found to be 22.4 ± 3.2 mm² six hours after the administration of indomethacin. Treatment of rats with B-Hb at doses of 100 mg/kg (24.3 ± 3.29 mm²), 300 mg/kg (16.2 ± 1.45 mm²) and 900 mg/kg (12.6 ± 1.85 mm²) produced a dose dependent decreased the lesion scores (ANOVA F = 4.50, P < 0.05). The ulcer index following one hour after 1 mL ethanol was 7.1 ± 0.31. Pretreatment of rats with B-Hb at the doses of 100 mg/kg (2.5 ± 0.42), 300 mg/kg (2.1 ± 0.4) and 900 mg/kg (0.7 ± 0.21) significantly inhibited the formation of gastric lesions (ANOVA F = 63.26, P < 0.0001). Histological examination of gastric mucosa following ethanol showed significant lesions in the form of gastric pits with detachment of the surface epithelium; vacuolation of epithelial cells and elongation of microvessels. The changes were dose-dependently attenuated by B-Hb. The treatment of rats with ethanol significantly decreased the Alcian blue binding capacity of gastric wall mucus (480 ± 25.6 μg Alcian blue/g of tissue) as compared to control rats (667 ± 25.8 μg). Pretreatment of rats with B-Hb at the doses of 100 mg/kg (516 ± 31.6 μg/g), 300 mg/kg (558 ± 28.8 μg/g) and 900 mg/kg (654 ± 33.8 μg/g) significantly attenuated ethanol induced depletion of gastric wall mucus (ANOVA F = 8.05, P < 0.005). A significant and dose dependent increase of gastric mucosal NP-SH (ANOVA F = 19.62, P < 0.001) and decrease in MPO activity (ANOVA F = 3.1, P < 0.05) was observed in B-Hb treated rats.

CONCLUSION: B-Hb possesses significant gastric antisecretory and gastroprotective activity against experimentally induced gastric lesion. The gastroprotective effects of B-Hb are accompanied by inhibition of neutrophils activity, reduction of oxidative stress and maintenance of mucosal integrity.

Inappropriate continuation of stress ulcer prophylaxis beyond the intensive care setting

OBJECTIVE

To determine how frequently stress ulcer prophylaxis (SUP) medications prescribed in the intensive care unit are inappropriately continued on the ward and on hospital discharge.

DESIGN

Retrospective cohort study; chart review.

SETTING

Two Australian ICUs: one tertiary centre and one metropolitan centre.

PARTICIPANTS

We included 387 adult, non-pregnant patients who were admitted to the ICU between 1 February 2011 and 31 March 2011 and who survived to hospital discharge.

MAIN OUTCOME MEASURES

Rate of unnecessary continuation of ICU-prescribed SUP medications on the ward and on discharge from hospital.

RESULTS

While in the ICU, 329 of the 387 patients (85%) were prescribed SUP medications. Of the 233 patients who had not been taking acid-suppressive medications before admission to the ICU, 190 were prescribed SUP medications in the ICU. Of these 190 patients, most (63%) had their SUP continued in the ward without any obvious indication, and many (39%) had their SUP medications inappropriately continued on discharge from hospital.

CONCLUSIONS

SUP medications commenced in ICU are frequently continued unnecessarily, both in the wards and hospital discharge.

Endoscopic evaluation of low-dose aspirin-induced gastric and duodenal ulcers during prophylaxis with lansoprazole

BACKGROUND/AIMS

To compare the endoscopic features of LDA-induced ulcers developing during secondary prophylaxis with lansoprazole (LPZ) and gefarnate (GFN).

METHODOLOGY

All ulcers that had developed during prophylaxis with LPZ (15mg once daily) and GFN (50mg twice daily) in a prospective, randomized, double-blind trial, were reviewed and compared by a panel of expert endoscopists, based on endoscopic images available from the trial, to provide evidence for efficacy of LPZ versus GFN in secondary prophylaxis in patients with endoscopically confirmed ulcer scars.

RESULTS

A total of 6 and 53 patients had developed gastric or duodenal ulcers during prophylaxis with LPZ and GFN, respectively. Six gastric ulcers seen in those given LPZ were "small" and "shallow", while, of the 38 gastric ulcers seen those given GFN, 44.7% and 55.3% were "medium" or "large" and "small", respectively. Ulcers associated with blood coagula were seen only in those given GFN. Duodenal ulcers developed in 15 and 0 patients given GFN and LPZ, respectively.

CONCLUSIONS

The ulcers developing during prophylaxis with GFN and LPZ varied in their features. The study findings may be useful when devising a strategy for prophylaxis of ulcers in high-risk patients receiving LDA therapy in a routine clinical setting.

Long-term follow-up study of gastroduodenal lesions after radioembolization of hepatic tumors

AIM: To evaluate the long-term natural history of the gastroduodenal lesions secondary to extrahepatic embolization with Ytrium 90 (⁹⁰Y) spheres.

METHODS: From September 2003 to January 2012, 379 procedures of liver radioembolization (RE) using resin microspheres loaded with ⁹⁰Y were performed in our center. We have retrospectively compiled the data from 379 RE procedures performed in our center. We report a comprehensive clinical, analytical, endoscopic and histologic long-term follow-up of a series of patients who developed gastroduodenal lesions after the treatment.

RESULTS: Six patients (1.5%) developed gastrointestinal symptoms and had gastrointestinal lesions as shown by upper endoscopy in the next 12 wk after RE. The mean time between RE and the appearance of symptoms was 5 wk. Only one patient required endoscopic and surgical treatment. The incidence of gastrointestinal ulcerations was 3.75% (3/80) when only planar images were used for the pre-treatment evaluation. It was reduced to 1% (3/299) when single-photon emission computed tomography (SPECT) images were also performed. The symptoms that lasted for a longer time were nausea and vomiting, until 25 mo after the treatment.

CONCLUSION: All patients were free from severe symptoms at the end of follow-up. The routine use of SPECT has decreased the incidence of gastrointestinal lesions due to unintended deployment of ⁹⁰Y particles.

Protective effect of standardized extract of Cleome viscosa against experimentally induced gastric lesions in the rat

CONTEXT

Cleome viscosa Linn. (Capparidaceae) is used traditionally in the Indian system of medicine as a carminative, anthelmintic, and diuretic, and used for healing wounds, ulcers and diarrhea.

OBJECTIVE

A 70% ethanol (EtOH) extract of the aerial parts of Cleome viscosa extract (CVE) was investigated for gastroprotective activity in different gastric ulcer models in order to validate ethnobotanical claims regarding the plant use in ulcers.

MATERIALS AND METHODS

CVE (100, 200 and 400 mg/kg body weight) was administered orally, twice daily for 5 d, for prevention from EtOH, pylorus ligation (PL) and cold restraint stress (CRS)-induced ulcers in rats. Estimation of H(+)K(+)ATPase activity and gastric wall mucous were performed in EtOH-induced ulcer, antioxidant enzyme activities in supernatant mitochondrial fraction of CRS-induced ulcer, and gastric secretion parameters were estimated in PL-induced ulcer model.

RESULTS

CVE showed significant (p < 0.01) dose-dependent inhibition of lesion index in EtOH 15.93-42.30%, PL 26.34-59.28% and CRS 22.58-54.03%, respectively. CVE prevents the oxidative damage of gastric mucosa by blocking lipid peroxidation and by a significant (p < 0.001) decrease in superoxide dismutase, and an increase in catalase activity. A significant (p < 0.01) decrease occurred in the level of H(+)K(+)ATPase, volume of gastric juice and total acidity. Simultaneously, the level of gastric wall mucus and pH were increased significantly (p < 0.05). High performance thin layer chromatography analysis showed the presence of quercetin and gallic acid (0.3% and 0.25% w/w, respectively) in CVE.

CONCLUSIONS

Results of our study showed that C. viscosa possesses significant gastroprotective activity, probably due to free radical scavenging activity, and validates the folklore claim.

Nonsteroidal anti-inflammatory drugs (NSAID) sparing effects of glucosamine hydrochloride through N-glycosylation inhibition; strategy to rescue stomach from NSAID damage

Gastrointestinal or cardiovascular complications limit nonsteroidal anti-inflammatory drugs (NSAID) prescription. Glucosamine hydrochloride (GS-HCl) alternatively chosen, but debates still exist in its clinical efficiency. COX-2 instability through inhibiting COX-2 N-glycosylation of GS-HCl raised the possibility of NSAID sparing effect. Study was done to determine whether combination treatment of glucosamine and NSAID contributes to gastric safety through NSAID sparing effect. IEC-6 cells were stimulated with TNF-α and compared the expressions of inflammatory mediators after indomethacin alone or combination of indomethacin and GS-HCl by Western blotting and RT-PCR. C57BL/6 mice injected with type II collagen to induce arthritis were treated with indomethacin alone or combination of reduced dose of indomethacin and GS-HCl after 3 weeks. TNF-α increased the expression of COX-2, iNOS and inflammatory cytokines, but GS-HCl significantly attenuated TNF-α-induced COX-2 expression. Decreased COX-2 after GS-HCl was caused by N-glycosylation inhibition as much as tunicamycin. Combination of reduced dose of indomethacin and GS-HCl significantly reduced the expressions of ICAM-1, VCAM-1, IL-8, IL-1β, MMP-2, MMP-7, MMP-9, and MMP-11 mRNA as well as NF-κB activation better than high dose indomethacin alone. These NSAID sparing effect of GS-HCl was further proven in collagen-induced arthritis model. Combination of GS-HCl and 2.5 mg/kg indomethacin showed significant protection from gastric damages as well as efficacious anti-arthritic effect. Taken together, COX-2 N-glycosylation inhibition by GS-HCl led to indomethacin sparing effects, based on which combination of GS-HCl and reduced dose of NSAID can provide the strategy to secure stomach from NSAID-induced gastric damage as well as excellent anti-arthritic effects.

Local protective effects of oral 45S5 bioactive glass on gastric ulcers in experimental animals

Bioactive glass has been shown to stimulate bone regeneration and soft tissue healing. In this study, we evaluated the local protective effects of bioactive glass on experimental gastric ulcers, in comparison with omeprazole and hydrotalcite. Single and multiple gavage of 45S5 bioactive glass dose-dependently protected stress ulcers in mice and chronic ulcers in rats. Multi-daily gavage of bioactive glass for 7 days prevented chronic ulcer recurrence by 50 %. Bioactive glass ionic dissolution produced marked proliferation of ethanol-injured GES-1 human gastric mucosa epithelial cells 48 and 72 h after exposure. Bioactive glass was shown to be hardly absorbed after single or multi-daily gavage. This study, for the first time, demonstrates that bioactive glass is effective in protecting against gastric ulcers, with its high efficacy comparable to omeprazole and superior to hydrotalcite. The lack of oral absorption makes bioactive glass a potential for treatment of peptic ulcers omitting systemic toxicity or side-effects.

[Antiulcer prevention in urological practice]

This article is a detailed analysis of the studies of Russian and foreign authors on the epidemiology, clinical features, pathogenesis, risk factors of stress-induced disease of the mucosa of the upper gastrointestinal tract. Also in the article the approaches to drug prevention of this complication are considered. Currently, there are several groups of drugs are suitable for use for this purpose. However, the choice of a specific drug is difficult because of insufficient knowledge of the matter. Data on the incidence and natural history of erosive and ulcerative complications in patients urological profile is limited and very controversial.

[Prophylactic effect of probiotic strains Bifidobacterium animalis VKL and VKB on stress-induced lesions in the gastric mucosa of rats]

It was investigated the effect of probiotic strains Bifidobacterium animalis VKL and VKB and their mixture on erosive and ulcerative lesions in the gastric mucosa (GM) of rats induced by water immersion restraint stress. It was found that separate prophylactic introduction for 14 days of Bifidobacterium animalis VKL or Bifidobacterium animalis VKB didn't protect the GM from erosive and ulcerative lesions induced by stress. Contrary prophylactic introduction of Bifidobacterium animalis VKL and VKB mixture has been effective in protecting the GM from the lesions. One of the mechanisms of the gastroprotection of these probiotic strains is prevention of mucus barrier from degradation, which was evident in decrease of free fucose and hexuronic acids content. These results confirm the expediency ofprobiotics use for the prevention of stress-induced lesions in the GM.

Bidirectional crosstalk between stress-induced gastric ulcer and depression under chronic stress

Stress contributes to a variety of diseases and disorders such as depression and peptic ulcer. The present study aimed to investigate the correlation between stress ulcer and depression in pathogenesis and treatment by using chronic stress depression (CSD), chronic psychological stress ulcer (CPSU) and water immersion restrain stress models in rats. Our data showed that the ulcer index of the animals after CSD exposure was significantly higher than that of controls. Depression-like behaviors were observed in rat after CPSU exposure. Fluoxetine hydrochloride significantly reduced the ulcer index of rats exposed to CPSU stress, while ranitidine inhibited depression-like behavior of the animals in CSD group. The ulcer index of rats administered with mifepristone after CPSU stress was markedly reduced compared to CPSU group, although there was no significant difference in the depression-like behavior between mifepristone-treated CSD group and naive controls. We also found that the rats exposed to CPSU or CSD stress displayed a lower level of corticosterone than naive controls, however, the acute stress (AS) group showed an opposite result. Additionally, in order to study the relevance of H(2) receptors and depression, we treated the CSD group with cimetidine and famotidine respectively. The data showed that cimetidine inhibited depression-like behavior in CSD rats, and famotidine had no impact on depression. Overall our data suggested that the hypothalamic-pituitary-adrenal (HPA) axis dysfunction may be the key role in triggering depression and stress ulcer. Acid-suppressing drugs and antidepressants could be used for treatment of depression and stress ulcer respectively. The occurrence of depression might be inhibited by blocking the central H(2) receptors.

Chronic gastric ulceration causes matrix metalloproteinases-9 and -3 augmentation: alleviation by melatonin

Matrix metalloproteinases (MMPs) are a family of zinc-dependent enzymes capable of degradation of extracellular matrix (ECM) and key player in various inflammatory diseases. We investigated the regulation of MMPs in chronic gastric ulceration in mice. We generated chronic gastric ulcers in mice by indomethacin and examined the activity and expression of MMP-9 and -3 in stomach. Melatonin (N-acetyl-5-methoxytryptamine) treatment has also been applied to mice to characterize the changes in expression and activities of MMPs in gastric tissues. We observed significant upregulation of MMP-9 and -3 expressions and activities in stomach with increasing doses and duration of indomethacin that corroborated with increased activity of activator protein (AP)-1. Substantial damage in gastric epithelial layer was found during chronic ulceration. Melatonin suppressed MMP-9 and -3 expressions and activities during prevention and healing of chronic gastric ulcers. It also suppressed protein oxidation, lipid peroxidation and antioxidant enzymes. Additionally, expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-8 was significantly high in ulcerated stomachs while melatonin treatment blocked them to control level. We found elevated phosphorylation of extracellular-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK) during chronic gastric ulceration, which were significantly reversed by melatonin. Moreover, expression of NF-κB, c-fos and c-jun were inhibited by melatonin resulting down regulation of MMP-9 and -3 expressions. In summary, oxidative stress is preceded by chronic inflammation that enhances the expression of MMP-9 and -3, while melatonin arrests both of them via reduction of AP-1 activity during protection of ulcer.

Antiulcer activity of the chloroform extract of Bauhinia purpurea leaf

CONTEXT

Bauhinia purpurea L. (Fabaceae) is a native plant species of many Asian countries, including Malaysia and India. In India, the root, stem, bark, and leaf of B. purpurea are used to treat various ailments, including ulcers and stomach cancer.

OBJECTIVE

In an attempt to establish its pharmacological potential, we studied the antiulcer activity of lipid-soluble extract of B. purpurea obtained via extraction of air-dried leaves using chloroform.

MATERIALS AND METHODS

The rats were administered the chloroform extract (dose range of 100-1000 mg/kg) orally after 24 h fasting. They were subjected to the absolute ethanol- and indomethacin-induced gastric ulcer, and pyloric ligation assays after 30 min. The acute toxicity study was conducted using a single oral dose of 5000 mg/kg extract and the rats were observed for the period of 14 days. omeprazole (30 mg/kg) was used as the standard control.

RESULTS

At 5000 mg/kg, the extract produced no sign of toxicity in rats. The extract exhibited significant (p < 0.05) dose-dependent antiulcer activity for the ethanol-induced model. The extract also significantly (p < 0.05) increased the gastric wall mucus production and pH of gastric content, while significantly (p < 0.05) reducing the total volume and total acidity of the gastric content in the pylorus ligation assay.

DISCUSSION AND CONCLUSION

The extract possesses antiulcer, antisecretory and cytoprotective activities, which could be attributed to its flavonoid and tannin content. These findings provide new information regarding the potential of lipid-soluble compounds of B. purpurea for the prevention and treatment of gastric ulcers.

Possible biochemical effects following inhibition of ethanol-induced gastric mucosa damage by Gymnema sylvestre in male Wistar albino rats

CONTEXT

Gymnema sylvestre (GS) R. Br. (Gymnema) (Asclepiadaceae) has been used from ancient times as a folk medicine for the treatment of diabetes, obesity, urinary disorder, and stomach stimulation.

OBJECTIVE

The present study was designed to investigate the effects of G. sylvestre leaves ethanol extract on gastric mucosal injury in rats.

MATERIALS AND METHODS

Gastric mucosal damage was induced by 80% ethanol in 36 h fasted rats. The effect of G. sylvestre on gastric secretions induced in Shay rats was estimated. In stomach, wall mucus, non-protein sulfhydryl groups (NP-SH), malondialdehyde (MDA), total proteins and nucleic acids levels were estimated. Histopathological changes were observed.

RESULTS

G. sylvestre pretreatment at doses of 100, 200 and 400 mg/kg provided 27, 49, and 63% protection against the ulcerogenic effect of ethanol, respectively. Pylorus ligation accumulated 10.24 mL gastric secretions with 66.56 mEq of acidity in control rats. Pretreatment with G. sylvestre significantly inhibited the secretions volume and acidity in dose-dependent manner. Ethanol caused significant depletion in stomach-wall mucus (p < 0.001), total proteins (p < 0.01), nucleic acids (p < 0.001), and NP-SH (p < 0.001) levels. Pretreatment with G. sylvestre showed protection against these depleted levels in dose-dependent manner. The MDA levels increased from 19.02 to 29.22 nmol/g by ethanol ingestion and decreased with G. sylvestre pretreatments in dose-dependent manner.

CONCLUSION

The protective effect of G. sylvestre observed in the present study is attributed to its effect on mucus production, increase in nucleic acid and NP-SH levels, which appears to be mediated through its free radical scavenging ability and/or possible cytoprotective properties.

Acute toxicity and gastroprotective effect of the Schiff base ligand ¹H-indole-3-ethylene-5-nitrosalicylaldimine and its nickel (II) complex on ethanol induced gastric lesions in rats

The present study was performed to evaluate the gastroprotective activity of Schiff base ligand derived from the condensation reaction of tryptamine (an indole derivative) and 5-nitrosalicylaldehyde (TNS) and its nickel (II) complex against ethanol-induced gastric ulcer in rats. The compounds were orally administered with low (30 mg/kg) and high (60 mg/kg) doses to ulcer-induced Sprague-Dawley rats. Macroscopically, the ulcer control group exhibited severe mucosal injury, whereas pre-treatment with either cimetidine or TNS and its nickel (II) complex each resulted in significant protection against gastric mucosal injury. Flattening of gastric mucosal folds was also observed in rats pretreated with TNS and its nickel complex. Histological studies of the gastric wall of ulcer control group revealed severe damage of gastric mucosa, along with edema and leucocytes infiltration of the submucosal layer compared to rats pre-treated with either cimetidine or TNS and its nickel (II) compound, where there was marked gastric protection along with reduction of edema and leucocytes infiltration of the submucosal layer. Acute toxicity study done on mice with a higher dose of 5 g/kg of TNS and its nickel (II) complex did not manifest any toxicological signs. Research finding suggest that TNS and its nickel (II) complex could be considered as effective gastroprotective compounds.

Role of Blepharis maderaspatensis and Ammannia baccifera plant extracts on in vitro oxygen radical scavenging, secretion of gastric fluid and gastroprotection on ulcer induced rats

CONTEXT

Blepharis maderaspatensis L. Roth (BM) (Acanthaceae) and Ammannia baccifera L. (AB) (Lythraceae) are used in folk medicine for various stomach disorders.

OBJECTIVE

The chloroform and ethanol extracts of both plants were evaluated for antioxidant, gastric antisecretory, and gastroprotective properties.

METHODS

Antioxidant properties of the extracts were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and nitric oxide (NO) scavenging assay. The gastric antisecretory properties of the extracts were assessed, at a dose of 100 and 200 mg/kg, using aspirin-pylorus ligation induced gastric ulcer models and the gastroprotective activity of the extracts was assessed, at a dose of 100 and 200 mg/kg, using HCl-ethanol induced ulcer models in rats.

RESULTS AND DISCUSSION

Ethanol extract of BM (EBM) possessed good antioxidant property with IC₅₀ values of 37.4 and 44.1 µg/mL in DPPH and NO scavenging assays respectively, where 25-250 µg/mL concentration in DPPH assay and 30-300 µg/mL concentration in NO scavenging assay were used. Ethanol extract of AB (EAB) at a dose of 200 mg/kg reduced the free acidity to 142.66 mEq/L and total acidity to 451.22 mEq/L. It reduced the gastric secretion with increase in pH from 2.2 to 3.15. Possessing good antisecretory activity, it also reduced the ulcer by 92.2% in aspirin and pylorus ligation induced gastric ulcer models. EAB increased the mucus secretion and adherent mucus in the tissues with a 71.43% reduction of ulcerin HCl-ethanol induced ulcer models, at a dose of 200 mg/kg. This activity can be attributed to the various flavonoids like rutin and kaempferol-3-O-β-glucopyranoside, and the phytosterol, β-sitosterol-3-O-β-glucopyranoside, and phenolics present in the extracts.

CONCLUSION

EBM possessed significant antioxidant property while EAB possessed good antisecretory and gastroprotective activity.

Cytoprotective effect of benzyl N'-(5-chloro-indol-3-yl-methylidene)-hydrazinecarbodithioate against ethanol-induced gastric mucosal injury in rats

Indolic compounds have attracted a lot of attention due to their interesting biological properties. The present study was performed to evaluate the subacute toxicity and anti-ulcer activity of BClHC against ethanol-induced gastric ulcers. Experimental animal groups were orally pre-treated with different doses of BClHC (50, 100, 200 and 400 mg/kg) in 10% Tween 20 solution (vehicle). Blank and ulcer control groups were pre-treated with vehicle. The positive group was orally pretreated with 20 mg/kg omeprazole. After one hour, all groups received absolute ethanol (5 mL/kg) to generate gastric mucosal injury except the blank control group which was administered the vehicle solution. After an additional hour, all rats were sacrificed, and the ulcer areas of the gastric walls determined. Grossly, the ulcer control group exhibited severe mucosal injury, whereas pre-treatment with either derivative or omeprazole resulted in significant protection of gastric mucosal injury. Flattening of gastric mucosal folds was also observed in rats pretreated with BClHC. Histological studies of the gastric wall of ulcer control group revealed severe damage of gastric mucosa, along with edema and leucocytes infiltration of the submucosal layer compared to rats pre-treated with either BClHC or omeprazole where there were marked gastric protection along with reduction or absence of edema and leucocytes infiltration of the submucosal layer. Subacute toxicity study with a higher dose of derivative (5 g/kg) did not manifest any toxicological signs in rats. In conclusions, the present finding suggests that benzyl N'-(5-chloroindol-3-ylmethylidene)hydrazinecarbodithioate promotes ulcer protection as ascertained by the comparative decreases in ulcer areas, reduction of edema and leucocytes infiltration of the submucosal layer.

Ellagic acid facilitates indomethacin-induced gastric ulcer healing via COX-2 up-regulation

The mechanism of indomethacin-induced gastric ulcer healing by ellagic acid (EA) in experimental mice model is described in our study. Ulcer index (UI) and myeloperoxidase (MPO) activity of the stomach tissues showed maximum ulceration on the third day after indomethacin (18 mg/kg, single dose) administration. Preliminary observation of UI and MPO activity suggests that EA possesses ulcer-healing activity. Other anti-ulcer parameters such as the levels of prostaglandin E(2), cyclooxygenase (COX) 1 and 2 enzymes, anti-inflammatory cytokines [interleukin (IL)-4 and -5], pro-angiogenic factors, e.g. vascular endothelial growth factor, hepatocyte growth factor (HGF), and endothelial growth factor (EGF) were down-regulated by indomethacin. EA (7 mg/kg/day) treatment for 3 days shifted the indomethacin-induced pro-inflammatory biochemical parameters to the healing side. These activities were correlated with the ability of EA to alter the COX-2-dependent healing pathways. The ulcer-healing activity of EA was, however, compromised by pre-administration of the specific COX-2 inhibitor, celecoxib, and NS-398. Taken together, these results suggested that the EA treatment accelerates ulcer healing by inducing IL-4, EGF/HGF levels and enhances COX-2 expression.

Gastroprotective activities of Turnera diffusa Willd. ex Schult. revisited: Role of arbutin

ETHNOPHARMACOLOGICAL RELEVANCE

Turnera diffusa Willd. ex Schult. has been used for the treatment of several human disorders including peptic ulcer.

OBJECTIVES OF THE STUDY

The current study is an attempt to evaluate the anti-ulcerogenic activities of arbutin, a major constituent of Turnera diffusa on two ulcer models. The possible involvement of lipid peroxidation, nitric oxide, IL-6, IL-10, TNF-α and mucus barrier mechanism has been investigated.

MATERIALS AND METHODS

Effects of arbutin on ulcer index, gastric juice acidity, mucus content and histochemistry, gross and histological gastric lesions, nitric oxide, cytokines levels (IL-6, IL-10 and TNF-α), and thiobarbituric acid reactive substances (TBARS), were evaluated in aspirin or ethanol-induced ulcer in vivo. Acute toxicity of arbutin was also examined in rodent model. MTT assay was used to assess the cytotoxicity of the compound on normal liver cells (WRL-68).

RESULTS

Pre-treatment with arbutin or omeprazole protected the gastric mucosa as seen by reduction in ulcer area and mucosal content, reduced or absence of edema, inflammation and leucocytes infiltration on both models. Arbutin significantly (P<0.05) lowered the elevated TBARS level into gasteric homogenate. Arbutin did not produce significant inhibition of NO. This natural compound has modulated the levels of interleukin-6, interleukin-10 and TNF-α. No in vitro or in vivo toxicities for arbutin were observed.

CONCLUSION

Thus it can be concluded that Turnera diffusa possesses anti-ulcer activity, which could be attributed to lipid peroxidation inhibitory, immuno modulatory and anti-oxidant mechanisms of arbutin but not to the intervention with nitric oxide inflammation pathway.

Antiulcer principle from Zingiber montanum

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizome of Zingiber montanum has been extensively used as a folk medicine to ameliorate peptic ulcer at northern part of Bangladesh.

AIM OF THE STUDY

To identify the antiulcer principle of the MeOH extract of the rhizome of Zingiber montanum by an ex vivo bioassay guided chromatographic separation and purification, and structure elucidation of the purified compound by spectroscopic methods.

MATERIALS AND METHODS

Dried powder of Zingiber montanum rhizomes was extracted with MeOH. The antiulcer activity of the crude extract and its chromatographic fractions were evaluated by the inhibition of 1N HCl induced gastric lesions in Swiss albino mice. The pure compound was purified from the active fraction by crystallization with hexanes. Structure of the pure compound was elucidated by spectroscopic methods. The antiulcer activity of the pure compound was evaluated by the inhibition of 1N HCl, 95% ethanol and indomethacin induced gastric lesions in mice.

RESULTS

The MeOH extract of Zingiber montanum showed 61.97% and 83.10% inhibition of the 1N HCl induced gastric lesions at doses of 200mg/kg and 400mg/kg, respectively, in mice. Chromatographic separation on silica gel of the extract was yielded seven fractions and the fraction 2 was found to have most potent antiulcer activity in mice. This fraction showed 77.46% inhibition of the 1N HCl induced gastric lesions at a dose of 40mg/kg in mice. Crystallization of the fraction yielded 1 (zerumbone, 180mg). It showed statistically 45.77% and 92.25% inhibition of 1N HCl induced gastric lesions in mice at doses of 20mg/kg and 40mg/kg, respectively. It also showed 29.07% and 45.35% inhibition of 95% ethanol induced gastric mucosal damage, and 64.76% and 72.38% inhibition of indomethacin induced gastric lesions in mice at doses of 20mg/kg and 40mg/kg, respectively.

CONCLUSION

Zerumbone (1) showed potent cytoprotective effect against necrotizing agent (HCl) and non-steroidal anti-inflammatory drug (indomethacin) induced gastric ulceration. It also exhibited moderate cytoprotective effect against noxious agent (EtOH) induced gastric lesions. It can be considered as a promising new antiulcer natural drug lead.

Evaluation of antiulcer activity of chromanone fraction from Calophyllum brasiliesnse Camb

ETHNOPHARMACOLOGICAL RELEVANCE

Calophyllum brasiliense Camb. (Clusiaceae), popularly known as 'guanandi', is found in the tropical areas and swampy lands. The latex exuding from its bark is used in the treatment of gastric ulcer in folk medicine. Several active compounds have been isolated from its stem bark among them, are the chromanone acids. Therefore, this study aimed to evaluate antiulcer activity and probable mechanism(s) of action of a fraction containing a mixture of chromanone acids (BI), derived by column chromatography fractionation of the hexane extract of the stem bark of Calophyllum brasiliense (HECb), using experimental in vitro and in vivo models.

MATERIALS AND METHODS

Ulcer was induced by oral administration of ethanol (75%, v/v) and indomethacin (50mg/kg). Malondialdehyde, reduced glutathione and catalase activity was measured in stomach tissue after ethanol induced ulcer. In order to evaluate the effect of BI on nitric oxide, ulcer was induced by ethanol in l-NAME pretreated animals. Anti-Helicobacter pylori activity was verified in disk diffusion and broth microdilution in vitro assays, using cagA+ and vacA+ Helicobacter pylori strains.

RESULTS

BI prevented the gastric ulceration caused by ethanol and indomethacin treatments. Its gastroprotective mechanism in ethanol-induced ulcer was partly due to reduction of MDA and CAT levels in the gastric tissue. BI did not affect the GSH levels and its gastroprotective effect was not reversed by pretreatment with l-NAME. BI showed anti-Helicobacter pylori in the both assays.

CONCLUSION

The results indicate that BI is partly responsible for the HECb antiulcer and anti-Helicobacter pylori effects.

Molecular mechanism of indomethacin-induced gastropathy

The probable cross talk among large numbers of inflammatory and angiogenic parameters in indomethacin (IND)-induced gastropathy and the associated signaling mechanism were studied in a mouse model. A single dose of IND (18 mg/kg, po) produced robust gastric ulceration in mice without any mortality, which peaked on the third day, but started healing from the fifth day onward. The ulceration was associated with increased myeloperoxidase activity and expression of proinflammatory (TNF-α, adhesion molecules, COX-2) and antiangiogenic (endostatin) parameters. The levels of proangiogenic factors such as COX-1, prostaglandin E, VEGF, and von Willebrand factor VIII were downregulated by IND. Our results revealed that although the maximal and minimal levels of these parameters were attained sequentially at different time points, TNF-α upregulation was the primary event to initiate and induce gastric ulceration. IND also activated NF-κB and all the MAP kinases, but only the inhibitors of TNF-α, NF-κB, and JNK MAP kinase could abrogate the IND-induced damages. Further TNF-α inhibition also reduced the IND-mediated activation of NF-κB and JNK MAP kinase. All this evidence strongly suggests that mitigation of TNF-α may offer a potential solution to IND-mediated gastropathy.

Anti-inflammatory, anti-hyperalgesic, antiplatelet and antiulcer activities of Byrsonima japurensis A. Juss. (Malpighiaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Decoctions or infusions of the stem bark of Byrsonima japurensis A. Juss. (Malpighiaceae) are widely used as an anti-inflammatory drug in folk medicine of Amazonas State (Brazil).

AIM OF THE STUDY

To evaluate the pharmacological potential of an aqueous extract of the stem bark of Byrsonima japurensis (BJEA) to scientifically verify of its traditional use.

MATERIALS AND METHODS

Anti-inflammatory, antihyperalgesic and antiulcer activities were evaluated in Wistar rats, a Hippocratic screening was performed in Swiss mice to evaluate the toxic effects, and antiplatelet evaluation was performed in human platelet rich plasma assay. Additionally, antioxidant activity was evaluated by superoxide radical scavenging method and β-carotene bleaching test.

RESULTS

Anti-inflammatory, antihyperalgesic and gastroprotective activities were observed in rats treated orally with different doses of BJEA. While signals of toxicity were observed in the mice treated with a very high dose of extract (5000mg/kg), no death occurred. BJEA also showed expressive antiplatelet and antioxidant activities in vitro.

CONCLUSION

According to our results, it was concluded that stem bark of Byrsonima japurensis has significant and safe anti-inflammatory activity, which is closely related with their potent antioxidant activity, supporting the folk medicinal use of this species.

Protective effect of a cysteine prodrug and antioxidant, L-2-oxothiazolidine-4-carboxylate, against ethanol-induced gastric lesions in rats

Earlier studies have suggested an important role of glutathione (GSH) in cytoprotection against free radicals induced oxidative damage. This study reports gastroprotective effects of a cysteine precursor, L-2-oxothiazolidine-4-carboxylate (OTC), in experimental models of gastric secretion and ulceration. Acid secretion studies (volume and acidity) were undertaken in pylorus-ligated rats whereas the gastric lesions were induced by ethanol. Different groups of animals were treated with OTC (0, 100, 200 and 400 mg/kg). The levels of gastric wall mucus, nonprotein sulfhydryls (NP-SH) and myeloperoxidase (MPO) were measured in the glandular stomach of rats following ethanol-induced gastric lesions. Both medium and high doses of OTC significantly reduced the volume and acidity of gastric secretion in pylorus-ligated rats. Pretreatment with OTC significantly and dose-dependently attenuated the formation of ethanol-induced gastric lesion. OTC significantly protected the gastric mucosa against ethanol-induced depletion of gastric wall mucus, NP-SH and MPO. The gastroprotective effects of OTC may be attributed to its ability to inhibit neutrophils activity and replenish GSH demand.

Campomanesia lineatifolia Ruiz & Pav. as a gastroprotective agent

ETHNOPHARMACOLOGICAL RELEVANCE

Campomanesia lineatifolia Ruiz and Pav. (Myrtaceae) is a native edible species found in the Amazon Rainforest, commonly known as gabiroba. In Brazil, Campomanesia species are frequently used in traditional medicine for gastrointestinal disorders.

MATERIALS AND METHODS

The present study performed phytochemical analyses and determined both the in vitro antioxidant activity of the ethanolic extract of Campomanesia lineatifolia leaves (EEC) as well as its ethyl acetate fraction (EAFC). In this analysis, quercetin was used as a positive control. Gastroprotective activity was also investigated at different oral doses in two experimental models in rats - gastric lesion induced by ethanol and gastric lesion induced by indomethacin. In this analysis, cimetidine and sucralfate were used as positive controls. The area of gastric lesion underwent macroscopic and histomorphometric evaluations, while the mucus content was estimated by applying the periodic acid-Schiff stain. Oral acute toxicity was also assessed.

RESULTS

Phytochemical studies revealed the presence of flavonoids and tannins. Catechin and quercitrin were isolated by bioguided chromatographic fractionation of EAFC. EEC and EAFC presented in vitro antioxidant activity. The oral administration of EEC and EAFC at doses 100-400 mg/kg (ethanol model) and at doses of 400-1200 mg/kg (indomethacin model) proved to be effective in preventing gastric ulcerations in rats. Pretreatment with EAFC (400mg/kg) significantly increased the gastric mucus content in the ethanol model. No animals died during the acute oral toxicology test.

CONCLUSIONS

Results confirm the Brazilian ethnopharmacological use of Campomanesia lineatifolia as a gastroprotective agent and indicate that the anti-ulcer effect is most likely mediated by scavenging free radicals due to the polyphenol content and, at least in part, by increasing the mucus secretion and the mucosal defense. In addition, EEC and EAFC were found to be safe when applied to a 2000 mg/kg single oral dose.

Psidium guajava Linn confers gastro protective effects on rats

BACKGROUND AND OBJECTIVES

The best alternatives to synthetic medicines, available, for the treatment of gastric ulcer disorders, are the natural products found in plants. They are known to exhibit a variety of activities. The present study is aimed at the screening of Psidium (P.) guajava Linn for its gastro protective effect.

MATERIAL AND METHODS

The methanol extracts of the leaves of P. guajava were tested in three different ulcer models viz. aspirin (ASP), pyloric ligation (PL) and ethanol (EtoH) induced ulcer models in rats.

RESULTS AND DISCUSSION

The treatment of P. guajava at varying doses (100 mg/kg and 200 mg/kg) significantly (p < 0.001) inhibited the gastric lesions induced by ASP (70.5%), PL (65.07%) and EtoH (70.4%) respectively and the potency was found to be equivalent as compared to the standard drug, omeprazole. Reduction in the gastric secretory volume, acid secretion and increased gastric pH were the factors observed in treated rats. The presence of volatile oil, flavonoids and saponins present in the extracts of P. guajava may be responsible for the anti-ulcer property exhibited.

CONCLUSIONS

The results further suggest that P. guajava possess gastro protective as well as ulcer healing properties which might also be due to its anti-secretory properties.

[Frequency of proton pump inhibitor prescription based in clinical practice guidelines in hospitalized patients in two academic hospitals in Lima, Peru]

OBJECTIVES

To evaluate if Proton Pump Inhibitor (PPI) prescription is based in Clinical Practice Guidelines (CPG) in hospitalized patients at two academic hospitals of Lima.

MATERIALS AND METHODS

The services of Intern Medicine, Tropical Medicine and General Surgery were visited. Therapeutic sheets and nursing transcript were checked. The prescription motifs were determined in patients who received PPI. These motifs were obtained according to a check list, which was made from different CPG.

RESULTS

54.57% of the PPI prescriptions in the two academic hospitals were not based in CPG. No statistic significant difference was found between the two academic hospitals in the PPI prescription based in CPG (p=0,208). Most of the prescriptions not base on CPG belong to the service of General Surgery (83.6%; p<0.0001). The main indication for the prescription of PPI based on CPG was prevention of NSAIDS induced gastric ulcers if advanced age (65.72%).

CONCLUSIONS

There is a high rate of PPI overuse in two academic hospitals.

[Hepatoprotective effect of deanol aceglumate on experimental stress-induced gastropathy and diabetes mellitus]

Experiments on mice with streptozotocin-induced diabetes mellitus and stress-induced erosive ulcerous damage of the mucous membrane of stomach showed evidence of the preventive activity of deanol aceglumate in the course of peroral introduction at a dose of 250 mg/kg per 24 h during 4 days. This effect is accompanied by activation of the peristalsis of bowels and by an increase in the blood flow in the wall of stomach.

Gastro-protective effect of crude hexane leaf extract of Sesamum indicum in rabbits

The gastroprotective effect of the hexane extract of the leaves of Sesamum indicum (HESI) was investigated in twenty-eight male rabbits. Gastroprotective activity against necrotizing agent induced ulceration was studied. Gastric wall mucus was determined by standard methods. Anti-secretory activity was determined in twelve pyloric-ligated rabbits. Phytochemical and acute toxicity tests were performed. Results showed that the hexane extract of S. indicum significantly reduced gastric ulcers induced by necrotizing agent when compared with values obtained with the negative control (p<0.01). Pre-treatment with graded doses of HESI significantly increased gastric mucous in a dose dependent manner when compared with negative control (p<0.001). Misoprostol significantly protected rabbits from necrotizing agent induced ulceration by 99.9% when compared with negative control (p<0.01). Misoprostol also significantly increased mucous turnover with mean gastric mucous of 597.75 ± 4.70μg Alcian blue/g wet tissue when compared with the negative control (p<0.001). Additionally, treatment with HESI resulted in a significant increase in gastric fluid after histamine stimulation in pyloric-ligated rabbits when compared with the negative control (p<0.001). The extract of S. indicum also significantly decreased titratable acidity of histamine treated rabbits and increased gastric pH when compared with negative control (p<0.001). HESI significantly protected rabbits from ulceration after histamine administration in 4 hour pyloric ligated rabbits with a percentage protection of 79.3% (p<0.001). The extract also increased the volume of gastric fluid significantly after 4 hr pyloric ligation (p<0.01). Cimetidine protected pyloric-ligated rabbits from ulceration (92.1%) (p<0.001) and also raised the gastric pH (p<0.001), protein concentration in the gastric fluid (p<0.001), and reduced the titratable acidity (p<0.001) when compared with the negative control. The leaves of S. indicum possess gastroprotective properties.

Analgesic, anti-inflammatory and antipyretic effects of the ethanol extract of Acalypha wilkesiana leaves in rats

The leaves of Acalypha wilkesiana are commonly used for the treatment of pain, fever and ulcer by traditional medical practitioners without any scientific data to evaluate the appropriateness of some of the practices. Therefore, this study was carried out to determine whether the ethanol extract of Acalypha wilkesiana has analgesic, anti-inflammatory and antipyretic as well as anti-ulcer effects. The hot plate latency assay and formalin- induced paw licking models were used to evaluate analgesic effects. Animals were divided into groups comprising of five rats each. There were control (administered saline) and reference (administered indomethacin) groups. Also there were three extract groups administered 25, 50 or 100 mg/Kg body weight of extracts. Ulcer was induced using absolute ethanol followed by pylorus ligation in all animals; inflammation was induced using carrageenan while pyrexia was induced by injecting brewer's yeast intramuscularly into the dorsal part of the abdominal cavities of the rats. Different sets of rats were used for the anti-ulcer, anti-inflammatory and antipyretic studies although animal grouping for extract administration were as in analgesic studies. The results show that the extract produced dose-dependent and significant (p<0.05) analgesic and anti-inflammatory activities. The extract also significantly protected against ethanol induced ulcer. Likewise, the extract significantly (p<0.05) reduced the pyretic states of the animals. This study has therefore further provides evidences that may support the ethnomedicinal uses of the ethanolic extracts of Acalypha wilkesiana leaves.

Gastric cytoprotection and honey intake in albino rats

Beneficial effect of honey has been widely reported particularly on wound healings, gastrointestinal disorders and as antibacterial agent. However, there is paucity of report on its cytoprotective effect on the gastric mucosa despite its common usage worldwide including Nigeria. This study was therefore carried out to evaluate the effect of this widely consumed substance on gastric mucosa using animal model and also to explore possible mechanism of its action on the gastric mucosa .Twenty male adult albino rats of Wistar strain, weighing between 210-220g were used in the experiment. They were randomly assigned into two groups, the control group and the honey-fed (test) group, each containing ten rats. The Control group was fed on normal rat feed and water while the test group was fed on normal rat feed with honey added to its drinking water (1ml of honey for every initial 10ml of water for each rat daily) for twenty two weeks. After twenty two weeks the rats were weighed after being starved overnight. They were anaesthetized with urethane (0.6ml/100g body weight). Gastric ulceration was induced using 1.5ml acid-alcohol prepared from equivolume of 0.1NHCl and 70% methanol introduced into the stomach via a portex cannula tied and left in place following an incision made on the antral-pyloric junction of the stomach. The acid-alcohol was allowed to stay for 1hr. After 1hr, laparatomy was performed and the stomach isolated, cut open along the greater curvature, rinsed with normal saline and fastened in place with pins on a dissecting board for ulcer examination and scores. The result obtained showed mean ulcer scores of 14.5+/-0.70 for the control group and 1.6+/-0.11 for the test group. The result showed that honey significantly reduced ulcer scores as well as caused scanty haemorrhage in the test group compared with increased ulcer scores and multiple haemorrhage in the control group. It is therefore concluded that honey intake offered cytoprotection on the gastric mucosa of albino rats.

Gastro-protective effect of methanol extract of Ficus asperifolia bark on indomethacin-induced gastric ulcer in rats

The gastro-protective and antioxidant effects of methanol extract of Ficus asperifolia bark on indomethacin induced gastric ulcer were investigated in male rats. Thirty two male rats divided into 4 equal groups and were treated as follows: group1 (control), 0.5ml of 5% tween 80 (vehicle for the extract), groups 2 and 3, 100 and 500mg/kg of Ficus asperifolia extract respectively and group 4, cimetidine (100mg/kg). After two weeks of daily oral administration of vehicle, extract or cimetidine, gastric ulcer was induced in all rats with indomethacin (40 mg/kg, p.o). Gastric juice pH, gastric acid concentration, gastric ulcer score, percentage gastric ulcer inhibition, activity levels of superoxide dismutase (SOD), catalase and malondiadehyde (MDA) were determined. Ficus asperifolia extract significantly increased gastric pH (p<0.05) but decreased (p<0.01) gastric acid secretion in dose dependent manner when compared with the control. Inhibition of gastric ulcer in extract and cimetidine treated rats was similar. Activities of SOD and catalase were significantly increased (p<0.05) while MDA was significantly decreased (p< 0.05) in extract treated rats when compared with the control. The results suggest that Ficus asperifolia possesses gastro-protective and antioxidant properties against gastric ulcer induced by indomethacin.

Gastroprotective activity of hydroalcoholic extract obtained from the leaves of Brassica oleracea var. acephala DC in different animal models

ETHNOPHARMACOLOGICAL RELEVANCE

Brassica oleracea var. acephala DC has been extensively used in Brazilian traditional medicine to treat gastric ulcer.

AIM OF THE STUDY

This study was conducted to evaluate the antiulcerogenic property of hydroalcoholic extract obtained from the leaves of Brassica oleracea.

MATERIALS AND METHODS

Antiulcer assays were performed using the protocol of ulcer induced by ethanol/HCl, and non-steroidal anti-inflammatory drugs (NSAIDs). Parameters of gastric secretion (volume, pH and [H(+)]) were determined by the pylorus ligation model and mucus in gastric contents.

RESULTS

In the ethanol-induced ulcer model, we observed a significant reduction in all the parameters analyzed, obtaining curative ratios of 58.8 ± 11.5, 86.2 ± 12.2 and 42.8 ± 6.6% for the groups treated with 50 and 100mg/kg of extract and omeprazole (30 mg/kg), respectively. The dose of 25mg/kg of hydroalcoholic extract of Brassica oleracea showed no significant results. In the indomethacin-induced ulcer, the percentages of ulcer inhibition were 64.3 ± 9.9, 66.4 ± 12.3 and 81.2 ± 7.5% for the groups treated with 50 and 100mg/kg extract and positive control (cimetidine, 100mg/kg), respectively. The results showed a significant increase in pH and mucus production in the groups treated with Brassica oleracea when compared with the control group. No sign of toxicity was observed in the acute toxicity study.

CONCLUSIONS

The results of the present study show that hydroalcoholic extract of Brassica oleracea displays antiulcer activity, as demonstrated by the significant inhibition of ulcer formation induced using different models. The data suggest that the effectiveness of the extract is based on its ability to stimulate the synthesis of mucus, increase pH and decrease H(+) ions in the stomach. This work corroborates the ethnopharmacology use of Brassica oleracea preparations, contributing to its pharmacological validation by suggesting that preparations obtained from Brassica oleracea could be used for the development of new phytopharmaceuticals for the treatment of gastric ulcer.