Gastroduodenal ulcer protective activity of Asparagus racemosus: an experimental,biochemical and histological study

Asparagus racemosus is an Ayurvedic rasayana, which finds mention in ancient Indian texts for treatment of gastric ulcers. The ulcer protective effect of methanolic extract of fresh roots of A. racemosus (ARM), 25-100 mg/kg given orally, twice daily for 5 days, was studied on different gastroduodenal ulcer models. ARM 50 mg/kg, twice daily, orally (total saponins 0.9%) showed significant protection against acute gastric ulcers induced by cold restraint stress (CRS), pyloric ligation, aspirin plus pyloric ligation, and duodenal ulcers induced by cysteamine. ARM in the above dose also significantly healed chronic gastric ulcers induced by acetic acid after 10 days treatment. However, ARM was ineffective against aspirin- and ethanol-induced gastric ulcers. Further, gastric juice and mucosal studies showed that ARM significantly increased the mucosal defensive factors like mucus secretion, cellular mucus, life span of cells and also possessed significant anti-oxidant effect, but had little or no effect on offensive factors like acid and pepsin.     

Antiulcerogenic effect and acute toxicity of a hydroethanolic extract from the cashew (Anacardium occidentale L.) leaves

The antiulcerogenic effect of a hydroethanolic extract of Anacardium occidentale L. leaves was investigated. The extract inhibited gastric lesions induced by HCl/ethanol in female rats. A dose-response effect study showed that the ED50 was 150 mg/kgb.w. Extract doses higher than 100 mg/kgb.w. were more effective than 30 mg/kg of lansoprazol in inhibiting gastric lesions. A methanolic fraction (257.12 mg/kg) which reduced gastric lesion at 88.20% is likely to contain the active principle of the antiulcer effect. No signs of acute toxicity were observed when mice were treated with extract dose up to 2000 mg/kgb.w. A chemical analysis of the extract allowed the identification of phenolic compounds as the major components. Glycosylated quercetin, amentoflavone derivate and a tetramer of proanthocyanidin were identified by liquid chromatography coupled to mass spectrometry. The level of total phenolics in the extract was evaluated at 35.5% and flavonoid content was 2.58%.     

Antiulcerogenic activity of Lantana camara leaves on gastric and duodenal ulcers in experimental rats

Ethnopharmacological relevance

Lantana camara L. (Verbenaceae), a widely growing shrub has been used in the traditional medicine for treating many ailments. The objective of the present study was to evaluate the effects of methanolic extract of Lantana camara leaves on gastric and duodenal ulcers.

Materials and methods

The antiulcerogenic effect of methanolic extract of Lantana camara was evaluated in aspirin induced gastric ulcerogenesis in pyloric ligated rats, ethanol induced gastric ulcer, and cysteamine induced duodenal ulcer models. The extract was administered orally at two different doses of 250 mg/kg and 500 mg/kg. The lipid peroxidation, reduced glutathione levels of ethanol induced gastric ulcer model and inhibition zone in diameter against Helicobacter pylori also determined.

Results

The L. camara extract significantly (P < 0.01) reduced ulcer index, total acidity and significantly (P < 0.01) increased the gastric pH of aspirin + pylorus-ligation induced ulcerogenesis and ethanol induced gastric ulcer models. The extract also significantly (P < 0.01) reduced the ulcer index of cysteamine induced duodenal ulcer. The L. camara showed significant (P < 0.01) reduction in lipid peroxidation and increase in reduced glutathione levels. The inhibition zone in diameter of extract against H. pylori was 20 mm.

Conclusion

The methanolic extract of Lantana camara leaves shown healing of gastric ulcers and also prevents development of duodenal ulcers in rats.     

Antiulcerogenic activity of Zizyphus lotus (L.) extracts

Oral administration of aqueous extracts of Zizyphus lotus root barks (50-200 mg/kg) leaves (50-200 mg/kg) and fruits (200-400 mg/kg) produced a significant (p<0.01) and dose dependent inhibition to the acute ulcer induced by HCl/ethanol solution. The methanolic (MeOH), ethyl acetate (EtOAc) and chloroformic (CHCl(3)) leaves extracts when administered orally at the dose of 200 mg/kg, exhibited a significant (p<0.01) inhibition of gastric lesions by 45%, 76% and 33%, respectively. Indeed, methanolic and ethyl acetate root barks extracts significantly reduced the gastric lesions by 47% and 41%, respectively. While the chloroformic root barks extract had no significant activity (19%). The effect of all extracts was compared with cimetidine (100 mg/kg, 62%) and omeprazole (30 mg/kg, 93%). Volume, pH and acidity of gastric juice were studied in pylorus-ligated rats. Root barks (200 mg/kg, p<0.01), leaves (200 mg/kg, p<0.01) and fruits (400 mg/kg, p<0.05) aqueous extracts showed significant reduction of gastric juice secretion in pylorus ligated rats, whereas the other extracts did not show any significance. Thus, Zizyphus lotus extracts act essentially as cytoprotective agents, which support the antiulcer effect of this plant in the traditional medicine.     

Studies on the anti-ulcer activity of a Bryophyllum pinnatum leaf extract in experimental animals

A methanolic fraction from an extract of Bryophyllum pinnatum leaves was found to possess significant anti-ulcer activity in nine different experimental animals models. Premedication tests in rats revealed that the extract possessed significant protective action against the gastric lesions induced by aspirin, indomethacin, serotonin, reserpine, stress and ethanol. Significant protection with extract treatment was observed to occur for aspirin-induced ulcer in pylorus-ligated rats and for histamine-induced duodenal lesions in guinea pigs. Significant enhancement of the healing process was also found to occur in acetic acid-induced chronic gastric lesions in rats.     

Antiulcer activity of methanolic extract of Momordica charantia L. in rats

Aim of the study

Momordica charantia L. (Cucurbitaceae) commonly known as ‘bitter gourd’ is a multi purpose herb cultivated in different parts of the world for its edible fruits. The objective of the present study was to evaluate the effect of standardized methanolic extract of Momordica charantia L. fruits on gastric and duodenal ulcers.

Materials and methods

The effect was evaluated in acetic acid induced chronic gastric ulcer, pylorus ligation induced gastric ulcer, ethanol induced gastric ulcer, stress induced gastric ulcer, indomethacin induced gastric ulcer and cysteamine induced duodenal ulcer model. The extract was administered orally at two different doses of 100 mg/kg and 500 mg/kg.

Results

The healing of acetic acid induced gastric ulcer was increased by both doses of the extract. In pylorus-ligated rats, the extract showed significant decrease in ulcer index, total acidity, free acidity and pepsin content and an increase in gastric mucosal content. The extract also reduced the ulcer index in stress induced, ethanol induced and indomethacin induced gastric ulcers and cysteamine induced duodenal ulcer.

Conclusion

The methanolic extract of Momordica charantia L. fruit increases healing of gastric ulcer and also prevents development of gastric ulcers and duodenal ulcers in rats.     

Anti-ulcer activity of crude alcoholic extract of Toona ciliata Roemer (heart wood)

The ethanol extract of Toona ciliata Roemer (heart wood) was evaluated for its anti-ulcer activity against aspirin plus pylorous ligation induced gastric ulcer (antisecretory), HCl-ethanol induced ulcer (cytoprotective) and water immersion stress induced ulcer in rats. We found that Toona ciliata extract at a dose of 300mg/kg p.o. markedly decrease the incidence of ulcers in all the three models. Ethanol extract of Toona ciliata showed significant reduction in gastric volume, free acidity, total acidity and ulcer index. The plant extract also showed gastro protective activity (52.94%), whereas standard drug sucralfate showed 94.85%. Toona ciliata extract showed protection index 43.0% in water immersion stress induced ulcer, whereas standard drug omeprazole showed protection index 100%.     

Evaluation of the gastric antiulcerogenic effect of large cardamom (fruits of Amomum subulatum Roxb)

Large cardamom (fruit of Amomum subulatum Roxb, N.O. Zingiberaceae) commonly known as 'Heel kalan' or 'Bari Ilaichi' is used in Unani system of medicine in gastrointestinal disorders. A crude methanolic extract and its different fractions, viz. essential oil, petroleum ether (60-80 degrees ), ethyl acetate and methanolic fractions, were studied in rats for their ability to inhibit the gastric lesions induced by aspirin, ethanol and pylorus ligature. In addition their effects on wall mucus, output of gastric acid and pepsin concentration were recorded. The crude methanolic extract of A. subulatum and its fractions, viz. essential oil, petroleum ether and ethyl acetate, inhibited gastric lesions induced by ethanol significantly, but not those which were induced by pylorus ligation and aspirin. However, ethyl acetate fraction increased the wall mucus in pylorus ligated rats. The results suggest a direct protective effect of ethyl acetate fraction on gastric mucosal barrier. While the observation of decrease in gastric motility by essential oil and petroleum ether fractions suggests the gastroprotective action of the test drug. These investigations validate the use of 'Heel kalan' in gastrointestinal disorders by Unani physicians.     

Gastroprotective effect of Dodonaea viscosa on various experimental ulcer models

AIM OF THE STUDY: Dodonaea viscosa Linn. (Sapindaceae) is used as a medicinal herb by the tribes of Shola forest regions of Western Ghats. It is used for headaches, backaches, stomach pain, piles and simple ulcers. The present study was performed to evaluate the gastroprotective effect and acute toxicity of this plant in various experimental models. MATERIALS AND METHODS: Studies were performed in two different models (ethanol and indomethacin induced gastric ulcer) in wistar rats. Gastric protection was evaluated by measuring the ulcer index, gastric glutathione assay, alkaline phosphate assay and histopathological studies. Gastric secretion studies were done by pyloric ligation experiment. RESULTS AND CONCLUSIONS: Water and ethanol extract (500 mg/kg body weight) showed moderate activity compared to hexane extract. Hexane extract of Dodonaea viscosa dose dependently inhibited ethanol induced gastric lesions, causing 90% protection at 500 mg/kg, 81% protection at 250 mg/kg, and 70% protection at 125 mg/kg and it also dose dependently inhibited indomethacin induced gastric lesions, causing 92% protection at 500 mg/kg, 77% protection at 250 mg/kg, and 52% protection at 125 mg/kg. The various degrees of inhibition were statistically significant (p相似文献   

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 1 N 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 1 N 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 1 N HCl induced gastric lesions at doses of 200 mg/kg and 400 mg/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 1 N HCl induced gastric lesions at a dose of 40 mg/kg in mice. Crystallization of the fraction yielded 1 (zerumbone, 180 mg). It showed statistically 45.77% and 92.25% inhibition of 1 N HCl induced gastric lesions in mice at doses of 20 mg/kg and 40 mg/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 20 mg/kg and 40 mg/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.     

Antiulcerogenic activity of Alchornea castaneaefolia: effects on somatostatin, gastrin and prostaglandin

The hydroethanolic extract of the leaves (HEL) and bark (HEB) obtained from Alchornea castaneaefolia (Euphorbiaceae) were investigated for their ability to prevent ulceration of the gastric mucosa in animal models. HEL (500 and 1000 mg/kg) and HEB (1000 mg/kg) significantly reduced the gastric injuries induced by the combination of HCl/ethanol and lowered the severity of gastric damage formation induced by indomethacin/bethanechol in mice. Further investigation showed that HEL also inhibited formation of ulcers in mice submitted to stress and pylorus ligature, but HEL did not modify gastric juice parameters in Shay mice. HEL was also effective in promoting the healing process in chronic gastric ulcer induced by acetic acid in rats. An enriched flavonoidic fraction (EFF at dose of 100mg/kg) obtained from HEL reduced gastric lesions induced by HCl/ethanol and indomethacin/bethanechol in mice. Although EFF did not modify the amount of free mucus production by gastric mucosa, it was able to increase prostaglandin production. When administered to rats submitted to ethanol-induced gastric lesions, EFF increased the somatostatin serum levels, while the gastrin serum levels were proportionally decreased. Phytochemical investigation on HEL and EFF led to the isolation of flavonoids glycosides as the main compounds, thus suggesting that these substances may be involved in the observed antiulcer activity.     

Evaluation of the antipeptic ulcer activity of the leaf extract of Plantago lanceolata L. in rodents

The effect of the leaf extract of Plantago lanceolata L. (Plantaginaceae) on gastric secretion and cytoprotection was evaluated using different models of gastroduodenal ulcer, including acetic acid induced chronic gastric ulcer, indomethacin induced gastric ulcer, cysteamine induced duodenal ulcer and pylorus ligation induced gastric ulcer. The aqueous extract was administered at 200 mg/kg and 400 mg/kg and 140 mg/kg and 280 mg/kg for mice and rats, respectively, and compared with vehicle or the standard, ranitidine (50 or 70 mg/kg) or misopristol (280 μg/kg). In addition, activity of the mucilage (172 mg/kg) was also evaluated in acetic acid induced chronic gastric ulcer. Administration was done orally except in pylorus ligation, where the intraduodenal route was used. In all cases, higher doses of the extract provided better protection than lower doses and the mucilage, hinting at a dose‐dependent effect. Whilst higher doses of the extract showed a better healing of the ulcer as well as protection in indomethacin and pylorus ligation models, activities of lesser magnitude than ranitidine were noted in the cysteamine model. Together these findings indicate that higher doses used in the present study provided an overall better protection against gastroduodenal ulcers than the standard drugs employed through antisecretory and cytoprotective mechanisms. Copyright © 2011 John Wiley & Sons, Ltd.     

Antiulcerogenic effect of methanolic extract of Emblica officinalis: an experimental study

The ulcer protective potential of methanolic extract of Emblica officinalis Gaertn. (EOE) was assessed in different acute gastric ulcer models in rats induced by aspirin, ethanol, cold restraint stress and pyloric ligation and healing effect in chronic gastric ulcers induced by acetic acid in rats. EOE, 10-50 mg/kg administered orally, twice daily for 5 days showed dose-dependent ulcer protective effects in all the above acute ulcer models (36.0-98.3% protection, P < 0.2 to P < 0.001) and significant ulcer healing effect in dose of 20 mg/kg after 5 (control ulcer index: 20.2+/-2.3 mm(2)/rat, % healing 59.6%, P < 0.001) and 10 (control UI: 11.0+/-1.7, % healing 65.5%, P < 0.01) days treatment. Further study on gastric mucosal factors showed that it significantly decreased the offensive factors like acid (acid output-control 118.7+/-12.1 microEq/4 h, EOE% decrease 65.9%, P < 0.01) and pepsin (peptic output-control 738.8 micromol/4 h, EOE% decrease 46.2%, P < 0.001) and increased the defensive factors like mucin secretion (TC:P ratio-control 1.21+/-0.15, EOE% increase 95.0%, P < 0.01), cellular mucus (TC:P ratio-control 1.16+/-0.13, EOE% increase 53.4%, P < 0.05) and life span of mucosal cells (DNA content of gastric juice-control 77.3+/-8.7 microg/m per 100 g body weight, EOE% decrease 42.1%, P < 0.05). EOE showed significant antioxidant effect in stressed animals (control UI 35.8+/-2.5, antioxidant status: LPO 0.58+/-0.03 nmol MDA/mg protein, SOD and CAT 227.8+/-6.3 and 18.4+/-1.2 U/mg protein respectively; EOE% decrease in UI 88.2%, mucosal LPO 69.0%, SOD 53.1% and increase in mucosal CAT 59.8%, P < 0.001 respectively) and did not have any effect on cell proliferation in terms of DNA microg/mg protein or glandular weight. The results showed that EOE had significant ulcer protective and healing effects and this might be due to its effects both on offensive and defensive mucosal factors.     

Gastric antisecretory and cytoprotective effects of hydroalcoholic extracts of Plumeria alba Linn. leaves in rats

OBJECTIVE:This study was conducted to evaluate the antiulcerogenic property of hydroalcoholic extract obtained from the leaves of Plumeria alba Linn.METHODS:Antiulcer assays were performed using the protocols of ulcer induced by nonsteroidal anti-inflammatory drugs,ethanol and pylorus ligation.The hydroalcoholic extract(HAPA),and various fractions of HAPA like,n-hexane extract(HPA),ethyl acetate extract(EAPA) and n-butanol extract(BPA) were administered at doses of 200 and 400 mg/kg for HAPA and 100 and 200 mg/kg for fractions of extracts.Parameters of gastric secretion(volume,pH,total protein,and free and total acidity) were determined by the pylorus ligation model.Parameters like aspartate aminotransferase and alanine aminotransferase were also determined in ethanolinduced ulcer model.To determine the mechanism of action,role of nitric oxide was also evaluated.RESULTS:EAPA and BPA(100 and 200 mg/kg,p.o.) showed gastric ulcer-healing effect in indomethacin-induced ulcer model,while HAPA(200 mg/kg) and HPA showed no significant antiulcer effect.Both EAPA and BPA showed gastric cytoprotective effect in ethanol-induced gastric ulcer and inhibited gastric secretion in pylorus-ligated rats.CONCLUSION:The results of the present study show that some hydroalcoholic extract of Plumeria alba L.displays antiulcer activity,as demonstrated by the significant inhibition of ulcer formation induced by different models,which is consistent with the literature report in folk medicine.     

Antiulcerogenic activity of ethanol extract of Solanum variabile (false "jurubeba")

The ethanol extract (EE) of the aerial parts of Solanum variabile Mart. (Solanaceae) was investigated for its ability to prevent ulceration of the gastric and duodenal mucosa at different doses. Its ability to heal chronic ulcer processes was also evaluated. When the HCl/ethanol solution was used to induce gastric ulcer, the EE produced a significant dose-dependent reduction of lesion formation of 51, 74 and 89%, at doses of 250, 500 and 1000 mg/kg, respectively. The 100 mg/kg dose had no significant activity. The EE also significantly reduced the gastric lesions induced by the combination of indomethacin and bethanechol (60 and 72%) at doses of 500 and 1000 mg/kg and also reduced stress-induced gastric ulcer (41%) but only at the doses of 1000 mg/g (P < 0.05). The pylorus-ligature experiment demonstrated that the highest EE dose affected significantly the gastric juice parameters by increasing pH values from 4.08 (negative control) to 5.42 and decreasing acid output from 7.16 (negative control) to 4.26 mEq.mL, 4h. A decrease of gastric contents from 370 mg (negative control) to 240 mg was also observed. The results obtained in the chronic gastric ulcer model indicated that a single oral dose of Solanum variabile (1000 mg/kg) administered for 14 consecutive days accelerated the ulcer healing by 46% compared to a 55% effect of cimetidine. Also, at the dose of 1000 mg/kg, the EE inhibited the onset of duodenal lesions by 64%. The data suggest that the EE of Solanum variabile has a significant preventive, curative and duodenal anti-ulcer effect.     

Antithrombotic activity of methanolic extract of Umbilicaria esculenta

Antithrombotic activity of methanolic extract of an edible lichen, Umbilicaria esculenta, was evaluated on platelet aggregation in vitro and pulmonary thrombosis in vivo. The extract showed concentration dependent inhibitory effects on platelet aggregation induced by ADP, with IC(50) value of 2.4 mg/mL. Orally administered extract protected mice against thrombotic death or paralysis induced by collagen and epinephrine in a dose dependent manner. It produced a significant inhibition of thrombotic death or paralysis at over 100 mg/kg body weight, while aspirin produced a significant inhibition of thrombosis at 10-20 mg/kg body weight. Mouse tail bleeding time was significantly prolonged by addition of the extract. On the other hand, the extract did not show any fibrinolytic activity and alter coagulation parameters such as activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) in rat platelet. These results suggested that the antithrombotic activity of Umbilicaria esculenta extract might be due to antiplatelet activity rather than anticoagulation activity.     

In vivo inhibition of gastric acid secretion by the aqueous extract of Scoparia dulcis L. in rodents

The freeze-dried aqueous extract (AE) from the aerial parts of Scoparia dulcis was tested for its effects on experimental gastric hypersecretion and ulcer in rodents. Administration of AE to animals with 4h pylorus ligature potently reduced the gastric secretion with ED(50)s of 195 mg/kg (rats) and 306 mg/kg (mice). The AE also inhibited the histamine- or bethanechol-stimulated gastric secretion in pylorus-ligated mice with similar potency suggesting inhibition of the proton pump. Bio-guided purification of the AE yielded a flavonoid-rich fraction (BuF), with a specific activity 4-8 times higher than the AE in the pylorus ligature model. BuF also inhibited the hydrolysis of ATP by H(+),K(+)-ATPase with an IC(50) of 500 microg/ml, indicating that the inhibition of gastric acid secretion of Scoparia dulcis is related to the inhibition of the proton pump. Furthermore, the AE inhibited the establishment of acute gastric lesions induced in rats by indomethacin (ED(50)=313 mg/kg, p.o.) and ethanol (ED(50)=490 mg/kg, p.o.). No influence of the AE on gastrointestinal transit allowed discarding a possible CNS or a cholinergic interaction in the inhibition of gastric secretion by the AE. Collectively, the present data pharmacologically validates the popular use of Scoparia dulcis in gastric disturbances.     

Protective effect of Cissus quadrangularis on neutrophil mediated tissue injury induced by aspirin in rats

Cissus quadrangularis (family: Vitaceae) is well known for the treatment of gastric disorders in traditional medicine, owing to its rich source of carotenoids, triterpenoids and ascorbic acid, and has received considerable attention regarding its role in human nutrition. In the search of new potential antiulcer agents, the present study evaluated the ethanol extract of Cissus quadrangularis (CQE) against the gastric toxicity induced by aspirin in rats. The optimum protective dose of 500 mg/kg of extract was selected by the pretreatment of gastric ulcers with different doses of CQE (250, 500 and 750 mg/kg) for 7 days which showed ulcer protection by 40, 71.2 and 72.6%, respectively, as compared to ranitidine (RTD) (30 mg/kg) by 71.9% in the aspirin model. In addition, results have shown that administration of aspirin increases lipid peroxidation status, xanthine oxidase (XO), myeloperoxidase and decrease in selenium-glutathione peroxidase activities in the gastric mucosa, resulting in mucosal damage at both cellular and subcellular level. Pretreatment with CQE ameliorated the observed effect significantly in the gastric mucosa of ulcerated rats. These findings suggest that the gastroprotective activity of CQE could be mediated possibly through its antioxidant effect as well as by the attenuation of the oxidative mechanism and neutrophil infiltration.     

Study of Mimusops elengi bark in experimental gastric ulcers

The present study was designed to investigate the effect of Mimusops elengi (Sapotaceae) against experimental gastric ulcers. The 50% alcoholic extract of Mimusops elengi (Ext E) and its different fractions namely ethyl acetate (Ext E1), n-butanol (Ext E2), methanol (Ext E3) and aqueous (Ext E4) were studied (p.o.) against ethanol-induced gastric damage. Ext E1 was also studied in ethanol-induced, pylorus-ligated and water-immersion plus stress-induced gastric ulcer models. Ranitidine HCl (80 mg kg(-1)) was used as a reference standard. In ethanol-induced gastric ulcer model, pantoprazole (20 mg kg(-1)) was also used as a reference standard. Ext E1 tested in mice up to the dose of 5000 mg kg(-1) (p.o.) did not produce any sign of toxicity. Ext E at the doses of 50, 100, 300 and 500 mg kg(-1) and its different fractions (100 mg kg(-1)) showed reduction in gastric ulceration (P < 0.05). Ext E1 at the doses of 10, 50 and 100 mg kg(-1) showed dose-dependent inhibition of gastric lesions against ethanol-induced gastric damage. In 19 h pylorus-ligated animals, Ext E1 at 50 and 100 mg kg(-1) doses showed significant reduction in ulcer index (P < 0.05). Significant reduction was also observed in total acidity, volume of gastric acid secretion, total acid output and pepsin activity (P < 0.05) when compared with the control group. Besides, Ext E1 showed increase in the mucosal glycoproteins that was evident from significant rise in total carbohydrates to protein ratio (TC:PR ratio) (P < 0.05), which is an indication of mucin activity. Ext E1 also showed protection against water-immersion plus stress-induced gastric lesions that was evident from dose-dependent decrease in ulcer index (P < 0.05), score for intensity (P < 0.05) and total lesion area (P < 0.05) when compared with the control group. It can be concluded from our study that Ext E1 possesses anti-ulcer activity against experimental gastric ulcers. The mechanism of anti-ulcer activity can be attributed to decrease in gastric acid secretory activity along with strengthening of mucosal defensive mechanisms.     

Effect of Brazilian green propolis on experimental gastric ulcers in rats

Propolis is a resinous hive product collected by honeybees from plants. The propolis produced in Southeastern of Brazil is known as green propolis because of its color. Modern herbalists recommend its use because it displays antibacterial, antifungal, antiviral, hepatoprotective, anti-inflammatory, immunomodulatory and anti-ulcer properties. The anti-ulcer activity of green propolis hydroalcoholic crude extract was evaluated by using models of acute gastric lesions induced by ethanol, indomethacin and stress in rats. Moreover, the effects of extract on gastric content volume, pH and total acidity, using pylorus ligated model were evaluated. Animals pretreated with propolis hydroalcoholic crude extract (50, 250 and 500 mg/kg) showed a significant reduction in lesion index, total affected area and percentage of lesion in comparison with control group (p < 0.05) in the ethanol-induced ulcer model. Green propolis extract, at a higher dose (500 mg/kg), displayed a significant protection by reducing (p < 0.05) the evaluated parameters in the gastric ulceration induced by indomethacin. In the stress-induced ulcer model it was observed a significant reduction (p < 0.05) in those parameters in animals treated with green propolis extract (250 and 500 mg/kg). Regarding the pylorus ligated model it was observed that green propolis extract (250 and 500 mg/kg) displayed an anti-secretory activity, which lead to a reduction in the gastric juice volume, total acidity and pH. These findings indicate that Brazilian green propolis displays good anti-ulcer activity, corroborating the folk use of propolis preparations, and contributing for its pharmacological validation.