Pylorus Ligation Research Articles

Gastric acid is the key modulator in the pathogenesis of non-steroidal anti-inflammatory drug-induced ulceration in rats

1. In the present study, we investigated the role of gastric acid (GA) secretion on non-steroidal anti-inflammatory drug (NSAID)-induced ulcerogenesis in vivo. Rats were administered single oral doses of selective cyclo-oxygenase (COX)-1 (SC-560; 2.5 mg/kg), COX-2 (DFU; 25 mg/kg) or non-selective COX (indomethacin; 25 mg/kg) inhibitors. Three groups (basal, histamine-stimulated and histamine with lansoprazole) were pylorus ligated 2 h after inhibitor administration and killed 2 h later. Another group without pylorus ligation received only inhibitors and was killed after 18 h. 2. At 4 h, indomethacin increased the ulcer index (UI) and myeloperoxidase (MPO) activity in basal and histamine-stimulated states, whereas SC-560 only increased MPO activity. Histamine-stimulated, but not basal, GA was further enhanced by indomethacin and SC-560 via increased proton pump expression. Lansoprazole (10 mg/kg) reduced the UI, MPO activity and GA to basal levels with SC-560 and DFU and to near basal with indomethacin. Indomethacin and SC-560 significantly inhibited prostaglandin (PG) E(2), without significantly affecting COX-1 and COX-2 expression. Although DFU inhibited PGE(2) by one-third, it did not affect COX expression. 3. At 18 h, indomethacin significantly increased the UI and MPO activity, whereas PGE(2) synthesis was less inhibited, indicating a return to control levels. In contrast, PGE(2) synthesis was higher than control with SC-560. Furthermore, COX-2 expression was significantly elevated with indomethacin and SC-560, explaining the source of augmented PGE(2) synthesis. Proton pump expression remained elevated, comparable with 4 h levels, with indomethacin and SC-560. However, DFU had no significant effect on the aforementioned parameters. 4. The data suggest that NSAID-induced ulcerogenesis is dependent on the amount of GA secretion derived from increased proton pump expression and requires inhibition of both COX-1 and COX-2.

Anti-ulcer role of herbomineral siddha drug — Thamira parpam on experimentally induced gastric mucosal damage in rats

Anti-ulcerogenic activity of Thamira parpam (TP) was investigated in two ulcer models (aspirin + pylorus ligation and HCl-ethanol). Aspirin-pylorus ligation (Asp 200 mg/kg-7 days + PL-4 hours) and HCl-ethanol (150 mM HCl in 70% ethanol) induction in rat resulted in elevation of thiobarbituric acid reactive substances (TBARS) and depletion of antioxidants (superoxide dismutase [SOD], glutathione [GSH], glutathione peroxidase [GPx]) with high ulcer scores (p < .01). In Asp + PL model, TP treatment showed mild inhibition on ulcer scores, changes in pH, gastric volume, total and free acidity, and elevation of TBARS and depletion of antioxidants. Compared to the ulcer-untreated rats (HCl-ethanol), the herbomineral drug TP treatment (0.5, 1, 2 mg/kg, per oral [p.o.]) attenuated the elevation of TBARS, decrease of antioxidants and nitrite (p < .05). Histopathological examinations were correlated with the antioxidant profile. In conclusion, the prophylactic cytoprotective nature of the herbomineral drug in experimentally induced ulcers could be mediated by its free radical quenching property.

Comparative study of proton pump inhibitors on dexamethasone plus pylorus ligation induced ulcer model in rats.

The present study was designed to compare ulcer protective effect of proton pump inhibitors viz. omeprazole, rabeprazole and lansoprazole against dexamethasone plus pylorus ligation induced ulcer model. Dexamethasone (5 mg/kg) was used as an ulcerogen. Dexamethasone suspended in 1% CMC in water was given orally to all the rats 15 min after the pylorus ligation. Omeprazole (20 mg/kg), rabeprazole (20 mg/kg), and lansoprazole (20 mg/kg) were administered by oral route 30 min prior to ligation was used for ulcer protective studies, gastric secretion and mucosal studies. Effects of proton pump inhibitors were determined by the evaluation of various biochemical parameters such as ulcer index, free and total acidity, gastric pH, mucin, pepsin and total proteins. Oral administration of proton pump inhibitors showed significant reduction in gastric acid secretion and ulcer protective activity against dexamethasone plus pylorus ligation induced ulcer model. The % protection of omeprazole, rabeprazole and lansoprazole was 84.04, 89.36 and 79.78, respectively. Rabeprazole significantly inhibited the acid-pepsin secretion and increased the gastric mucin secretion. The observations made in the present study suggest that rabeprazole is the most effective gastric antisecretory and ulcer healing agent as compared to omeprazole and lansoprazole.

Determination of the antiulcer properties of sodium cromoglycate in pylorus-ligated albino rats.

Objectives:To study the ulcer protective property of sodium cromoglycate in pylorusligated rats and the biochemical role in ulcer protection by various biochemical tests.Materials and Methods:The ulcer protective effect of sodium cromoglycate was studied using a Pyloric Ligation Model using Wistar albino rats. The antiulcer effect of sodium cromoglycate 40 mg/kg b.w., i.p., was compared with the reference drug ranitidine 27 mg/kg b.w., i.p. The ulcer index was calculated and other biochemical parameters like free acidity, total acidity, pH, mucin, pepsin and volume of gastric juice were determined.Results:Pylorus ligation showed a significant (P < 0.01) reduction in gastric volume, free acidity, total acidity and ulcer index as compared to the control.Conclusion:Sodium cromoglycate has activity equipotent to ranitidine.

Acute gastric lesions induced by the administration of histamine to rats with partial vascular occlusion: evidence for the gastroprotective effect of prostaglandin

Histamine is not only a potent stimulator of gastric acid secretion, but it also plays a central role in gastroduodenal ulcerogenesis. In the present study we tested the effect of pre-treatment with exogenous prostaglandin E(2) (PGE(2)) in a new rat model of experimental gastric ulcers induced by combination of histamine and gastric ischemia. In male Wistar rats, a chronic ischemia of gastric mucosa was induced via the clamping of the left gastric artery and vein (L-AV) in combination with pylorus ligation. The following treatment groups of rats (6 rats/group) were investigated: 1) histamine alone (40 mg/kg twice s.c.); 2) vehicle (saline) followed 30 min later by gastric mucosal L-AV ischemia and pylorus ligation combined with histamine (40 mg/kg twice s.c.) and 3) PGE(2) (5 microg/kg i.g.) followed 30 min later by gastric mucosal L-AV ischemia combined with histamine (40 mg/kg twice s.c.) and pylorus ligation. At 4 hr after the clamping of L-AV and pylorus ligation, the area of gastric lesions and gastric acid secretion was determined. Histamine treatment failed to produce gastric lesions, but when it was combined with ischemia, the widespread gastric lesions in the corpus mucosa, but not in the antrum, were observed. This damaging effect and decrease in the GBF were significantly attenuated by pretreatment with PGE(2). The present study demonstrates that gastric hypersecretion induced by histamine in combination with gastric mucosal ischemia results in gastric lesions which progress into chronic gastric ulcers.

Effect of Centrally Administered Losartan on Gastric and Duodenal Ulcers in Rats

The effect of centrally administered losartan, an AT₁ receptor antagonist, on gastric acid secretion and gastric cytoprotection was studied using different models of gastric ulcers, such as acetic acid-induced chronic gastric ulcers, pylorus ligation, ethanol-induced and stress-induced acute gastric ulcers and cysteamine hydrochloride-induced duodenal ulcer. Losartan was administered intracerebroventrically (i.c.v.) at 2 different doses (125 and 250 μg/kg). Both doses of losartan increased the healing of acetic acid-induced chronic gastric ulcers. In pylorus-ligated rats, a significant reduction in free acidity, total acidity and ulcer index was observed with high dose (250 μg/kg, i.c.v.), while low dose (125 μg/kg, i.c.v.) produced reduction only in free acidity and ulcer index. Both doses also produced a significant antiulcer effect in ethanol-induced and stress-induced gastric ulcers. Losartan also reduced ulcer area in cysteamine-induced duodenal ulcer. We conclude that AT₁ receptor antagonism in the brain increases healing of gastric ulcers and reduces gastric acid secretion and increases gastric mucin content.

Beneficial Preventive Effects of Gastric Mucosal Lesion for Soy−Skim Milk Fermented by Lactic Acid Bacteria

In this study, Lactobacillus paracasei subsp. paracasei NTU101 and Lactobacillus plantarum NTU 102 were used as starter to ferment soy-skim milk, and the optimal mixing ratio was evaluated. The influence of lactic acid bacteria (LAB)-fermented soy-skim milk on mucosal integrity in a gastric mucosal lesion rat model was also investigated. After 24 h, cell densities of L. paracasei subsp. paracasei NTU 101 and L. plantarum NTU 102 fermented in 75% soy milk and 25% milk (optimal condition) were 1.2 × 10(9) and 2.5 × 10(9) CFU/mL. After 180 days at 4 °C, the cell densities of the freeze-dried powders of the fermented soy-skim milks were 1 × 10(9) CFU/g; slight variations in pH and acidity were observed. Pylorus ligation with acidified ethanol treatment was used as the gastric lesion animal model. LAB-fermented soy-skim milk reduced the gastric lesion index and the lipid peroxides (LPO) of gastric mucosa and serum. Administration of the fermented soy-skim milk enhanced superoxide dismutase (SOD) activity and prostaglandin E(2) (PGE(2)) synthesis. Therefore, LAB-fermented soy-skim milk at 10(9) CFU/day protects against gastric injury.

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.

The anti-ulcer activities of bisabolangelone from Angelica polymorpha

Aim of the study Evaluate the anti-ulcer effects of bisabolangelone from Angelica polymorpha Maxim and provide the basic data to further study for the Angelica polymorpha and bisabolangelone. Materials and methods Bisabolangelone was isolated from Angelica polymorpha Maxim collected from Shennongjia Forest District of China. The structure of bisabolangelone was elucidated by NMR and MS spectrums. The anti-ulcer effects were evaluated with length of lesion (mm) and activity of H +/K +-ATPase in two models induced by ethanol and Pylorus ligation. Experimental groups were administered with different doses of bisabolangelone (3.8, 7.6 and 15.3 mg/kg). The positive control group was administered omeprazole with a dose of 3.3 mg/kg. Results Bisabolangelone significantly reduced the length of lesion (3.8, 7.6 and 15.3 mg/kg, P < 0.01), inhibited the activity of H +/K +-ATPase (3.8, 7.6 and 15.3 mg/kg, P < 0.01), decreased the volume of gastric juice (7.6 and 15.3 mg/kg, P < 0.05), and increased the pH value of gastric juice (7.6 and 15.3 mg/kg, P < 0.01, 3.8 mg/kg, P < 0.05). Conclusions Bisabolangelone is the main anti-ulcer active compound of Angelica polymorpha, and remarkably preventive and therapeutic action on gastric ulcer. It is possible that bisabolangelone inhibited the activity of the H +/K +-ATPase, then reducing the secretion of H +, and the anti-ulcer mechanism of bisabolangelone was deserved to be further studied.

Effect of Lonicerae Flos extracts on reflux esophagitis with antioxidant activity

To observe the effects of traditional antiinflammatory medicine Lonicerae Flos (LF) on rat reflux esophagitis (RE) induced by pylorus and forestomach ligation compared with the well-known proton antioxidant, alpha-tocopherol. Rats were pretreated with three different dosages of LF (500, 250 and 125 mg/kg) orally, once a day for 14 d before pylorus and forestomach ligation. Nine hours after pylorus and forestomach ligation, changes to the stomach and esophagus lesion areas, gastric volumes, acid and pepsin outputs, antioxidant effects, esophageal lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), myeloperoxidase and glutathione (GSH) levels, and collagen contents (marker of flexibility) were observed on the esophageal and fundic histopathology. The results were compared with an alpha-tocopherol (once orally, 1 h before operation, 30 mg/kg) treated group in which the effects on RE were already confirmed. Pylorus and forestomach ligations caused marked increases of gross esophageal and gastric mucosa lesion areas, which corresponded with histopathological changes. In addition, increases of esophageal lipid peroxidation, decreases of SOD, CAT, and GSH-free radical scavengers, increases of collagen were observed. However, these pylorus and forestomach ligation induced RE were dose-dependently inhibited by treatment of 500, 250 and 125 mg/kg of LF extract, mediated by antioxidant effects. RE at 250 mg/kg showed similar effects alpha-tocopherol. The results suggest that antioxidant effects of LF could attenuate the severity of RE and prevent the esophageal mucosal damage, and validate its therapeutic use in esophageal reflux disease.

Protective effect of ginger oil on aspirin and pylorus ligation-induced gastric ulcer model in rats

The present investigation was performed in aspirin and pylorus ligation-induced ulcer model in Wistar rats, in which ability of ginger oil to provide gastric protection was studied at two different doses, 0.5 and 1 g/kg po. Gastric protection was evaluated by measuring the ulcer index, serum γ-GTP levels, total acidity of gastric juice and gastric wall mucus thickness. The results obtained in the present study indicated that ginger oil has a protective action against gastric ulcers induced by aspirin plus pylorus ligation in Wistar rats.

Antiulcerogenic action of ethanolic extract of the resin from Virola surinamensis Warb. (Myristicaceae)

Ethnopharmacological relevance Virola surinamensis (Myristicaceae), popularly known as “mucuíba”, “ucuuba” or “ucuúba do igapó” is a large tree that grows abundantly in “Várzea” forest and on river banks in the Brazilian states of Amazonas and Tocantins. The resin obtained by cuts on the stem bark is a reputed folk remedy in its natural form for the treatment of ulcer, gastritis, inflammation and cancer. Aim of the study The present work evaluated the pharmacological activity of the resin obtained from bark of V. surinamensis as antiulcerogenic in experimental in vivo model in order to observe whether its traditional use is justified. Materials and methods The preventive action of ethanolic extract of V. surinamensis was evaluated in experimental in vivo models in rodents that simulated this disease in human gastric mucosa. Results Oral administration of acidified ethanol solution produced severe hemorrhagic lesions in glandular mucosa with ulcerative lesion of 50 ± 11.5 mm. In animals pretreated with V. surinamensis (500 mg/kg, p.o.) a significant inhibition of mucosal injury of 2.40 ± 0.56 mm (95% inhibition) was detected. The V. surinamensis, at the same dose, also reduced significantly ( p < 0.05) the formation of gastric lesions induced by indomethacin (39%), stress (45%) and by pylorus ligature in mice (31%) when compared to animals treated with vehicle. The extract from V. surinamensis exerts gastroprotective action only when this extract contacts gastric mucosa (oral route) with increased pH values and reduced H + concentration of gastric contents. The ethanolic extract of V. surinamensis resin was analyzed by TLC and spectrometric methods (NMR and ES-MS) and the main constituent of this extract was epicatechin. Conclusions We suggest that the epicatechin present in V. surinamensis resin may be among active principles responsible for the antiulcer activity shown by the tested resin but their used suggest carefulness because toxicological symptoms mentioned by population.

Brazilian Medicinal Plant Acts on Prostaglandin Level andHelicobacter pylori

Among the current treatment strategies for the peptic ulcer patient with Helicobacter pylori infection, the method of choice is triple therapy based on the concurrent use of proton inhibitors and two antibiotics. Alchornea triplinervia is a medicinal plant commonly used by people living in the Cerrado region of Brazil to treat gastrointestinal ulcers. In the present work we proposed therapy based on this medicinal plant that presents effective gastroprotective action with antibiotic effects. Oral pretreatment with methanolic extract (ME) of A. triplinervia in rats and mice decreased the gastric injuries induced by ethanol and HCl/ethanol. Increasing the dose reduced the gastroprotective effects of ME on the gastric lesions induced by nonsteroidal anti-inflammatory drug. After pylorus ligature of mice, oral administration of ME induced a decrease not only in total acid but also in the ulcer index. We also observed that ME displayed antibacterial activity against H. pylori. Liquid-liquid separation of ME indicated that active constituents responsible for the gastroprotective action are concentrated in the ethyl acetate fraction (EAF) (50% protection) rather than in the aqueous fraction, which did not induce significant gastroprotection at the same dose (100 mg/kg). EAF induced an increase of gastric mucosa prostaglandin (PG) E(2) levels, which remained high even after previous administration of indomethacin. The phytochemical profile of ME revealed that EAF contains mainly flavonoids. In conclusion, all these results suggest that ME did not show acute toxicity, but exhibited an antisecretory property, anti-H. pylori effect, and gastroprotective action. The observed effect did not involve the participation of nitric oxide or endogenous sulfhydryl groups. However, EAF showed a more efficient gastroprotective effect than ME at a lower dose and protected the gastric mucosa by increasing PGE(2).

The anti-ulcerogenic effects of Curatella americana L.

Ethnopharmacological relevance: Curatella americana L. (Dilleneaceae) is a medicinal plant very frequently cited as acting against gastrointestinal disorders in ethnopharmacological inventories of the Cerrado region of Brazil. Aim of the study The ethanolic extract (CEB) and infusion (BI) of Curatella americana bark were investigated for their ability to prevent and heal ulceration of the gastric mucosa. Materials and methods The preventive and healing actions of Curatella americana were evaluated in experimental in vivo models in rodents that simulated this disease in human gastric mucosa. Results CEB significantly decreased the severity of gastric damage formation induced by the combination of several gastroprotective models (HCl/ethanol, indomethacin/bethanecol, absolute ethanol, stress and pylorus ligature). But, unlike CEB, the BI did not exert gastroprotective effect. The gastroprotective action of CEB involved antisecretory action, augmentation of gastric mucus (48%) and participation of endogenous sulfhydryl compounds that increase efficacy of barrier mucosa against injurious agents. CEB also presents effective healing action in chronic gastric disease (1.90 ± 0.55 vs. 6.86 ± 0.46 mm 2 in the control) and its action mechanisms consisted of increasing the PGE 2 (40%) and somatostatin levels (269%) while decreasing the gastrin level in rat plasma (79%). Conclusions The gastroprotective effect and healing action of Curatella americana involved modulation of PGE 2, somatostatin and gastrin levels, probably due to the presence of oligomeric and polymeric proanthocyanidins in the bark.

Empirical study in the relation of gastric mucosal lesion with gastric emptying and gastric acid secretion

To study the precise cause and the specific procedure about gastric mucosal lesion in rats with water immersion-restraint stress(WRS). One hundred and forty-four Wistar rats were divided into 9 groups randomly: A, B, C, D, E, F, G, H and I group. There were 16 rats in each group. A, B and C groups underwent gastric emptying determination. Emptying rate of gastric fluid was determined with radiate nuclide (99m)Tc. D, E and F groups underwent gastric acid secretion determination after cleaning gastric contents and pylorus ligation. G, H and I groups underwent gastric acid secretion determination after pylorus ligation without cleaning gastric contents. Gastric mucosal lesion ulcer index(UI) was evaluated. The relationship between of gastric mucosal lesion and gastric emptying rate and gastric acid secretion were examined. Gastric emptying rate decreased obviously when the WRS time was prolonged. There were significant differences among B (WRS 2 h), C group (WRS 4 h) and A group (controlled group) (P<0.01). There was also significant difference between B and C group (P<0.01).The rats' gastric acid secretion was inhibited significantly. The differences among E (WRS 2 h), F (WRS 4 h) and D groups (controlled group) were significant (P<0.01). There was no significant difference between F and E groups (P>0.05). The gastric mucosal lesions were aggravated with time of stress. Gastric contents cleaning could effectively prevent gastric mucosal lesions originated by stress .The operation had no influence on this test. There were significant gastric mucosal lesion UI in B and C groups compared with A group (P<0.01). The difference between B and C group was significant (P<0.01).There were no gastric mucosal lesions in A, D, E, F and G groups. However, There was significant difference between I and F group (P<0.01). No significant difference were found among A, D, E, F and G groups (P>0.05). There were significant difference between H and B group and also between I and C group (P<0.01). WRS can induce gastric emptying disturbance, reduce gastric acid secretion and cause gastric mucosal lesion. As a factor inducing gastric mucosal lesion, acid can damage gastric mucosa as long as it exists without necessary peracid. The prolongation of acid with gastric mucosa contact period and the decrease of gastric mucosa resistance are perhaps the major causes of gastric mucosal lesion. Besides anti-acid, giving facilitative gastric emptying drugs and gastric lavage during stress ulcer prevention and cure should be considered. Acid evacuation in time is also a major cure for gastritis and recurrent ulcer.

Hancornia speciosa: Indications of gastroprotective, healing and anti- Helicobacter pylori actions

Ethnopharmacological relevance Mangaba ( Hancornia speciosa Gomez) is a medicinal plant frequently cited in ethnopharmacological inventories of the central region of Brazil against gastrointestinal disorders such as diarrhoea, ulcer, gastritis and stomachache. Aim of the study The hydroalcoholic extract (HE) and infusion (BI) of Hancornia speciosa bark were investigated for their ability to prevent and heal rodent gastric ulcer. Materials and methods The preventive and healing action of both preparations of Hancornia speciosa were evaluated in experimental models in rodents that simulated this disease in human gastric mucosa. Results BI did not exert gastroprotective effect, in contrast to HE (500 mg/kg, p.o.) that decreased ( p < 0.05) the severity of gastric damage induced by HCl/ethanol (52%), indomethacin/bethanechol (51%), stress (52%) or pylorus ligature experiments (54%). HE increased ( p < 0.05) the pH and decreased acid output of gastric juice. This extract promoted increase of mucus amount (3.62 mg/wt. tissue vs. 5.81 mg/wt. tissue), healing action (67%) and displayed anti- Helicobacter pylori effect. Conclusions The antiulcer action of Hancornia speciosa resulted in increase of gastric mucus formation and antioxidant properties of polymeric proanthocyanidins present in the bark composition of this medicinal plant.

Anti-ulcerogenic properties of the aqueous and methanol extracts from the leaves of Solanum torvum Swartz (Solanaceae) in rats

Ethnopharmacological relevance Solanum torvum (Solanaceae) is a plant currently used in Cameroon ethnomedicine for the treatment of stomach ailments. Aim of the study The present study was undertaken to determine the anti-ulcer potential of the aqueous and methanol extracts from the leaves of Solanum torvum. Materials and methods The aqueous and methanol extracts from the leaves of Solanum torvum were tested orally at the doses of 250, 500 and 750 mg/kg, on gastric ulcerations experimentally induced by HCl/ethanol, indomethacin, pylorus ligation and stress. The fractionation of the methanol extract through silica gel column chromatography produced seven different fractions (A–G) which were tested orally at the dose of 100 mg/kg against HCl/ethanol-induced ulceration. Results The methanol extract at the dose of 750 mg/kg produced 98.12, 99.16, 98.70 and 96.03% inhibition when gastric ulcerations were induced by HCl/ethanol, indomethacin, pylorus ligation and stress, respectively. The aqueous extract at the same dose produced 96.55, 96.86, 98.63 and 98.63% inhibition on ulcerations induced respectively by HCl/ethanol, indomethacin, pylorus ligation and stress. All the fractions of the methanol extract significantly inhibited ulcer formation. Fraction F which contains flavonoids and triterpens was the most active and exhibited an inhibitory percentage of 84.74. Both extracts significantly increased mucus production and reduced gastric acid secretion. Conclusions The aqueous and methanol extracts of the leaves of Solanum turvum possess anti-ulcerogenic properties that may be due to cytoprotective mechanism. These results support the ethnomedical uses of the plant in the treatment of gastric ulcer.

Anti-Inflammatory and Anti-Ulcer Effects of Calotropis gigantea R.Br Flowers in Rodent

Objective: To evaluate the chloroform extract of Calotropis gigantea flowers (CCGF) and ethanol extract of Calotropis gigantea flowers (ECGF) for their possible anti-inflammatory (AI) and anti-ulcer (AU) activities. Method: The anti-inflammatory effect of CCGF and ECGF (200mg/kg; p.o.) was investigated in carrageenan induced rat paw edema and cotton pellet induced granuloma model. The AU activity studied in pylorus ligation and aspirin induced gastric ulcers model. The aspirin and ranitidine were used as standards for AI and AU studies respectively. Results: The CCGF and ECGF significantly reduced rat paw edema (p > 0.05 to > 0.01) and dry weight granuloma (p > 0.01). Similarly, both extracts treated group were significantly (p > 0.01) protected from pyloric ligation and aspirin induced gastric ulcers. These effects were statistically significant. Conclusion: The results suggest that the CCGF and ECGF possess significant AI and AU activities. The observed effect may be due to the presence of protease like bioactive constituent.

Antiulcerogenic activity of bark extract of Tabebuia avellanedae, Lorentz ex Griseb

Tabebuia avellanedae is commonly used for the treatment of peptic ulcers. We carried out this study with the ethanolic extract of bark from Tabebuia avellanedae (EET) (30–1000 mg/kg) to determine its gastroprotective activity and to clarify the pathways involved in this effect. Acute gastric ulceration in rats was produced by oral administration of ethanol and ibuprofen. After ethanol administration, the gastric wall mucus was examined. Chronic gastric ulceration was produced by injection of acetic acid in rat gastric subserosa. Anti-secretory studies were undertaken using Shay rat pylorus ligature technique and measurement of enzymatic activity of H +, K +-ATPase in vitro. Administration of EET p.o. or i.p. significantly inhibited gastric mucosa damage induced by ethanol and ibuprofen. The anti-ulcer effect was further confirmed by enhanced gastric mucus production. In pylorus ligature rats, EET significantly reduced the basal gastric acid secretion and total acidity; moreover, it inhibited the increase in total acidity induced by histamine. In addition, EET reduced the activity of H +, K +, ATPase. The results obtained in the present pharmacological assay indicate that this plant has a protective action against gastric lesions, involving the maintenance of protective factors, such as mucus and prostaglandin, besides the reduction of gastric total acidity.

Differences in Gastroprotective and Mutagenic Actions Between Polar and Apolar Extracts ofAnanas ananassoides

Several plants are used in folk medicine to treat gastrointestinal disorders. Ananas ananassoides (Baker) L.B. Smith (Family Bromeliaceae) is a medicinal plant commonly used in the central region of Brazil against gastric pain. We evaluated two extracts (methanol [MeOH] and dichloromethane [DCM]) obtained from the leaves of A. ananassoides for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCl/60% ethanol, absolute ethanol, non-steroidal anti-inflammatory drugs, and pylorus ligation) in mice and rats. The best results were obtained after pretreatment with the DCM extract, whereas the MeOH extract did not show any significant anti-ulcerogenic activity but presented mutagenic action. The mechanism of action of the DCM extract suggested the effective participation of endogenous sulfhydryl group in the gastroprotective action. The data, taken together with the absence of acute toxicity and mutagenicity, indicate the apolar extract, instead of the polar, extract of A. ananassoides as a safe and potential new anti-ulcerogenic drug.