Study of the antisecretory and antiulcer mechanisms of a new indenopirydazinone derivative in rats

Comparative Evaluation of Antiulcer Activity of Ficus religiosa (Stem Bark) Extracts Prepared by Different Methods of Extraction

Background:

The stem bark of Ficus religiosa L. (Family-Moraceae) is traditionally used to treat gonorrhea, diarrhea, dysentery, leucorrhea, menorrhagia, vaginal and other urogenical disorders, ulcers and gastrohelcosis.

Objective:

The study was aimed at comparing antiulcer activity (ethanol induced gastric ulcer) for stem bark extracts of Ficus religiosa Linn. prepared by different extraction methods viz. soxhlet, ultrasonication and microwave assisted extraction.

Methods:

The powdered drug material was extracted by soxhlet (time 48 hours., temperature 60°C and solvent 60% ethanol), Ultrasonic (90 min., 50°C and acetone as solvent)and Microwave (3 min., 60°C and acetone as solvent) assisted extraction method. The acute toxicity study was carried out in adult female albino rats by “fix dose” method of OECD guideline no. 420 for selection of doses. Antiulcerogenic effect of prepared extracts (200mg/kg) was evaluated by ethanol induced ulcer method using omeprazole (40 mg/kg) as standard drug and absolute alcohol 99.5% as necrotizing agent.

Result and Conclusion:

Acute toxicity study did not show any significant toxicity signs and extracts were said to be practically non-toxic at tested dose level of 2000 mg/kg, b.w. The best antiulcer activity was shown by the hydroalcoholic extract prepared by soxhlet extraction method. Administration of ethanol produced significant ulcer index (41.00 ± 1.75) in the control group. Standard drug omeprazole (40 mg/kg) produced percentage protection of 70.31%. Among all three extracts, Ulcer index is significantly (p<0.001) protected by hydroalcoholic extract (Soxhlet Extraction Method) with percentage protection 52.02%.

Effects of Thymus hirtus sp. algeriensis Boiss. et Reut. (Lamiaceae) essential oil on healing gastric ulcers according to sex

BACKGROUND

Thymus algeriensis Boiss. et Reut. (Lamiaceae), popularly known as "mougecha" or "mazoukcha" is prolific in Mediterranean regions, mostly in North Africa, and is used in folk medicine to treat of stomach diseases.

METHODS

In this study, animals were induced with gastric ulcers using HCl/ethanol (0.3 M HCl/60% ethanol) and treated orally with essential oil of Thymus algeriensis (EOTa) in various doses ranging from 54 mg/kg body weight to 180 mg/kg body weight.

RESULT

The dose found to be effective was 180 mg/kg body weight, since this dose brought about a maximum reduction in lesion index in female rats. In gastric tissues, levels of total glutathiones (GSH, GST and GPx) and thiobarbituric acid reactive substances (TBARS) were evaluated. The activities of the antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD) were measured. Histopathological changes were observed using a cross section of gastric tissue. Chemical analysis revealed the presence of 13 components accounting for 77.7% of the essential oil from dried leaves. Oral administration of EOTa (54, 117 and 180 ml/kg) inhibited HCl/ethanol-induced ulcers. Lesion index was significantly reduced in ulcer induced animals treated with EOTa (HCl/ethanol + EOTa) compared to those ulcerated with HCl/ethanol but with no treatment given. Females showed a greater resistance to ulcers and gastric lesions occurred less often than in males. GSH, pH, enzymic antioxidants, and adherent mucus content were all significantly increased.

CONCLUSION

From the data presented in this study, it can be concluded that male rats are more sensitive to gastric ulcers induced by HCl/ethanol than females.

Antiulcer activity of Muntingia calabura leaves involves the modulation of endogenous nitric oxide and nonprotein sulfhydryl compounds

Abstract Context: Muntingia calabura L. (Muntingiaceae) is a native plant species of the American continent and is widely cultivated in warm areas in Asia, including Malaysia. The plant is traditionally used to relieve pain from gastric ulcers. Objective: This study was designed to determine the antiulcer activity of a methanol extract of M. calabura leaves (MEMC) and the possible mechanisms of action involved. Materials and methods: An acute toxicity study was conducted using a single oral dose of 2000 mg/kg MEMC. The antiulcer activity of MEMC was evaluated in absolute ethanol- and indomethacin-induced gastric ulcer rat models. MEMC was administered orally (dose range 25-500 mg/kg) to rats fasted for 24 h. The animals were pretreated with NG-nitro-l-arginine methyl esters (l-NAME) or N-ethylmaleimide (NEM) prior to MEMC treatment to assess the possible involvement of endogenous nitric oxide (NO) and nonprotein sulfhydryl (NP-SH) compounds in the gastroprotective effect of MEMC. Results: As the administered dose did not cause toxicity in the rats, the oral median lethal dose (LD50) of MEMC was >2000 mg/kg in rats. MEMC exerted significant (p < 0.001) gastroprotective activity in the ethanol- and indomethacin-induced ulcer models dose-dependently. Histological evaluation supported the observed antiulcer activity of MEMC. l-NAME and NEM pretreatment significantly (p < 0.05) reversed and abolished the gastroprotective effect of MEMC, respectively. Discussion and conclusion: The results obtained indicate that MEMC has significant antiulcer activity that might involve the participation of endogenous NO and NP-SH compounds. These findings provide new pharmacological information regarding the potential use of M. calabura.

Antiulcerogenic activity of chlorogenic acid in different models of gastric ulcer

Chlorogenic acid (CGA) is found in many foods, including coffee, berries, potatoes, carrots, wine, apples, and various herbs, and has anti-inflammatory, antidiabetic, and antitumoral actions. The CGA is well absorbed orally, and its effects on gastric ulcer have not been previously reported. The present manuscript evaluated the effect of oral administration of CGA on ethanol/HCl (Et/HCl) or nonsteroidal anti-inflammatory drug (NSAID)-induced gastric ulcer model in male Swiss mice. Animals were pretreated with 0.2 % carboxymethylcellulose (vehicle, p.o.), omeprazole (positive control, 30 mg/kg, p.o.), carbenoxolone (antioxidant positive control, 100 mg/kg, p.o.), or CGA (5, 25, or 50 mg/kg, p.o.). One hour later, the gastric ulcer was induced by injecting Et/HCl solution (100 μL/10 g body weight; Et 60 % + HCl 0.03 M) or piroxicam (100 mg/kg, p.o). After another hour or 4 h later, gastric tissues were collected from Et/HCl or piroxicam-treated animals, respectively, to evaluate the size of the lesion, histological alterations, secretion of gastric acid, neutrophil migration, oxidative/antioxidative enzymes, markers of lipid peroxidation, or concentrations of inflammatory mediators. CGA treatment had a gastroprotective effect in both models, reducing the percentage of lesioned area. CGA treatment did not alter the secretion of gastric action but inhibited neutrophil migration and restored the levels of catalase, superoxide dismutase, glutathione peroxidase, glutathione, and thiobarbituric acid reactive substances in mice treated with Et/HCl. Additionally, CGA treatment blocked the increase of tumor necrosis factor alpha and leukotriene B4 but did not restore the reduced prostaglandin levels in the NSAID-induced ulcer. Together, the data presented herein show that CGA may be a suitable natural compound for the prevention and treatment of gastric lesions caused by a different etiology.

Gastroprotection of suaveolol, isolated from Hyptis suaveolens, against ethanol-induced gastric lesions in Wistar rats: role of prostaglandins, nitric oxide and sulfhydryls

Hyptis suaveolens is a medicinal plant that is, according to traditional medicine, considered useful in the treatment of gastric ulcers. Although its gastroprotective activity was reported, the active compounds have not been identified. Therefore, the aim of the present study was to identify at least one active compound potentially responsible for the gastroprotective activity of H. suaveolens by using a bioassay guided study with an ethanol-induced gastric ulcer experimental model in rats. The results show that the hexane extract had protective activity (close to 70% when using doses between 10 and 100 mg/kg), and that the compound suaveolol, isolated from this extract, was one of the active gastroprotective agents. This is the first report about the gastroprotective activity of suaveolol. Rats treated with this compound at 3, 10, 30 and 100 mg/kg showed 12.6, 21.3, 39.6 and 70.2% gastroprotection respectively. The effect elicited by suaveolol (at 100 mg/kg) was attenuated by pretreatment with either N^G-nitro-L-arginine methyl ester (70 mg/kg, i.p.), a nitric oxide (NO) synthase inhibitor, indomethacin (10 mg/kg, s.c.), a blocker of prostaglandin synthesis, or N-ethylmaleimide (10 mg/kg, s.c.), a blocker of sulfhydryl groups. This suggests that the gastroprotective mechanism of action of this compound involves NO, prostaglandins and sulfhydryl groups.

Protective effect of Chresta martii extract against indomethacin-induced gastric lesions in mice

Chresta martii (Asteraceae) is a plant found in the Xingó region (semi-arid area) in Northeastearn Brazil, and is recognized by the local population as a traditional herb used to treat gastric diseases. This is the first report of the chemical composition, acute toxicity, and gastroprotective effect in mice of the hydroalcoholic extract (HAE) from the aerial parts (leaves and flowers) of Chresta martii. Animals received HAE doses from 10 to 2000 mg/kg, i.p. or 50 to 3000 mg/kg, p.o.) and were observed over 48 h for toxicity signs and mortality; sub-chronic toxicity was evaluated through 14 days treatment with once-daily HAE doses (400 mg/kg, p.o.). The gastroprotective effect of HAE was demonstrated on the indomethacin-induced gastric ulcer model after the administration of extracts. Data comparison of ulcer index averages between saline and HAE (100 or 400 mg/kg, p.o.) groups showed significant (P < 0.01) inhibition (71.73 and 76.72 %, respectively) of indomethacin-induced gastric lesions. Histological analyses showed significant (P < 0.05) inhibition of leukocyte migration in HAE-treated groups. A fingerprint of the HAE obtained by HPLC/UV/MS analysis showed major peaks characteristic of sesquiterpene lactones. Compound 1 was isolated and elucidated as a new natural product. Its capacity to prevent leukocyte chemotaxis was demonstrated in vitro, corroborating the pharmacological effects observed for C. martii HAE.

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.

In vivo antiulcer activity of the aqueous extract of Bauhinia purpurea leaf

ETHNOPHARMACOLOGICAL RELEVANCE

Bauhinia purpurea (Fabaceae) is a medicinal plant traditionally used to treat various ailments, including ulcers. In order to establish pharmacological properties of the leaf of Bauhinia purpurea, studies were performed on antiulcer activity of the plant's aqueous extract.

MATERIALS AND METHODS

The Bauhinia purpurea aqueous extract (BPAE) was prepared in the doses of 100, 500 and 1,000 mg/kg. Antiulcer activity of BPAE was evaluated by absolute ethanol- and indomethacin-induced gastric ulcer, and pyloric ligation models. Acute toxicity was also carried out.

RESULTS

BPAE, at the dose of 5,000 mg/kg, did not cause any signs of toxicity to rats when given orally. Oral administration of BPAE exhibited antiulcer activity (p<0.05) in all models used. However, the dose-dependent activity was observed only in the absolute ethanol-induced gastric ulcer model. Histological studies supported the observed antiulcer activity of BPAE. In pyloric ligation assay, BPAE increased the gastric wall mucus secretion.

CONCLUSIONS

The BPAE exhibits antiulcer activity, which could be due to the presence of saponins or sugar-free polyphenols, and, thus, confirmed the traditional uses of Bauhinia purpurea in the treatment of ulcers.

Evaluation of the antiulcerogenic activity of Maytenus robusta (Celastraceae) in different experimental ulcer models

Maytenus robusta (Celastraceae) is used in folk medicine for the treatment of stomach ulcers and is very well adapted to the South of Brazil. Maytenus ilicifolia is the main species of the Celastraceae family, and is used in the treatment of gastric ulcers. However, Maytenus ilicifolia is presently at the stage of extinction, due to indiscriminate use in Brazil. Thus, the use of Maytenus robusta in phytotherapeutic preparations, instead of Maytenus ilicifolia, is suggested. However, there have been no reports regarding the antiulcer activity of Maytenus robusta extract. Therefore, this study was carried out to evaluate the antiulcerogenic property of the hydroalcoholic extract of aerial parts of Maytenus robusta. The antiulcer assays were performed using the following protocols: nonsteroidal anti-inflammatory drug (NSAID)-induced ulcer, ethanol-induced ulcer, and stress-induced ulcer. The effects of the extract on gastric content volume, pH and total acidity, using the pylorus ligated model, were also evaluated. In the ethanol-induced ulcer model, it was observed that the treatment with Maytenus robusta extract significantly reduced the lesion index in 75.1 +/- 8.6, 85.0 +/- 9.2, 86.6 +/- 7.4 and 75.5 +/- 5.3 for the groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (omeprazole 30 mg/kg), respectively. Also were observed significant inhibition in lesion index in the indomethacin-induced ulcer model, being the decrease of the 62.5 +/- 7.1, 62.5 +/- 6.1, 63.6 +/- 5.5 and 96.2 +/- 3.6 for groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (cimetidine 100 mg/kg), respectively. Results similar were observed in the stress-induced ulcer model, where the inhibition of ulcer lesions were 71.3 +/- 5.5, 72.7 +/- 6.3, 76.5 +/- 7.1 and 92.3 +/- 7.5 for the groups treated with 50, 250 and 500 mg/kg of Maytenus robusta and positive control (cimetidine 100 mg/kg), respectively. Regarding the model of gastric secretion, a reduction in the volume of gastric juice volume and total acidity was observed, as well as an increase in gastric pH. The results of the present study showed that Maytenus robusta hydroalcoholic extract displays gastroprotective activity. These results were similar to those obtained in studies carried out with Maytenus ilicifolia, which indicate that this species could be used in phytotherapeutic preparations as a substitute for Maytenus ilicifolia. This work also corroborates the traditional indication of Maytenus robusta, contributing to its pharmacological validation.

Effect of modulation of serotonergic, cholinergic, and nitrergic pathways on murine fundic size and compliance measured by ultrasonomicrometry

Reduced fasting or postprandial gastric volumes have been implicated in the pathophysiology of functional dyspepsia. The mechanisms that underlie the control of gastric fundic volume are incompletely understood, partly because of an inability to accurately measure fundic volume in vivo in small animals. Small animals are useful models to evaluate mechanisms, e.g., in knockout animals. The aim of this study was to determine whether an ultrasonometric technique accurately monitors fundic contraction and relaxation in mice in vivo and to determine the effect of modulation of cholinergic, nitrergic, and serotonergic pathways on fundic size and compliance in the intact mouse innervated stomach. Two to four piezoelectric crystals (diameter 1 mm, 24-microm resolution) were glued to the serosal side of fundus and used to measure distance. Validation studies showed excellent correlation between measured changes and actual changes in distances between crystals and excellent reproducibility. The expected responses to pharmacological modulation with bethanechol and nitroglycerin were demonstrated. Atropine increased the distance between the crystals, suggesting a baseline cholinergic regulation of fundic volume. Bethanechol, Nomega-nitro-L-arginine, and the 5-HT1B/D agonist sumatriptan decreased the distance between the crystals, suggesting fundic contraction. Atropine, nitroglycerin, and buspirone caused an increase in intercrystal distance consistent with fundic relaxation. Fundic compliance was investigated by changing intragastric pressure via an implanted catheter. Sumatriptan increased compliance, whereas buspirone increased the distance between crystals but did not change compliance. The data suggest that ultrasonomicrometry is a useful tool that can reproducibly and accurately measure changes in fundic size and the response to pharmacological agents.

Antiulcerogenic activity of a crude hydroalcoholic extract and coumarin isolated from Mikania laevigata Schultz Bip

The leaves of Mikania (Asteraceae) species are used in folk medicine as antispasmodic, antiulcerogenic and antirheumatic agents. Phytochemical screening of the crude hydroalcoholic 70% extract (CHE) of Mikania laevigata Shultz Bip. revealed coumarins, terpenes and organic acids. Antiulcerogenic activity of CHE was evaluated, employing different experimental models in rats, to discern the pharmacological mechanism of action. Both the antisecretory and the cytoprotection hypothesis were evaluated. The crude hydroalcoholic extract (1000 mg/kg body wt., vo) decreased the ulcerative lesion index produced by indomethacin, ethanol, stress and reserpine in rats by 85%, 93%, 82% and 50%, respectively. In the pyloric ligation model, a decrease of hydrogenionic concentration (53%) was observed, suggesting that the pharmacological mechanism has a relationship to antisecretory activity. The antisecretory mechanisms of CHE and the coumarin isolated from M. laevigata were confirmed by acid hypersecretion induced by histamine, pentagastrin and bethanechol. Duodenal administration of CHE (1000 mg/kg body wt.) and coumarin (100 mg/kg body wt.) inhibited only the gastric acid secretion produced by bethanecol. These results suggest that both CHE and coumarin may influence the secretion control mediated by the parasympathetic system.