Computer-assisted visualization and quantitation of experimental gastric lesions in rats

LC-ESI-MS phenolic contents assessment, antioxidant, and protective ability of Punica granatum root bark extract against ethanol-induced gastric ulcer in rats: in silico H+, K+-ATPase inhibitory pathway study

The objectives of the current study were to evaluate the Punica granatum root bark extract's (PGE) antioxidant and gastroprotective activities against ethanol-induced gastric ulcers in Wistar rats and to elucidate the putative mechanism of action using in silico analysis. The PGE phytochemical study shows high levels of phenolics, flavonoids, tannins, and polysaccharides. In vitro, the PGE was more effective at scavenging hydroxyl radicals than quercetin and had lower ferric reducing activity than catechin. In vivo, it was revealed that pretreatment of ethanol-ulcerated rats with PGE at oral doses of 100, 200, and 400 mg/kg b.w. offered a dose-dependent shield against ethanol-induced ulcers when compared to Omeprazole (20 mg/kg b.w.) by preventing the development of deep ulcer lesions, lowering gastric juice output and pH rises, boosting gastric mucus production and antioxidant enzyme levels, and attenuating malondialdehyde and myeloperoxidase contents. Moreover, the liquid chromatography-mass spectrometry analysis of PGE identified 5 phenolic acids and 4 flavonoids, which revealed an in silico high oral bioavailability, drug-likenesses, and good binding affinities and thus inhibitory effects on the gastric H+, K+-ATPase enzyme. PGE may have synergistic antioxidant, anti-inflammatory, and H+, K+-proton pump inhibitory actions that contribute to its antiulcer efficacy.

A Mixture of Kaempferol-3-O-sambubioside and Kaempferol-3-O-sophoroside from Malvaviscus arboreus Prevents Ethanol-Induced Gastric Inflammation, Oxidative Stress, and Histologic Changes

Malvaviscus arboreus is used in traditional Mexican medicine to treat gastrointestinal diseases. Therefore, a mixture of Kaempferol-O-sambubioside and Kaempferol-O-sophoroside (MaSS) isolated from flowers of this species was tested as a preventive treatment on gastric lesions induced with ethanol in rats. MaSS was obtained by chromatographic methods and administered by oral pathway to male Sprague Dawley rats with ethanol-induced gastric lesions. Pretreatment with MaSS at doses of 30, 90, 120, and 180 mg/kg significantly prevents gastric lesions, inhibits the increment in relative stomach weight (%) in gastric IL-6, and also provokes an increment of IL-10 concentration and catalase activity. Finally, MaSS prevented edema in the mucosa and submucosa and diminished microscopic gastric lesions provoked by ethanol.

Snail Mucus Protective Effect on Ethanol-Induced Gastric Ulcers in Mice

Nowadays, an increased interest in natural compounds with preventive or therapeutic potential for various diseases has been observed. Given the involvement of oxidative stress in the pathogenesis of gastric ulcer (GU) and the wide range of bioactive compounds isolated from snails, this study aimed to investigate the protective effect of Cornu aspersum (Müller, 1774) mucus on ethanol-induced GUs. Male albino mice were divided into Control, Ethanol, Mucus + Ethanol and Mucus + Omeprazole treated groups. The GUs were induced by administration of 96% ethanol (10 mL/kg, per os). One hour before ulcer induction, the mice of Mucus + Ethanol group were pretreated with mucus (20 mg/kg, per os), and the mice of Mucus + Omeprazole group were pretreated with omeprazole (20 mg/kg, per os). Ethanol administration caused grave lesions of gastric mucosa and a significant decrease of glutathione (GSH) and superoxide dismutase (SOD), catalase, and glutathione reductase (GR) activities. In the animals with mucus or omeprazole pre-administration compared to the Ethanol group, the following were observed: only a small number of hemorrhagic fields, significantly reduced GU index with calculated 73% protection by mucus and 78% protection by omeprazole, and significant recovery of mucosal GSH and SOD and GR activities. In addition, the mucus inhibited Helicobacter pylori growth. Thus, the protective effect of C. aspersum mucus on both gastric mucosa and gastric antioxidant potential in ethanol-induced GU model suggests that it may serve as a good tool for prevention of this disease.

Antiulcer Potential of Psidium guajava Seed Extract Supported by Metabolic Profiling and Molecular Docking

One of the most severe human health problems is gastric ulceration. The main aim of our study is to explore the gastroprotective effect of the Psidium guajava seeds extract (PGE). Metabolic profiling based on LC-HRMS for the extract led to the dereplication of 23 compounds (1–23). We carried out a gastric ulcer model induced by indomethacin in male albino rats in vivo and the extract of PGE was investigated at a dose of 300 mg/kg in comparison to cimetidine (100 mg/kg). Furthermore, the assessment of gastric mucosal lesions and histopathology investigation of gastric tissue was done. It has been proved that Psidium guajava seeds significantly decreased the ulcer index and protected the mucosa from lesions. The antiulcer effect of Psidium guajava seed extract, which has the power of reducing the ensuing inflammatory reactions, can counteract the inflammation induced by indomethacin by the downregulation of relative genes expression (IL-1β, IL-6, and TNF-α). Moreover, PGE significantly downregulated the increased COX-2, TGF-β, and IGF-1 relative genes expression, confirming its beneficial effect in ulcer healing. Moreover, the possible PGE antioxidant potential was determined by in vitro assays using hydrogen peroxide and superoxide radical scavenging and revealed high antioxidant potential. Additionally, on the putatively annotated metabolites, an in silico study was conducted, which emphasized the extract’s antiulcer properties might be attributed to several sterols such as stigmasterol and campesterol. The present study provided evidence of Psidium guajava seeds considered as a potential natural gastroprotective agent.

Evaluation of the gastroprotective effects of Chihuahua propolis on indomethacin- induced gastric ulcers in mouse

The aim of this work was to evaluate the gastroprotective activity of a Mexican propolis on indomethacin-induced gastric ulcers in a mouse model. The following contents of the ethanolic extract of propolis of Chihuahua (EEPCh) were determined: antioxidant activity (SA50), total phenolic content (TPC), total flavonoid content (TFC), and chemical composition by HPLC-DAD and HPLC-MS, as well as acute toxicity by OECD Guideline 423. Gastric lesions were induced by intragastric indomethacin treatment in male ICR mice. As the positive control, omeprazole was administered, and three doses of EEPCh were evaluated (50, 150 and 300 mg/kg). Gastric mucosal injury, histological changes and mucosal content were evaluated by means of H&E and PAS staining. For homogenized gastric tissues, the following were evaluated: TBARS, MPO, and PGE2 levels; SOD and GPx antioxidant enzymatic activity; and the concentrations of the proinflammatory cytokines, TNF-α, IL-1β and IL-6. EEPCh had a significant SA50 of 41.55 µg/mL. The TPC of EEPCh was 860 mg GAE/g, and its TFC was 49.58 mg QE/g. Different phenolic compounds were identified in the extract and were not toxic. The EEPCh doses decreased mucosal damage and histological injuries, maintained the mucosal content and reduced the TBARS, MPO and concentrations of proinflammatory cytokines in gastric ulcer tissues. The 150 and 300 mg/kg doses increased the SOD activity and maintained the PGE2 content. Only the 300 mg/kg dose increased the GPx activity. The results of this study suggest that EEPCh displays gastroprotective effects by means of its antioxidant activity and anti-inflammatory effects and promotes ulcer protection through the maintenance of mucosal content and PGE2 levels.

Gastroprotective activity of kaempferol glycosides from Malvaviscus arboreus Cav

ETHNOPHARMACOLOGICAL RELEVANCE

Malvaviscus arboreus is traditionally used in Mexico and Central America for culinary and medicinal purposes. Leaves and flowers of this species are commonly used for preparation of salads, herbal teas and herbal dyes. Panamanian, Guatemalan and Mexican healers use this medicinal plant for the management of fever, respiratory complications, dysentery, liver and gallbladder problems, stomachache and gastritis between other health troubles.

AIM OF THE STUDY

Considering the traditional use of M. arboreous as well as its content in flavonoids and other polyphenols, the objective of this work was to evaluate the gastroprotective effect of an aqueous extract and identify the potential bio-active principles from flowers of this species.

MATERIAL AND METHODS

Fresh flowers of Malvaviscus arboreus were collected, dried, and macerated with water. The aqueous extract (ExAq) was partitioned using an immiscible mixture of water and ethyl acetate, giving an aqueous (MaAq) and organic (MaEA) fractions. The gastroprotective effect was carried out using an ethanol-induced gastric ulcer experimental test in male rats. While tween 20 was used as a negative control, famotidine (10 mg/kg) and L-arginine (300 mg/kg) were used as positive controls. Compounds 1 and 2 were isolated by several chromatographic techniques and the chemical characterization was carried out by means of the analysis of the NMR spectra in one and two dimensions.

RESULTS

The integrate extract (ExAq) to 250, 500 and 750 mg/kg showed gastroprotective effect with high levels of 97.8%, 79.5% and 91.1% respectively. The organic fraction (MaEA) displayed a protection of 91.2%, 96.0% and 99.4% when it was evaluated at 125, 250 and 500 mg/kg respectively. Comparison of these results with famotidine at 10 mg/kg (83% of gastroprotection) indicated that ethyl acetate fraction showed a better gastroprotection. The bio-guided separation of this organic mixture, allowed obtaining the most active fraction (C1F4, 60 mg/kg) which was finally purified to obtain two glycosylated flavonols: kaempferol 3-O-D-sophoroside (1) and kaempferol 3-O-D-sambubioside (2). This mixture of flavonoids (40 y 60 mg/kg) showed 93.7 and 92% of gastroprotective activity respectively.

CONCLUSION

This study allowed demonstrating that an aqueous extract and its organic fraction (MaEA) from M. arboreous contain glycosylated flavonoids (1 and 2) which are responsible of the gastroprotective properties of M. arboreous. These results will be used in the future development of a standardized treatment useful in the therapeutic management of gastric ulcers.

Sphaeranthus senegalensis DC: Evaluation of chemical constituents, oral safety, gastroprotective activity, and mechanism of action of its hydroethanolic extract

ETHNOPHARMACOLOGICAL RELEVANCE

Sphaeranthus senegalensis DC is a seasonal herb with a spicy smell that grows wild in wet grounds of tropical Africa and Asia. The plant is used in folk medicine for the treatment of various diseases; that includes its use to treat gastric ulcers.

AIM OF THE STUDY

This study aimed to investigate the chemical constituents of the hydroethanolic extract of Sphaeranthus senegalensis DC and evaluate its oral safety, gastroprotective activity, and mechanisms of action using laboratory models in rats and mice.

MATERIALS AND METHODS

Hydroethanolic extract (70%) of the powdered whole dried material was prepared, and chemical constituents of the resultant extract (denoted HESs) standardized using the high-performance liquid chromatography (HPLC) method. The safety profile of HESs was assessed using 2000 mg/kg, oral (p.o.) for Hippocratic screening in mice, and 800 mg/kg, p.o. for 28 days subchronic toxicity assay in rats. The gastroprotective effect of HESs (25, 100, and 400 mg/kg, p.o.) was investigated using acidified ethanol, piroxicam, water immobilization stress, and acetic acid-induced ulcer models. The gastroprotective mechanisms of HESs were evaluated using its effect on gastric mucus protection, nitric oxide modulation, gastric juice secretory parameters, catalase and myeloperoxidase activities. Histological analysis of the stomach tissues was also carried out.

RESULTS

The HPLC analysis indicated the presence of 25.94% phenolics (gallic acid, caffeic acid, and ferulic acid) and 14.53% flavonoids (rutin, morin, luteolin, quercetin, and apigenin). Hippocratic screening and the 28 days subchronic study indicated that HESs is generally safe. Result shows that oral administration of HESs (25, 100 and 400 mg/kg) alleviated the severity of the gastric ulcers induced by acidified ethanol by 35.65% (p < 0.05), 48.70% (p < 0.05) and 78.02% (p < 0.001) respectively; exhibited gastroprotective effect against the gastric lesions induced by piroxicam by 37.97% (p < 0.05), 53.27% (p < 0.05) and 76.23% (p < 0.001) respectively; and decreased the severity of the water immobilization stress-induced gastric ulcers by 32.43% (p < 0.05), 55.26% (p < 0.01) and 74.05% (p < 0.001) respectively, when compared to the vehicle control group. The mechanisms of action assays indicated that the gastroprotective activity was mediated mainly through gastroprotection, antisecretory, and antioxidant activities. Histological analysis showed it inhibited epithelial cell loss, vascular damage, and leucocyte infiltration.

CONCLUSION

HESs contains useful phytochemicals, is safe, and exhibited significant gastroprotective action. The results provided justification for its claim in the treatment of gastric ulcers and its evaluation for potential application as a gastroprotective agent.

Antinociception and less gastric injury with the dexketoprofen-tapentadol combination in mice

The purpose of this study was to evaluate the antinociceptive interaction between dexketoprofen and tapentadol in three different dose ratios, as well as the ulcerogenic activity of this combination. Dose-response curves were carried out for dexketoprofen, tapentadol, and dexketoprofen-tapentadol combinations in the acetic acid-induced writhing test in mice. On the other hand, the gastric damage of all treatments was assessed after the surgical extraction of the stomachs. Intraperitoneal administration of dexketoprofen and tapentadol induced a dose-dependent antinociceptive effect, reaching a maximal effect of about 58% and 99%, respectively. Isobolographic analysis and the interaction index showed that the three proportions produced an analgesic potentiation (synergistic interaction). Interestingly, the 1:1 and 1:3 ratios of the drugs combination produced minor gastric injury in comparison with the 3:1 proportion. Our data suggest that all proportions of the dexketoprofen-tapentadol combination produced a synergistic interaction in the acetic acid-induced visceral pain model in mice with a low incidence of gastric injury.

Cochlospermum regium (Mart. ex Schrank) Pilg.: Evaluation of chemical profile, gastroprotective activity and mechanism of action of hydroethanolic extract of its xylopodium in acute and chronic experimental models

ETHNOPHARMACOLOGICAL RELEVANCE

Cochlospermum regium (Bixaceae) is a native shrub of Brazil and its xylopodium (infusion/decoction) is being used for the treatment of gastritis, ulcers, arthritis, intestinal infections, gynaecological infections, skin diseases, among others. The aim of the present study was to evaluate the gastroprotective/antiulcer activity and the mechanism of action of hydroethanolic extract of C. regium xylopodium (HECr), using in vitro and in vivo models. Additionally, phytochemical constituents were identified by high-performance liquid chromatography (HPLC).

MATERIALS AND METHODS

C. regium xylopodium was macerated with ethanol/water to obtain the HECr. The phytochemical characterisation was carried out by HPLC. The antiulcer efficacy of HECr (25, 100 and 400 mg/kg, p.o.) was evaluated using acute acidified ethanol (HCl/EtOH), piroxicam and water immersion-induced experimental ulcer models. Chronic gastric ulcer healing activity of HECr was evaluated through acetic acid (99.8%) - induced model. Histological analysis and myeloperoxidase (MPO), glutathione (GSH), catalase (CAT) activities were also evaluated in chronic ulcer induced gastric tissues. The plausible mode of action of the HECr was assessed by estimation of gastric wall mucus production and the role of gastric secretion in pylorus ligature. The animals were also pre-treated with various inhibitors which includes indomethacin (10 mg/kg, p.o.) a selective inhibitor of cyclooxygenase, L-NAME (10 mg/kg, i.p.), an inhibitor of nitric oxide synthase, glibenclamide, a ATP-sensitive potassium channels (K⁺_ATP) blocker (5 mg/kg, p.o.) or yohimbine (2 mg/kg, i.p.), an α₂-adrenergic receptor antagonist. In vitro, Helicobacter pylori action was done by broth microdilution method.

RESULTS

The HPLC analysis data revealed the presence of gallic acid, rutin, myricetin, morin and kaempferol. HECr promoted protective effect against acute ulcers induced by HCl/EtOH with inhibitions of 47.52% (p < 0.01) and 62.69% (p < 0.001) at 100 and 400 mg/kg, and in piroxicam by 34.11% (p < 0.05), 49.14% (p < 0.01) and 61.34% (p < 0.001), at 25, 100 or 400 mg/kg, respectively, and in water restraint stress by 78.26% inhibition, p < 0.001, at the dose of 400 mg/kg when compared to the vehicle control group respectively. In the chronic gastric ulcer model, HECr (25, 100 and 400 mg/kg p.o.) significantly (p < 0.001) decreased the injured area by 58.80%, 77.87% and 71.10% respectively. Histological examination indicated that oral treatment of HECr promoted healing of gastric lesions by regenerating gastric mucosa layer with less inflammatory cells. HECr augmented the GSH, CAT activities and reduced MPO level. The pre-treatment with HECr increased the gastric wall mucus production. It also significantly altered the gastric secretion parameters by causing the reduction in the gastric juice volume, elevated the pH level and reduced the total acidity at all doses tested when compared with the vehicle group. HECr at the most active dose (100 mg/kg) reversed completely the reduction of PGs, NO production, closure of K⁺_ATP- channels and α₂-adrenoreceptor blockage - induced damages. In microdilution assay, the HECr showed good anti-Helicobacter pylori effect with MIC = 100 µg/mL.

CONCLUSION

The HECr presented preventive and curative effects in the experimental gastric ulcer models, besides good anti-Helicobacter pylori activity, which supports the traditional medicinal use of the xylopodium of this plant for gastrointestinal diseases. The underlying mechanisms of this antiulcerogenic/antiulcer action involve, at least, augmentation of mucus production, inhibition of gastric secretion, stimulation of PGs and NO synthesis. And that it involves activation of K⁺_ATP channels and α-2-adrenergic receptors, in addition to an antioxidant activity, probably due to the presence of gallic acid and flavonoids in HECr.

Assessment of the antinociceptive and ulcerogenic activity of the tapentadol-diclofenac combination in rodents

Preclinical Research & Development The objective of the present study was to evaluate the tapentadol-diclofenac combination in three dose-ratios in the mouse acetic acid-induced visceral pain and their ulcerogenic activity on the stomachal mucous. Dose-response curves were generated for tapentadol, diclofenac, and their combination in the acetic acid-induced writhing test in mice. Moreover, the stomachs of animals were surgically removal and gastrointestinal ulcerogenic action of the combination was assessed. The isobolographic analysis, interaction index, and ANOVA were used to analyze the data. The isobolographic analysis and interaction index showed a similar antinociceptive activity for the three combinations of the analgesic mixture. Moreover, tapentadol and the proportions 1:1 or 3:1 of the analgesic combination caused a mild gastrointestinal damage. These data indicate that the systemic co-administration of tapentadol and diclofenac produced a synergistic interaction in the acetic acid-induced visceral pain test with an acceptable gastric damage profile in mice.

Gastroprotective effect and mode of action of methanol extract of Sphenodesme involucrata var. paniculata (C.B. Clarke) Munir (Lamiaceae) leaves on experimental gastric ulcer models

Sphenodesme involucrata var. paniculata (C. B. Clarke) Munir, endemic to South Asia, is used by tribal for alleviation from abdominal disorders, inflammation and body pain. However, the gastroprotective properties of this species have not yet been studied. The leaves of S. involucrata were extracted by Soxhlet extraction using different solvents successively and the extracts were analyzed for antioxidant and anti-Helicobacter pylori activities using different in vitro assays. The chemical composition of methanol extract of S. involucrata (MESi) was analysed by gas chromatography-mass spectrometry (GC-MS). The gastroprotective action of the MESi at the doses of 100, 200, and 400 mg/kg were evaluated in absolute ethanol, acidified ethanol (EtOH/HCl) and nonsteroidal anti-inflammatory drug (NSAID) induced rat experimental models. To elucidate the mode of antiulcerogenic action, the antisecretory parameters (gastric juice volume, pH, and total acidity) and the catalase (CAT) and superoxide dismutase (SOD) enzymes activity and malondialdehyde (MDA) level were evaluated in gastric ulcer tissue. Also the stomachs of the animals were subjected to histological assessment. MESi presented a high antioxidant activity in several oxidants in vitro systems (DPPH^•, ABTS^•+ and FRAP) and it demonstrated a good spectrum of inhibitory activity against H. pylori growth (MIC, 100 μg/mL). GC-MS analysis of MESi indicated the presence of twenty one compounds, among them phenol (21.84%), hexadecanoic acid (15.96%), (9E, 12E)-9, 12-octadecadienoyl chloride (11.15%) and palmitic acid-β-monoglyceride (8.80%) were found higher. MESi (100, 200 and 400 mg/kg, p.o.) produced significant reduction (p < 0.01) of lesion area in the ethanol, acidified ethanol and indomethacin-induced ulcer models. In the pylorus ligation induced ulcer model, the treatment with MESi significantly altered the gastric secretion by decreasing total gastric juice volume and gastric acidity as well as by increasing the gastric pH. MESi pre-treatment significantly (p < 0.05) restored the depleted activity of SOD, CAT enzymes and reduced MDA levels in the gastric tissue as well as the histological analysis of the stomachs of the animals showed that the MESi also prevents local action of offensive factors. Collectively, the present study results suggest that the methanol extract of S. involucrata leaves demonstrates gastroprotective action, supporting the folkloric usage of the plant to treat gastro-intestinal disturbances.

Chemical characterization, toxicology and mechanism of gastric antiulcer action of essential oil from Gallesia integrifolia (Spreng.) Harms in the in vitro and in vivo experimental models

Gallesia integrifolia is a Brazilian Amazon tree whose bark decoction is popularly used to treat peptic ulcer. The essential oil from the inner stem bark of G. integrifolia (EOGi) was chemically characterized by GC/MS. The in vitro cytotoxicity and genotoxicity were evaluated in CHO-K1 cells, while the in vivo oral acute toxicity was performed in mice. The gastroprotective effect of EOGi was assessed in acidified ethanol and piroxicam and ulcer healing on acetic acid -induced ulcer models in rodents. Anti-secretory, mucus, K⁺-ATP channels, prostaglandins (PGs), nitric oxide (NO), TNF-α, IL-1β, IL-10, catalase (CAT) and myeloperoxidase (MPO) activities and in vitro Helicobacter pylori action by EOGi were evaluated. EOGi exhibited cytotoxic effects only at 72h and no acute toxicity. EOGi showed gastroprotective and ulcer healing effects. EOGi gastroprotection was attenuated by indomethacin pre-treatment. Gastric volume and total acidity were reduced, while gastric pH was elevated. EOGi increased mucus and NO productions and CAT activity, and inhibited MPO activity, TNF-α and IL-1β concentrations and augmented IL-10. EOGi was not active against H. pylori. These results indicated that EOGi is safe and exerts preventive and curative gastric ulcer effects by multitarget actions. Twenty compounds were identified and (-)-alpha-santalene was the main compound.

Gastroprotective potential of hydro-alcoholic extract of Pattanga (Caesalpinia sappan Linn.)

ETHNO-PHARMACOLOGICAL RELEVANCE

Pattanga is botanically equated as Caesalpinia sappan Linn. (Family: Caesalpiniaceae) and is used in Ayurveda system of medicine since ages. According to Ayurveda, useful part is Heartwood, which is bitter, astringent and acrid and is useful in vitiated conditions of vata and pitta, burning sensation, wounds, ulcers, leprosy, skin diseases, menorrhagia, leucorrhea, and diabetes. It is used as a major ingredient in Ayurvedic formulations and preparations like Patrangasava, Chandanadya Thalia, and Karpuradyarka.

AIM OF THE STUDY

The present study is planned to evaluate the gastroprotective activity of the selected Ayurvedic drug using three different in vivo gastric ulcer models, so as to provide scientific evidence for the Ayurvedic claims.

MATERIALS AND METHODS

For this study, Wistar albino rats fasted overnight were selected. The hydroalcoholic extract of Caesalpinia sappan heartwood at the dose level 250 and 500mg/kg body weight was selected and administered orally before necrotizing agents. Antioxidant and antiulcer parameters were evaluated and the stomach samples were subjected for histopathological studies. In addition, PGE2 estimation and protein expressions of COX-1, COX-2 and iNOS were analyzed by Western blot. The plant extract was subjected to LCMS/MS analysis. In addition, Cytoprotective effect in isolated gastric mucosal cells, TUNEL Assay, Acid neutralizing capacity assay, H⁺/K⁺ ATPase inhibitory assay were performed.

RESULTS

The ulcer protection was found to be 92%, 86% and 64% against ethanol, NSAID and pylorus ligation induced ulcer respectively. The hydro-alcoholic extract of C. sappan heartwood exhibited cytoprotective effect with 76.82% reduction against indomethacin-induced cytotoxicity at the concentration of 25µg/ml. C. sappan showed 63.91% inhibition in H⁺/K⁺ ATPase inhibitory assay at the concentration 500µg/ml.

CONCLUSIONS

Our results depict that Caesalpinia sappan heartwood possesses gastroprotective activity, possibly mediated through cytoprotection and antioxidant mechanisms. The data obtained in the present study provides scientific support for the traditional use of Caesalpinia sappan in the management of peptic ulcer.

Protective Effect of Cod (Gadus macrocephalus) Skin Collagen Peptides on Acetic Acid-Induced Gastric Ulcer in Rats

This research was performed to explore the protective effect of cod skin collagen peptides (CCP) on gastric ulcer induced by acetic acid. The CCP were fractionated into low molecular CCP (LMCCP, Mw < 3 kDa) and high molecular CCP (HMCCP, Mw > 3 kDa). In HMCCP and LMCCP, glycine of accounted for about one-third of the total amino acids without cysteine and tryptophan, and hydrophobic amino acids accounted for about 50%. After 21 d CCP treatment (60 or 300 mg/kg, p.o./daily), the healing effects on acetic acid-induced gastric ulcers were evaluated by macroscopic measure, microscopic measure, and immune histochemistry. Moreover, the expression levels of the growth factors, such as vascular endothelial growth factor, epidermal growth factor, transforming growth factor β1 (TGFβ1), and the heat shock protein 70 (HSP70) was detected. The results showed that both LMCCP and HMCCP could significantly decrease the ulcer areas and promote the healing of the lesions. They also could improve the levels of hexosamine, glutathione, superoxide dismutase, and glutathione peroxidase, and reduce the content of malondialdehyde and inducible nitric oxide synthase. In addition, the expression level of TGFβ1 gene and HSP70 mRNA was significantly improved by the treatment. It suggested that CCP could be able to improve symptoms of gastric ulcer and probably be used in the treatment of gastric ulcer.

Effects of kramecyne on LPS induced chronic inflammation and gastric ulcers

Preclinical Research Krameria cytisoides is used for the treatment of inflammation, stomach pain, and gastric ulcers. The active ingredient from this plant is a peroxide, kramecyne (KACY) which has anti-inflammatory effects. The aim of the present study was to evaluate the anti-inflammatory activities of KACY in lipopolysaccharide (LPS)-induced systemic chronic inflammation in mice for 60 days, using dexamethasone (DEX) as the positive control, vehicle (the LPS group) as the negative control and the control group (mice without inflammation). KACY did not affect survival, body weight or relative organ weight in mice but it: decreased nitric oxide (NO) production by 68%; prostaglandin E2 (PGE2 ) by 67%; increased release of anti-inflammatory cytokine IL-10 (2.0-fold), and reduced production of the proinflammatory cytokines, IL-6 (2.0-fold), IL-1β (2.4-fold), and TNF-α (2.0-fold). Furthermore, the gastroprotective effects of KACY in mice were evaluated in an ethanol-induced gastric ulcer model. The results showed that KACY at 50 and 100 mg/kg exerted gastroprotective effects with similar activity to 50 mg/kg ranitidine. In gastric tissues, KACY decreased the level of malondialdehyde (MDA) but increased the catalase (CAT) activity. KACY have potential for the treatment of chronic inflammatory diseases due its similar activity to that of DEX. It also has gastroprotective effects.

Evaluation of the safety, gastroprotective activity and mechanism of action of standardised leaves infusion extract of Copaifera malmei Harms

ETHNOPHARMACOLOGICAL RELEVANCE

Copaifera malmei Harms (Fabaceae) is a plant that occurs in the central region of Brazil, where the plant's leaves infusion is popularly used to treat gastric ulcer and inflammatory diseases. This study was aimed to investigate the gastroprotective activity and mode of action of the plants' leaves infusion in order to establish the scientific basis for such usage, and to assess its potential as a source of an anti-ulcer agent.

MATERIALS AND METHODS

Leaves infusion extract of the plant (SIECm) was prepared, freeze dried and lyophilised. Its qualitative and quantitative phytochemical constituents were investigated using TLC and HPLC techniques. The safety profile was evaluated on CHO-k1 epithelial cells viability using the Alamar blue assay, and by acute toxicity test in mice. The gastroprotection and anti-ulcer efficacy of the SIECm (25, 100 and 400mg/kg, p.o.) were tested using acute (acidified ethanol, piroxicam and water restrain stress), and chronic (acetic acid) experimental ulcer models. The plausible mode of action of the SIECm was assessed using gastric secretion, gastric barrier mucus, nitric oxide, and its antioxidant (myeloperoxidase and catalase) effects in mice and rats. The histopathological analyses of the ulcerated tissues as well as the extract's activity on Helicobacter pylori were also investigated.

RESULTS

Phytochemical tests indicated the presence of mainly phytosterols, phenolics and flavonoids. The SIECm exhibited no cytotoxic effects on the CHO-k1 cells, and no oral acute toxicity in mice. It prevented against the acute induced ulcerations by enhancing gastroprotection through gastric mucus production, NO modulation, antioxidant, reduced gastric secretion and enhanced chronic ulcers healing process, as shown by reduction/prevention of epithelial and vascular damage, in addition to reduction in leucocyte infiltration. The SIECm however did not exhibit activity against H. pylori.

CONCLUSION

The SIECm is safe, contain useful phytochemicals and exhibited significant gastroprotective/anti-ulcer effects. The results justify its folkloric usage, and provided scientific evidence of its potential as a source of new phytodrug to treat gastric ulcers.

Helicteres sacarolha A. St.- Hil. et al.: gastroprotective and possible mechanism of actions in experimental animals

ETHNOPHARMACOLOGICAL RELEVANCE

Helicteres sacarolha A. St.- Hil. et al. popularly known in Brazil as 'semente-de-macaco', is widely employed in the popular medicine in many of parts of Brazil in the alleviation of symptoms of ailments such as peptic ulcer and inflammation. Up to the present, there is no study addressing the gastroprotective activity of the hydroethanolic extract of H. sacarolha and its possible mechanism of actions.

MATERIALS AND METHODS

The hydroethanolic (70%) extract of H. sacarolha (HEHs) was obtained by maceration. The gastroprotective activity was assessed using gastric ulcer models induced by acidified ethanol, piroxicam, and water restraint stress in mice and rats at doses of 20, 50 and 250mg/kg p.o. Mechanistic studies involved the antisecretory assay evaluated with pylorus ligation in rats and pre-treatments with appropriate antagonists/inhibitors such as yohimbine, glibenclamide, indomethacin and l-NAME, effect on catalase and myeloperoxidase activities and gastric mucus determination using acidified ethanol- induced ulcer in mice.

RESULTS

HEHs at all doses tested demonstrated potent gastroprotective activities in the acute ulcer models. The gastroprotective activity of HEHs was attenuated by pre-treatments with yohimbine, glibenclamide, indomethacin and l-NAME. HEHs effectively reduced basal gastric juice production without any effect on the free and total acidity. The gastroprotective action of HEHs involved increasing the antioxidant enzyme catalase and mucus secretion and inhibition of neutrophyl infiltration as reflected by the reduction in the myeloperoxidase activity.

CONCLUSION

The results of this study gave a scientific support for the popular use of the leaves of H. sacarolha in the treatment of gastric ulcers and that it has a multi-targeted action.

Gastroprotective effect of alpha-pinene and its correlation with antiulcerogenic activity of essential oils obtained from Hyptis species

Background:

Alpha-pinene (α-pinene) is a monoterpene commonly found in essential oils with gastroprotective activity obtained from diverse medicinal plants, including Hyptis species. The genus Hyptis (lamiaceae) consists of almost 400 species widespread in tropical and temperate regions of America. In the north and northeastern Brazil, some Hyptis species are used in traditional medicine to treat gastrointestinal disturbances.

Objective:

The present study has investigated the gastoprotective effect of purified α-pinene in experimental gastric ulcer induced by ethanol and indomethacin in mice.

Materials and Methods:

Gastric ulcers were induced in male Swiss mice (20-30 g) by oral administration of absolute ethanol or indomethacin 45 min after oral pretreatment with vehicle, standard control drugs or α-pinene (10, 30, and 100 mg/kg). One hour after the ulcerative challenges, the stomach were removed, and gastric lesions areas measured. The effects of α-pinene on the gastric juice acidity were determined by pylorus ligation model. The gastrointestinal motility and mucus depletion were determined by measuring the gastric levels of phenol red and alcian blue, respectively. Hematoxylin and eosin stained sections of gastric mucosa of the experimental groups were used for histology analysis.

Results:

α-pinene pretreatment inhibited ethanol-induced gastric lesions, reduced volume and acidity of the gastric juice and increased gastric wall mucus (P < 0.05). Furthermore, we showed an interesting correlation between concentration of α-pinene and gastroprotective effect of Hyptis species (P Pearson = 0.98).

Conclusion:

Our data showed that the α-pinene exhibited significant antiulcerogenic activity and a great correlation between concentration of α-pinene and gastroprotective effect of Hyptis species was also observed.

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.

Protective effect of aqueous extract of Oroxylum indicum Linn. (root bark) against DNBS-induced colitis in rats

Objective:

Aqueous root extract of Oroxylum indicum was evaluated in rats against dinitrobenzene sulfonic acid (DNBS) induced colitis.

Materials and Methods:

Rats were pre-treated orally for seven days and continued for four days after the induction of colitis with OI_aq (100, 200, and 400 mg/kg) or vehicle. Colitis was induced by intracolonic instillation of 25 mg of DNBS per rat dissolved in 50% alcohol and 4 days later, the colonic mucosal damage was analyzed along with food intake, body weight, colon weight, spleen weight, histological damage, myeloperoxidase (MPO) activity, malondialdehyde (MDA) levels, reduced glutathione (GSH), and nitric oxide levels in colonic tissue homogenate.

Results:

Significant reduction in gross damage area, weight loss and increase in colonic and spleen weight were evident in test substance-pretreated animals’ dose dependently as compared to vehicle treated control. These effects were confirmed biochemically by a reduction in colonic myeloperoxidase activity, malondialdehyde levels, nitric oxide levels, and increase in reduced glutathione (GSH) levels. Furthermore, microscopic examination revealed diminution of inflammatory cell infiltration and submucosal edema in colon segments of rats treated with OI_aq.

Conclusion:

The results demonstrate the protective effect of OI_aq in the animal model of acute colitis possibly through an antioxidant, anti-lipoperoxidative or due to reduction in nitric oxide generation.

Gastric antisecretory and cytoprotective effects of leaf extracts of Amaranthus tricolor Linn. in rats

OBJECTIVE

The present study was aimed to evaluate the antiulcer activity of leaf extracts of Amaranthus tricolor Linn. (Amaranthaceae) in rats.

METHODS

The effects of A. tricolor leaves on gastric secretion and the effect of gastric cytoprotection were evaluated using five different models of gastric ulcers: acetic acid-induced, pylorus ligation-induced, ethanol-induced, indomethacin-induced and ischemia-reperfusion-induced gastric ulcers. The different extracts, namely, ethanolic extract (EAT), petroleum ether extract (PEAT), chloroform extract (CAT) and ethyl acetate extract (EAAT) of A. tricolor leaves were administered at a dose of 200 mg/kg per oral (p.o.).

RESULTS

The acute oral toxicity study revealed that all the extracts were safe up to 2 000 mg/kg, p.o; hence one-tenth of this dose was selected for evaluation of antiulcer activity. The EAT and EAAT (200 mg/kg, p.o.) showed gastric ulcer-healing effect in acetic acid-induced chronic gastric ulcers. The EAT and EAAT inhibited gastric secretion in pylorus-ligated rats and showed gastric cytoprotective effect in ethanol-induced and indomethacin-induced gastric ulcers, while PEAT and CAT showed no significant antiulcer effect.

CONCLUSION

The leaf extracts of A. tricolor are found to possess very good antiulcer property in the experimental animal models of gastric ulcers which is consistent with the literature report in folk medicine.

Mechanisms of action underlying the gastric antiulcer activity of the Rhizophora mangle L

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizophora mangle, the red mangrove, has long been known as a traditional antiulcer medicine. The present work evaluated the mechanisms of action involved in the anti-ulcer properties of the Rhizophora mangle bark extracts.

MATERIALS AND METHODS

Gastroprotection of Rhizophora mangle was evaluated in rodent experimental models (ethanol). To elucidate the mechanisms of action the antisecretory action and involvement of NO, SH, mucus and PGE(2) were evaluated. The acetic acid-induced gastric ulcer model, Western blotting assay (COX-1, COX-2 and EGF) and immunohistochemical localization of HSP-70, PCNA and COX-2 were also used to evaluate the Rhizophora mangle healing properties.

RESULTS

Results showed that Rhizophora mangle bark crude extract (CE), as well as ethyl acetate (EtOAc) and butanolic fractions (BuOH) provided significant gastroprotection at all the tested doses. Thereby, the following protocols were performed using the lowest dose capable of producing the most effective gastroprotection, which was the BuOH 0.5mg/kg (P<0.001). Several mechanisms are involved in the antiulcer activity of Rhizophora mangle, such as, participation of NO, SH and mucus. The enhancement of PGE(2) levels and the upregulation of COX-2 and EGF seem to be directly linked to the antisecretory, cytoprotective and healing effects of BuOH. HSP-70 and PCNA are also involved in this cicatrisation process. No sign of toxicity was observed in this study, considering the analyzed parameters.

CONCLUSION

Our study reinforces its traditional medicinal use. Considering that the current therapies are based on the use of antisecretory or cytoprotective drugs, the Rhizophora mangle arises as a promising alternative antiulcer therapy.

Abarema cochliacarpos: gastroprotective and ulcer-healing activities

ETHNOPHARMACOLOGICAL RELEVANCE

Abarema cochliacarpos (Gomes) Barneby & Grimes (Mimosaceae) is a species--in folk medicine of Lagarto city, Sergipe state, northeastern Brazil--reputed to heal gastric ulcer and gastritis.

AIM OF THE STUDY

Chloroform (CE) and methanolic (ME) extracts as well as ethyl acetate fraction (AF), butanolic fraction (AC) and aqueous fraction (AQF) of the methanolic extract of Abarema cochliacarpos bark were evaluated against acute gastric ulcer. The AC fraction was selected to assess its activity in ulcer healing and its gastroprotective effects via mucus and gastric secretion.

MATERIAL AND METHODS

The gastroprotective action of CE and ME extracts and the fractions of the latter were evaluated in a rodent experimental model. The action mechanisms, involvements of the antisecretory action and mucus production, toxicological and healing activity of the AC (150 mg/kg, p.o.) were evaluated. We also used histological analysis (HE and PAS) and immunohistochemical (PCNA, COX-2, VEGF and HSP-70) assays to evaluate the effects of Abarema cochliacarpos.

RESULTS

CE (200 and 400 mg/kg, p.o.) and ME (100, 200 and 400 mg/kg, p.o.) extracts were able to protect gastric mucosa against absolute ethanol. Respective inhibitions produced were: 65.31% and 83.80% by the first; 91.69%, 96.75% and 99.80% by the second; and 74.24% by the AC fraction. Antisecretory and mucus production effects were exhibited by the AC fraction, which also accelerated the healing of ulcerated gastric mucosa by stimulating proliferation factors (PCNA) and induced healing factors including COX-2, VEGF and HSP-70.

CONCLUSION

All these results suggest that Abarema cochliacarpos (Gomes) Barneby & Grimes presents gastroprotective effects and wound-healing properties.

Anti-inflammatory intestinal activity of Abarema cochliacarpos (Gomes) Barneby & Grimes in TNBS colitis model

AIM OF THE STUDY

To assess the anti-inflammatory effect of butanolic fraction of methanolic extract from bark of Abarema cochliacarpos in acute ulcerative colitis model induced by intracolonic administration of trinitrobenzene sulfonic acid (TNBS) in Wistar rats.

MATERIALS AND METHODS

Abarema cochliacarpos (100 and 150mg/kg/day) was administered by gavage 48, 24 and 1h prior to the induction of colitis with 10mg/kg of TNBS and, 24h later.

RESULTS

Phytochemical studies by mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) revealed that catechins were a major component into condensate class of tannins. Treatment with Abarema cochliacarpos decreased significantly macroscopic damage as compared with TNBS (p<0.05). Histological analysis showed that both doses of the extract improved the microscopic structure and preserved some areas of the colonic mucosa structure. In addition, myeloperoxidase activity (MPO), as a marker of neutrophil infiltration, was decreased in a dose-dependent way (p<0.01 and p<0.001 respectively), TNF-alpha level was also diminished with the highest dose of the extract (p<0.001) and, IL-10 level obtained no significant results. In order to elucidate some of the mechanisms, expression of inducible inflammatory enzymes, such as cyclooxygenase (COX)-2 and nitric oxide synthase (iNOS), were studied showing a significant reduction. Finally, the involvement of c-Jun N-terminal kinase (JNK) signalling demonstrated a reduction in the JNK activation with the highest dose (p<0.05 vs TNBS).

CONCLUSIONS

We have shown for the first time that the extracts obtained from Abarema cochliacarpos bark possess active substances, which exert marked protective effects in acute experimental colitis, confirming and justifying, at least in part, the popular use of this plant to treat gastrointestinal diseases.

Protective effects of electroacupuncture on acetylsalicylic acid-induced acute gastritis in rats

AIM: To investigate the protective effects of electroacupuncture (EA) pretreatment on acetylsalicylic acid (ASA)-induced ulceration in rats.

METHODS: We randomly divided 72 rats into three groups including control (administered with distilled water), ASA group (administered 100 mg/kg ASA) and EA group (administered EA + 100 mg/kg ASA). Each rat was fasted for 18 to 24 h before experimentation, and lesion scores, gastric acidity, cyclooxygenase (COX)-1 and -2 mRNA levels, and total nitric oxide (NO) concentration were measured.

RESULTS: The lesion scores of the EA group were significantly lower than those of the ASA group. Gastric acidity of the ASA and EA groups was reduced compared to the control group. COX-1 and -2 mRNA levels were significantly increased in the EA group as compared to the control and ASA groups, and NO levels were also significantly increased in the EA group as compared to the ASA group.

CONCLUSION: These results suggest that EA-mediated protection against ASA-induced ulceration in rats may occur via gastric defense components.

Vernonia polyanthes as a new source of antiulcer drugs

Methanolic (VPME) and chloroformic (VPCL) extracts, obtained from the aerial parts of Vernonia polyanthes, were investigated for its antiulcerogenic properties. Administration of VPME (250 mg/kg) and VPCL (50 mg/kg) significantly inhibited the gastric mucosa damage (64% and 90%, respectively) caused by absolute ethanol (p.o.). Otherwise, in NSAID-induced gastric damage, their gastroprotective effects have decreased. Since the VPCL extract resulted to be more effective than the VPME we focused our efforts over VPCL action mechanism of action.

Effect of peroxisome proliferator-activated receptor-alpha agonist (bezafibrate) on gastric secretion and gastric cytoprotection in rats

The effect of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) on gastric secretion and gastric cytoprotection was evaluated using five different models of gastric ulcers: acetic acid-induced chronic gastric ulcers, pylorus ligation, ethanol-induced, indomethacin-induced and ischemia-reperfusion-induced gastric ulcers. Bezafibrate, a PPAR-alpha agonist was administered at two different doses of 10 and 100 mg/kg body weight intraperitoneanally. Both doses of bezafibrate showed significant antiulcer effect in ethanol-induced, indomethacin-induced and pylorus ligation-induced gastric ulcers. Bezafibrate increased healing of ulcer in acetic acid-induced chronic gastric ulcer model. Both doses were also effective in preventing gastric lesions induced by ischemia-reperfusion. It was concluded that PPAR-alpha activation increases healing of gastric ulcers and also prevents development of gastric ulcers in rats.