Contribution to the ethnopharmacological and anti-Helicobacter pylori knowledge of Cyrtocarpa procera Kunth (Anacardiaceae)

Ethnopharmacological relevance

Cyrtocarpa procera Kunth (Anacardiaceae) is a Mexican endemic tree; its bark has been traditionally employed in Mexico since prehispanic times to relieve digestive disorders.

Aim of the study

To perform an acute evaluation of the toxicity, gastroprotective, and anti-inflammatory properties, as well as the anti-Helicobacter pylori action of C. procera bark extracts, in order to determine polypharmalcological activities.

Materials and methods

Five different polarity extracts (hexanic, CH₂Cl₂, CH₂Cl₂-MeOH, methanolic, and aqueous) were prepared. Each of them was evaluated in the following acute mice models: toxicity Lorke test, ethanol-induced gastric ulcer, TPA-induced ear edema; and the in vitro anti-H. pylori activity with a broth dilution method.

Results

None of the extracts were toxic under acute administration. The methanolic, hexanic, and aqueous extracts possess remarkable gastroprotective activity. All the extracts inhibit H. pylori growth, being the hexanic the most active, and only this one showed significant anti-inflammatory effect.

Conclusions

This work demonstrates that C. procera bark has polypharmacological activities; which makes it a promising asset to the development of an integral treatment for gastritis or peptic ulcer related or not to H. pylori. Our findings contribute to the ethnopharmacological knowledge about this species.     

Gastroprotective activity of the stem bark of Amphipterygium adstringens in rats

The methanol extract of the stem bark of Amphipterygium adstringens (Julianiaceae) showed a dose-dependent inhibitory effect on ethanol-induced gastric ulcers in rats. Fractionation of this extract, guided by gastroprotective activity in rats, led to four active fractions rich in triterpenoid compounds. These fractions showed higher antiulcer activity than bismuth subsalicylate, used as a positive control. 3α-Hydroxy- masticadienonic acid was isolated from the active fractions, however, this compound showed lower antiulcer activity than the positive control. © 1998 John Wiley & Sons, Ltd.     

Protective effect of Calotropis procera latex extracts on experimentally induced gastric ulcers in rat

Aim of the study

Calotropis procera is a wild growing plant with multifarious medicinal properties. The present study was carried out to evaluate the effect of dried latex (DL) of Calotropis procera and its methanol extract (MeDL) against gastric ulcers induced in rats.

Materials and methods

Aqueous suspension of DL (20 and 100 mg/kg) and MeDL (10 and 50 mg/kg) were given orally to 36 h fasted rats and ulcers were induced by ethanol, pyloric ligation and aspirin. Parameters like ulcer score and levels of oxidative stress markers were measured in all the models. The effect on gastric hemorrhage and tissue histology was studied in ethanol model and on acidity, pH and volume of gastric secretion was evaluated in pyloric ligation model. The protective effect of DL and MeDL was compared with that of standard anti-ulcer drug famotidine (20 mg/kg).

Results

DL and MeDL produced 85–95% inhibition of gastric mucosal damage in ethanol model and 70–80% inhibition in aspirin model. The protective effect of these extracts was associated with marked reduction in gastric hemorrhage, maintenance of tissue integrity and normalization of levels of oxidative stress markers like glutathione, thiobarbituric acid reactive substances and superoxide dismutase. Like famotidine, DL and MeDL decreased the gastric acidity from 376.17 ± 21.47 mequiv./l to 163.88 ± 6.86 and 201.48 ± 8.86 mequiv./l respectively in pyloric ligation model. These extracts increased the gastric pH without affording any protection to gastric mucosa in this model.

Conclusion

The latex of Calotropis procera has the therapeutic potential to relieve gastric hyperacidity and to prevent gastric ulceration induced by necrotizing agents.     

Anti-Helicobacter pylori activity of anacardic acids from Amphipterygium adstringens

Amphipterygium adstringens (Schltdl.) Standl. (Anacardiaceae) is widely used in traditional Mexican medicine for the treatment of gastritis and ulcers. In this work, we studied the anti-Helicobacter pylori activity of its bark, this Gram-negative bacterium is considered the major etiological agent of chronic active gastritis and peptic ulcer disease, and it is linked to gastric carcinoma. From a bio-guided assay of the fractions obtained form a continuous Soxhlet extraction of the bark, we identified that petroleum ether fraction had significant antimicrobial activity against Helicobacter pylori. From this fraction, we isolated an anacardic acids mixture and three known triterpenes: masticadienonic acid; 3α-hydroxymasticadienonic acid; 3-epi-oleanolic; as well as the sterol β-sitosterol. Only the anacardic acids mixture exhibits a potent dose-dependent antibacterial activity (MIC = 10 μg/ml in broth cultures). It is enriched in saturated alkyl phenolic acids (C_15:0, C_16:0, C_17:0 C_19:0) which represents a novel source of these compounds with potent anti-Helicobacter pylori activity. The promising use of anacardic acids and Amphipterygium adstringens bark in the development of an integral treatment of Helicobacter pylori diseases is discussed.     

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

Ethnopharmacological relevance

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

Materials and methods

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

Results

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

Conclusion

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

Protective effect of ethyl acetate fraction of Acacia ferruginea DC. against ethanol-induced gastric ulcer in rats

Ethnopharmacological relevance

In traditional systems of medicine, stem bark of Acacia ferruginea DC. is used for the treatment of itching, leucoderma, ulcers, stomatitis and diseases of the blood. In the present study, we determined antioxidant and anti-ulcerogenic activities of Acacia ferruginea stem bark.

Materials and methods

Acetone extract and its sub-fractions of Acacia ferruginea stem bark were subjected to assess their antioxidant potential using various in vitro systems such as DPPH^•, ABTS^•+ scavenging, FRAP and phosphomolybdenum reduction activities. Based on the antioxidant potential, the ethyl acetate fraction was used to evaluate the protective effect of ethanol-induced gastric damage in rat model. Enzyme activities such as superoxide dismutase, glutathione, catalase and lipid peroxidation were also determined in the stomach tissues.

Results

Ethyl acetate fraction (AFE) of Acacia ferruginea stem bark registered higher antioxidant and free radical scavenging activities than the crude acetone extract and other fractions. In addition, AFE exhibited that the IC₅₀ values of DPPH (2.5 µg/ml) and ABTS (1.8 µg/ml) were lower when compared to the standard quercetin (12.4 µg/ml and 4.7 µg/ml, respectively). In ethanol induced gastric ulcer, administration of AFE at doses of 10 mg/kg, 50 mg/kg and 100 mg/kg body weight prior to ethanol ingestion significantly protected the stomach ulceration. Consequently significant changes were observed in enzyme activities such as SOD, CAT, GSH and LPO in the stomach tissues when compared with ethanol control group.

Conclusion

It is concluded that the ethyl acetate fraction of Acacia ferruginea stem bark possessed higher antioxidant and anti-ulcerogenic activities. Based on the results, we suggest that Acacia ferruginea stem bark has potential to provide a therapeutic approach to ethanol mediated ulcer as an effective anti-ulcer agent.     

Gastroprotective effect of standardized leaf extract from Argyreia speciosa on experimental gastric ulcers in rats

Ethnopharmacological relevance

Argyreia speciosa (L.f), Sweet (Family Convolvulaceae) is used traditionally in Indian System of Medicine as aphrodisiac, rejuvenating agent, intellect promoting agent, brain tonic and in the therapy of hepatomegaly, diabetes and chronic ulcer.

Aim of the study

To study the gastroprotective effect of standardized butanol fraction of Argyreia speciosa leaf (ASE).

Materials and methods

The butanol fraction of Argyreia speciosa leaf (ASE; 50, 100 and 200 mg/kg body weight) was administered orally, twice daily for 5 days for prevention from Aspirin (ASP)-, ethanol (EtOH)-, cold-restraint stress (CRS) - and pylorus ligation (PL)-induced ulcers. Estimation of antioxidant enzymes activity was carried out in CRS-induced ulcer model, and various gastric secretion parameters like volume of gastric juice, acid output, and pH value were estimated in PL-induced ulcer model.

Result

ASE showed dose-dependent ulcer protective effect in ASP 23.64-58.76% (p < 0.01 to p < 0.001), EtOH 15.45-58.45% (p < 0.001), CRS 19.39-78.36% (p < 0.001) and PL 19.67-69.04% (p < 0.05 to p < 0.01), respectively. The percentage of protection by standard drug ranitidine was 77.77-84.32% (p < 0.01 to p < 0.001) in various gastric ulcer models. The gastric wall mucus was significantly (p < 0.001) enhanced by ASE and is regarded as the first line of defence against EtOH-induced gastric ulcers showing cytoprotective property. ASE showed a marginal decrease in volume, acid pepsin concentration and acid pepsin output. However, ASE reduced the ulcer index with significant decrease in LPO level (p < 0.001), and SOD level (p < 0.01 to p < 0.001) as compared with CRS-induced group. A gradual and significant increase in CAT values were observed at 100 and 200 mg/kg dose levels (p < 0.01 to p < 0.001).

Conclusions

The results of our study revealed that Argyreia speciosa possess significant dose dependent gastroprotective activity, probably due to its free radical scavenging activity.     

Gastroprotective activity of Cinnamomum tamala leaves on experimental gastric ulcers in rats

Ethnopharmacological relevance

Cinnamomum tamala T. Nees & Eberm (Family Lauraceae) is used traditionally in Indian System of Medicine as carminative, anthelmintic, diuretic, and used in colic, dyspepsia, and diarrhea.

Aim of the study

This study was aimed to evaluate the gastroprotective effects of Cinnamomum tamala leaves.

Methods

Cinnamomum tamala leaves extract (CTE; 50,100 and 200 mg/kg body weight) was administered orally, twice daily for 5 days for prevention from ethanol (EtOH)-, cold-restraint stress (CRS)- and pylorus ligation (PL)-induced ulcers. Estimation of H⁺K⁺ATPase activity and gastric wall mucous were performed in EtOH-induced ulcer model, antioxidant enzyme activities was carried out in CRS-induced ulcer model, and various gastric secretion parameters like volume of gastric juice, acid output, and pH value were estimated in PL-induced ulcer model.

Results

A significant reduction in lesion index was observed in ulcer-induced animals treated with CTE at different doses when compared with ulcerated rats in all models. A significant decrease occurred in the level of H⁺K⁺ATPase, volume of gastric juice, and acid output. Simultaneously the level of gastric wall mucus and pH were increased significantly. These showed dose-dependent action of CTE. The antioxidant enzyme levels of LPO and SOD were decreased while administering CTE at different doses, compared with their control values. Contrary to this the level of CAT enzyme showed significant increase.

Conclusions

The results of our study showed that Cinnamomum tamala possess significant gastroprotective activity, probably due to its free radical scavenging activity.     

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.     

Antiulcerogenic activity of hydroalcoholic extract of Achillea millefolium L.: Involvement of the antioxidant system

Achillea millefolium L. is a member of the Asteraceae family that is commonly referred to as “yarrow” and has been used in folk medicine against several disturbances including skin inflammations, spasmodic and gastrointestinal disorders, as well as hepato-biliary complaints.     

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

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

Effect of Mouriri pusa tannins and flavonoids on prevention and treatment against experimental gastric ulcer

Aim of the study

Mouriri pusa, popularly known as “manapuçá” or “jaboticaba do mato”, is a plant from Brazilian cerrado that has been found to be commonly used in the treatment of gastrointestinal disturbs in its native region. The present work was carried out to investigate the effect of tannins (TF) and flavonoids (FF) fractions from Mouriri pusa leaves methanolic extract on the prevention and cicatrisation process of gastric ulcers, and also evaluate possible toxic effects.

Materials and methods

The following protocols were taken in rats: acute assay, in which ulcers were induced by oral ethanol after pre-treatment with the fractions; and 14 days treatment assay, in which ulcers were treated for 14 days after induction by local injection of acetic acid.

Results

In the acute model, treatment with either, TF (25 mg/kg) or FF (50 mg/kg), was able to reduce lesion area, showing gastroprotective effect. In addition, FF proved itself anti-inflammatory by reducing COX-2 levels. In acetic acid model, both fractions exhibited larger ulcers’ regenerative mucosa, indicating cicatrisation enhancement. FF group also showed augmented cell proliferation, anti-inflammatory action and enhanced angiogenesis as well as increased mucus secretion. Moreover, concerning the toxicity parameters analyzed, no alteration in the fractions groups was observed.

Conclusions

Tannins and flavonoids from Mouriri pusa provide beneficial effects against gastric ulcers with relative safety.     

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.     

Byrsonima intermedia A. Juss.: gastric and duodenal anti-ulcer, antimicrobial and antidiarrheal effects in experimental rodent models

Ethnopharmacological relevance

An ethnopharmacological survey indicated that the leaves of Byrsonima intermedia A. Juss. (Malpighiaceae), a medicinal species commonly found in the Brazilian Cerrado, can be used against gastroduodenal disorders, such as gastric ulcers and diarrhea.

Aim of the study

The objective of this study was to evaluate the effects of a methanolic extract of Byrsonima intermedia (MBI) leaves on gastric and duodenal ulcers and to assess the antimicrobial and antidiarrheal effects of this extract.

Material and methods

The anti-ulcerogenic effect of MBI was investigated with different ulcerogenic agents in rodents (mice and rats), including non-steroidal anti-inflammatory drug (NSAID), HCl/ethanol, pyloric ligature, absolute ethanol, cysteamine and ischemia–reperfusion. The gastroprotective effect of MBI was assessed by analysing the volume of gastric juice, pH, total acidity, mucus, NO, sulfhydryl compound, vanilloid receptor, glutathione (GSH) levels, and myeloperoxidase (MPO) activity in the gastric and duodenal mucosa. The gastric and duodenal healing effects of MBI were also evaluated during 7 or 14 days of treatment. The antidiarrheal action (measured by intestinal motility and diarrhea induced by castor oil) and anti-bacterial action of MBI against Staphylococcus aureus, Escherichia coli and Helicobacter pylori were also evaluated by microdilution methods.

Results

The phytochemical profile from MBI indicated the presence of phenolic acids, flavan-3-ols, oligomeric proanthocyanidins, and flavonoids. MBI (500 mg/kg, p.o.) significantly inhibited totally gastric and duodenal lesions (69%) and healed gastric (49% on 14 days) and duodenal lesions (45% on 7 and 14 days). The MBI exert gastroprotective action by participation of endogenous sulfhydryl compounds, vanilloid receptors and increase in GSH level to effective gastric and duodenal protection. MBI also displayed curative (42%) and preventive (49%) antidiarrheal effects by involvement of opiate receptors and also antimicrobial effects in vitro.

Conclusions

Byrsonima intermedia leaves present gastroprotective, healing and antidiarrheal activities, supporting previous claims that its traditional use can treat gastrointestinal disorders.     

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.     

Gastroprotective effect of standardized extract of Ficus glomerata fruit on experimental gastric ulcers in rats

ETHNOPHARMACOLOGICAL RELEVANCE: Traditionally fruits of Ficus glomerata Roxb (Family: Moraceae) are used to treat anemia and gastrointestinal disorders. AIM: Gastroprotective effect of 50% ethanolic extract of F. glomerata fruit (FGE) was studied in different gastric ulcer models in rats. METHODS: FGE (50, 100 and 200 mg/kg body weight) was administered orally, twice daily for 5 days for prevention from pylorus ligation (PL), ethanol (EtOH) and cold restraint stress (CRS)-induced ulcers. Estimation of H+K+ATPase activity and gastric wall mucous were performed in EtOH-induced ulcer and antioxidant enzyme activities in supernatant mitochondrial fraction of CRS-induced ulcers. RESULTS: FGE showed dose dependent inhibition of ulcer index in pylorus ligation, ethanol and cold restraint stress-induced ulcers. FGE prevents the oxidative damage of gastric mucosa by blocking lipid peroxidation and by significant decrease in superoxide dismutase, H+K+ATPase and increase in catalase activity. High performance thin layer chromatography (HPTLC) analysis showed the presence of 0.57% and 0.36% w/w of gallic acid and ellagic acid in FGE. CONCLUSIONS: Our results show that F. glomerata possess significant gastroprotective activity which might be due to gastric defence factors and phenolics might be the main constituents responsible for this activity.     

Mechanism(s) of action involved in the gastroprotective activity of Muntingia calabura

Ethnopharmacological relevance

Muntingia calabura L. (Muntingiaceae) is locally known as kerukup siam. Its leaves, flowers, barks and roots have been used traditionally in East Asia and South America to treat various diseases including ulcer-related diseases. The present study aimed to investigate the mechanism(s) of gastroprotective effect of methanol extract of Muntingia calabura leaves (MEMC) using the pylorus ligation induced gastric ulceration in rats.

Materials and methods

Five groups of rats (n=6) were administered orally once daily for 7 days with 8% Tween 80 (negative control), 100 mg/kg ranitidine (positive control), or MEMC (100, 250 or 500 mg/kg), followed by the ulcer induction via ligation of the pyloric part of the rat’s stomach. This was followed by the macroscopic analysis of the stomach, evaluation of gastric content parameters, and quantification of mucus content. The antioxidant (measured using the superoxide anion and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging, oxygen radical absorbance capacity (ORAC) and total phenolic content (TPC) assays), anti-inflammatory (evaluated using the in vitro lipoxygenase and xanthine oxidase assays), phytoconstituents and HPLC analysis of MEMC were also carried out.

Results

The MEMC significantly (p<0.05) reduced gastric lesion in this model. Furthermore, the extract also significantly (p<0.01) reduced the volume of gastric content whereas the total acidity was significantly (p<0.05) reduced in the doses of 100 and 500 mg/kg MEMC. Moreover, the mucus content increased significantly (p<0.01) in MEMC-treated rats. The extract also showed high antioxidant and anti-inflammatory activities in all assays tested, and demonstrated the presence of high tannins and saponins followed by flavonoids.

Conclusion

The MEMC exerted gastroprotective effect via several mechanisms including the anti-secretory, antioxidant and anti-inflammatory activities. These activities could be attributed to the presence of tannins, saponins and flavonoids (e.g. rutin, quercitrin, fisetin and dihydroquercetin).     

胃肠乐对应激性胃溃疡大鼠胃黏膜NOS活性及CGRP含量的影响

[目的]探讨胃肠乐抗溃疡的机制及对胃黏膜细胞的保护作用。[方法]将48只大鼠随机分为正常对照组、模型对照组、胃肠乐高剂量组、胃肠乐中剂量组、胃肠乐低剂量组、洛赛克组 ;用游标尺计算各组溃疡指数 ,采用放免分析方法检测胃黏膜一氧化氮合酶(NOS)活性、降钙素基因相关肽 (CGRP)的含量。[结果]胃肠乐高、中、低剂量组及洛赛克组胃黏膜溃疡指数均较模型对照组明显下降 (P<0.01)。胃肠乐高、中、低3剂量组胃黏膜NOS活性及CGRP含量均较模型组显著升高 (P<0.01)。[结论]胃肠乐抗溃疡、促进溃疡愈合的作用机制可能与其通过增加NOS、CGRP含量而起到胃黏膜细胞保护作用有关     

Antiulcerogenic activity of Zizyphus lotus (L.) extracts

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

Gastroprotective activity of Trichosanthes cucumerina in rats

Aim of the study

The aim of the present study was to scientifically investigate whether Trichosanthes cucumerina Linn (Family: Cucurbitaceae) has gastroprotective activity.

Materials and methods

All the experiments were conducted using Wistar strain rats (weight: 200–220 g). The food and water given to rats was withdrawn for 36 and 12 h respectively, before the commencement of the experiment. These rats were randomly divided into 6 groups (n = 8 rats/group; 4 males + 4 females) and groups 1–3 were orally administrated with hot water extract (HWE) at a dose of 375, 500 and 750 mg/kg, respectively. Group 4 was orally treated with equal volume of distilled water (1 mL; control), group 5 was orally treated with a reference drug, cimetidine (100 mg/kg) while the group 6 was orally treated with another reference drug, sucralfate (400 mg/kg). In the indomethacin experiment, only one dose of HWE (750 mg/kg) was tested, as this was found to have the maximum effect in the alcohol model also.

Results

Results show that the HWE of Trichosanthes cucumerina possesses significant (P ≤ 0.05) and dose dependent gastroprotective effects in the alcohol model in terms of the length and number of gastric lesions mediated by alcohol, with a maximum effect at 750 mg/kg (inhibition of lesion length by 92%; number of gastric lesions by 88%). The same dose also mediated a significant (P ≤ 0.05) gastroprotective activity in the indomethacine model (inhibition of lesion length by 88%; number of gastric lesions by 84%). In both models, the protective effect demonstrated by the HWE was comparable with that produced by cimetidine. The HWE significantly (P ≤ 0.05) increased the amount of mucus produced by the rat gastro mucosa (by 39%) and reduced the gastric acidity (total acidity by 36%; free acidity by 40%). pH of the gastric juice increased from 4.1 to 6.0. However, no change in the volume of gastric juice was observed. Further, HWE showed potent antihistamine activity.

Conclusion

It may be concluded that HWE of Trichosanthes cucumerina exerts a significant protection against ethanol or indomethacin induced gastric damage. Increasing the protective mucus layer, decreasing the acidity of the gastric juice and antihistamine activity are probable mechanisms by which the HWE of Trichosanthes cucumerina mediates its gastroprotective actions.