Mouririelliptica: Validation of gastroprotective,healing and anti-Helicobacter pylori effects

Ethnopharmacological relevance

Mouriri elliptica Martius (Melastomataceae) is species reputed in folk medicine to heal gastric ulcer and gastritis.

Aim of the study

Methanolic extract (ME) and ethyl acetate fraction (EAF) from leaves of Mouriri elliptica were evaluated for their gastroprotective, healing, immunological, toxicological and anti-Helicobacter pylori activities.

Material and methods

The gastroprotective action of ME and EAF was evaluated in rodent experimental models and to elucidate mechanisms of action, the antisecretory action, involvements of NO, SH, PGE₂, anti-Helicobacter pylori action of ME was evaluated. We also used immunohistochemical (PCNA and COX-2) and immunomodulatory (murine peritoneal macrophages) assays to evaluate Mouriri elliptica effects.

Results

ME present gastroprotective action without antisecretory effect. Otherwise, ME showed anti-Helicobacter pylori action (MIC = 0.025 μg/mL) and was able to inhibit NO production by macrophages. This species also accelerate the healing of ulcerated gastric mucosa by stimulating proliferation factors (PCNA), COX-2 and maintained basal PGE₂ level independent action of NSAID in gastric mucosa. The phytochemical investigation showed that this species possesses phenolic acid derivatives, acylglycoflavonoids and condensed tannins which probably influenced their pharmacological action.

Conclusion

All these results suggest the efficacy and safety of Mouriri elliptica in combating and healing gastric ulcer.     

Bioevaluation of Anisomeles indica extracts and their inhibitory effects on Helicobacter pylori-mediated inflammation

Ethnopharmacological relevance

Helicobacter pylori is associated with the majority of gastric disorders and the antibiotic resistant rates have increased annually worldwide. Anisomeles indica and its constituent, ovatodiolide (OVT), were shown to have bactericide activity against Helicobacter pylori. The aim of this study was to manufacture extracts containing the effective constituent, OVT, and evaluate their bactericidal function and the inhibition of inflammatory responses to Helicobacter pylori infection.

Materials and methods

Various concentrations of ethanol for extraction of Anisomeles indica were performed and the content of OVT was analyzed by high-performance liquid chromatography (HPLC). The anti-bacterial activity of Anisomeles indica ethanol extracts and the constituent OVT were determined. Additional experiments were performed to investigate the Anisomeles indica ethanol extracts and OVT to inhibit the Helicobacter pylori-induced inflammation of both gastric epithelial cells and macrophages.

Results

Amongst the extracts tested, 50% and 95% ethanol extracts contained large amount of OVT and showed potent anti-Helicobacter pylori activity. An in vitro Helicobacter pylori-infection model revealed that 95% ethanol extract attenuated Helicobacter pylori-induced nuclear factor kappa B (NF-κB) activity and interleukin (IL)-8 secretion of gastric epithelial cells. In addition, 95% ethanol extract significantly inhibited lipopolysaccharide (LPS)-induced expression of inducible nitric oxide synthase (iNOS), as well as production of nitric oxide (NO) and tumor necrosis factor α (TNF-α) by macrophages.

Conclusions

This study reveals that Anisomeles indica ethanol extracts containing OVT may be a potent and economic therapeutic agent for Helicobacter pylori infection and attenuation of Helicobacter pylori-mediated inflammation.     

Davilla elliptica and Davilla nitida: Gastroprotective,anti-inflammatory immunomodulatory and anti-Helicobacter pylori action

Ethnopharmacological relevance

Davilla elliptica and Davilla nitida are species commonly found in the Brazilian Cerrado biome.

Aim of the study

Based on ethnopharmacological and phytochemical analyses, methanolic extracts from leaves of Davilla elliptica (EDE) and Davilla nitida (EDN) were evaluated for their anti-ulcer, anti-inflammatory, immunological and anti-Helicobacter pylori activities.

Materials and methods

The gastroprotective action of both extracts was evaluated in rodent experimental models (HCl/ethanol, ethanol or NSAID). We also evaluated anti-inflammatory (carrageenin-induced rat hind paw edema), immunomodulatory (murine peritoneal macrophages) and antibacterial action of both extracts against a standard strain of Helicobacter pylori.

Results

EDE and EDN (500 mg/kg) were able to protect gastric mucosa against HCl/ethanol solution (EDE 63%; EDN 59%), absolute ethanol (EDE 95%; EDN 88%), and also against injurious effect of NSAID (EDE 77%; EDN 67%). When EDE and EDN were challenged with sulfhydryl depleter compound, the gastroprotective action of both extracts was completely abolished. EDE had gastroprotective effect related to increase of glutathione bioavailability and stimulated higher levels of NO, H₂O₂ and TNF-α production. Otherwise EDN showed better anti-Helicobacter pylori action than EDE. Neither extracts presented anti-inflammatory activity by oral route.

Conclusion

The phytochemical investigation showed that both extracts possess phenolic acid derivatives, acylglycoflavonoids and condensed tannins with evident quantitative variations that probably influenced the pharmacological differences between extracts.     

Qualea parviflora Mart.: An integrative study to validate the gastroprotective,antidiarrheal, antihemorragic and mutagenic action

Ethnopharmacological relevance

Qualea parviflora Mart. is a medicinal species commonly found in the Brazilian Cerrado biome.

Aim of the study

Based on ethnopharmacological data, methanolic extract from Qualea parviflora (QP) bark was evaluated for its antiulcer, analgesic, anti-hemorrhagic, mutagenic and anti-Helicobacter pylori activities.

Material and methods

The gastroprotective action of the extract was evaluated in rodent experimental models (HCl/ethanol, ethanol or NSAID). We also evaluated mutagenic effect (Ames assay), anti-Helicobacter pylori, anti-hemorrhagic action, analgesic and inflammatory effects (hot-plate test and carrageenin-induced hind paw edema) of methanolic extract from Qualea parviflora.

Results

QP (500 mg/kg, p.o.) was able to protect gastric mucosa against HCl/ethanol solution (77%), absolute ethanol (97%), and also against injurious effect of NSAID (36%). When QP was challenged with sulfhydryl depletor compound, the gastroprotective action of extract was abolished. QP treatment was able to maintain the GSH level and show a concentration-dependent inhibition effect on the lipid peroxidation. QP present anti-Helicobacter pylori effect (MIC = 75 μg/mL), anti-hemorrhagic and antidiarrheal action but not present analgesic or anti-inflammatory effect.

Conclusion

methanolic extract from Qualea parviflora had gastroprotective effect related to the increase of gastric mucosa defensive factors such PGE₂ levels and maintain the basal gastric glutathione levels. The methanolic extract also showed anti-Helicobacter pylori activity, anti-hemorrhagic effect and antioxidant action, but absence of analgesic, mutagenic and toxic effects, a profile that adds safety to its use.     

On the potential of Tephrosia purpurea as anti-Helicobacter pylori agent

Aim of the study

Since Tephrosia purpurea (Linn.) Pers. (Fabaceae) has traditional use in curing different types of wounds including gastroduodenal ulcers, it was of interest to evaluate the in vitro anti-Helicobacter pylori activity profile of the plant extract and its fractions with a view to examining its therapeutic potential, if any.

Materials and methods

Employing clinical isolates and standard strains of Helicobacter pylori, the extract and fractions were bioevaluated in terms of MIC and MBC values, acid stability, time-kill kinetics, drug resistance, and synergistic potential.

Results

The methanolic extract showed promising activity against clinical isolates and standard strains of Helicobacter pylori, including metronidazole-resistant strains. Fractionation of the extract revealed the n-hexane and chloroform fractions to possess marked activity. The extract and the less polar fractions remained functionally active in acidic condition similar to stomach environment, exhibited consistent bacteriostatic activity during repeated exposure, and demonstrated synergism, complete or partial, even with antibiotic-resistant strains.

Conclusion

Apolar fractions of Tephrosia purpurea may have therapeutic potential in combating Helicobacter pylori mediated gastroduodenal disorders.     

Bactericidal activity of medicinal plants,employed for the treatment of gastrointestinal ailments,against Helicobacter pylori

Aim of the study

Helicobacter pylori infection plays a crucial role in the pathogenesis of peptic ulcer, and gastric cancer. The current PPI-based triple regimens for the eradication of Helicobacter pylori faces uprising resistance problem demanding for the search of novel candidates. Medicinal plants have always been a source of lead compounds for drug discovery.In the present study, we evaluated the anti-Helicobacter pylori activity of 50 commonly used Unani (traditional) medicine plants from Pakistan that are extensively utilized for the cure of gastrointestinal disorders to explore the natural source for pilot compounds against Helicobacter pylori.

Materials and methods

Total seven clinical isolates and one standard strain were employed to examine the bactericidal effects of medicinal plants. Helicobacter pylori was isolated from the antral biopsy specimens and confirmed through the standard microbiology procedures. Minimum bactericidal concentration (MBC) of the active plants was determined at the concentration range from 7.8 to 500 μg/ml.

Results

Among the herbs evaluated, more than 50% inhibited the growth of eight strains at the concentration of 500 μg/ml. The 70% aqueous-ethanol extracts of Curcuma amada Roxb., Mallotus phillipinesis (Lam) Muell., Myrisctica fragrans Houtt., and Psoralea corylifolia L. demonstrated strong anti-Helicobacter pylori activity with MBC value ranged from 15.6 to 62.5 μg/ml. The most potent bactericidal activity was exhibited by Mallotus phillipinesis (Lam) Muell. which completely killed the bacteria at the concentration of 15.6–31.2 μg/ml.

Conclusion

The results revealed significant anti-Helicobacter pylori activity of medicinal plants which could be the potential source of new bactericidal agents.     

In vitro and in vivo anti-Helicobacter pylori activity of Calophyllum brasiliense Camb.

Aims of the study

Calophyllum brasiliense (Camb.) is a medicinal tree that grows particularly in the hilly and forested regions of Brazil. Preparations from its stem bark are popular remedies for the treatment of chronic ulcers. Since earlier investigations on bark extracts evidenced gastroprotective and gastric acid inhibitory properties, this study evaluated the effects of hydroethanolic extract (HEECb) and the dichloromethanic fraction (DCMF), from Calophyllum brasiliense stem bark, against Helicobacter pylori, in vitro and in vivo.

Materials and methods

The in vitro assays were performed using the disk diffusion and broth microdilution methods to determine the minimum inhibitory concentration (MIC) values. The test substances were evaluated in vivo taking into account the delay in the gastric ulcer healing in Wistar rats, infected with Helicobacter pylori.

Results

DCMF appeared the most active and potent in vitro against Helicobacter pylori growth with an MIC of 31 μg/mL. In the in vivo assays, rats ulcerated by acetic acid, and inoculated with Helicobacter pylori showed a marked delay in ulcer healing. Treatment with HEECb (50, 100 and 200 mg/kg) and DCMF (100 and 200 mg/kg) reduced the ulcerated area in a dose-dependent manner. While DCMF, at 200 mg/kg, increased the prostaglandin E₂ (PGE₂) level, both HEECb and DCMF decreased the number of urease-positive animals, as confirmed by the reduction of Helicobacter pylori presence in histopathological analysis.

Conclusion

The results suggest that the antiulcer activity of Calophyllum brasiliense is due, in part, to its anti-Helicobacter pylori action, validating the popular use of this species.     

Evidence of the anti-Helicobacter pylori, gastroprotective and anti-inflammatory activities of Cuphea aequipetala infusion

Ethnopharmacological relevance

Cuphea aequipetala (Lythraceae) is a medicinal plant highly appreciated in Mexico to treat stomach ailments such as pain and burning sensation, stomach infections, ulcers, diarrhea, dysentery, and different types of tumors and bruises. In this work, the infusion of aerial parts of this plant (CAI) was investigated for its polypharmacological potential.

Materials and methods

In vitro anti-Helicobacter pylori activity was assessed by broth dilution method. Pharmacological studies included acute toxicity in mice using Lorke´s model, anti-inflammatory activity by xylene and TPA induced ear edema assay, as well as gastroprotection with ethanol-induced gastric ulcer model. DPPH and ABTS assays were used to determine antioxidant capacity. Polyphenols and flavonoid contents were determined by Folin–Ciocalteu method and AlCl₃ reaction, respectively.

Results

CAI showed good anti-Helicobacter pylori activity with a MIC of 125 μg/mL. The infusion was not toxic according to Lorke's model with a LD₅₀ greater than 5 g/kg. CAI exhibited low anti-edematogenic action in the models assayed. Oral administration of 300 mg/kg CAI significantly reduced gastric lesions by 87.9%. The effect was reversed only by indomethacin and N-ethylmaleimide demonstrating the role of endogenous prostaglandins and sulfhydryl compounds in gastroprotection. Total phenolic and flavonoid contents of CAI were 109.9 mg GAE/g DW and 28.1 mg QE/g DW, respectively, and the infusion exhibited a good antioxidant activity that is thought to play a role in its biological activity. The analysis of a preliminary fractionation of the infusion indicates that the complete extract conserves all its pharmacological activities in contrast to fractionated extracts.

Conclusions

Cuphea aequipetala is a promising native herb in an integral therapy for the treatment of bacterial or non-bacterial gastric ulcer because it possesses some anti-inflammatory properties, as well as exhibits good gastroprotective and antibacterial effects. It represents an important source for the isolation of anti-Helicobacter pylori compounds. This work provides ethnopharmacological evidence that supports the traditional use of this species.     

Gastroprotective activity of the ethanol extract from the inner bark of Caesalpinia pyramidalis in rats

Ethnopharmacological relevance

Caesalpinia pyramidalis Tul. (Fabaceae), known as “catingueira”, has been used in folk medicine in the treatment of various disorders such as gastritis, heartburn, indigestion, and stomach ache. However, the gastroprotective properties of this species have not yet been studied.

Materials and methods

The ethanol extract of Caesalpinia pyramidalis inner bark was used in rats via oral route, at the doses of 30, 100, and 300 mg/kg. The antiulcer assays were performed using the ethanol- and nonsteroidal anti-inflammatory drug-induced ulcer models. Gastric secretion parameters (volume, pH, and total acidity) were also evaluated by the pylorus ligated model, and the mucus in the gastric content was determined. The anti-Helicobacter pylori activity of the ethanol extract of Caesalpinia pyramidalis was performed using the agar-well diffusion and broth microdilution methods.

Results

The ethanol extract (30, 100, and 300 mg/kg) produced dose dependent inhibition (P<0.01) on the ulcer lesion index, the total lesion area, and the percentage of lesion area in the ethanol-induced ulcer model. The ethanol extract (30, 100, and 300 mg/kg) also reduced (P<0.001) the ulcer index in the indomethacin-induced ulcer model. In the model ligature pylorus, the treatment with Caesalpinia pyramidalis ethanol extract failed to significantly change the gastric secretion parameters. However, after treatment with the ethanol extract of Caesalpinia pyramidalis (30, 100, and 300 mg/kg), there was a significant increase (P<0.05) in mucus production. The ethanol extract showed anti-Helicobacter pylori activity, with inhibition halos of 12.0±1.7 mm at 10,000 μg/mL. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the ethanol extract were of 625 and 10,000 μg/mL, respectively.

Conclusions

Collectively, the present results suggest that the ethanol extract of Caesalpinia pyramidalis displays gastroprotective actions, supporting the folkloric usage of the plant to treat various gastrointestinal disturbances.     

Anti-secretory,anti-inflammatory and anti-Helicobacter pylori activities of several fractions isolated from Piper carpunya Ruiz & Pav.

Ethnopharmacological relevance

The leaves of Piper carpunya Ruiz & Pav. (syn Piper lenticellosum C.D.C.) (Piperaceae), are widely used in folk medicine in tropical and subtropical countries of South America as an anti-inflammatory, anti-ulcer, anti-diarrheal and anti-parasitical remedy as well as an ailment for skin irritations.

Aims of the study

To study the anti-inflammatory, anti-secretory and anti-Helicobacter pylori activities of different fractions isolated from an ethanolic extract of the leaves of Piper carpunya, in order to provide evidence for the use of this plant as an anti-ulcer remedy. Moreover, to isolate the main compounds of the extract and relate their biological activity to the experimental results obtained with the fractions.

Materials and methods

Sixteen fractions were obtained from the ethanolic extract (F I–XVI) and 16 pure compounds were isolated and identified from these fractions. We studied the effects of the fractions (0.1–400 μg/mL) on the release of myeloperoxidase (MPO) enzyme from rat peritoneal leukocytes, on rabbit gastric microsomal H⁺, K⁺-ATPase activity and anti-Helicobacter pylori anti-microbial activity using the microdilution method (MM). The main compounds contained in the fractions were isolated and identified by ¹H- and ¹³C NMR spectra analysis and comparison with the literature data.

Results

Eight fractions showed inhibition of MPO enzyme (F I–IV, X, XII, XIV and XV). The highest inhibition was observed with F XIV (50 μg/mL, 60.9%, p < 0.001). F X and XII were the most active ones, inhibiting the gastric H⁺, K⁺-ATPase activity with IC₅₀ values equal to 22.3 μg/mL and 28.1 μg/mL, respectively. All fractions, except F XV, presented detectable anti-Helicobacter pylori activity, with a diameter of inhibition zones ranging from 11 mm up to 50 mm. The best anti-Helicobacter pylori activity was obtained with F III and V. Both fractions killed Helicobacter pylori with lowest concentration values, about 6.25 μg/mL. Sixteen pure compounds were isolated, five of them are flavonoids that possess strong anti-oxidant and free radical scavenging activity, e.g. vitexin, isovitexin, and rhamnopyranosylvitexin. Terpenoids like sitosterol, stigmasterol and phytol, which have shown gastroprotective activity, and dihydrochalcones, like asebogenin, with anti-bacterial activity, were also isolated. Furthermore, the rare neolignan 1, that is a DNA polymerase β lyase inhibitor, and (6S, 9S)-roseoside, that shows strong anti-bacterial activity, were isolated, for the first time, from the genus Piper.

Conclusions

We suggest that the flavonoids isolated from F I and II (vitexin, isovitexin, rhamnopyranosylvitexin and isoembigenin) contribute to the anti-MPO activity, as well as to their anti-Helicobacter pylori activity. These flavonoids may also be responsible for the important inhibition of H⁺, K⁺-ATPase activity. Also the phytosterols and phytol obtained from F XIV and XV could be involved in these gastroprotective activities. These results encourage us to continue phytochemical studies on these fractions in order to obtain full scientific validation for this species.     

Evaluation of antiulcer activity of chromanone fraction from Calophyllum brasiliesnse Camb

Ethnopharmacological relevance

Calophyllum brasiliense Camb. (Clusiaceae), popularly known as ‘guanandi’, is found in the tropical areas and swampy lands. The latex exuding from its bark is used in the treatment of gastric ulcer in folk medicine. Several active compounds have been isolated from its stem bark among them, are the chromanone acids. Therefore, this study aimed to evaluate antiulcer activity and probable mechanism(s) of action of a fraction containing a mixture of chromanone acids (BI), derived by column chromatography fractionation of the hexane extract of the stem bark of Calophyllum brasiliense (HECb), using experimental in vitro and in vivo models.

Materials and methods

Ulcer was induced by oral administration of ethanol (75%, v/v) and indomethacin (50 mg/kg). Malondialdehyde, reduced glutathione and catalase activity was measured in stomach tissue after ethanol induced ulcer. In order to evaluate the effect of BI on nitric oxide, ulcer was induced by ethanol in l-NAME pretreated animals. Anti-Helicobacter pylori activity was verified in disk diffusion and broth microdilution in vitro assays, using cagA+ and vacA+ Helicobacter pylori strains.

Results

BI prevented the gastric ulceration caused by ethanol and indomethacin treatments. Its gastroprotective mechanism in ethanol-induced ulcer was partly due to reduction of MDA and CAT levels in the gastric tissue. BI did not affect the GSH levels and its gastroprotective effect was not reversed by pretreatment with l-NAME. BI showed anti-Helicobacter pylori in the both assays.

Conclusion

The results indicate that BI is partly responsible for the HECb antiulcer and anti-Helicobacter pylori effects.     

Anti-Helicobacter pylori activity of plants used in Mexican traditional medicine for gastrointestinal disorders

Aim of the study

Helicobacter pylori is the major etiological agent of chronic active gastritis and peptic ulcer disease and is linked to gastric carcinoma. Treatment to eradicate the bacteria failed in many cases, mainly due to antibiotic resistance, hence the necessity of developing better therapeutic regimens. Mexico has an enormous unexplored potential of medicinal plants. This work evaluates the in vitro anti-H. pylori activity of 53 plants used in Mexican traditional medicine for gastrointestinal disorders.

Materials and methods

To test the in vitro antibacterial activity, agar dilution and broth dilution methods were used for aqueous and methanolic extracts, respectively.

Results

Aqueous extracts of Artemisia ludoviciana subsp. mexicana, Cuphea aequipetala, Ludwigia repens,and Mentha × piperita (MIC 125 to <250 μg/ml) as well as methanolic extracts of Persea americana, Annona cherimola, Guaiacum coulteri, and Moussonia deppeana (MIC <7.5 to 15.6 μg/ml) showed the highest inhibitory effect.

Conclusions

The results contribute to understanding the mode of action of the studied medicinal plants and for detecting plants with high anti-Helicobacter pylori activity.     

Anti-nociceptive activity of Pereskia bleo Kunth. (Cactaceae) leaves extracts

Ethnopharmacological relevance

Local communities in Malaysia consume Pereskia bleo Kunth. (Cactaceae) leaves as raw vegetables or as a concoction and drink as a tea to treat diabetes, hypertension, rheumatism, cancer-related diseases, inflammation, gastric pain, ulcers, and for revitalizing the body.

Aim of the study

To evaluate anti-nociceptive activity of the extracts and vitexin, isolated for the first time in this species, in two analgesic models; formalin-induced licking and acetic acid-induced abdominal writhing.

Materials and methods

Three and a half kilos of P. bleo leaves were extracted using Soxhlet apparatus with ethanol for 72 h. The crude ethanol extract was treated with activated charcoal overnight and subjected to a liquid–liquid partition yielding hexane, dichloromethane, ethyl acetate and butanol extracts. All extracts, including the crude ethanol and vitexin isolated from the ethyl acetate partition were tested for peripheral anti-nociceptive activity using formalin test and acetic acid-induced abdominal writhing, besides having their acute toxicity assays performed.

Results

The phytochemical analyses resulted in the isolation of vitexin (1), β-sitosterol glucoside (2) and β-sitosterol (3) isolated from the ethyl acetate, dichloromethane and hexane extracts, respectively. This is the first time vitexin and β-sitosterol glucoside are isolated from this species. The anti-nociceptive activities for all extracts were only moderate. Vitexin, which was isolated from the ethyl acetate extract did not show any activity in all models tested when used alone at the same concentration as it appears in the extract.

Conclusion

This study showed that all the extracts possess moderate anti-nociceptive activity. Vitexin is not the compound responsible for the anti-nociceptive effect in the ethyl acetate extract. Further investigations are needed to identify the compound(s) that might be responsible for the anti-nociceptive activity in this plant.     

In vitro anti-Helicobacter pylori activity of a flavonoid rich extract of Glycyrrhiza glabra and its probable mechanisms of action

Ethnopharmacological relevance

Glycyrrhiza glabra Linn. is regarded useful for peptic ulcer in traditional systems of medicine in India and Helicobacter pylori has been considered as one of the causative factors for peptic ulcer. Aim of the present study is to evaluate the anti-Helicobacter pylori action of GutGard^®, a flavonoid rich extract of Glycyrrhiza glabra and further to elucidate the possible mechanisms of its anti-Helicobacter pylori action.

Materials and methods

Agar dilution and microbroth dilution methods were used to determine the minimum inhibitory concentration of GutGard^® against Helicobacter pylori. Protein synthesis, DNA gyrase, dihydrofolate reductase assays and anti-adhesion assay in human gastric mucosal cell line were performed to understand the mechanisms of anti-Helicobacter pylori activity of GutGard^®.

Results

GutGard^® exhibited anti-Helicobacter pylori activity in both agar dilution and microbroth dilution methods. Glabridin, the major flavonoid present in GutGard^® exhibited superior activity against Helicobacter pylori while glycyrrhizin did not show activity even at 250 μg/ml concentration. In protein synthesis assay, GutGard^® showed a significant time dependent inhibition as witnessed by the reduction in ³⁵S methionine incorporation into Helicobacter pylori ATCC 700392 strain. Additionally, GutGard^® showed a potent inhibitory effect on DNA gyrase and dihydrofolate reductase with IC₅₀ value of 4.40 μg/ml and 3.33 μg/ml respectively. However, the extract did not show significant inhibition on the adhesion of Helicobacter pylori to human gastric mucosal cell line at the tested concentrations.

Conclusion

The present study shows that, GutGard^® acts against Helicobacter pylori possibly by inhibiting protein synthesis, DNA gyrase and dihydrofolate reductase.     

Antimicrobial activity of Artemisia douglasiana and dehydroleucodine against Helicobacter pylori

Ethnopharmacological relevance

The increasing resistance of Helicobacter pylori to antibiotics demands the search for novel compounds from plant based sources. Artemisia douglasiana Besser is widely used in Cuyo region (Argentina) as folk medicine for the treatment of gastric ailments.

Aim of study

Based on our previous studies that Artemisia douglasiana exert cytoprotective actions against ethanol-induced gastric mucosal injury we assayed the anti-Helicobacter pylori effect of the Artemisia douglasiana extract and its active compound, dehydroleucodine.

Materials and methods

The in vitro anti-bacterial activity of Artemisia douglasiana extract and its active compound, dehydroleucodine were determined against one standard strain and six clinical isolates of Helicobacter pylori by using the agar dilution methods.

Results

The results showed that both dehydroleucodine and Artemisia douglasiana extract had activity against the microorganism with MICs between 1–8 and 60–120 mg/L, respectively.

Conclusions

Artemisia douglasiana may be a useful alternative treatment strategy principally in eradication of metronidazole and clarithromycin-resistant strain.     

A bioactivity-guided study on the anti-diarrheal activity of Polygonum chinense Linn

Ethnopharmacological relevance

Polygonum chinense Linn., a folk medicine, has long been used for the treatment of diarrhea and enteritis in southwestern China. However, the components responsible for its anti-diarrheal activity are still poorly understood.

Aim of the study

To determine anti-diarrheal activities of Polygonum chinense L. and to identify its active components through bioactivity-guided isolation technique.

Materials and methods

Animals were orally administered with the extract of Polygonum chinense L. The anti-diarrheal effects of 75% ethanol extract, four fractions with different polarities from 75% ethanol extract, different eluates collected from Diaion HP-20 macroporous resin chromatography, ellagic acid and corilagin, were examined based on mouse models of castor oil- and magnesium sulfate-induced diarrhea.

Results

The results showed that the 75% ethanol extract of Polygonum chinense L. exhibited significant anti-diarrheal activities in a dose-dependent manner in two mouse models. Through in vivo bioactivity-guided fractionation processes, n-butanol and aqueous fractions were found to exhibit prominent anti-diarrheal activities, and two major compounds, ellagic acid and corilagin, from these active fractions were found to possess anti-diarrheal effects.

Conclusion

Present study provides evidence of the utilization of Polygonum chinense L. for diarrhea, and ellagic acid and corilagin are two components contributing to the anti-diarrheal effect.     

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.     

Anti-Helicobacter pylori, gastroprotective,anti-inflammatory,and cytotoxic activities of methanolic extracts of five different populations of Hippocratea celastroides collected in Mexico

Ethnopharmacological relevance

The root barks of Hippocratea celastroides have been used for decades in Mexican traditional medicine to treat gastritis and ulcers. To investigate the anti-Helicobacter pylori, gastroprotective, anti-inflammatory, and cytotoxic activities of methanolic extracts obtained from the leaves, stems, and root bark of Hippocratea celastroides collected in five different localities in Mexico, during the winter of 2009, in order to establish differences in biological activities in terms of plant organs, as well as places of collection.

Materials and methods

Whole individuals were collected in five separate localities in Mexico: La Mancha, Veracruz (VL), Yautepec, Morelos (MY), Jojutla, Morelos (MJ), Temalac, Guerrero (GT), and Landa de Matamoros, Querétaro (QL). Methanolic crude extracts from wild plant specimens were tested using in vivo ethanol-induced mice gastric ulcer model, and 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ear edema in mice assay, and in vitro anti-Helicobacter pylori model, and carcinoma cell line cytotoxic assays.

Results and conclusions

The leaves, stems, and root bark from MY specimens, as well as the leaves and root bark of materials from VL, presented the highest activity against Helicobacter pylori (MIC values ranging from 7.81 to 31.25 μg/ml). Most gastroprotective effects were displayed by the leaves of plants collected in MY, with 89.85±1.91% of protection (300 mg/kg) and an ED₅₀=27 mg/kg, which was corroborated by histological analysis. The root bark extracts from MY achieved the highest edema inhibition values (ED₅₀=0.18 mg/ear), which were comparable to indomethacin (ED₅₀=0.16 mg/ear). Finally, all extracts from MY (three plant parts) were cytotoxic against nasopharyngeal (KB), breast (MCF-7), and colon (HCT-116) carcinoma cell lines with IC₅₀ values between 1.18 and 9.77 μg/ml, except that no activity was detected for root bark extracts against HCT-116 normal fibroblasts. The activities of methanolic extracts from leaves, stems and root bark of plants collected in five different locations varied considerably, representing a notable problem facing the quality control of the plant material from Hippocratea celastroides used for medicinal purposes. The ethnomedical information of this plant in regards to treating gastritis and ulcers was strongly evidenced by the findings of the experimental models employed in this study.     

Red ginseng extract inhibits the expression of MCP-1 and iNOS in Helicobacter pylori-infected gastric epithelial cells by suppressing the activation of NADPH oxidase and Jak2/Stat3

Ethnopharmcological relevance

Helicobacter pylori induced oxidative stress represents an important mechanism leading to expression of inflammatory mediators. Korean red ginseng is used in traditional medicine to inhibit inflammation. However, the anti-inflammatory mechanism of red ginseng is still under investigation. Thus, we investigated whether Korean red ginseng extract (RGE) inhibits NADPH oxidase, a source of reactive oxygen species (ROS), and the Jak2/Stat3 pathway, which mediates the expression of inflammatory mediators, in Helicobacter pylori-infected gastric epithelial cells.

Materials and methods

A standardized RGE was supplied by the Korea Ginseng Corporation. Human gastric epithelial cells (AGS) were treated with RGE and stimulated with Helicobacter pylori. NADPH oxidase activity, ROS levels, activation of Jak2/Stat3, and induction of MCP-1 and iNOS were determined.

Results

Helicobacter pylori infection resulted in an increase in ROS and activation of NADPH oxidase and Jak2/Stat3, which induced the expression of MCP-1 and iNOS in AGS cells. The induction of MCP-1 and iNOS was inhibited by both the Jak2/Stat3 inhibitor AG490 and RGE in Helicobacter pylori-infected cells. RGE suppressed NADPH oxidase activity by inhibiting translocation of cytosolic subunits p67phox and p47phox to the membrane and reduced ROS levels in Helicobacter pylori-infected cells.

Conclusion

RGE inhibits the expression of MCP-1 and iNOS by suppressing the activation of NADPH oxidase and Jak2/Stat3 in Helicobacter pylori-infected gastric epithelial cells.     

Antibacterial and anti-inflammatory activities of extract and fractions from Pyrrosia petiolosa (Christ et Bar.) Ching

Ethnopharmacological relevance

Pyrrosia petiolosa is commonly used as a traditional Chinese medicine for treatment of acute pyelonephritis, chronic bronchitis and bronchial asthma. This study aims to evaluate the antibacterial activity of the ethanol extract and its derived fractions of Pyrrosia petiolosa obtained with solvents of different polarities and to perform the anti-inflammatory screening.

Materials and methods

The powdered aerial parts of Pyrrosia petiolosa were used to extract various fractions with ethanol, petroleum ether, ethyl acetate, N-butanol and aqueous. Qualitative phytochemical screening was performed on the ethanol extract, petroleum ether fraction, ethyl acetate fraction, N-butanol fraction and aqueous fraction. The agar diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were employed to evaluate antibacterial activity of the ethanol extract and fractions. The in vitro cytotoxicity of ethanol extract and fractions was determined using MTT assay. The anti-inflammatory activity was analyzed using the mouse ear swelling induced by xylene.

Results

The phytochemical screening revealed the presence of anthraquinones, flavonoids, terpenoids, steroids, saponins, phenols and reducing sugars in the extract and fractions. Antibacterial results showed that petroleum ether fraction and N-butanol fraction inhibited all the tested microorganisms with the maximum inhibition zone of 15.25±0.35 mm. Ethyl acetate fraction also exhibited good antibacterial activity except Pseudomonas aeruginosa ATCC 27853, while extract and aqueous fraction inhibited 8 out of 13 (61.5%) of the tested microorganisms. The MIC values of ethanol extract and fractions ranged from 1.25 to 10.00 mg/mL and most of the MBC values were equal or twice as high as the corresponding MIC values. The in vitro cytotoxicity showed the ethanol extract and fractions exhibited non-toxic or low toxic activity against lung cancer cell lines A549 and mouse spleen cells. In anti-inflammatory experiment, ethanol extract at 5.0 and 10.0 mg/kg exhibited significant anti-inflammatory activity against the mouse ear swelling induced by xylene and the maximum inhibition rate reached as high as 67%.

Conclusions

Pyrrosia petiolosa could be a potential candidate for future development of a novel antibacterial and anti-inflammatory agent.