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.     

Water extract of Cinnamomum cassia Blume inhibited human respiratory syncytial virus by preventing viral attachment,internalization, and syncytium formation

Ethnopharmacological relevance

Cinnamomum cassia Blume is a popular traditional Chinese herbal medicine that has been used to manage respiratory tract disease, including common cold and chronic bronchitis for thousand years. Human respiratory syncytial virus (HRSV) is one of the leading causes of severe lower respiratory tract illness worldwide. No effective therapeutic modality against HRSV infection has been proved. It is unknown whether Cinnamomum cassia is effective against HRSV.

Aim of the study

This study tested the hypothesis that Cinnamomum cassia can effectively decrease HRSV-induced plaque formation and syncytium formation in respiratory mucosal cell lines.

Materials and methods

Antiviral activity of the hot water extract of Cinnamomum cassia against HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Its ability to inhibit the synthesis of viral fusion (F) protein was examined by Western blot assay.

Results

Cinnamomum cassia dose-dependently inhibited HRSV-induced plaque formation in both HEp-2 and A549 cell lines (p<0.0001). Cinnamomum cassia was more effective when given before viral infection (p<0.0001) mainly by inhibition of viral attachment (p<0.0001) and internalization (p<0.0001). Cinnamomum cassia could inhibit F protein production and syncytium formation to interfere with HRSV spreading.

Conclusions

Cinnamomum cassia prevented airway epithelia from HRSV infection through inhibiting viral attachment, internalization and syncytium formation. Cinnamomum cassia could be a candidate to develop therapeutic modalities to manage HRSV infection in the future.     

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.     

Anti-Helicobacter pylori compounds from the ethanol extracts of Geranium wilfordii

Ethnopharmocological relevance

Geranium wilfordii Maxim has been extensively used in Chinese Herbal Medicine for treating gastrointestinal disorders, diarrhea and dysentery. In the current study we aimed to investigate the anti-Helicobacter pylori activity of ethanol extracts of Geranium wilfordii Maxim and its main active compounds, corilagin and 1,2,3,6-tetra-O-galloyl-β-d-glucose.

Materials and methods

The plant materials were extracted three times with ethanol and the concentrated filtrate was successively fractioned into chloroform, ethyl acetate, and n-BuOH-soluble portions which were examined in vitro for the anti-Helicobacter. pylori activity. Employing a standard strain and five clinical isolates of Helicobacter pylori, the extract, fractions and compounds of Geranium wilfordii Maxim were assessed in vitro.

Results

The ethanol fraction, ethyl acetate fraction, corilagin, and 1,2,3,6-tetra-O-galloyl-β-d-glucose were found to be strongly inhibitory to Helicobacter. pylori (MICs: 40, 30, 4, and 8 μg/ml respectively).

Conclusions

The results of the present study showed that the ethanol and the ethyl acetate extracts from Geranium wilfordii Maxim displayed as well the most significant inhibition to the growth of Helicobacter. pylori, of which corilagin and 1,2,3,6-tetra-O-galloyl-β-d-glucose have been identified main anti-Helicobacter pylori active constituents.     

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

Ethnopharmacological relevance

Mangaba (Hancornia speciosa Gomez) is a medicinal plant frequently cited in ethnopharmacological inventories of the central region of Brazil against gastrointestinal disorders such as diarrhoea, ulcer, gastritis and stomachache.

Aim of the study

The hydroalcoholic extract (HE) and infusion (BI) of Hancornia speciosa bark were investigated for their ability to prevent and heal rodent gastric ulcer.

Materials and methods

The preventive and healing action of both preparations of Hancornia speciosa were evaluated in experimental models in rodents that simulated this disease in human gastric mucosa.

Results

BI did not exert gastroprotective effect, in contrast to HE (500 mg/kg, p.o.) that decreased (p < 0.05) the severity of gastric damage induced by HCl/ethanol (52%), indomethacin/bethanechol (51%), stress (52%) or pylorus ligature experiments (54%). HE increased (p < 0.05) the pH and decreased acid output of gastric juice. This extract promoted increase of mucus amount (3.62 mg/wt. tissue vs. 5.81 mg/wt. tissue), healing action (67%) and displayed anti-Helicobacter pylori effect.

Conclusions

The antiulcer action of Hancornia speciosa resulted in increase of gastric mucus formation and antioxidant properties of polymeric proanthocyanidins present in the bark composition of this medicinal plant.     

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.     

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.     

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.     

An ethnopharmacological survey and in vitro confirmation of ethnopharmacological use of medicinal plants used for wound healing in Bosomtwi-Atwima-Kwanwoma area,Ghana

Aims of the study

Wounds represent a major health burden and drain on healthcare resources in the world including Ghana and Africa. The majority of the people of Ghana and Africa still patronize traditional medicine for their health needs including various forms of wounds. The aim of this study is the identification of medicinal plants, type of wounds, dosage forms and collection methods used traditionally in treating wounds in the Bosomtwi-Atwima-Kwanwoma district, Ghana. In vitro screening of selected extracts from these plants on cell physiology of human dermal fibroblasts and keratinocytes was to be performed.

Materials and methods

Validated questionnaires were administered to 78 traditional healers in 54 communities of the district. Interviews and structured conversations were used to administer the questionnaires. Selected herbal material dominantly used by the healers was collected, identified and aqueous and ethanolic extracts were investigated in vitro on influence on cell physiology of keratinocytes and dermal fibroblasts (MTT-, BrdU-, LDH-assay). Antioxidant activities of ethanolic extracts were determined by free radical scavenging activity. Antiadhesive activity against Helicobacter pylori on human stomach cells was investigated for extracts reported to be used for stomach ulcer treatment.

Results

The ethnopharmacological survey revealed 104 plants species belonging to 47 families. The detailed use of these plants is documented. Aqueous extracts of Phyllanthus muellerianus, Pycnanthus angolensis and Combretum smeathmanni influenced the mitochondrial activity and proliferation of dermal fibroblasts and keratinocytes significantly. Ethanolic extracts of selected plants exhibited strong antioxidant activities comparable to α-tocopherol. For Spathodea campanulata, Hoslundia opposita and Pycnanthus angolensis, which were reported by the healers to be used also for wound healing in case of stomach ulcers, strong antiadhesive activity against Helicobacter pylori was demonstrated, while the extracts did not exhibit any direct cytotoxicity against the bacterium.

Conclusions

Traditional use of many wound-healing plants from Ghana can be well rationalized by the in vitro investigation of aqueous extracts. E.g. extracts of Phyllanthus muellerianus, Pycnanthus angolensis and Combretum smeathmanni exhibited significant influence on the cell viability and proliferation of keratinocytes and dermal fibroblasts.     

Ethnobotanical survey and antibacterial activity of plants used in the Altiplane region of Mexico for the treatment of oral cavity infections

Ethnopharmacological relevance

The ethnobotanical survey conducted in this study showed 47 plant species used in the Altiplane region of Mexico for the treatment of dental diseases such as toothache, dental caries, periodontal disease and gingivitis.

Materials and methods

Information was collected by performing interviews. The following data were recorded: name of the patients or herbalists with their age, sex; date and place of gathering information; pathology of persons interviewed; name of the drug (vernacular name); parts used (leaves, bark, fruits, seeds, aerial parts), mode of preparation and administration, and possible combinations.The inhibitory effects of the aqueous and ethanolic extracts of the medicinal plants detected during the survey the on the growth of Streptococcus mutans and Phrophyromonas gingivalis were determined using microdilution method. The minimum bactericidal concentrations (MBC) were determined from the wells of microplate with no visible bacterial growth.

Results

In total, tree places of the Altiplane region of Mexico were visited and five healers and 100 patients were questioned. 47 wild and cultivated species were recorded. The most frequent uses were to treat tooth pain, gum diseases, bad breath and cavities. Infusions were the most frequently prepared formulation. Other applied preparations mentioned with decreasing frequency were decocts, syrups, tinctures, direct application of the plant material without prior preparation and finally macerations.The ethanolic extracts of Haematoxylon brasiletto, Punica granatum, Iostephane heterophyla, Bursera simaruba, Cedrela odorata and Rhus standleyi (12.5–65.0 μg/mL) as well as water extracts of Haematoxylon brasiletto, Punica granatum, Iostephane heterophyla, Amphipterygium adstringens, Argemone mexicana, Cedrela odorata, Eysenhardtia polystachya, Persea americana, Syzygium aromaticum, Cinnamomun zeylanicum, Cnidoscolus multilobus and Rhus standleyi (10.5–78.0 μg/mL) showed the highest inhibitory effect against Streptococcus mutans and Porphyromonas gingivalis.

Conclusions

Many plants are used in the Mexican traditional medicine to treat oral bacterial diseases by the healers or patients. Our study demonstrated that most of the medicinal plants showed an antibacterial effect in vitro, and justified at least in part their use in traditional medicine. These results encourage further investigations to extract and identify the active chemical compounds responsible for the antibacterial effect observed.     

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.     

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.     

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.     

Antimalarial activities of medicinal plants traditionally used in the villages of Dharmapuri regions of South India

Ethnopharmacological relevance

An ethnopharmacological investigation of medicinal plants traditionally used to treat diseases associated with fevers in Dharmapuri region of South India was undertaken. Twenty four plants were identified and evaluated for their in vitro activity against Plasmodium falciparum and assessed for cytotoxicity against HeLa cell line.

Aim of the study

This antimalarial in vitro study was planned to correlate and validate the traditional usage of medicinal plants against malaria.

Materials and methods

An ethnobotanical survey was made in Dharmapuri region, Tamil Nadu, India to identify plants used in traditional medicine against fevers. Selected plants were extracted with ethyl acetate and methanol and evaluated for antimalarial activity against erythrocytic stages of chloroquine (CQ)-sensitive 3D7 and CQ-resistant INDO strains of Plasmodium falciparum in culture using the fluorescence-based SYBR Green I assay. Cytotoxicity was determined against HeLa cells using MTT assay.

Results

Promising antiplasmodial activity was found in Aegle marmelos [leaf methanol extract (ME) (IC₅₀ = 7 μg/mL] and good activities were found in Lantana camara [leaf ethyl acetate extract (EAE) IC₅₀ = 19 μg/mL], Leucas aspera (flower EAE IC₅₀ = 12.5 μg/mL), Momordica charantia (leaf EAE IC₅₀ = 17.5 μg/mL), Phyllanthus amarus (leaf ME IC₅₀ = 15 μg/mL) and Piper nigrum (seed EAE IC₅₀ = 12.5 μg/mL). The leaf ME of Aegle marmelos which showed the highest activity against Plasmodium falciparum elicited low cytotoxicity (therapeutic index > 13).

Conclusion

These results provide validation for the traditional usage of some medicinal plants against malaria in Dharmapuri region, Tamil Nadu, India.     

Effect on blood pressure of a dietary supplement containing traditional medicinal plants of Côte d'Ivoire

Ethnopharmacological relevance

A medicinal composition containing salt (sodium chloride) is given as a traditional dietary supplement to hypertensive patients (TDSHP) in Côte d’Ivoire. It consists of whole plant of Bidens pilosa (Asteraceae) and fresh leaves of Moringa oleifera (Moringaceae).

Aim of the study

The aim of this study was to establish the scientific basis for the use of this traditional recipe rich in sodium chloride in hypertension settings.

Materials and methods

We used a total aqueous extract of this traditional dietary supplement containing medicinal plants (Bidens pilosa, Moringa oleifera) and salt (sodium chloride). Experiment was carried out to evaluate its effect on arterial blood pressure of rabbits. The experimental device used for recording blood pressure in rabbits is based on the principle of Ludwig mercury manometer.

Results

TDSHP between 5 × 10⁻⁸ and 5 × 10⁻² mg/kg caused a dose-dependent hypotension. TDSHP elicited drops in blood pressure ranging between 7.14 ± 4 and 100 ± 7.5%, compared to normal blood pressure of rabbits. Fifty percent effective dose of TDSHP was 3.95 × 10⁻⁴ mg/kg. Similarly as the hypotension induced by acetylcholine, the one caused by TDSHP at dose of 3.95 × 10⁻⁴ mg/kg in rabbit was progressively inhibited by atropine, dosed between 5 × 10⁻⁴ to 5 × 10⁻² mg/kg. The percentage drop of recorded blood pressure ranged from 50.3 ± 1.87 to 3.71 ± 1.09% compared to the normal value of blood pressure. In the presence of atropine, TDSHP effect was partially inhibited. The same increasing doses of TDSHP reduced significantly the increase of blood pressure induced by adrenaline dosed at 4.76 × 10⁻⁴ mg/kg from 89.3 ± 2.19 to 1.19 ± 0.59%.

Conclusion

The consumption of this traditional dietary supplement is justified in hypertensive patients according to its composition and its ability to reduce blood pressure has been demonstrated experimentally. TDSHP should not be considered as an antihypertensive drug, it remains to us a salt substitute to be taken with moderation with strict adherence to the traditional dose.     

Aqueous extracts and polysaccharides from Liquorice roots (Glycyrrhiza glabra L.) inhibit adhesion of Helicobacter pylori to human gastric mucosa

Aims

Aqueous extracts from the roots of Glycyrrhiza glabra L. (Fabaceae) are widely used for treatment of stomach ulcer. The clinical proven effects are related to the presence of anti-inflammatory 12-keto-triterpensaponins in the extracts. Apart from that the influence of Glycyrrhiza glabra extract on the bacterial adhesion of Helicobacter pylori to stomach tissue was to be investigated. Additionally the influence of Glycyrrhiza glabra secondary compounds on the bacterial adhesion of Porphyromonas gingivalis, a major pathogen for induction of periodontal inflammations was to be investigated.

Methodology

In vitro cytotoxicity against Helicobacter pylori was investigated by agar diffusion assay; antiadhesive properties of aqueous extract, raw polysaccharides and purified polysaccharide fractions was investigated by means of an in situ adhesion assay with FITC-labelled bacteria on tissue slides of human stomach resectates.

Results

Aqueous extract (1 mg/mL) of Glycyrrhiza glabra significantly inhibited the adhesion of Helicobacter pylori to human stomach tissue. This effect was related to the polysaccharides isolated from the extract, with one purified acidic fraction (0.25 SPB) as main active polymer. Purified polysaccharides did not exhibit direct cytotoxic effects against Helicobacter pylori and did not influence hemagglutination. Additionally raw polysaccharides from Glycyrrhiza glabra were shown to have strong antiadhesive effects against Porphyromonas gingivalis.

Conclusion

Aqueous extracts and polysaccharides from the roots of Glycyrrhiza glabra are strong antiadhesive systems, which may be used as potent tools for a further development of cytoprotective preparations with anti-infectious potential.     

A topoisomerase II poison screen of ethnomedicinal Thai plants using a yeast cell-based assay

Ethnopharmacological relevance

The plants used in this study had previously been identified and used by Thai folk practitioners, who had knowledge of Thai traditional medicine, as alternative treatments for cancer. Investigation into the mechanism of the Topoisomerase II (Top2) poison of these plants may give rise to new drug leads for cancer treatment.

Aim of the study

This study aimed to screen ethnomedicinal plants used in Thai traditional medicine for Top2 poison activity using a yeast cell-based assay and also to validate the traditional uses of these plants by examining the Top2 poison activity.

Materials and methods

Thirty Thai medicinal plants were harvested and identified. Plant methanol extracts were prepared and screened in vitro using a yeast cell-based assay. Mutant yeast strains carrying the top2-1 allele, which encodes a temperature-sensitive topoisomerase, were used to establish the yeast spot test. Strains carrying this mutation grow normally at 25 °C and generally have a wild-type drug sensitivity. These yeast strains are able to grow at 30 °C, but the Top2 activity is greatly reduced at this temperature, which causes the strains to be highly drug resistant to anti-Top2 agents. Cell growth was measured by colony survival after exposure to various concentrations of extracts at different temperatures.

Results

The extracts of six out of thirty ethnomedicinal plants, Curcuma longa, C. zedoaria, Derris scandens, Grangea maderaspatana, Stephania pierrei and S. suberosa, were found to have Top2 poison activity against the yeast cells.

Conclusions

The yeast screening system confirmed the proposed anti-cancer mechanisms of plants used in Thai traditional medicine by traditional doctors.     

The effects of Rhizoma drynariae on interleukin-2 and T-lymphocyte levels in rats after severe head injury

Objective

To investigate the effects of Rhizoma drynariae on the levels of interleukin-2(IL-2) and T-lymphocyte subset in rats with severe head injury (SHI).

Methods

72 Sprague Dawley (SD) rats were randomly divided into 3 groups: control group, model group, and R. drynariae group. The experimental group received intragastrical infusions of with aqueous R. drynariae extract four hours after SHI while the other groups were administered with equivalent volumes of physiological saline. Infusions were administered to the 3 groups once a day for 7 d. IL-2 and T-lymphocyte (CD3, CD4, CD8) levels were measured at 24, 72, and 168 h after initial infusion.

Results

The levels of IL-2 and CD4 T cells reduced obviously after 24 h in the model group (P<0.05), but recovered to the levels of the control group after 72 h, and remained elevated after 168 h. In the R. drynariae group, IL-2 and CD4 levels were did not decrease while the level of CD8 T cells was reduced significantly (P<0.05).

Conclusions

R. drynariae can protect against immune dysfunction or improve immunity in rats with severe head injury (SHI).     

Biofilm inhibition by Cymbopogon citratus and Syzygium aromaticum essential oils in the strains of Candida albicans

Ethnopharmacological relevance

Oils of Cymbopogon citratus and Syzygium aromaticum have been used in traditional medicine to treat fungal infections of skin, mouth, urinary and vaginal tract in Asian countries particularly India and other developing countries.

Aim of the study

To evaluate essential oils of Cymbopogon citratus and Syzygium aromaticum for their anti-biofilm activity against strong biofilm forming strains of Candida albicans.

Materials and methods

XTT reduction assay, Time kill assays, light microscopy and scanning electron microscopy (SEM) were employed to determine the effect of test oils on the Candida albicans biofilms.

Results

Most of the Candida albicans strains tested displayed formation of moderate to strong biofilms. Preformed Candida biofilms showed ≥1024 times increased resistance to antifungal drugs, 2 times to Syzygium aromaticum, but no increased tolerance for Cymbopogon citratus. Test oils were more active against preformed biofilms compared to amphotericin B and fluconazole. At 0.5× MIC, Cymbopogon citratus followed by Syzygium aromaticum were most inhibitory against biofilm formation. Light and electron microscopic studies revealed the deformity of three dimensional structures of biofilms formed in the presence of sub-MICs of Cymbopogon citratus. The cell membranes appeared to be the target site of compounds in sessile cells as displayed by SEM observations.

Conclusion

Our data had demonstrated promising in vitro anti-biofilm activity by Cymbopogon citratus and Syzygium aromaticum and confirm the ethnopharmacological use of these oils in muco-cutaneous Candida infections. Furthermore, it suggests exploitation of these oils as new anti-biofilm products to deal with the problem of drug-resistance and recurrent infection associated with biofilm mode of growth of Candida spp.     

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.