Antimicrobial Effect of a Proteolytic Enzyme From the Fruits of Solanum granuloso-leprosum (Dunal) Against Helicobacter pylori

Helicobacter pylori is a gram-negative, helix-shaped, and microaerophilic bacteria that colonizes the human gastric mucosa, causing chronic infections, gastritis, peptic ulcer, lymphomas associated with lymphoid mucosa tissue, and gastric cancer. H. pylori is considered a Type 1 human carcinogen by WHO. The prevalence of the infection is estimated in more than half of the world population. Treatment of H. pylori infection includes antibiotics and proton pump inhibitors, but the increasing antibiotic resistance promotes the research of novel, more effective, and natural antibacterial compounds. The aim of this work was to study the effect of the partially purified proteolytic extract (RAP) of the fruits from Solanum granuloso-leprosum (Dunal), a South American native plant, and a purified fraction named granulosain I, against H. pylori, to obtain natural food additives for the production of anti-H. pylori functional foods. Furthermore, granulosain I and RAP could be used as natural adjuncts to conventional therapies. Granulosain I and RAP antibacterial activity was evaluated as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against H. pylori NCTC 11638 (reference strain) and twelve H. pylori wild strains, using a microdilution plating technique (Clinical and Laboratory Standards Institute). All the strains tested were susceptible to granulosain I with MIC from 156.25 to 312.5 μg/mL and MBC from 312.5 to 625 μg/mL, respectively. Besides, all the strains tested were susceptible to the RAP with MIC from 312.5 to 625 μg/mL and MBC from 625 to 1,250 μg/mL, respectively. The effect of granulosain I and RAP on the transcription of H. pylori genes encoding pathogenic factors, omp18, ureA, and flaA, with respect to a housekeeping gene (16S rRNA), was evaluated by RT-PCR technique. The band intensity between pathogenic factors and control gene was correlated under treated or untreated conditions, using the ImageJ program. Granulosain I and RAP significantly decreased the expression of pathogenic factors: omp18, ureA, and flaA. The combined inhibitory effect of granulosain I or RAP and an antibiotic such as, amoxicillin (AML, 10 μg), clarithromycin (CLA, 15 μg), levofloxacin (LEV, 5 μg), and metronidazole (MTZ, 5 μg) was evaluated, using the agar diffusion technique. Granulosain I and RAP showed significant synergistic effect on AML, CLA, and LEV, but no significant effect on MTZ was observed. Besides, granulosain I and RAP did not show toxicological effects at the concentrations studied. Finally, granulosain I and RAP could be used as safe natural food additives and as adjuvants for conventional therapies against H. pylori.

Download Full-text

Synthesis and In Vitro Enzymatic Studies of New 3-Aryldiazenyl Indoles as Promising Helicobacter pylori IMPDH Inhibitors

Current Topics in Medicinal Chemistry ◽

10.2174/1568026619666190227212334 ◽

2019 ◽

Vol 19 (5) ◽

pp. 376-382 ◽

Cited By ~ 4

Author(s):

Sachin Jangra ◽

Gayathri Purushothaman ◽

Kapil Juvale ◽

Srimadhavi Ravi ◽

Aishwarya Menon ◽

...

Keyword(s):

Helicobacter Pylori ◽

Bacterial Infections ◽

Immunosuppressive Drugs ◽

Multi Drug Resistance ◽

Metabolic Enzyme ◽

World Population ◽

Inhibitor Molecule ◽

Nucleotide Synthesis ◽

H Pylori

Background & Objective:Helicobacter pylori infection is one of the primary causes of peptic ulcer followed by gastric cancer in the world population. Due to increased occurrences of multi-drug resistance to the currently available antibiotics, there is an urgent need for a new class of drugs against H. pylori. Inosine 5′-monophosphate dehydrogenase (IMPDH), a metabolic enzyme plays a significant role in cell proliferation and cell growth. It catalyses guanine nucleotide synthesis. IMPDH enzyme has been exploited as a target for antiviral, anticancer and immunosuppressive drugs. Recently, bacterial IMPDH has been studied as a potential target for treating bacterial infections. Differences in the structural and kinetic parameters of the eukaryotic and prokaryotic IMPDH make it possible to target bacterial enzyme selectively.Methods:In the current work, we have synthesised and studied the effect of substituted 3-aryldiazenyl indoles on Helicobacter pylori IMPDH (HpIMPDH) activity. The synthesised molecules were examined for their inhibitory potential against recombinant HpIMPDH.Results:In this study, compounds 1 and 2 were found to be the most potent inhibitors amongst the database with IC50 of 0.8 ± 0.02µM and 1 ± 0.03 µM, respectively.Conclusion:When compared to the most potent known HpIMPDH inhibitor molecule C91, 1 was only four-fold less potent and can be a good lead for further development of selective and potent inhibitors of HpIMPDH.

Download Full-text

Helicobacter pylori (H. pylori) infection increases IL-8 and IL-6 production from human gastric mucosa

Gastroenterology ◽

10.1016/0016-5085(95)27387-5 ◽

1995 ◽

Vol 108 (4) ◽

pp. A769

Author(s):

T. Ando ◽

K. Kusugami ◽

M. Sakakibara ◽

T. Shimizu ◽

M. Shinoda ◽

...

Keyword(s):

Helicobacter Pylori ◽

Gastric Mucosa ◽

Human Gastric Mucosa ◽

H Pylori

Download Full-text

Small Molecule Inhibitors of the Response Regulator ArsR Exhibit Bactericidal Activity against Helicobacter pylori

Microorganisms ◽

10.3390/microorganisms8040503 ◽

2020 ◽

Vol 8 (4) ◽

pp. 503 ◽

Cited By ~ 3

Author(s):

Andrés González ◽

Javier Casado ◽

Eduardo Chueca ◽

Sandra Salillas ◽

Adrián Velázquez-Campoy ◽

...

Keyword(s):

Helicobacter Pylori ◽

Antibiotic Resistance ◽

High Throughput Screening ◽

Lithocholic Acid ◽

Response Regulator ◽

Bacterial Pathogen ◽

Antimicrobial Effect ◽

Chemical Library ◽

Secondary Bile Acid ◽

H Pylori

Helicobacter pylori is considered the most prevalent bacterial pathogen in humans. The increasing antibiotic resistance evolved by this microorganism has raised alarm bells worldwide due to the significant reduction in the eradication rates of traditional standard therapies. A major challenge in this antibiotic resistance crisis is the identification of novel microbial targets whose inhibitors can overcome the currently circulating resistome. In the present study, we have validated the use of the essential response regulator ArsR as a novel and promising therapeutic target against H. pylori infections. A high-throughput screening of a repurposing chemical library using a fluorescence-based thermal shift assay identified several ArsR binders. At least four of these low-molecular weight compounds noticeably inhibited the DNA binding activity of ArsR and showed bactericidal effects against antibiotic-resistant strains of H. pylori. Among the ArsR inhibitors, a human secondary bile acid, lithocholic acid, quickly destroyed H. pylori cells and exhibited partial synergistic action in combination with clarithromycin or levofloxacin, while the antimicrobial effect of this compound against representative members of the normal human microbiota such as Escherichia coli and Staphylococcus epidermidis appeared irrelevant. Our results enhance the battery of novel therapeutic tools against refractory infections caused by multidrug-resistant H. pylori strains.

Download Full-text

Therapeutic Vaccination against Helicobacter pylori in the Beagle Dog Experimental Model: Safety, Immunogenicity, and Efficacy

Infection and Immunity ◽

10.1128/iai.72.6.3252-3259.2004 ◽

2004 ◽

Vol 72 (6) ◽

pp. 3252-3259 ◽

Cited By ~ 65

Author(s):

Giacomo Rossi ◽

Paolo Ruggiero ◽

Samuele Peppoloni ◽

Laura Pancotto ◽

Damiano Fortuna ◽

...

Keyword(s):

Helicobacter Pylori ◽

Bacterial Colonization ◽

Human Infection ◽

Human Gastric Mucosa ◽

Therapeutic Vaccination ◽

Beagle Dogs ◽

Beagle Dog ◽

Vaccine Approach ◽

H Pylori ◽

Different Doses

ABSTRACT Helicobacter pylori is a gram-negative bacterium that colonizes the human gastric mucosa causing gastritis and peptic ulcer and increasing the risk of gastric cancer. The efficacy of current antibiotic-based therapies can be limited by problems of patient compliance and increasing antibiotic resistance; the vaccine approach can overcome these limits. The present study describes the therapeutic vaccination of experimentally H. pylori-infected beagle dogs, an animal model that reproduces several aspects of the human infection with H. pylori. The vaccine consisted of three recombinant H. pylori antigens, CagA, VacA, and NAP, formulated at different doses (10, 25, or 50 μg each) with alum and administered intramuscularly either weekly or monthly. No adverse effects were observed after vaccination and a good immunoglobulin G response was generated against each of the three antigens. Bacterial colonization and gastritis were decreased after the completion of the vaccination cycle, especially in the case of the monthly immunization schedule. In conclusion, therapeutic vaccination in the beagle dog model was safe and immunogenic and was able to limit H. pylori colonization and the related gastric pathology.

Download Full-text

Helicobacter pylori is killed by nitrite under acidic conditions

Gut ◽

10.1136/gut.42.3.334 ◽

1998 ◽

Vol 42 (3) ◽

pp. 334-337 ◽

Cited By ~ 96

Author(s):

R S Dykhuizen ◽

A Fraser ◽

H McKenzie ◽

M Golden ◽

C Leifert ◽

...

Keyword(s):

Helicobacter Pylori ◽

Anaerobic Bacteria ◽

Antimicrobial Effect ◽

Human Stomach ◽

Bacterial Survival ◽

Novel Host ◽

Potassium Nitrite ◽

Acidic Conditions ◽

H Pylori ◽

Facultative Anaerobic Bacteria

Background—Due to the expression of urease,Helicobacter pylori is able to establish itself in the human stomach under acidic conditions. A novel host defence mechanism was recently proposed, suggesting that the formation of salivary nitrite in symbiosis with facultative anaerobic bacteria in the oropharynx, is aimed at enhancing the antimicrobial activity of gastric juice.Aims—To investigate whether the addition of nitrite in physiological concentrations influences the resistance ofH pylori to acid.Methods—H pylori cultured from fresh gastric biopsy specimens was exposed for 30 minutes to normal saline and to HCl/KCl buffer (0.2M) at pH 2 with urea (5 mM) added. The influence of potassium nitrite (50–1000 μmol/l) on bacterial survival was determined.Results—Addition of nitrite (1 mM) to acidic solutions (pH 2) resulted in complete kill of H pyloriwithin 30 minutes exposure time whereas acid alone allowed the organism to survive (p<0.001). The antimicrobial effect of nitrite at pH 2 against H pylori was dose dependent and complete kill of organisms occurred at concentrations ⩾500 μmol/l.Conclusion—Acidified nitrite has antibacterial activity against H pylori. This should prompt further research into the effect of salivary nitrite on the survival of H pylori in the human stomach.

Download Full-text

Helicobacter pylori–binding nonacid glycosphingolipids in the human stomach

Journal of Biological Chemistry ◽

10.1074/jbc.ra118.004854 ◽

2018 ◽

Vol 293 (44) ◽

pp. 17248-17266 ◽

Cited By ~ 6

Author(s):

Chunsheng Jin ◽

Angela Barone ◽

Thomas Borén ◽

Susann Teneberg

Keyword(s):

Helicobacter Pylori ◽

Gastric Mucosa ◽

Structural Complexity ◽

Human Stomach ◽

Carbohydrate Binding ◽

Human Gastric Mucosa ◽

H Pylori ◽

Contrast Information

Helicobacter pylori has a number of well-characterized carbohydrate-binding adhesins (BabA, SabA, and LabA) that promote adhesion to the gastric mucosa. In contrast, information on the glycoconjugates present in the human stomach remains unavailable. Here, we used MS and binding of carbohydrate-recognizing ligands to characterize the glycosphingolipids of three human stomachs from individuals with different blood group phenotypes (O(Rh−)P, A(Rh+)P, and A(Rh+)p), focusing on compounds recognized by H. pylori. We observed a high degree of structural complexity, and the composition of glycosphingolipids differed among individuals with different blood groups. The type 2 chain was the dominating core chain of the complex glycosphingolipids in the human stomach, in contrast to the complex glycosphingolipids in the human small intestine, which have mainly a type 1 core. H. pylori did not bind to the O(Rh−)P stomach glycosphingolipids, whose major complex glycosphingolipids were neolactotetraosylceramide, the Lex, Lea, and H type 2 pentaosylceramides, and the Ley hexaosylceramide. Several H. pylori-binding compounds were present among the A(Rh+)P and A(Rh+)p stomach glycosphingolipids. Ligands for BabA-mediated binding of H. pylori were the Leb hexaosylceramide, the H type 1 pentaosylceramide, and the A type 1/ALeb heptaosylceramide. Additional H. pylori-binding glycosphingolipids recognized by BabA-deficient strains were lactosylceramide, lactotetraosylceramide, the x2 pentaosylceramide, and neolactohexaosylceramide. Our characterization of human gastric receptors required for H. pylori adhesion provides a basis for the development of specific compounds that inhibit the binding of this bacterium to the human gastric mucosa.

Download Full-text

PREVALENCE OF HELICOBACTER PYLORI TEN YEARS AGO COMPARED TO THE CURRENT PREVALENCE IN PATIENTS UNDERGOING UPPER ENDOSCOPY

ABCD Arquivos Brasileiros de Cirurgia Digestiva (São Paulo) ◽

10.1590/0102-6720201600030006 ◽

2016 ◽

Vol 29 (3) ◽

pp. 151-154 ◽

Cited By ~ 6

Author(s):

Sandra FRUGIS ◽

Nicolau Gregori CZECZKO ◽

Osvaldo MALAFAIA ◽

Artur Adolfo PARADA ◽

Paula Bechara POLETTI ◽

...

Keyword(s):

Helicobacter Pylori ◽

Cross Sectional Study ◽

World Population ◽

Upper Endoscopy ◽

Sectional Study ◽

Cross Sectional ◽

Current Prevalence ◽

Number Of Patients ◽

Two Samples ◽

H Pylori

ABSTRACT Background: Helicobacter pylori has been extensively studied since 1982 it is estimated that 50% of the world population is affected. The literature lacks studies that show the change of its prevalence in the same population over time. Aim: To compare the prevalence of H. pylori in 10 years interval in a population that was submitted to upper endoscopy in the same endoscopy service. Method: Observational, retrospective and cross-sectional study comparing the prevalence of H. pylori in two samples with 10 years apart (2004 and 2014) who underwent endoscopy with biopsy and urease. Patients were studied in three consecutive months of 2004, compared to three consecutive months of 2014. The total number of patients was 2536, and 1406 in 2004 and 1130 in 2014. Results: There were positive for H. pylori in 17 % of the sample as a whole. There was a significant decrease in the prevalence from 19.3% in 2004 to 14.1% in 2014 (p<0.005). Conclusion: There was a 5.2% reduction in the prevalence of H. pylori comparing two periods of three consecutive months with 10 years apart in two equivalent population samples.

Download Full-text

RESISTANCE TO AMOXICILLIN, CLARITHROMYCIN AND CIPROFLOXACIN OF Helicobacter pylori ISOLATED FROM SOUTHERN BRAZIL PATIENTS

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652014000300003 ◽

2014 ◽

Vol 56 (3) ◽

pp. 197-200 ◽

Cited By ~ 16

Author(s):

Simone Ulrich Picoli ◽

Luiz Edmundo Mazzoleni ◽

Heriberto Fernández ◽

Laura Renata De Bona ◽

Erli Neuhauss ◽

...

Keyword(s):

Helicobacter Pylori ◽

Eradication Therapy ◽

Empirical Therapy ◽

British Society ◽

World Population ◽

Southern Brazil ◽

First Line ◽

The World ◽

Antibiotics Susceptibility ◽

H Pylori

Introduction: Helicobacter pylori is a bacteria which infects half the world population and is an important cause of gastric cancer. The eradication therapy is not always effective because resistance to antimicrobials may occur. The aim of this study was to determine the susceptibility profile of H. pylori to amoxicillin, clarithromycin and ciprofloxacin in the population of Southern Brazil. Material and methods: Fifty four samples of H. pylori were evaluated. The antibiotics susceptibility was determined according to the guidelines of the British Society for Antimicrobial Chemotherapy and the Comité de l'Antibiogramme de la Société Française de Microbiologie. Results: Six (11.1%) H. pylori isolates were resistant to clarithromycin, one (1.9%) to amoxicillin and three (5.5%) to ciprofloxacin. These indices of resistance are considered satisfactory and show that all of these antibiotics can be used in the empirical therapy. Conclusion: The antibiotics amoxicillin and clarithromycin are still a good option for first line anti-H. pylori treatment in the population of Southern Brazil.

Download Full-text

The Action of Bismuth against Helicobacter pylori Mimics but Is Not Caused by Intracellular Iron Deprivation

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.6.1983-1988.2004 ◽

2004 ◽

Vol 48 (6) ◽

pp. 1983-1988 ◽

Cited By ~ 35

Author(s):

Michael V. Bland ◽

Salim Ismail ◽

Jack A. Heinemann ◽

Jacqueline I. Keenan

Keyword(s):

Helicobacter Pylori ◽

Antimicrobial Effect ◽

Iron Limitation ◽

Intracellular Iron ◽

Colloidal Bismuth Subcitrate ◽

Iron Deprivation ◽

Atp Levels ◽

Bismuth Subcitrate ◽

Membrane Changes ◽

H Pylori

ABSTRACT Helicobacter pylori is highly susceptible to bismuth, a heavy metal with antimicrobial activity linked to its effect on bacterial iron uptake. Three strains of H. pylori were analyzed for indicators of iron limitation following exposure to the MIC of colloidal bismuth subcitrate (MICCBS). Similar morphologic and outer membrane changes were observed following growth in iron-limiting medium and at the MICCBS that inhibited the growth of all three strains. These changes, which were also observed for iron-limited bacteria, were alleviated by the addition of iron to the cultures. H. pylori ATP levels, reduced in iron-limiting medium, were below the limits of detection in two of the three strains following exposure to bismuth. The addition of iron partially restored bacterial ATP levels in these two strains, although not to normal concentrations. In contrast, exposure of the same strains to the MICCBS failed to deplete intracellular levels of iron, which were significantly reduced by culturing in iron-limiting medium. Thus, the antimicrobial effect of bismuth and of iron limitation on H. pylori may be similar. However, the respective mechanisms of intracellular action would appear to be mediated by different pathways within the cell.

Download Full-text

Effect of FliK mutation on the transcriptional activity of the σ 54 sigma factor RpoN in Helicobacter pylori

Microbiology ◽

10.1099/mic.0.026062-0 ◽

2009 ◽

Vol 155 (6) ◽

pp. 1901-1911 ◽

Cited By ~ 7

Author(s):

Francois P. Douillard ◽

Kieran A. Ryan ◽

Jason Hinds ◽

Paul W. O'Toole

Keyword(s):

Helicobacter Pylori ◽

Sigma Factor ◽

Transcriptional Activity ◽

Human Gastric Mucosa ◽

Hook Length ◽

Altered Expression ◽

Flagellar Assembly ◽

Gene Regulatory ◽

H Pylori ◽

And Control

Helicobacter pylori is a motile Gram-negative bacterium that colonizes and persists in the human gastric mucosa. The flagellum gene regulatory circuitry of H. pylori is unique in many aspects compared with the Salmonella/Escherichia coli paradigms, and some regulatory checkpoints remain unclear. FliK controls the hook length during flagellar assembly. Microarray analysis of a fliK-null mutant revealed increased transcription of genes under the control of the σ 54 sigma factor RpoN. This sigma factor has been shown to be responsible for transcription of the class II flagellar genes, including flgE and flaB. No genes higher in the flagellar hierarchy had altered expression, suggesting specific and localized FliK-dependent feedback on the RpoN regulon. FliK thus appears to be involved in three processes: hook-length control, export substrate specificity and control of RpoN transcriptional activity.

Download Full-text