Pylori Clearance Research Articles

Sustain-release lipid-liquid crystal formulations of pexiganan against Helicobacter pylori infection: in vitro evaluation in C57BL/6 mice

IntroductionThe Gram-negative bacterium Helicobacter pylori, H. pylori, is associated with significant digestive disorders. However, the effectiveness of bacterial eradication is declining due to drug resistance. A potent anti-H. pylori activity is shown by the natural antimicrobial peptide pexiganan.ObjectiveThe current study aimed to evaluate the effectiveness of pexiganan and its lipid-liquid crystals (LLCs) in inducing Helicobacter pylori in mice.MethodsIn this experimental study, H. pylori infection was first induced in C57BL/6 mice. Secondly, the antibacterial efficacy of pexiganan and its LLCs formulations was investigated to eliminate H. pylori infection.ResultsThe H. pylori infection could not be completely eradicated by pexiganan peptide alone. However, incorporating pexiganan within the LLC formulation resulted in an increased elimination of H. pylori. Under the H&E strain, the pexiganan-LLCs formulation revealed minimal mucosal alterations and a lower amount of inflammatory cell infiltration in the stomach compared to the placebo.ConclusionClarithromycin was more effective than pexiganan at all tested concentrations. Furthermore, the pexiganan-loaded LLCs exhibited superior efficacy in curing H. pylori infection in a mouse model compared to pexiganan alone. This formulation can enhance H. pylori clearance while mitigating the adverse effects, typically associated with conventional drugs, leading to a viable alternative to current treatment options.

Effects of Multi-Strain Probiotics on Immune Responses and Metabolic Balance in Helicobacter pylori-Infected Mice.

Chronic inflammation caused by Helicobacter pylori infection increases the risk of developing gastric cancer. Even though the prevalence of H. pylori infection has been decreased in many regions, the development of antibiotic resistance strains has increased the difficulty of eradicating H. pylori. Therefore, exploring alternative approaches to combat H. pylori infection is required. It is well-known that probiotic therapy can improve H. pylori clearance. In this study, H. pylori-infected mice were treated with Lactobacillus fermentum P2 (P2), L. casei L21 (L21), L. rhamnosus JB3 (JB3), or a mixture including the aforementioned three (multi-LAB) for three days. All the lactic acid producing bacteria (LAB) treatments decreased H. pylori loads in the stomach and vacA gene expression, H. pylori specific immunoglobulin (Ig) A, and IgM levels in stomach homogenates, as well as serum levels of interferon-gamma and interleukin-1 beta. The multi-LAB and JB3 treatments further restored the superoxide dismutase and catalase activities suppressed by H. pylori infection. Furthermore, H. pylori infection decreased serum concentrations of 15 kinds of amino acids as well as palmitic acid. The multi-LAB treatment was able to recover the serum levels of alanine, arginine, aspartate, glycine, and tryptophan, which are all important in modulating immune functions. In addition, butyric acid, valeric acid, palmitic acid, palmitoleic acid, stearic acid, and oleic acid levels were increased. In this study, multi-LAB revealed its ability to adjust the composition of metabolites to improve health. To date, the mechanisms underlying how LAB strains crosstalk with the host are not fully understood. Identifying the mechanisms which are regulated by LABs will facilitate the development of effective therapies for infection in the future.

Study on the clinical effect of ranitidine combined with omeprazole in the treatment of peptic ulcers

The clinical safety and efficacy of a novel pharmaceutical material (ranitidine combined with omeprazole) for treating peptic ulcers was analyzed using gastroscopy. The subjects were from the Department of Gastroenterology, Nankai hospital, Tianjin, China. Gastroscopy was performed from March 2017 to March 2018. A 100 eligible patients with gastric ulcers were selected. The patients with peptic ulcers were randomly divided into two groups with 50 patients each. For the control group, 150 mg ranitidine was administered orally, twice a day before meals, for four weeks. For the combined group, 150 mg ranitidine was administered orally, twice a day before meals, along with 20 mg omeprazole once a day, for four weeks. The clinical efficacy of the therapy, disease recurrence, and adverse reactions were compared between the two groups. The antacid effect of combined therapy was stronger and longer lasting when compared with the control group (P < 0.05). After six months of follow-up, the Helicobacter pylori (HP) clearance in the combined treatment group was more efficient than in the control group (P < 0.05). Serious adverse reactions were not found in both the groups. Ranitidine combined with omeprazole is effective and safe in the treatment of peptic ulcers and worthy of clinical application.

Induction and Prevention of Gastric Cancer with Combined Helicobacter Pylori and Capsaicin Administration and DFMO Treatment, Respectively.

Gastric cancer risk evolves over time due to environmental, dietary, and lifestyle changes, including Helicobacter pylori (H. pylori) infection and consumption of hot peppers (i.e., capsaicin). H. pylori infection promotes gastric mucosal injury in the early phase of capsaicin exposure. This relationship suggests a need to investigate the mechanism of how both H. pylori infection and capsaicin contribute to gastric inflammation and lead to gastric cancer. C57-Balb/c mice were infected with the H. pylori (SS1) strain and then fed capsaicin (0.05% or 0.2 g/kg/day) or not. Consequently, tumor size and phenotype were analyzed to determine the molecular mechanism driving the shift from gastritis to stomach cancer. Moreover, we used 2-difluoromethylornithine (DFMO) in mice to prevent gastric tumorigenesis by reducing inflammation and promoting recovery of disease-free stasis. This study provides evidence showing that a combination of H. pylori infection and capsaicin consumption leads to gastric carcinogenesis mediated through interleukin-6 (IL-6) stimulation with an incidence rate of 50%. The anti-inflammatory role of DFMO highlights the injurious effect of inflammation in gastric cancer development and the need to reduce gastric inflammation for cancer prevention by inhibiting IL-6. Accordingly, preventive measures such as reduced capsaicin consumption, H. pylori clearance, and DFMO treatment may lessen gastric cancer incidence.

In vitro antimicrobial activity of immobilised essential oil components against Helicobacter pylori.

Available disinfection methods and therapies against Helicobacter pylori have multiple disadvantages, such as increased prevalence of antibiotic-resistant strains, which requires the search for novel effective antimicrobial agents against H. pylori. Among them, naturally-occurring antimicrobial compounds, like essential oil components (EOCs), have been reported as substances with anti-H. pylori potential. To avoid the disadvantages associated with using EOCs in their free form, including volatility, low water solubility and intense sensory properties, their immobilisation in inert supports has recently been developed. This study sought to evaluate the inhibitory properties of EOCs immobilised on silica microparticles against H. pylori and to elucidate the mechanism of action of the immobilised antimicrobials. After the preparation and characterisation of the antimicrobial supports, the susceptibility of H. pylori in the presence of the immobilised compounds was assessed by plate count, fluorescent viability staining and direct viable count-fluorescent in situ hybridisation analyses. The antimicrobial supports were found to inhibit H. pylori growth, and to induce morphological and metabolic alterations to the H. pylori membrane, with a minimum bactericidal concentration value between 25 and 50μg/ml according to the tested EOC. These findings indicate that immobilised EOCs can be used as potential antimicrobial agents for H. pylori clearance and treatment.

Genome-wide profiling of normal gastric mucosa identifies Helicobacter pylori- and cancer-associated DNA methylome changes.

The large geographic variations in the incidence of gastric cancer (GC) are likely due to differential environmental exposures, in particular to Helicobacter pylori (H. pylori) infection. We aimed to investigate the impact of H. pylori on the epigenome in normal gastric mucosa and methylation changes associated with cancer risk independent of H. pylori. A discovery set of normal gastric mucosa from GC cases (n = 42) and controls (n = 42), nested in a large case-control study and stratified by H. pylori status, were subjected to genome-wide methylation profiling. Single-nucleotide polymorphism arrays from peripheral blood leukocytes were used to conduct methylation quantitative trait loci (mQTL) analysis. A validation set of gastric mucosa samples (n = 180) was used in the replication phase. We found 1,924 differentially methylated positions (DMPs) and 438 differentially methylated regions (DMRs) associated with H. pylori infection, most of which were hypermethylated. Significant methylation alterations identified in the initial set were successfully replicated. Furthermore, the H. pylori-associated DMP/Rs showed marked stability ('epigenetic memory') after H. pylori clearance. Interestingly, we found 152 DMRs associated with cancer risk independent of the H. pylori status in normal gastric mucosa. The methylation score derived from three biomarkers was a strong predictor of GC. Finally, the mQTL analysis indicated that the H. pylori- and cancer-specific methylation signatures were minimally affected by genetic variation. The comprehensively characterized methylome changes associated with H. pylori infection and GC risk in our study might serve as potential biomarkers for early cancer progression in tumour-free gastric mucosa.

Probiotic monotherapy and Helicobacter pylori eradication: A systematic review with pooled-data analysis.

AIMTo define probiotic monotherapy effect on Helicobacter pylori (H. pylori) status by performing a systematic review.METHODSMethods of analysis and inclusion criteria were based on PRISMA recommendations. Relevant publications were identified by searching PubMed, MEDLINE, Science Direct, and EMBASE. The end-point was to estimate eradication rate and urea breath test delta value before and after probiotic monotherapy across all studies and, overall, with a pooled data analysis. Adverse events of probiotic therapy were evaluated. The data were expressed as proportions/percentages, and 95%CIs were calculated. For continuous variables, we evaluated the weighted mean difference. Odd ratios (ORs) were calculated according to the Peto method for the comparison of eradication rates between probiotics and placebo.RESULTSEleven studies were selected. Probiotics eradicated H. pylori in 50 out of 403 cases. The mean weighted eradication rate was 14% (95%CI: 2%-25%, P = 0.02). Lactobacilli eradicated the bacterium in 30 out of 235 patients, with a mean weighted rate of 16% (95%CI: 1%-31%). Saccharomyces boulardii achieved eradication in 6 out of 63 patients, with a pooled eradication rate of 12% (95%CI: 0%-29%). Multistrain combinations were effective in 14 out of 105 patients, with a pooled eradication rate of 14% (95%CI: 0%-43%). In the comparison of probiotics vs placebo, we found an OR of 7.91 in favor of probiotics (95%CI: 2.97-21.05, P < 0.001). Probiotics induced a mean reduction in delta values higher than placebo (8.61% with a 95%CI: 5.88-11.34, vs 0.19% for placebo, P < 0.001). Finally, no significant difference in adverse events was found between probiotics and placebo (OR = 1, 95%CI: 0.06-18.08).CONCLUSIONProbiotics alone show a minimal effect on H. pylori clearance, thus suggesting a likely direct role.

Clinical effect of probiotics combined with triple therapy in the treatment of helicobacter pylori infection in children

Objective To discuss the application of combined probiotics pretreatment and late triple therapy with helicobacter pylori infection in children. Methods 300 children with helicobacter pylori infection were randomly divided into three groups according to the way of random table.Group A was treated with standard triple therapy, omeprazole, amoxicillin and clarithromycin treatment, and 10 d was 1 treatment course.B group was given probiotic pretreatment, prior to the triple therapy using compound lactobacillus acidophilus piece 1 piece/time, cold water to take after meals, taking 2 weeks, follow-up treatment with triple therapy for 10d.In group C, triple therapy before using compound lactobacillus acidophilus piece 1 piece/time, cold water to take after meals, taking 2 weeks, follow-up treatment with triple therapy for 10d.To take one week after the completion of compound lactobacillus acidophilus piece 1 piece/time, cold water after meals.The clinical therapeutic effects were recorded. Results The helicobacter pylori clearance rate of group A was 55.00%, that of group B was 86.00%, that in group C was 89.00%, the helicobacter pylori clearance rate of group B and group C was significantly higher than that in group A, the difference was statistically significant (χ2=23.103 7, 28.670 6, all P 0.05). In A group, nausea and vomiting occurred in 5 cases, 2 cases of diarrhea, abdominal distension abdominal pain in 4 cases, skin rash in 5 cases.In group B, nausea and vomiting occurred in 2 cases, 0 cases of diarrhea, abdominal distension abdominal pain in 1 case, skin rash in 1 case.In group C, nausea and vomiting occurred in 1 case, 0 cases of diarrhea, abdominal distension abdominal pain 0 cases, skin rashes in 1 case.The incidence rate of adverse reactions in group B and group C was lower than that in group A, the difference was statistically significant (χ2=11.965 8, 8.000 0, all P 0.05). Conclusion Joint probiotics pretreatment and late triple therapy application in helicobacter pylori in children can promote helicobacter pylori clearance, reduce the triple therapy drug adverse reactions, it is worthy of popularization and application in clinic. Key words: Probiotics; Triple therapy; Children; Helicobacter pylori infection

Critical Role of Antimicrobial Peptide Cathelicidin for Controlling Helicobacter pylori Survival and Infection.

The antimicrobial peptide cathelicidin is critical for protection against different kinds of microbial infection. This study sought to elucidate the protective action of cathelicidin against Helicobacter pylori infection and its associated gastritis. Exogenous cathelicidin was found to inhibit H. pylori growth, destroy the bacteria biofilm, and induce morphological alterations in H. pylori membrane. Additionally, knockdown of endogenous cathelicidin in human gastric epithelial HFE-145 cells markedly increased the intracellular survival of H. pylori. Consistently, cathelicidin knockout mice exhibited stronger H. pylori colonization, higher expression of proinflammatory cytokines IL-6, IL-1β, and ICAM1, and lower expression of the anti-inflammatory cytokine IL-10 in the gastric mucosa upon H. pylori infection. In wild-type mice, H. pylori infection also stimulated gastric epithelium-derived cathelicidin production. Importantly, pretreatment with bioengineered Lactococcus lactis that actively secretes cathelicidin significantly increased mucosal cathelicidin levels and reduced H. pylori infection and the associated inflammation. Moreover, cathelicidin strengthened the barrier function of gastric mucosa by stimulating mucus synthesis. Collectively, these findings indicate that cathelicidin plays a significant role as a potential natural antibiotic for H. pylori clearance and a therapeutic agent for chronic gastritis.

Comparison of clinical efficacy of esomeprazole in treatment of gastric ulcer in young and elderly patients

Objective To compare the clinical efficacy and safety of esomeprazole in treatment of elderly and young patients with gastric ulcer. Methods 120 cases of elderly patients with gastric ulcer and 95 cases of young and middle-aged patients with gastric ulcer were selected this study. Two groups of patients were treated with amoxicillin and clavulanate potassium dispersible tablets 0.457 g, tinidazole tablets 0.5 g and esomeprazole magnesium enteric coated tablets 20mg orally, once daily treatment 1 week for a course of treatment,1 week after continue to every morning fasting taking esomeprazole 20mg,1 times/D,treatment for 3weeks. The clinical curative effect, Hp clearance rate and incidence of adverse reactions between two groups of patients after treatment were compared. Results The total effective rate in the treatment of elderly group patients(87.50%)compared with young and middle-aged group(92.63%), there was no significant difference(χ2=1.52,P>1.52). Elderly group of patients with helicobacter pylori clearance rate(71.67%)compared with young and middle-aged group(76.84%),there was no significant difference (χ2=0.74,P>0.74). The incidence of adverse reactions(8.33%)of elderly group had obvious differences by comparing with young and middle-aged group(2.11%), and the difference was statistically significant(χ2=3.90,P<0.05). Conclusion Application of esomeprazole based triple therapy in the treatment of the elderly and young people in the gastric ulcer could heal ulcers and eradicate Hp, but young and middle-aged patients is superior to the elderly group in terms of adverse reactions. Key words: Esomeprazole; Aged; Young and middle-aged. Gastric ulcer

Helicobacter pylori Outer Membrane Protein 18 (Hp1125) Is Involved in Persistent Colonization by Evading Interferon- γ Signaling.

Outer membrane proteins (OMPs) can induce an immune response. Omp18 (HP1125) of H. pylori is a powerful antigen that can induce significant interferon-γ (IFN-γ) levels. Previous studies have suggested that IFN-γ plays an important role in H. pylori clearance. However, H. pylori has multiple mechanisms to avoid host immune surveillance for persistent colonization. We generated an omp18 mutant (H. pylori 26695 and H. pylori SS1) strain to examine whether Omp18 interacts with IFN-γ and is involved in H. pylori colonization. qRT-PCR revealed that IFN-γ induced Omp18 expression. qRT-PCR and western blot analysis revealed reduced expressions of virulence factors CagA and NapA in H. pylori 26695 with IFN-γ treatment, but they were induced in the Δomp18 strain. In C57BL/6 mice infected with H. pylori SS1 and the Δomp18 strain, the Δomp18 strain conferred defective colonization and activated a stronger inflammatory response. Signal transducer phosphorylation and transcription 1 (STAT1) activator was downregulated by the wild-type strain but not the Δomp18 strain in IFN-γ-treated macrophages. Furthermore, Δomp18 strain survival rates were poor in macrophages compared to the wild-type strain. We concluded that H. pylori Omp18 has an important function influencing IFN-γ-mediated immune response to participate in persistent colonization.

Ethyl cellulose nanoparticles: Clarithomycin encapsulation and eradication of H. pylori

The extreme acidic environment of the stomach, its regular voidance of contents and the restricted access to the mucus covered habitat combined with the antibiotic resistance of the bacteria, all contribute to the poor success in the treatment of Helicobacter pylori gastric infections. Here, we demonstrate that by encapsulating clarithromycin into ethyl cellulose (EC) nanoparticles, the efficiency of H. pylori clearance in C57BL/6 mice infected with these bacteria was significantly improved. Clarithomycin-loaded EC nanoparticles were prepared via a simple yet effective anti-solvent particle induction method, to yield sub-micron sized particles with 22.3±0.17% (w/w) clarithromycin loading at 86±0.5% (w/w) encapsulation efficiency. The particles dispersed well in water and simulated gastric fluid and gave a minimum inhibitory concentration of 0.09–0.18μg/ml against four strains of H. pylori. Encapsulation into EC particles not only enhanced the anti-adhesion activity of clarithromycin when tested with H. pylori and Hep-2 cells, but also gave significant enhancement of H. pylori clearance in the stomach of C57BL/6 mice infected with the bacteria.

Development and characterization of nanolipobeads-based dual drug delivery system for H. Pylori targeting

The objective of the present investigation was to prepare and evaluate nanolipobeads which permit the targeting of drugs to H. Pylori and potentially used for the treatment of gastric ulcer. For this polyvinyl alcohol nanoparticles were prepared by freeze thaw cyclizing method and surface acylation was done by treating with (1M) palmitoyl chloride in hexane followed by addition of 0.1 N NaOH to induce acylation by adjusting pH below 6.5. Finally, nanolipobeads synthesis was carried out by combining equal parts of suspension of acylated poly vinyl alcohol nanoparticles (PVA-NPs) and AMOX encapsulated PE liposomes suspension. The uniformity of supported PE lipid layer on acylated PVA-NPs was examined using fluorescence and confocal laser scanning electron microscopy. The optimized nanolipobeads formulation demonstrated 773.3 ± 4.3 nm average age size and 84.7 ± 2.9% of AMOX and 67.5 ± 2.8% of RBC release up to 72 h, respectively. Furthermore, binding specificity and targeting propensity toward H. pylori (SKP-56) was confirmed by agglutination and in situ adherence assay. Reduction of the absolute alcohol induced ulcerogenic index from 3.01 ± 0.25 to 0.31 ± 0.09 and 100% H. pylori clearance rate was observed. These results suggested that nanolipobeads are potential vector for development of dual drug delivery for effective treatment of H. pylori associated peptic ulcer.

Cathelicidin is a host defense peptide in controlling Helicobacter pylori survival and infection

Cathelicidin, a host defense antibacterial peptide in humans can eradicate different kinds of microbial infection. This study sought to elucidate the actions of cathelicidin in protection against Helicobacter pylori (H. pylori) infection both in vitro and in vivo. To examine the direct antimicrobial action of cathelicidin, H. pylori survival, biofilm formation and morphology change were determined after exposure to different doses of cathelicidin in vitro. Intracellular H. pylori in gastric epithelial cells and in cathelicidin wild‐type (Cnlp+/+) and knockout (Cnlp−/−) mice stomachs were also investigated. Results showed that exogenous cathelicidin could affect H. pylori growth, destroy bacteria biofilm and cause pore formation in H. pylori membranes. Endogenous cathelicidin in gastric epithelial cells could be induced by active form of vitamin D (1,25D3). We also showed that 1,25D3 eliminated the intracellular H. pylori in vitro. Furthermore, Cnlp−/−mice exhibited stronger H. pylori colonization in both acute and chronic H. pylori infection when compared with Cnlp+/+ mice. To further confirm this antibacterial action was due to endogenous cathelicidin, a high level of mouse gastric cathelicidin (CRAMP) production was found in Cnlp+/+ mice but not in Cnlp−/− animals. This finding could partially explain why there was less bacterial infection in wild type mice. Taken together, these results indicate that human cathelicidin plays a significant role as a host defense peptide for H. pylori clearance and infection.

Preparation and characterization of a novel pH-sensitive coated microsphere for duodenum-specific drug delivery

The aim of this study is to develop a duodenum-specific drug delivery system on the basis of a pH-sensitive coating and a mucoadhesive inner core for eradication of Helicobacter pylori (H. pylori) in the ulcer duodenum. Hydroxypropyl methylcellulose acetate maleate (HPMCAM) was used as the pH-sensitive material, which dissolves around pH 3.0. The mucoadhesive microspheres loaded with furazolidone (FZD-ad-MS) were prepared by the emulsification-solvent evaporation method using Carbopol 971NP as the mucoadhesive polymer. The prepared pH-sensitive coated mucoadhesive microspheres (AM-coated-MS) were characterized in regards to particle size, drug loading efficiency, morphological change, drug stability, drug release and in vitro anti-H. pylori activity. The particle size was 160.97 ± 47.24 μm and 336.44 ± 129.34 μm, and the drug content was 42.33 ± 3.43% and 10.96 ± 1.29% for FZD-ad-MS and AM-coated-MS, respectively. The morphological changes in different pH media were characterized by scanning electron microscopy (SEM). HPMCAM coating improved the stability of the FZD-ad-MS and these particles were expected to remain intact until their arrival in the duodenum. The drug release was extremely suppressed at pH 1.2 for AM-coated-MS, but increased at pH 4.0 after regeneration of FZD-ad-MS. In addition, FZD-ad-MS exhibited excellent anti-H. pylori activity in vitro. Thus, the HPMCAM-coated microspheres developed in this study hold great promise for use as a duodenum-specific drug delivery system for H. pylori clearance.

Preparation and characterization of amoxicillin mucoadhesive microparticles using solution-enhanced dispersion by supercritical CO2

The purpose of this research was to formulate and systemically evaluate in vitro and in vivo performances of mucoadhesive amoxicillin microparticles for the potential use in the treatment of gastric and duodenal ulcers, which were associated with Helicobacter pylori. The chitosan/amoxicillin microparticles were successfully prepared in a process of solution-enhanced dispersion by supercritical CO2 (SEDS). The morphological characteristics of the mucoadhesive microparticles were studied under scanning electron microscope. The resulted microparticles with mean sizes ranged from 1.0 and 2.5 µm had good mucoadhesive properties. In vitro and in vivo mucoadhesive tests showed that chitosan/amoxicillin mucoadhesive microparticles adhered more strongly to gastric mucous layer and could retain in gastrointestinal tract for an extended period of time. The X-Ray Powder Diffractometry and Differential Scanning Calorimetry analysis demonstrated that the SEDS process was a typical physical coating process to produce drug-polymer composite microparticles, which is favourable for drugs since there is no changes in chemistry. In vitro release test showed that amoxicillin released faster in pH 1.0 hydrochloric acid (HCl) than in pH 7.8 phosphate buffer. In vivo H. pylori clearance tests were also carried out by administering amoxicillin powder and mucoadhesive microparticles to H. pylori infectious Wistar rats under fed conditions at single dose or multiple dose(s) in oral administration. The results showed that amoxicillin mucoadhesive microparticles had a better clearance effect than amoxicillin powder. In conclusion, the prolonged gastrointestinal residence time and enhanced amoxicillin stability resulting from the mucoadhesive microparticles of amoxicillin might make a contribution to H. pylori complete eradication.

Dendritic Cells Prevent Rather Than Promote Immunity Conferred by a Helicobacter Vaccine Using a Mycobacterial Adjuvant

Immunization against the gastric bacterium Helicobacter pylori could prevent many gastric cancers and other disorders. Most vaccination protocols used in preclinical models are not suitable for humans. New adjuvants and a better understanding of the correlates and requirements for vaccine-induced protection are needed to accelerate development of vaccines for H pylori. Vaccine-induced protection against H pylori infection and its local and systemic immunological correlates were assessed in animal models, using cholera toxin or CAF01 as adjuvants. The contribution of B cells, T-helper (Th)-cell subsets, and dendritic cells to H pylori-specific protection were analyzed in mice. Parenteral administration of a whole-cell sonicate, combined with the mycobacterial cell-wall-derived adjuvant CAF01, protected against infection with H pylori and required cell-mediated, but not humoral, immunity. The vaccine-induced control of H pylori was accompanied by Th1 and Th17 responses in the gastric mucosa and in the gut-draining mesenteric lymph nodes; both Th subsets were required for protective immunity against H pylori. The numbers of memory CD4+ T cells and neutrophils in gastric tissue were identified as the best correlates of protection. Systemic depletion of dendritic cells or regulatory T cells during challenge infection significantly increased protection by overriding immunological tolerance mechanisms activated by live H pylori. Parenteral immunization with a Helicobacter vaccine using a novel mycobacterial adjuvant induces protective immunity against H pylori that is mediated by Th1 and Th17 cells. Tolerance mechanisms mediated by dendritic cells and regulatory T cells impair H pylori clearance and must be overcome to improve immunity.

Floating In Situ Gelling System of Acetohydroxamic Acid for Clearance of H. pylori

The objective of this study was to develop a novel floating in situ gel system for sustained drug delivery of acetohydroxamic acid (FIGA) for eradication of Helicobacter pylori (H. pylori). The FIGA was prepared by dissolving the different concentration of gellan in deionized water at 80°C. Different concentration of drug and calcium carbonate as floating agents were dispersed with stirring. In vitro results revealed that in situ gelling formulation forms rigid gels instantaneously and floated for longed period time of time in SGF pH 1.2. The formulation parameters, such as concentration of polymer, concentration of calcium carbonate, and concentration of drug, affected the in vitro drug release characteristic significantly. Absence of drug-polymer interaction was confirmed by differential scanning calorimetry analysis. The in vivo H. pylori clearance efficacy of prepared FIGA in reference to acetohydroxamic acid suspension following repeated oral administration to H. pylori-infected Mongolian gerbils was examined by microbial culture method. FIGA showed a significant anti-H. pylori effect in the in vivo gerbil model. It was noted that the required amount of acetohydroxamic acid for eradication of H. pylori was very less in FIGA than in the corresponding acetohydroxamic acid suspension. From the above results, it was concluded that the floating in situ gelling system has feasibility for forming rigid gels in the stomach and eradicated H. pylori from the gastrointestinal tract more effectively than acetohydroxamic acid suspension because of the prolonged gastrointestinal residence time of the formulation.

IL-4 -588C>T polymorphism and IL-4 receptor alpha [Ex5+14A>G; Ex11+828A>G] haplotype concur in selecting H. pylori cagA subtype infections

BackgroundThe Th2 cytokine IL-4 might limit H. pylori associated gastric inflammation and favour H. pylori clearance. The aim of the study was to verify whether IL-4 -588C>T SNP, or two SNPs of the gene coding the alpha chain of IL-4 receptor (IL-4RA Ex5+14A>G, IL-4RA Ex11+828A>G) considered singly or as haplotypes, are correlated with H. pylori virulence genes or H. pylori associated diseases. MethodsWe studied 144 patients with non-cardia gastric cancer (NCGC)(41/50 with present or past H. pylori infection), 75 with duodenal ulcer (DU)(66 H. pylori infected) and 171 with gastritis (CG)(107 H. pylori infected). cagA gene was present in 24/28 NCGC, 45/59 DU and 56/107 CG. ResultsAll SNPs were in Hardy–Weinberg equilibrium. IL-4RA haplotypes frequencies were estimated using Arlequin software. Neither the SNPs nor the IL-4RA haplotype correlated with disease diagnosis, H. pylori infection, degree of mucosal inflammation or intestinal metaplasia. IL-4 -588T allele (OR=3.69, 95% CI:1.34–10.16) and IL-4RA GA haplotype (p<0.05) enhanced the risk for cagA positive infections. IL-4RA GA haplotype correlated with IL-4 protein levels in H. pylori infected gastric mucosa. ConclusionsIL-4 and IL-4RA gene polymorphisms concur in selecting the H. pylori infecting strain, probably influencing the IL-4 signalling pathway.

Open Posters: Adhesion molecules

Urease is one of the key enzymes involved in the establishment of infection by the stomach-colonizing pathogen Helicobacter pylori.The recombinant enzyme was co-administered parenterally with a range of adjuvants and their combinations. Over 6 months, we measured a number of immunological parameters to characterize both the intensity and quality of the ensuing immune responses. Of the formulations test-ed, alum þ Quil-A gave the highest peak humoral antibody titres, with chitosan and alum þ MDP reaching comparable levels. In contrast, MDP induced a lower response, however, titres were sustained throughout the duration of the study. Following splenocyte proliferation and supernatant cytokine analysis, alum þ MDP showed by far the highest proliferation index, with corresponding increased IL-2, IL-4, IL-6 and IFN-g concentrations. Alum þ Quil-A, produced the second highest proliferation index,superseding the alum þ MDP formulation only in IL-2 levels. Otherwise,IFN-g was observed only in the chitosan and alum formulations, chitosan being the only up-regulator of IL-4 alone or in combination with MDP,apart from free rURE. Surprisingly, MDP alone showed very low proliferation, with very low IL-6 and strongly down-regulated IL-4. In conclusion, the alum adjuvant combinations with MDP or Quil-A offer a significant potential in the process of eliciting CD4þ cells recently identified as essential for H. pylori clearance.