Helicobacter pylori infection, chronic gastritis, and proton pump inhibitors

Green Chemistry Within the Circular Bioeconomy to Harness Chestnut Burr Extract's Synergistic Antimicrobial Activity Against Helicobacter pylori

Green chemistry principles are pivotal in driving sustainable and innovative solutions to global health challenges. This study explores a hydroalcoholic extract from Castanea sativa (chestnut) burrs, an underutilized natural resource, as a potent source of antimicrobial compounds against Helicobacter pylori (H. pylori). The extract demonstrated significant bactericidal activity, synergizing effectively with clarithromycin and showing additive effects with metronidazole. Remarkably, combining the extract with clarithromycin and sub-inhibitory concentrations of pantoprazole reduced clarithromycin's Minimum Bactericidal Concentration (MBC) to just 1.56% of its original value. Mechanistic studies suggest that the extract's polyphenolic compounds compromise bacterial membrane integrity, enhancing antibiotic uptake, while pantoprazole disrupts bacterial ATPase activity. This research highlights the critical role of natural product extraction within the framework of green chemistry, offering a sustainable and environmentally friendly alternative to synthetic antimicrobials. By harnessing bioactive compounds from plant sources, this approach addresses the pressing issue of antibiotic resistance while promoting the responsible use of natural resources. The findings underscore the transformative potential of green chemistry in developing effective, eco-conscious antimicrobial therapies that align with global sustainability goals.

Preclinical evaluation of anti-Helicobacter spp. activity of Hippocratea celastroides Kunth and its acute and sub-acute toxicity

Background

Hippocratea celastroides Kunth, commonly known as “cancerina”, is used in Mexican Traditional Medicine for the treatment of gastric and intestinal infections, systemic and skin inflammation, injuries and gastritis. The aim of this research was to assess the anti-Helicobacter pylori activities of hydro-ethanolic root-bark extracts from Hippocratea celastroides Kunth in naturally infected dogs, after testing their acute and subacute toxicities in mice.

Methods

To determine in vivo acute toxicity, a hydro-ethanolic extract was obtained and administered orally in female and male Balb-C mice, at doses ranging from 2000 to 5000 mg/kg. For the subacute study, a hydro-ethanolic extract was given to male and female Balb-C mice at doses ranging from 200 to 2000 mg/kg body weight. The animals were observed daily over a period of 42 days for signs of toxicity. In the pre-clinical anti-Helicobacter spp. assay, 60 dogs were included. Eighteen and 19 dogs for the experimental and control groups respectively, concluded the study. The experimental treatment consisted of H. celastroides hydro-ethanolic extract and the control treatment of amoxicillin-clarithromycin-omeprazole.

Results

Oral LD₅₀ (lethal dose 50) values for hydro-ethanolic extract were indeterminable at the highest tested doses. Under the subacute administration, neither mortality nor any sign of toxicity were observed when the hydro-ethanolic extract was administered. There were no significant alterations in biochemical parameters. The prevalence of Helicobacter spp. infection in dogs was 97.1 % for the experimental group and 100 % for the control group. Effectiveness was of 33.3 and 55 % in the experimental and control group respectively. The oral administration of H. celastroides was well-tolerated and safe.

Conclusion

The root-bark of H. celastroides produced no signs of toxicity, and manifested pharmacological activity that indicated the possibility of an alternative treatment for H. pylori infection. Effectiveness is still low so it is necessary to continue research.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1412-6) contains supplementary material, which is available to authorized users.

Negative Effect of Proton-pump Inhibitors (PPIs) on Helicobacter pylori Growth, Morphology, and Urease Test and Recovery after PPI Removal--An In vitro Study

BACKGROUND

Proton-pump inhibitor (PPI) consumption does lead to false-negative results of Helicobacter pylori diagnostic tests such as biopsy culture and rapid urease test (RUT).

MATERIALS AND METHODS

Helicobacter pylori isolates from 112 dyspeptic patients with (56.5%) or without (43.5%) PPI consumption were recruited for examining the negative effects of omeprazole (OMP), lansoprazole (LPZ), and pantoprazole (PAN) on H. pylori viability, morphology, and urease, in vitro. The effect of a sublethal concentration of OMP on bacterial features and their recovery after removal of OMP was also assessed.

RESULTS

Of 112 culture-positive gastric biopsies, 87.5% were RUT positive and 12.5% RUT negative. There was a significant correlation between negative RUT results and PPI consumption (p < .05). OMP (minimum inhibitory concentration, MIC 32 μg/mL) and LPZ (MIC 8 μg/mL) inhibited the growth of 78.6% of H. pylori isolates. OMP and LPZ inhibited urease of 90.3% of isolates between 0 and 40 minutes and 54.4% between 20 and 40 minutes, respectively. PAN did not inhibit H. pylori growth and urease. Three 3-day (9 days) consecutive subcultures of H. pylori on brucella blood agar (BBA) supplemented with OMP resulted in reduced bacterial viability (1+), compared with control (4+), change of spiral morphology to coccoid, and reduction in pink color intensity in urea agar. Bacterial growth (1+), morphology, and urease test did not improve after the first 3-day and second 3-day (6 days) subcultures on BBA. However, relative recovery occurred after the third 3-day (9 days) subculture and complete recovery was observed after the fourth 3-day (12 days) subculture, as confluent growth (4+), 100% spiral cells, and strong urease test.

CONCLUSION

Proton-pump Inhibitors exert transient negative effects on H. pylori viability, morphology, and urease test. Accordingly, cessation of PPI consumption at least 12 days before endoscopy could help avoiding false-negative results of H. pylori diagnostic tests.

Acid and weakly acid gastroesophageal refluxes and type of respiratory symptoms in children

OBJECTIVES

To evaluate the association between the frequency of acid reflux (AR) and weakly acid reflux (WAR) and specific respiratory symptoms (RS) in childhood.

STUDY DESIGN

We retrospectively reviewed medical records of children with difficult-to-treat RS, not under acid suppressive therapy, and with a positive multiple intraluminal esophageal impedance (pH/MII) monitoring. To discriminate children with prevalent AR and WAR events, a ROC curve was designed and the distribution of the different RS in children with prevalent AR or WAR events was analyzed.

RESULTS

A higher number of AR over WAR events was detected (p < 0.0001) but the WAR-to-AR events ratio progressively decreased with the age of the subjects (p < 0.01). Similar total number of reflux events was found in the three age group and in children with a more prevalent WAR or AR. The most prevalent RS, equally distributed among the three age groups, were persistent and/or nocturnal cough, wheezy bronchitis/asthma, and recurrent lower respiratory tract infections (RLRTI). Apnoea was most frequent in infants (p = 0.036). A higher frequency of RLRTI, but not of nocturnal cough or wheezy bronchitis/asthma, was shown in WAR as compared with AR patients (p = 0.040), and specifically those in the school-aged group (p = 0.013). Age and WAR were respectively identified as independent predictors of apnoea and RLRTI (p < 0.05).

CONCLUSION

WAR events are common in children with gastroesophageal reflux and difficult-to-treat RS and often associated with RLRTI. These findings support the role of pH/MII monitoring in the evaluation of these patients and may explain the disappointing clinical results often observed with anti-acid treatments.

Helicobacter pylori eradication: role of individual therapy constituents and therapy duration

Treatment of Helicobacter pylori (H. pylori) infection has become a key factor in the management of dyspepsia and is the treatment of choice for peptic ulcer disease. First-line eradication regimens combining a proton pump inhibitor (PPI) with clarithromycin and amoxicillin or metronidazole are considered most effective when given for a minimum period of 1 week. Eradication regimens of shorter duration have shown promising results but clinical experience remains limited. Pharmacological properties such as bioavailability and plasma concentrations of individual PPIs differ between individuals but it remains unclear whether these differences impact on the efficacy of eradication therapy and are influenced by renal or hepatic impairment. Bioavailability of PPIs also differs and is impacted on by factors including intragastric pH, metabolic pathways, potency on an mg-for-mg basis and intrinsic antibacterial activity. Several significant pharmacokinetic differences between the PPIs do not seem to influence overall H. pylori eradication rates for first-line triple therapy. However, comparison of factors including pharmacokinetics and treatment duration may prove important in achieving successful eradication with second- and third-line treatments. Based on the factors which influence therapy outcome, we suggest an algorithm for the use of H. pylori eradication therapies.

Potent Gastric Acid Inhibition in Helicobacter pylori Eradication

At present, antisecretory drugs--foremost among them the proton pump inhibitors (PPIs)--represent a keystone in Helicobacter pylori eradication therapy. The present article shall first compare the role of PPIs as compared with histamine H2 receptor antagonists, both of them in the role of antibiotic-associated antisecretory therapy, and shall then address the contribution of each of the various PPIs that have been developed until the present time to the H. pylori eradication therapies. In summary, it may be concluded that PPIs are more effective overall than H2 receptor antagonists when the two groups of antisecretory drugs are given at the usual standard doses together with antibiotics with the intention of eradicating H. pylori infection. However, all PPIs (omeprazole, lansoprazole, pantoprazole, rabeprazole, and esomeprazole) are equivalent when given together with two antibiotics to cure the infection.

Pantoprazole based therapies in Helicobacter pylori eradication: a systematic review and meta-analysis

AIM

To perform a systematic review on the efficacy of pantoprazole based therapies in Helicobacter pylori eradication, and to conduct a meta-analysis comparing the efficacy of pantoprazole and other proton pump inhibitors (PPIs) when co-prescribed with antibiotics.

METHODS

Studies evaluating pantoprazole combined with antibiotics were considered. Only randomized clinical trials comparing pantoprazole and other PPIs when co-prescribed with antibiotics, and differing only in the PPI (pantoprazole vs other), were eligible for inclusion in the meta-analysis. Bibliographical searches in several electronic databases, and manual search of abstracts from congresses, were conducted. The percentage (weighted mean) of patients with eradication success was calculated. Meta-analysis was performed combining the odds ratios (ORs) of the individual studies in a global OR.

RESULTS

The mean eradication rate with pantoprazole plus clarithromycin for 14 days was 60%. Cure rates with 7 day pantoprazole based triple regimens were higher: pantoprazole, amoxicillin and clarithromycin (78%); pantoprazole, clarithromycin and nitroimidazole (84%); and pantoprazole, amoxicillin and nitroimidazole (74%). Twelve studies comparing pantoprazole and other PPIs were selected for the meta-analysis, including 534 and 603 patients, respectively. The mean eradication rate for H. pylori using pantoprazole plus antibiotics was 83%, and 81% when other PPIs were used (OR = 1; 95% confidence interval (CI) from 0.61 to 1.64). When sub-analysis was performed, including only studies comparing pantoprazole with omeprazole, or pantoprazole with lansoprazole, differences were also statistically non-significant. The meta-analysis of the six studies prescribing equivalent doses of all PPIs demonstrated similar results with pantoprazole and with other PPIs (OR = 1.07; 95% CI from 0.71 to 1.62), the results being statistically homogeneous.

CONCLUSIONS

Pantoprazole achieves similar cure rates to those of omeprazole and lansoprazole when co-prescribed with antibiotics for the eradication of H. pylori infection.

Meta-analysis: comparative efficacy of different proton-pump inhibitors in triple therapy for Helicobacter pylori eradication

BACKGROUND

It is not known whether certain proton-pump inhibitors are more efficacious than others when used in triple therapy for Helicobacter pylori eradication.

AIM

To compare the efficacy of different proton-pump inhibitors in triple therapy by performing a meta-analysis.

METHODS

A MEDLINE search was performed. Abstracts of the European Helicobacter pylori Study Group and the American Gastroenterological Association congresses from 1996 to 2002 were also examined. Randomized studies with at least two branches of triple therapy that differed only in terms of type of proton-pump inhibitor were included in a meta-analysis using Review Manager 4.1.

RESULTS

Fourteen studies were included. Intention-to-treat cure rates were similar for omeprazole and lansoprazole: 74.7% vs. 76%, odds ratio (OR) 0.91 [95% confidence interval (CI) 0.69-1.21] in a total of 1085 patients; for omeprazole and rabeprazole: 77.9% vs. 81.2%, OR 0.81 (95% CI 0.58-1.15) in a total of 825 patients; for omeprazole and esomeprazole: 87.7% vs. 89%, OR 0.89 (95% CI 0.58-1.35) in 833 patients; and for lansoprazole and rabeprazole: 81% vs. 85.7%, OR 0.77 (95% CI 0.48-1.22) in 550 patients.

CONCLUSION

The efficacy of various proton-pump inhibitors seems to be similar when used for H. pylori eradication in standard triple therapy.

Prolonged use of proton pump inhibitors, CagA status, and the outcome of Helicobacter pylori gastritis

GOALS AND BACKGROUND

To assess whether prolonged use of proton pump inhibitors (PPIs) in patients infected with Helicobacter pylori has adverse effects on gastritis.

STUDY

We studied 34 H. pylori-positive individuals with reflux esophagitis, Barrett esophagus, or nonulcer dyspepsia. Half of them were on maintenance treatment with PPIs (mean, 8 years) and half were not.H. pylori and CagA status were tested serologically. Gastric biopsies were classified histopathologically by the updated Sydney classification.

RESULTS

Proton pump inhibitors in H. pylori gastritis are associated with significantly less antral inflammation and lower H. pylori density, regardless of CagA status. There was a tendency toward more antral atrophy in patients with the CagA strain who were undergoing maintenance treatment with PPIs (p = 0.08), but there was an opposite tendency in CagA-negative individuals (p = 0.08). Intestinal metaplasia was seen more frequently in CagA-positive, treated individuals (p = 0.028).

CONCLUSIONS

These findings support the hypothesis that CagA status is important in the progression to atrophy and that maintenance treatment with PPIs accelerate this progression, while reducing inflammatory infiltration.

Different effects of short-term omeprazole, lansoprazole or pantoprazole on the accuracy of the (13)C-urea breath test

BACKGROUND

Proton pump inhibitors may interfere with the accuracy of the (13)C-urea breath test, but little information is available on the effect of standard doses of various proton pump inhibitors on this test.

AIM

To evaluate the effect of short-term standard doses of omeprazole, lansoprazole and pantoprazole on the accuracy of the standardized (13)C-urea breath test.

METHODS

A total of 124 patients with Helicobacter pylori infection, diagnosed on the basis of gastric histology, rapid urease test and (13)C-urea breath test, were studied. These patients received omeprazole, 20 mg/day, lansoprazole, 30 mg/day, or pantoprazole, 40 mg/day, for 2 weeks according to a randomized protocol. (13)C-Urea breath test was repeated on days 4, 7 and 14 while on therapy and 7 days after proton pump inhibitor withdrawal.

RESULTS

Of the patients receiving omeprazole and lansoprazole, 30% (12/40) and 20% (8/41), respectively, became (13)C-urea breath test negative during therapy, compared with none of the 42 patients treated with pantoprazole (P < 0.05). All the false negative (13)C-urea breath test results returned to positive within 1 week of drug withdrawal, with a mean recovery to 84.7 +/- 15.6% of baseline delta(13)CO(2).

CONCLUSIONS

Short-term omeprazole and lansoprazole interfere with the 13C-urea breath test, although a return to positive test results invariably occurs within 1 week of proton pump inhibitor withdrawal. In contrast, the accuracy of the (13)C-urea breath test does not appear to be significantly impaired by short-term pantoprazole, which therefore may not necessarily be withdrawn before this test.

Pantoprazole: a new proton pump inhibitor

OBJECTIVE

This paper reviews the pharmacology, clinical efficacy, and tolerability of pantoprazole in comparison with those of other available proton pump inhibitors (PPIs).

METHODS

Relevant English-language research and review articles were identified by database searches of MEDLINE, International Pharmaceutical Abstracts, and UnCover, and by examining the reference lists of the articles so identified. In selecting data for inclusion, the author gave preference to full-length articles published in peer-reviewed journals.

RESULTS

Like other PPIs, pantoprazole exerts its pharmacodynamic actions by binding to the proton pump (H+,K+ -adenosine triphosphatase) in the parietal cells, but, compared with other PPIs, its binding may be more specific for the proton pump. Pantoprazole is well absorbed when administered as an enteric-coated, delayed-release tablet, with an oral bioavailability of approximately 77%. It is hepatically metabolized via cytochrome P2C19 to hydroxypantoprazole, an inactive metabolite that subsequently undergoes sulfate conjugation. The elimination half-life ranges from 0.9 to 1.9 hours and is independent of dose. Pantoprazole has similar efficacy to other PPIs in the healing of gastric and duodenal ulcers, as well as erosive esophagitis, and as part of triple-drug regimens for the eradication of Helicobacter pylori from the gastric mucosa. It is well tolerated, with the most common adverse effects being headache, diarrhea, flatulence, and abdominal pain. In clinical studies, it has been shown to have no interactions with various other agents, including carbamazepine, cisapride, cyclosporine, digoxin, phenytoin, theophylline, and warfarin.

CONCLUSIONS

Pantoprazole appears to be as effective as other PPIs. Its low potential for drug interactions may give it an advantage in patients taking other drugs.

Influence of Helicobacter pylori eradication therapy on 13C aminopyrine breath test: comparison among omeprazole-, lansoprazole-, or pantoprazole-containing regimens

OBJECTIVE

Proton pump inhibitors and antimicrobial agents are widely used to eradicate Helicobacter pylori (H. pylori) infection. In the general population the prevalence of infection and of polypharmacy increases the possibility of drug-drug interactions during H. pylori eradication therapy. The purpose of the present study was to assess the prevalence, degree, and clinical relevance of metabolic interference with the cytochrome P450 enzymatic system occurring during 1 wk of administration of omeprazole, lansoprazole, or pantoprazole followed by the association of clarithromycin and metronidazole for another week. The 13C aminopyrine breath test (ABT) was chosen to screen for possible interactions.

METHODS

We studied 30 patients referred to our Unit for H. pylori eradication therapy. They were randomized to receive either omeprazole (20 mg b.i.d.), lansoprazole (30 mg b.i.d.), or pantoprazole (40 mg b.i.d.) for 2 wk. During the second week clarithromycin (250 mg b.i.d.) and metronidazole (500 mg b.i.d.) were added. ABT was performed before, and at the end of the first and second week of therapy. Percentage of the administered dose of 13C recovered per hour at the peak (percent 13C dose/h at the peak) and cumulative percentage of administered dose of 13C recovered over time at 120 min (percent 13C dose cum120) were the ABT evaluated parameters.

RESULTS

At baseline all patients showed a normal liver function. In individual patients during treatment we observed various liver metabolic interactions both as inhibition and induction, as well as after the first and the second week of therapy. However, mean modifications of the ABT parameters during the 2 weeks of therapy were not statistically significant compared to baseline values. None of the patients who had ABT variations complained of side effects.

CONCLUSIONS

H. pylori eradication therapy interferes with cytochrome P450-dependent liver metabolic activity. However, the clinical relevance of these metabolic interactions is not yet apparent, and further investigation is needed. H. pylori eradication therapy appears safe, but these interactions should be considered in the choice of proton pump inhibitor and antimicrobial agents.

Review article: comparison of the pharmacokinetics, acid suppression and efficacy of proton pump inhibitors

Proton pump inhibitors have dramatically influenced the management of acid-peptic disorders in recent years. They all have a broadly similar mechanism of action and are extensively metabolized in the liver via cytochromes P450 2C19 and 3A4. There is some variation in their potential for drug interactions due to differences in enzyme inhibition. Relatively few serious adverse effects have been reported for the proton pump inhibitors. Comparative studies of acid suppression suggest that lansoprazole and pantoprazole have a potency similar to that of omeprazole on a mg for mg basis; however, rabeprazole may have a greater potency than omeprazole. Lansoprazole and rabeprazole display a more rapid onset of maximal acid suppression than the other proton pump inhibitors. Comparative studies using proton pump inhibitors for the treatment of reflux oesophagitis, duodenal ulcer healing and Helicobacter pylori eradication show little overall difference in outcome between the proton pump inhibitors when used in their standard doses. Lansoprazole and rabeprazole provide earlier and better symptom relief than the other proton pump inhibitors in some studies of peptic ulcer treatment. The few studies of gastric ulcer treatment suggest that there is an advantage in using the proton pump inhibitors that have a higher standard daily dose.

Morphological changes of the human gastric mucosa under long-term proton pump inhibitor therapy and their clinical relevance

Proton pump inhibitors are potent drugs for the treatment of acid-related diseases. The moderate hypergastrinaemia observed during therapy is a physiological response to low intragastric pH and the increase is limited to the first months of therapy with no further changes thereafter. Reports on endocrine cell changes in the antral mucosa under chronic PPI therapy are controversial and lack clinical relevance. In contrast, in the oxyntic mucosa hyperplastic argyrophil cell changes have been reported, dependent on the degree and duration of hypergastrinaemia, the severity of oxyntic mucosal gastritis, especially atrophy, and the presence of H. pylori infection. Current data do not support a progression from hyperplastic to dysplastic argyrophil cell lesions in humans in the absence of additional genetic factors. Data on the progression of oxyntic gastritis under chronic PPI treatment in comparison to untreated controls could not be confirmed in more recent studies including a well-matched control population. The main factor for gastritis progression is the presence of Helicobacter pylori infection. The bacterium not only causes a chronic inflammation of the gastric mucosa, resulting in atrophy and intestinal metaplasia, but also influences endocrine cell populations involved in the regulation of gastric acid secretion. The clinical benefit of H. pylori eradication in reflux esophagitis patients is still a matter of debate. The complex relations in humans between hypergastrinaemia, (oxyntic) gastritis and atrophy, H. pylori infection, argyrophil cell hyperplasia, and the effects of long-term PPI treatment of acid-related diseases do not allow a quantification of the contribution of each single factor for the observed changes.

Pantoprazole suppresses Helicobacter pylori without affecting cure

BACKGROUND

Short-term, low-dose triple regimens composed of proton-pump inhibitors (PPI) and two antibiotics are the current gold standard therapy for cure of Helicobacter pylori infection. To date, the effect of PPI pretreatment on eradication outcome is not known. The aim of this study was to evaluate the influence of pretreatment with pantoprazole on the efficacy of an ensuing triple therapy.

METHODS

In this open, randomized, monocenter, parallel group comparison, 107 patients with duodenal ulcer or functional dyspepsia were assigned to receive one of the following treatment regimens: a 7-day triple therapy with pantoprazole, 40 mg bid; clarithromycin, 250 mg bid; and metronidazole, 400 mg bid, which was either preceded or followed by a 7-day therapy with pantoprazole, 40 mg (P-PCM or PCM-P). Assessment of H. pylori status was performed by a biopsy urease test and 13C urea breath test at the initial visit and 13C urea breath test at all follow-up visits.

RESULTS

The 7-day pantoprazole pretreatment resulted in a significant decline of the delta values of the 13C urea breath test. H. pylori infection was cured in 47 of 52 intention-to-treat patients of the P-PCM group (90%; 95% confidence interval, 79-97%) and in 46 of 53 of the PCM-P group (87%; 95% confidence interval, 75-95%).

CONCLUSIONS

Pretreatment with pantoprazole suppresses H. pylori but does not impair the efficacy of a consecutive short-term, low-dose triple therapy.