Search Results (289)

Helicobacter pylori infection represents one of the most prevalent and persistent bacterial infections worldwide, closely linked to a spectrum of gastroduodenal diseases, including chronic gastritis, peptic ulceration, and gastric cancer. Recent advances have shed light on the critical role of endogenous lectins, particularly galectins, in modulating host–pathogen interactions within the gastric mucosa. Galectins are β-galactoside-binding proteins with highly conserved structures but diverse biological functions, ranging from regulation of innate and adaptive immunity to modulation of cell signaling, apoptosis, and epithelial integrity. This review provides a comprehensive synthesis of current knowledge on the involvement of key galectin family members—especially Galectin-1, -2, -3, -8, and -9—in the context of H. pylori infection. Their dual roles in enhancing mucosal defense and facilitating bacterial persistence are examined along with their contributions to immune evasion, inflammation, and gastric carcinogenesis. Understanding the interplay between galectins and H. pylori enhances our knowledge of mucosal immunity. This interaction may also reveal potential biomarkers for disease progression and identify novel therapeutic targets. Modulating galectin-mediated pathways could improve outcomes in H. pylori-associated diseases. Full article

Background/Objectives: Tegoprazan (TPZ) is a potassium-competitive acid blocker (P-CAB) used to treat conditions such as gastroesophageal reflux disease, peptic ulcer, and Helicobacter pylori infection. It exists in three solid forms: amorphous, Polymorph A, and Polymorph B. This study investigates the molecular basis of polymorph selection, focusing on conformational bias and solvent-mediated phase transformations (SMPTs). Methods: The conformational energy landscapes of two TPZ tautomers were constructed using relaxed torsion scans with the OPLS4 force field and validated by nuclear Overhauser effect (NOE)-based nuclear magnetic resonance (NMR). Hydrogen-bonded dimers were analyzed using DFT-D. Powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), solubility, and slurry tests were conducted using methanol, acetone, and water. Kinetic profiles were modeled with the Kolmogorov–Johnson–Mehl–Avrami (KJMA) equation. Results: Polymorph A was thermodynamically stable across all analyses. Both amorphous TPZ and Polymorph B converted to A in a solvent-dependent manner. Methanol induced direct A formation, while acetone showed a B → A transition. Crystallization was guided by solution conformers and hydrogen bonding. Conclusions: TPZ polymorph selection is governed by solution-phase conformational preferences, tautomerism, and solvent-mediated hydrogen bonding. DFT-D and NMR analyses showed that protic solvents favor the direct crystallization of stable Polymorph A, while aprotic solvents promote the transient formation of metastable Polymorph B. Elevated temperatures and humidity accelerate polymorphic transitions. This crystal structure prediction (CSP)-independent strategy offers a practical framework for rational polymorph control and the mitigation of disappearing polymorph risks in tautomeric drugs. Full article

Rare presentations are surprising and may disturb the day-to-day routine of a medical unit; however, they are expected (not as individual entities, but as a group of “uncommon causes”). While reviewing the literature in relation to three clinical cases of upper gastrointestinal bleeding (UGIB) encountered in our institution—gastric metastases of breast cancer (GMB), pyloric gland adenoma, and gastrointestinal stromal tumor (GIST)—we identified seven and 29 case reports for the first two entities, and over 100 publications addressing GIST. This prompted a shift in focus from novel reporting to diagnostic contextualization. We found it difficult to obtain an overview of the spectrum of UGIB etiologies, as most publications refer to a few individual entities or to a subgroup of rare causes. The narrative review we conducted arose from this particular research methodology. Based on a broad literature search, UGIB etiologies were organized in five categories (lesions of the mucosa, neoplasms, vascular causes, bleeding predisposition, and external sources of bleeding). In the management of patients with UGIB, the underlying etiology deviates from the classic peptic ulcer disease/esophageal varices dyad in approximately half of the cases. This underscores the need for heightened clinical vigilance, particularly in complex scenarios, where endoscopic findings, imaging results, and histopathological interpretations may be unexpected or prone to misinterpretation. As an illustration, we conducted two systematic reviews of case reports of bleeding GMB and PGA. Our findings support a proactive diagnostic and research mindset and advocate for improved awareness of uncommon UGIB etiologies. Full article

Proton pump inhibitors (PPIs) are widely prescribed medications primarily used to treat gastroesophageal reflux disease, peptic ulcer disease, and upper gastrointestinal bleeding. Despite clear therapeutic benefits in appropriate contexts, widespread overprescribing and extended use without clear indications have prompted significant concerns about associated risks. Accumulating evidence, predominantly from observational studies, suggests that long-term PPI use may lead to complications such as vitamin and mineral deficiencies, increased risks of infections, dysbiosis, renal dysfunction, bone fractures, cardiovascular disease, and certain malignancies. This narrative review not only synthesizes the current evidence surrounding PPI-related harms and existing deprescribing guidelines but also offers a novel perspective on how stewardship principles can be applied to promote responsible PPI prescribing. In particular, we propose a stewardship-oriented deprescribing framework rooted in implementation science, focusing on provider behavior, patient engagement, and health system-level integration. Recognizing these potential harms, evidence-based deprescribing strategies such as tapering, intermittent dosing, and transitions to alternative therapies are critical to mitigate unnecessary patient exposure. Effective implementation of deprescribing requires addressing patient, provider, and institutional barriers through educational initiatives, policy support, and structured monitoring. By promoting judicious PPI prescribing and proactive stewardship practices, clinicians can significantly reduce medication-related harm and improve patient safety. Full article

Helicobacter pylori is a gastric pathogen implicated in peptic ulcer disease and gastric cancer. The increasing prevalence of antibiotic-resistant strains underscores the urgent need for alternative therapeutic strategies. In this study, we investigated the chemical composition and antibacterial activity of an aqueous extract from Caulerpa lentillifera (sea grape), a farm-cultivated edible green seaweed collected from Krabi Province, Thailand. Ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) revealed that the extract was enriched in bioactive nucleosides and phenolic compounds. In vitro assays demonstrated dose-dependent inhibition of H. pylori growth following exposure to sea grape extract. Furthermore, untargeted intracellular metabolomic profiling of H. pylori cells treated with the extract uncovered significant perturbations in central carbon and nitrogen metabolism, including pathways associated with the tricarboxylic acid (TCA) cycle, one-carbon metabolism, and alanine, aspartate, and glutamate metabolism. Pyrimidine biosynthesis was selectively upregulated, indicating a potential stress-induced shift toward nucleotide salvage and DNA repair. Of particular note, succinate levels were markedly reduced despite accumulation of other TCA intermediates, suggesting disruption of electron transport-linked respiration. These findings suggest that bioactive metabolites from C. lentillifera impair essential metabolic processes in H. pylori, highlighting its potential as a natural source of antimicrobial agents targeting bacterial physiology. Full article

Helicobacter pylori (H. pylori) is one of the most prevalent chronic bacterial infections globally, significantly contributing to gastritis, peptic ulcers, and gastric malignancies. Its pathogenesis involves a complex array of virulence factors—including cagA, vacA, and urease—which facilitate mucosal colonization, immune evasion, and persistent inflammation. A major challenge in vaccine development is the bacterium’s ability to manipulate both innate and adaptive immune responses, resulting in limited natural clearance and long-term persistence. This review synthesizes H. pylori pathogenesis and host immune dynamics, highlighting their implications for vaccine design. By elucidating the molecular and cellular mechanisms underlying host–pathogen interactions, we explore how these insights inform antigen selection, adjuvant optimization, and delivery strategies. By integrating basic science with translational objectives, this review aims to support the development of an effective H. pylori vaccine, addressing global health needs, particularly in regions with a high infection burden and limited access to treatment. Full article

Background and Objectives: Chronic mucosal infection with Helicobacter pylori (H. pylori) plays a key role in the development of gastroduodenal disorders such as chronic gastritis, peptic ulcers, gastric lymphoma, and gastric cancer by triggering local immune responses and inducing hypoxic and inflammatory conditions in the gastric mucosa. This study aims to evaluate the potential diagnostic value of hypoxia-inducible factors HIF-1α and HIF-2α, along with transmembrane prolyl 4-hydroxylase (P4H-TM), as biomarkers in H. pylori-positive patients. Additionally, the study investigates the association between these markers and alterations in lipid profiles, as well as their involvement in the molecular mechanisms underlying gastric conditions like gastritis, particularly in the context of H. pylori infection. Materials and Methods: This study was conducted at Istanbul Avcılar Murat Kölük State Hospital’s General Surgery Outpatient Clinic. A total of 60 participants were included: 40 patients diagnosed with chronic gastritis (20 H. pylori-positive and 20 H. pylori-negative) and 20 healthy controls confirmed negative by 13C-urea breath test. Blood samples were collected for ELISA analysis of HIF-1α, HIF-2α, and P4H-TM levels. Additionally, lipid profiles were measured and compared among the groups. Results: No significant differences were found among the groups in terms of demographic factors such as age, sex, or body mass index (BMI). However, significant variations were observed in the levels of HIF-1α, HIF-2α, and P4H-TM across all groups (p < 0.001 for each marker). These markers were substantially elevated in the H. pylori-positive gastritis group compared to both the H. pylori-negative and healthy control groups. Receiver Operating Characteristic (ROC) curve analysis revealed that all evaluated markers exhibited strong diagnostic accuracy in differentiating H. pylori-positive individuals from other groups. HIF-1α (AUC: 0.983) and HIF-2α (AUC: 0.981) both achieved 100% sensitivity with specificities of 93.3% and 91.1%, respectively. P4H-TM showed an AUC of 0.927, with 85% sensitivity and 95.6% specificity. Conclusions: These findings indicate that HIF-1α, HIF-2α, and P4H-TM may serve as effective biomarkers for diagnosing H. pylori-positive patients and may be linked to changes in lipid metabolism. The elevated expression of these markers in response to H. pylori infection highlights their potential roles in the inflammatory and hypoxic pathways that contribute to the pathogenesis of gastric diseases such as gastritis. Full article

Helicobacter pylori (H. pylori) infection is a leading cause of gastritis, peptic ulcers, and gastric cancer, affecting more than half of the global population. Its persistence in the acidic gastric environment and its ability to evade host immunity present major treatment challenges. Although antibiotics remain the standard therapy, rising antimicrobial resistance has reduced treatment efficacy, prompting the search for alternative and adjunct approaches. Emerging therapies include probiotics, antimicrobial peptides (AMPs), and plant-derived compounds, which target H. pylori through membrane disruption, immunomodulation, or direct antimicrobial activity. Novel drug delivery systems and microbiota-sparing interventions are also being investigated. Additionally, vaccine development offers a promising strategy for long-term protection, though challenges related to antigenic variability and host-specific responses remain. Despite these advances, treatment variability and the limited clinical validation of alternatives hinder progress. A multifaceted approach integrating microbiome research, host–pathogen interactions, and new therapeutic agents is essential for future success. Full article

Helicobacter pylori (H. pylori) is regarded as a significant risk factor for gastritis, peptic ulcer disease, and gastric cancer. However, the increasing resistance of H. pylori strains has resulted in low eradication rates and ineffective treatments. Herein, we report on identification of a new quipazine derivative—compound 9c (N-(3-chlorobenzyl)-2-(piperazin-1-yl)quinolin-4-amine), which displayed antibacterial properties (MIC range 2–4 µg/mL) against H. pylori CagA-positive reference strains associated with an increased risk of gastric cancer, including metronidazole-resistant ATCC 43504, clarithromycin-resistant ATCC 700684 and susceptible J99 strain, as well as clinical, multidrug-resistant isolate (3CML, resistant to clarithromycin, metronidazole and levofloxacin). Compound 9c showed bacteriostatic activity (MBC/MIC ratio > 4), demonstrated antibiofilm-forming properties and prevented auto-aggregation of microbial cells. It also displayed an additive effect in ½ MIC (2 µg/mL) when administered with clarithromycin and/or metronidazole. Compound 9c had no impact on gut microbiota reference strains of S. aureus, E. coli, E. faecalis and L. paracasei as well as no hemolytic activity against sheep erythrocytes. Finally, by reducing the viability of the SNU-1 human gastric cancer cell line (IC₅₀ = 3.28 μg/mL), compound 9c might offer important implications regarding the oncogenic characteristics of cagA+ H. pylori strains. Full article

Helicobacter pylori is a Gram-negative bacterium that infects almost half of the global population and is linked to gastric conditions like peptic ulcers and gastric cancer, as well as other diseases such as neurological disorders, cardiovascular problems, and iron deficiency anemia. Its survival in the acidic stomach environment is due to virulence factors like urease, flagella, and adhesion proteins (BabA, SabA). Current treatments involve a combination of antibiotics (clarithromycin, metronidazole, amoxicillin, tetracycline) and proton pump inhibitors, but increasing antibiotic resistance, especially to clarithromycin and metronidazole, poses a major challenge. Resistance mechanisms include mutations in drug targets, efflux pump overexpression, and enzymatic degradation of antibiotics. This has prompted exploration of alternative therapies targeting bacterial processes like urease activity, biofilm formation, and metabolic pathways (energy production, amino acid synthesis, iron acquisition). Natural compounds, such as chitosan and plant extracts, show promise in combating H. pylori growth and virulence. Vaccine development is also ongoing, with DNA vaccines showing potential for broad immune responses. However, no vaccine is yet close to widespread clinical use. Full article

Previous studies showed a potent anti-inflammatory activity of Solanum tuberosum L. polysaccharide (STP), which inhibited pro-inflammatory cytokines and stimulated anti-inflammatory ones in peptic ulcer models. Thus, the main goal of this study was to find out the molecular background of such activity and possible applications in different anti-inflammatory models. This study investigated the anti-inflammatory potential of the polysaccharide STP using model of LPS-induced inflammation in THP-1 macrophage-like cells (on the expression of IL1B, IL6, IL10, TNF, NFKB1, BCL2, NRF2, and BAX—genes involved in the regulation of inflammatory processes and oxidative stress), rat pocket granuloma, and carrageenan-induced oedema models. STP significantly reduced oedema volume, exhibiting a comparable anti-exudative effect to ibuprofen and surpassing the control group. The anti-inflammatory mechanism of STP extends beyond suppression of proinflammatory cytokine (IL1B, IL6, TNF) expression, as it also activates cellular defence mechanisms (NRF2, BCL2, BAX) and expression of anti-inflammatory cytokine (IL10). This complex, multifactorial action suggests that STP may possess significant therapeutic value for inflammatory conditions. The combined functional and molecular findings underscore STP’s potent anti-inflammatory properties, comparable to ibuprofen. Full article

Background: Hypolipidemia has been shown to be a factor that elevates the risk of bleeding. This study aimed to investigate the relationship between cholesterol levels and the risk of peptic ulcer bleeding (PUB). Methods: A total of 15,547 patients who underwent esophagogastroduodenoscopy (EGD) between May 2017 and December 2020 were screened. Of these, 317 were included in this retrospective cohort study. PUB was diagnosed by EGD. Serum cholesterol levels were measured at six-month intervals, and cumulative mean cholesterol concentrations were calculated using all available data during the observation period. Results: Ulcer bleeding was detected in 173 (45.6%) patients with peptic ulcer. Patients with bleeding peptic ulcer exhibited significantly lower TC, LDL-C, and HDL-C levels compared to non-bleeding peptic ulcer patients and controls (p < 0.001). The optimal LDL cut-off was 91.50 (p < 0.001), with 75.1% sensitivity and 24.1% specificity. For HDL, the cut-off was 42.50 (p < 0.001), yielding 72.3% sensitivity and 30.1% specificity. A one-unit increase in LDL and HDL reduced the risk of PUB by 0.95-fold and 0.97-fold, respectively. Conclusions: Our findings suggest that reduced cholesterol levels, particularly LDL-C and HDL-C, may elevate the risk of PUB. Therefore, monitoring cholesterol levels in peptic ulcer patients, especially those at higher bleeding risk, could be beneficial. Full article

Helicobacter pylori (H. pylori), a prevalent human pathogen affecting nearly half the global population, is a major contributor to chronic gastritis, peptic ulcer, and gastric cancer. H. pylori develops biofilms (BFs) allowing bacteria to evade the immune response. Differences in composition between planktonic and biofilm cells influence the host’s immune response, yet the specific biofilm components modulating this response remain uncharacterized. Considering the above, this study evaluated the effect of in vitro-generated H. pylori BF on the antibacterial activity of neutrophils. This work utilized sonication to obtain disaggregated H. pylori BF (d-BF-Hp) to challenge human neutrophils, assessing their bactericidal and phagocytic activity against Staphylococcus aureus. S. aureus survival in the presence of neutrophils was enhanced by 10 μg/mL of d-BF-Hp’s protein. Conversely, S. aureus survival was significantly lower at 30 µg/mL compared to 10 µg/mL d-BF-Hp. Furthermore, 10 and 30 µg/mL of d-BF-Hp significantly reduced the neutrophil phagocytosis rate. Our findings suggest that d-BF-Hp components diminish neutrophil bactericidal activity, although this effect was not observed at higher d-BF-Hp concentrations. Increased d-BF-Hp concentrations proportionally reduced neutrophil phagocytic capacity. Future work should explore the mechanisms underlying the alteration of neutrophil microbicidal properties. Full article

Ellagitannins are bioactive phenolic acids found in various fruits, plants, and beverages such as wine and spirits. This review aims to discuss the metabolism, absorption, and some health benefits related to the intestinal activity of these molecules, as well as some supplements developed from them. Ellagitannins are first biodegraded to ellagic acid and then to urolithins, which are more easily absorbed. This process is mediated by specific enzymes and intestinal microbiota. Not all individuals can metabolize ellagitannins into urolithins due to differences in the composition of the intestinal microbiota, resulting in three phenotypes: metabotypes A, B, and 0. In recent decades, ellagitannins and their derivatives (ellagic acid and urolithins) have gained significant attention for their potential benefits against various digestive diseases, including irritable bowel syndrome, peptic ulcers, gastritis, colon cancer, esophageal cancer, and pancreatic cancer. As a result, nutraceutical supplements have been developed to treat these conditions, representing significant and promising applications of these compounds in digestive health. Full article

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human stomach and is associated with several gastric diseases, including gastritis, peptic ulcer disease, and gastric cancer. The bacterium’s ability to thrive in the harsh gastric environment is due, to some extent, to its stress response mechanisms, with its heat shock proteins (HSPs) playing a putative, yet not fully understood, role in these adaptive processes. HSPs are a family of molecules, highly conserved throughout phylogenesis, that assist in protein folding, prevent aggregation, and ensure cellular homeostasis under stressful conditions. In H. pylori, HSPs contribute to survival in the stomach’s acidic environment and oxidative stress. Furthermore, they aid in the bacterium’s ability to adhere to gastric epithelial cells, modulate the host immune response, and form biofilms, all contributing to chronic infection and pathogenicity. The role of microbial HSPs in antibiotic resistance has also emerged as a critical area of research, as these proteins help stabilize efflux pumps, protect essential proteins targeted by antibiotics, and promote biofilm formation, thereby reducing the efficacy of antimicrobial treatments. Among bacterial HSPs, GroEL and DnaK are probably the major proteins that control most of the H. pylori’s functioning. Indeed, both proteins possess remarkable acid resistance, high substrate affinity, and dual roles in protein homeostasis and host interaction. These features make them critical for H. pylori’s adaptation, persistence, and pathogenicity in the gastric niche. In addition, recent findings have also highlighted the involvement of HSPs in the crosstalk between H. pylori and gastric epithelial cells mediated by the release of bacterial outer membrane vesicles and host-derived exosomes, both of these extracellular vesicles being part of the muco-microbiotic layer of the stomach and influencing cellular signalling and immune modulation. Considering their critical role in the survival and persistence of bacteria, microbial HSPs also represent potential therapeutic targets. Strategies aimed at inhibiting microbial HSP function, combined with conventional antibiotics or developing vaccines targeting microbial HSPs, could provide new avenues for the treatment of H. pylori infections and combat antibiotic resistance. This review explores the multifaceted roles of microbial HSPs in the pathogenesis of H. pylori, highlighting their contributions to bacterial adhesion, immune evasion, stress response, and antibiotic resistance. Full article