Mechanochemical synthesis and in vitro anti-Helicobacter pylori and uresase inhibitory activities of novel zinc(II)-famotidine complex

An all-in-one therapeutic platform for the treatment of resistant Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is a major cause of gastric diseases. Currently, bismuth-based quadruple therapy is widely adopted for eradicating H. pylori infection. However, this first-line strategy faces several challenges such as drug resistance, intestinal dysbacteriosis, and patients' poor compliance. To overcome these problems, an all-in-one therapeutic platform (CLA-Bi-ZnO2@Lipo) that composed of liposomes loading clarithromycin (CLA), Bi, and ZnO2 hybrid nanoparticles was developed for eradicating multidrug-resistant (MDR) H. pylori. The in vitro and in vivo results showed that CLA-Bi-ZnO2@Lipo could target the infection-induced inflammatory mucosa through liposome mediated nanoparticle-tissue surface charge interaction and quickly respond to the gastric acid environment to release CLA, Bi3+, Zn2+, and H2O2. By oral administration per day, the acid triggered decomposition of CLA-Bi-ZnO2@Lipo could significantly increase intragastric pH to 6 within 30 min; The released CLA, Zn2+, and H2O2 further exerted synergistical anti-bacterial effects in which a ∼2 order higher efficacy in reducing MDR H. pylori burden was achieved in comparison with standard quadruple therapy (p < 0.05); The released Zn2+ and Bi3+ could also alleviate mucosal inflammation. Most importantly, the CLA-Bi-ZnO2@Lipo exhibited superior biosafety and nearly no side effects on intestinal flora. Overall, this study developed a highly integrated and safe anti-MDR H. pylori agent which had great potential to be used as an alternative treatment for MDR H. pylori eradication.

Heat shock protein 70 is involved in polaprezinc driven cell protection against Helicobacter pylori-induced injury

Polaprezinc (PZ) plays a role in the protection of gastric mucosa and inhibiting Helicobacter pylori (H. pylori) growth in vitro. The objective of this study was to determine the protective effects of PZ on human gastric epithelial cells (GES-1) against H. pylori-induced damage, while also examining heat shock protein 70 (HSP70) as a potential underlying factor in this protection. Our findings revealed that PZ exerted bactericidal effects against H. pylori strains. We also observed that PZ mitigated the H. pylori-induced damage to GES-1 cells by increasing cell viability, reducing LDH release, and decreasing the secretion of pro-inflammatory factors such as MCP-1 and IL-6. Co-culturing PZ with GES-1 cells significantly up-regulated the GES-1 HSP70 expression in both a time and dose-dependent manner. Pre-incubating (for 12 h) or co-culturing (for 24 h) GES-1 cells with PZ reversed the down-regulation of HSP70 in GES-1 cells caused by H. pylori infection. However, when quercetin was used to inhibit the up-regulation of HSP70 in GES-1 cells, the protective effect of PZ on GES-1 cells was significantly reduced. Based on the results of this study, PZ exhibits a protective role on GES-1 cells against H. pylori injury, as well as a direct bactericidal effect on H. pylori. HSP70 is involved in the PZ-driven host cell protection against H. pylori injury. These findings provide insight into alternative strategies for H. pylori treatment.

Pharmacological Evaluation of Acacia nilotica Flower Extract against Helicobacter pylori and Human Hepatocellular Carcinoma In Vitro and In Silico

The resistance of cancer and Helicobacter pylori to several drugs reflects a worldwide problem, and it has been the intention of numerous researchers to overcome this problem. Thus, in this study, Acacia nilotica fruits were subjected to HPLC analysis to detect their phenolic compounds and flavonoids. Moreover, A. nilotica's anti-H. pylori activity and its inhibitory activity against human hepatocellular carcinoma (HepG-2 cells) were reported. Various compounds with different concentrations, such as ferulic acid (5451.04 µg/mL), chlorogenic acid (4572.26 µg/mL), quercetin (3733.37 µg/mL), rutin (2393.13 µg/mL), gallic acid (2116.77 µg/mL), cinnamic acid (69.72 µg/mL), hesperetin (121.39 µg/mL) and methyl gallate (140.45 µg/mL), were detected. Strong anti-H. pylori activity at 31 mm was reported, compared to the positive control of the 21.67 mm inhibition zone. Moreover, the MIC and MBC were 7.8 µg/mL and 15.62 µg/mL, respectively, while the MIC and MBC of the positive control were 31.25 µg/mL. The concentration of MBC at 25%, 50% and 75% reflected H. pylori's anti-biofilm activity of 70.38%, 82.29% and 94.22%, respectively. Good antioxidant properties of the A. nilotica flower extract were documented at 15.63, 62.50, 250 and 1000 µg/mL, causing the DPPH scavenging percentages of 42.3%, 52.6%, 65.5% and 80.6%, respectively, with a IC50 of 36.74 µg/mL. HepG-2 cell proliferation was inhibited (91.26%) using 500 µg/mL of flower extract with an IC50 of 176.15 µg/mL, compared to an IC50 of 395.30 µg/mL used against human normal melanocytes. Molecular docking was applied to investigate ferulic acid with the H. pylori (4HI0) crystal structure to determine the best binding mode that interacted most energetically with the binding sites. Molecular docking indicated that ferulic acid was a proper inhibitor for the 4HI0 protein enzyme of H. pylori. A low energy score (-5.58 Kcal/mol) was recorded as a result of the interaction of ferulic acid with the residue's SER 139 active site caused by the O 29 atom, which was important for its antibacterial activity.

Efficacy and Safety of Polaprezinc-Based Therapy versus the Standard Triple Therapy for Helicobacter pylori Eradication: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Helicobacter pylori (H. pylori) is the most prevalent etiology of gastritis worldwide. H. pylori management depends mainly on antibiotics, especially the triple therapy formed of clarithromycin, amoxicillin, and proton pump inhibitors. Lately, many antibiotic-resistant strains have emerged, leading to a decrease in the eradication rates of H. pylori. Polaprezinc (PZN), a mucosal protective zinc-L-carnosine complex, may be a non-antibiotic agent to treat H. pylori without the risk of resistance. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of a PZN-based regimen for the eradication of H. pylori. This study used a systematic review and meta-analysis synthesizing randomized controlled trials (RCTs) from WOS, SCOPUS, EMBASE, PubMed, and Google Scholar until 25 July 2022. We used the odds ratio (OR) for dichotomous outcomes presented with the corresponding 95% confidence interval (CI). We registered our protocol in PROSPERO with ID: CRD42022349231. We included 3 trials with a total of 396 participants who were randomized to either PZN plus triple therapy (n = 199) or triple therapy alone (control) (n = 197). Pooled OR found a statistical difference favoring the PZN arm in the intention to treat and per protocol H. pylori eradication rates (OR: 2.01 with 95% CI [1.27, 3.21], p = 0.003) and (OR: 2.65 with 95% CI [1.55, 4.54], p = 0.0004), respectively. We found no statistical difference between the two groups regarding the total adverse events (OR: 1.06 with 95% CI [0.55, 2.06], p = 0.85). PZN, when added to the triple therapy, yielded a better effect concerning the eradication rates of H. pylori with no difference in adverse event rates, and thus can be considered a valuable adjuvant for the management of H. pylori. However, the evidence is still scarce, and larger trials are needed to confirm or refute our findings.

Helicobacter Pylori-Induced Gastric Infections: From Pathogenesis to Novel Therapeutic Approaches Using Silver Nanoparticles

Helicobacter pylori is the first formally recognized bacterial carcinogen and the most important single digestive pathogen responsible for the induction of gastroduodenal diseases such as gastritis, peptic ulcer, and, finally, gastric neoplasia. The recently reported high rates of antimicrobial drug resistance hamper the current therapies of H. pylori, with therapeutic failure reaching up to 40% of patients. In this context, new treatment options and strategies are urgently needed, but the successful development of these new therapeutic tools is conditioned by the understanding of the high adaptability of H. pylori to the gastric acidic environment and the complex pathogenic mechanism. Due to several advantages, including good antibacterial efficiency, possible targeted delivery, and long tissular persistence, silver nanoparticles (AgNPs) offer the opportunity of exploring new strategies to improve the H. pylori therapy. A new paradigm in the therapy of H. pylori gastric infections using AgNPs has the potential to overcome the current medical limitations imposed by the H. pylori drug resistance, which is reported for most of the current organic antibiotics employed in the classical therapies. This manuscript provides an extensive overview of the pathology of H. pylori-induced gastritis, gastric cancer, and extradigestive diseases and highlights the possible benefits and limitations of employing AgNPs in the therapeutic strategies against H. pylori infections.

Bionanofactories for Green Synthesis of Silver Nanoparticles: Toward Antimicrobial Applications

Among the various types of nanoparticles and their strategy for synthesis, the green synthesis of silver nanoparticles has gained much attention in the biomedical, cellular imaging, cosmetics, drug delivery, food, and agrochemical industries due to their unique physicochemical and biological properties. The green synthesis strategies incorporate the use of plant extracts, living organisms, or biomolecules as bioreducing and biocapping agents, also known as bionanofactories for the synthesis of nanoparticles. The use of green chemistry is ecofriendly, biocompatible, nontoxic, and cost-effective. We shed light on the recent advances in green synthesis and physicochemical properties of green silver nanoparticles by considering the outcomes from recent studies applying SEM, TEM, AFM, UV/Vis spectrophotometry, FTIR, and XRD techniques. Furthermore, we cover the antibacterial, antifungal, and antiparasitic activities of silver nanoparticles.

Recent advances on polaprezinc for medical use (Review)

The present study described the chemical and biological properties of zinc complex of L-carnosine (L-CAZ; generic name, polaprezinc; chemical name, catena-(S)-[µ-[N(α)-(3-aminopropionyl) histidinato (2-) N1, N2, O: N(τ)]-zinc], molecular formula, C₉H₁₄N₄O₃Zn; molecular weight, 291.6404; CAS registry number, 107667-60-7). Characterized as a white or yellowish white crystalline powder, this drug is insoluble in glacial acetic acid and almost insoluble in water, methanol, ethanol and ether. It is soluble in dilute hydrochloric acid, dilute nitric acid and sodium hydroxide solution, and its melting point is 260-270˚C. Polaprezinc is an anti-ulcer drug that was jointly studied and developed by Hamari Chemicals Co., Ltd. and Zeria Pharmaceutical Co., Ltd., and was first approved in Japan in 1994. This review article summarizes the research advances of polaprezinc, including the patents, preparations, synthetic routes, pharmacokinetics, pharmacological effects and application in clinical research.

A review on the structures and biological activities of anti-Helicobacter pylori agents

Helicobacter pylori is one of the main causal risk factor in the generation of chronic gastritis, gastroduodenal ulcers and gastric carcinoma. Thus, the eradication of H. pylori infection is an important way for preventing and managing the gastric diseases. Multiple-therapy with several antibacterial agents is used for the eradication of H. pylori infections; however the increase of resistance to H. pylori strains has resulted in unsatisfactory eradication and unsuccessful treatment. Furthermore, the combination therapy with high dosing leads to the disruption of intestinal microbial flora and undesired side effects. Therefore, the search for new therapeutic agents with high selectivity against H. pylori is a field of current interest. In recent years, diverse compounds originating from natural sources or synthetic drug design programs were evaluated and tried to optimize for applying against H. pylori. In this review, we have described various classes of anti-H. pylori compounds, their structure-activity relationship studies, and mechanism of actions, which could be useful for the development of new drugs for the treatment of H. pylori infections.

In Vitro and In Vivo Activities of Zinc Linolenate, a Selective Antibacterial Agent against Helicobacter pylori

Helicobacter pylori is a major global pathogen, and its infection represents a key factor in the etiology of various gastric diseases, including gastritis, peptic ulcers, and gastric carcinoma. The efficacy of current standard treatment for H. pylori infection including two broad-spectrum antibiotics is compromised by toxicity toward the gut microbiota and the development of drug resistance, which will likely only be resolved through novel and selective antibacterial strategies. Here, we synthesized a small molecule, zinc linolenate (ZnLla), and investigated its therapeutic potential for the treatment of H. pylori infection. ZnLla showed effective antibacterial activity against standard strains and drug-resistant clinical isolates of H. pyloriin vitro with no development of resistance during continuous serial passaging. The mechanisms of ZnLla action against H. pylori involved the disruption of bacterial cell membranes and generation of reactive oxygen species. In mouse models of multidrug-resistant H. pylori infection, ZnLla showed in vivo killing efficacy comparable and superior to the triple therapy approach when use as a monotherapy and a combined therapy with omeprazole, respectively. Moreover, ZnLla treatment induces negligible toxicity against normal tissues and causes minimal effects on both the diversity and composition of the murine gut microbiota. Thus, the high degree of selectivity of ZnLla for H. pylori provides an attractive candidate for novel targeted anti-H. pylori treatment.

Famotidine, an Antiulcer Agent, Strongly Inhibits Helicobacter pylori and Human Carbonic Anhydrases

Famotidine, an antiulcer drug incorporating a sulfamide motif, was investigated as carbonic anhydrase inhibitor (CAI). It acts as a nanomolar inhibitor of several human (hCA II, VI, VII and XII) and Helicobacter pylori CAs. The high resolution X-ray structures of famotidine bound to hCA I and II revealed interesting aspects related to its CA inhibition mechanism, offering the possibility to develop antibacterials with a novel mechanism of action.

Polaprezinc combined with clarithromycin-based triple therapy for Helicobacter pylori-associated gastritis: A prospective, multicenter, randomized clinical trial

The efficacy and safety of polaprezinc combined with triple therapy was compared with triple therapy alone in the eradication of Helicobacter pylori. A randomized, parallel-group, open-label, controlled, prospective multicenter study was conducted in 11 cities in China. Treatment-naive patients with H. pylori-associated gastritis were randomly assigned to one of three arms for a 14-day treatment: Arm A triple therapy (omeprazole 20 mg, amoxicillin 1 g, and clarithromycin 500 mg, each twice daily) plus polaprezinc 75 mg twice daily; Arm B triple therapy plus polaprezinc 150 mg twice daily, or Arm C triple therapy alone. The rate of H. pylori eradication was the primary endpoint. Secondary endpoints were symptom improvement and lower incidence of adverse events. 303 patients completed the study- 106, 96, and 101 patients in Arms A, B, and C, respectively. Intention-to-treat (ITT) analysis showed that the rate of H. pylori eradication was significantly higher for Arms A (77.0%) and B (75.9%) compared to Arm C (58.6%) (P < 0.01), whereas there was no difference between Arms A and B (P = 0.90). Per-protocol (PP) analysis showed that the rate of H. pylori eradication was significantly higher for Arms A (81.1%) and B (83.3%) compared to Arm C (61.4%) (P < 0.01), whereas there was no significant difference between Arms A and B (P = 0.62). All three groups reported significant symptom improvement at 7, 14, and 28 days after treatment, compared to baseline (P < 0.0001). The adverse event rate for Arm B (5.1%) was higher than for Arms A (2.8%) (P = 0.04) and C (1.9%) (P = 0.02). There were no serious adverse events in any group. It appears that standard dose polaprezinc combined with triple therapy can significantly improve the H. pylori eradication rate, without an increase in toxicity.

Green Synthesis of Silver Nanoparticles: Structural Features and In Vivo and In Vitro Therapeutic Effects against Helicobacter pylori Induced Gastritis

This study evaluates in vivo and in vitro anti-Helicobacter pylori (H. pylori) efficacy of silver nanoparticles (Ag-NPs) prepared via a cost-effective green chemistry route wherein Peganum harmala L. seeds extract was used as a reducing and capping agent. The structural features, as elucidated by surface plasmon resonance spectrophotometry, transmission electron microscopy, and powder X-ray diffraction spectroscopy, revealed the Ag-NPs synthesized to be polydispersed in nature and spherical in shape with 5–40 nm size. A typical Ag-NPs suspension (S₅), with size being 15 nm, when tested in vitro against forty-two local isolates and two reference strains, showed a considerable anti-H. pylori activity. In case of in vivo trial against H. pylori induced gastritis, after oral administration of 16 mg/kg body weight of S₅ for seven days, a complete clearance was recorded in male albino rates. In comparative time-killing kinetics, S₅ exhibited dose- and time-dependent anti-H. pylori activity that was almost similar to tetracycline and clarithromycin, less than amoxicillin, but higher than metronidazole. Furthermore, S₅ was found to be an equally effective anti-H. pylori agent at low (≤4) and high pH with no drug resistance observed even up to 10 repeated exposures while a significant drug resistance was recorded for most of the standard drugs employed. The present results revealed the potential of the synthesized Ag-NPs as safer bactericidal agents for the treatment of H. pylori induced gastritis.

Does long-term use of silver nanoparticles have persistent inhibitory effect on H. pylori based on Mongolian gerbil's model?

BACKGROUND

It is urgent to find alternative agents due to increasing failure rate of Helicobacter pylori (H. pylori) eradication. The study surveyed the long-term effect of silver nanoparticles (AgNP) on H. pylori based on Mongolian gerbil's model.

MATERIALS AND METHODS

Fifty gerbils were randomly allocated to six groups (A-F). Group (Gr) A: the gerbils were fed with broth; Gr B and D: the gerbils were fed with AgNP/clay complex (0.1% of weight); Gr C and E: the gerbils were fed with AgNP/clay complex(1% of weight); and Gr D, E, and F: the gerbils were inoculated with H. pylori. At the 20th experimental week, the gerbils were sacrificed. Histology was evaluated according to the classification of the Sydney system. P < 0.05 was considered to be statistically significant.

RESULTS

The AgNP/clay has more obvious inhibitory effect on H. pylori in vitro. There was a trend of higher concentrations of AgNP with stronger inhibitory effect on H. pylori growth (P = 0.071). There were no significant differences of inflammation among groups D, E, and F (P = 0.688).

CONCLUSION

AgNP/clay would be a potential and safe agent for inhibiting H. pylori. It should be helpful for eradication of H. pylori infection.

Anti-Helicobacter pylori and urease inhibition activities of some traditional medicinal plants

Different parts of Acacia nilotica (L.) Delile, Calotropis procera (Aiton) W.T. Aiton, Adhatoda vasica Nees, Fagoniaar abica L. and Casuarina equisetifolia L. are traditionally used in folk medicine for the treatment of a variety of common ailments like nausea, cold, cough, asthma, fevers, diarrhea, sore throat, swelling, etc. The present study was aimed to evaluate the anti-Helicobacter pylori and urease inhibition activities of extracts produced from the above selected medicinal plants native to Soon Valley (home to an old civilization) in the Punjab province of Pakistan. Methanol, acetone and water extracts of the plants were evaluated for anti-bacterial activity against thirty four clinical isolates and two reference strains of H. pylori. Minimum inhibitory concentrations (MICs) of the extracts were determined using the agar dilution method and compared with some standard antibiotics like amoxicillin (AMX), clarithromycin (CLA), tetracycline (TET) and metronidazole (MNZ), used in the triple therapy for H. pylori eradication. H. pylori urease inhibition activity of the extracts was assessed by the phenol red method, wherein, Lineweaver-Burk plots were used to determine Michaelis-Menten constants for elucidating the mechanism of inhibition. Methanol and acetone extracts from Acacia nilotica and Calotropis procera exhibited stronger anti-H. pylori activity than MNZ, almost comparable activity with TET, but were found to be less potent than AMX and CLT. The rest of the extracts exhibited lower activity than the standard antibiotics used in this study. In the H. pylori urease inhibitory assay, methanol and acetone extracts of Acacia nilotica and Calotropis procera showed significant inhibition. Lineweaver-Burk plots indicated a competitive mechanism for extract of Acacia nilotica, whereas extract of Calotropis procera exhibited a mixed type of inhibition.

Green synthesis of silver nanoparticles through reduction with Solanum xanthocarpum L. berry extract: characterization, antimicrobial and urease inhibitory activities against Helicobacter pylori

A green synthesis route for the production of silver nanoparticles using methanol extract from Solanum xanthocarpum berry (SXE) is reported in the present investigation. Silver nanoparticles (AgNps), having a surface plasmon resonance (SPR) band centered at 406 nm, were synthesized by reacting SXE (as capping as well as reducing agent) with AgNO(3) during a 25 min process at 45 °C. The synthesized AgNps were characterized using UV-Visible spectrophotometry, powdered X-ray diffraction, and transmission electron microscopy (TEM). The results showed that the time of reaction, temperature and volume ratio of SXE to AgNO(3) could accelerate the reduction rate of Ag(+) and affect the AgNps size and shape. The nanoparticles were found to be about 10 nm in size, mono-dispersed in nature, and spherical in shape. In vitro anti-Helicobacter pylori activity of synthesized AgNps was tested against 34 clinical isolates and two reference strains of Helicobacter pylori by the agar dilution method and compared with AgNO(3) and four standard drugs, namely amoxicillin (AMX), clarithromycin (CLA), metronidazole (MNZ) and tetracycline (TET), being used in anti-H. pylori therapy. Typical AgNps sample (S1) effectively inhibited the growth of H. pylori, indicating a stronger anti-H. pylori activity than that of AgNO(3) or MNZ, being almost equally potent to TET and less potent than AMX and CLA. AgNps under study were found to be equally efficient against the antibiotic-resistant and antibiotic-susceptible strains of H. pylori. Besides, in the H. pylori urease inhibitory assay, S1 also exhibited a significant inhibition. Lineweaver-Burk plots revealed that the mechanism of inhibition was noncompetitive.