anti-Helicobacter Pylori Activity Research Articles

Retraction Note: Gastroprotective effect of desmosdumotin C isolated from Mitrella kentii against ethanol-induced gastric mucosal hemorrhage in rats: possible involvement of glutathione, heat-shock protein-70, sulfhydryl compounds, nitric oxide, and anti-Helicobacter pylori activity.

Retraction Note: Gastroprotective effect of desmosdumotin C isolated from Mitrella kentii against ethanol-induced gastric mucosal hemorrhage in rats: possible involvement of glutathione, heat-shock protein-70, sulfhydryl compounds, nitric oxide, and anti-Helicobacter pylori activity.

Some Schiff Bases Containing Eugenol and Guaiacol: Comparison of Urease Inhibition and Anti-Helicobacter pylori Activities with Its Azo Analogs

Some Schiff Bases Containing Eugenol and Guaiacol: Comparison of Urease Inhibition and Anti-Helicobacter pylori Activities with Its Azo Analogs

Characterization of phenolic compounds in Eugenia uniflora leaves by ESI(-) FT-ICR MS, analysis of cytotoxic activity on gastric adenocarcinoma (AGS cells), and anti-Helicobacter pylori activity

Eugenia uniflora leaves are a source of flavonoids and ellagitannins, and the Brazilian population uses them to treat various diseases, including gastrointestinal disorders. This study aimed to determine if the ethanol extract and other derivatives are effective cytotoxic agents against gastric adenocarcinoma (AGS cells) and anti-H. pylori agent, its chemical composition, and mass spectrometry characterization of the more abundant compounds. The results were compared with the literature. The aqueous fraction, rich in Oenothein B and Gemin D/Hippomanin A, showed anti-H. pylori activity and higher cytotoxicity on AGS cells compared to the other samples analysed. Furthermore, the ESI(-) FT-ICR MS characterized the more abundant phenolic compounds, including Quinic Acid, Myricitrin, Gemin D/Hippomanin A, and Oenothein. Therefore, the activity of the ethanolic extract and aqueous fraction for gastric cancer and against H-pylori seems to originate from the antiproliferative and bacteriostatic effects of tannins and flavonoids.

Nature-Inspired Compounds: Synthesis and Antibacterial Susceptibility Testing of Eugenol Derivatives against H. pylori Strains.

The antimicrobial properties of one of the most important secondary metabolites, Eugenol (EU), inspired us to design and synthesize three different series of derivatives enhancing its parent compound's anti-Helicobacter pylori activity. Thus, we prepared semisynthetic derivatives through (A) diazo aryl functionalization, (B) derivatization of the hydroxy group of EU, and (C) elongation of the allyl radical by incorporating a chalcogen atom. The antibacterial evaluation was performed on the reference NCTC 11637 strain and on three drug-resistant clinical isolates and the minimal inhibitory and bactericidal concentrations (MICs and MBCs) highlight the role of chalcogens in enhancing the antimicrobial activity (less than 4 µg/mL for some compounds) of the EU scaffold (32-64 µg/mL).

Newer, Older, and Alternative Agents for the Eradication of Helicobacter pylori Infection: A Narrative Review.

Although discovered 40 years ago, Helicobacter pylori infection is still raising diagnostic and therapeutic problems today. The infection is currently managed based on statements in several guidelines, but implementing them in practice is a long process. Increasing antibiotic resistance and weak compliance of the patients limit the efficacy of eradication regimens, leaving much room for improvement. Third-generation proton pump inhibitors have added little to the results of the first two generations. Potassium-competitive acid blockers have a stronger and longer inhibitory action of acid secretion, increasing the intragastric pH. They obtained superior results in eradication when compared to proton pump inhibitors. Instead of innovative antibiotics, derivatives of existing antimicrobials were developed; some new fluoroquinolones and nitazoxanide seem promising in practice, but they are not recommended by the guidelines. Carbonic anhydrase inhibitors have both anti-secretory and bactericidal effects, and some researchers are expecting their revival in the treatment of infection. Capsules containing components of the eradication regimens have obtained excellent results, but are of limited availability. Probiotics, if containing bacteria with anti-Helicobacter pylori activity, may be useful, increasing the rates of eradication and lowering the prevalence and severity of the side effects.

Anti-Helicobacter pylori activity and gastroprotective effects of human stomach-derived Lactobacillus paragasseri strain LPG-9.

The eradication of Helicobacter pylori is an urgent global issue. However, the traditional regimens have several limitations. Thus, we propose the idea of treating bacterial gastric disease with the objective of eliminating gastric pathogenic bacteria and enhancing gastroprotective effects using gastric probiotics. In this study, a total of 12 Lactobacillus strains were isolated from the gastric mucosa of healthy donors. After evaluation using a weight scoring system, Lactobacillus paragasseri strain LPG-9 was identified as the most promising probiotic for gastric disease, with the highest acid-resistance and the best adhesion characteristics. Gastric colonisation, H. pylori inhibition, anti-inflammatory, and gastric homeostasis effects of LPG-9 were confirmed in C57BL/6 mice. Finally, a safety evaluation and whole-genome sequencing were performed. Based on the results of this study, LPG-9 originates from the gastric microbiota and is a promising probiotic for gastric disease, particularly H. pylori-induced gastritis, providing a solution to this global issue.

Antiulcer mechanisms of the hydroalcoholic extract from Aztec marigolds' medicinal and edible flowers (Tagetes erecta L.).

The antiulcer mechanisms of the dry extract of T. erecta flowers (DETe) were studied here. The acute ulcers induced by acidified ethanol or indomethacin were reproduced in mice pretreated with DETe (3 - 300 mg/kg). The antiulcer activity of DETe was also verified in mice pretreated with NEM, L-NAME, indomethacin, or yohimbine. The antisecretory effect of DETe was verified in rats, and its anti-Helicobacter pylori activity was determined in vitro. DETe (300 mg/kg, p.o) reduced the ethanol- or indomethacin-induced ulcer by 49 and 93%, respectively. The pre-treatment with L-NAME, NEM or yohimbine abolished the gastroprotective effect of DETe. However, DETe did not change the volume, acidity, or peptic activity in rats and did not affect H. pylori. This study expands knowledge about the antiulcerogenic potential of DETe, evidencing the role of nitric oxide, non-protein sulfhydryl groups, α2 adrenergic receptors, and prostaglandins, but not antisecretory or anti-H. pylori properties.

Helicobacter pylori-Positive Gastric Biopsies-Association with Clinical Predictors.

Although Helicobacter pylori's role in gastric oncogenesis is well-known, only a fraction of infected patients develop cancer. Hence, more factors are supposed to be involved. The objectives of the present study were to investigate the impact of clinicopathological parameters on Helicobacter pylori status. The study included 1522 patients referred for endoscopy: study group consisted of 557 patients with Helicobacter pylori-positive biopsies confirmed using histochemical stains or immunohistochemistry methods; and the control group consisted of 965 patients with Helicobacter pylori-negative status on histology. Severe endoscopic lesions were more frequent in the Helicobacter pylori group (p < 0.001), with no difference noticed in the distribution of premalignant gastric lesions (p = 0.82). Anemia and dyslipidemia were independent factors associated with Helicobacter pylori-positive biopsies (p < 0.05). Non-steroidal anti-inflammatory therapy was more frequently administered in the study group, while proton-pump inhibitors had an anti-Helicobacter pylori activity on histology (p < 0.0001). In the studied population, patients with Helicobacter pylori-positive biopsies had a more frequent history of gastrotoxic medication, severe endoscopic lesions, and anemia. Helicobacter pylori was unpredictable by gastrointestinal symptoms. The frequency of premalignant gastric lesions was similar irrespective of the actual status of infection, underlining the importance of unintentional clearance of bacteria in old infection and the remaining risk for cancer in this population.

Digestive and gastroprotective effects of Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae): From traditional uses to preclinical studies

Ethnopharmacological relevanceAchillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae) is an alpine endemic plant whose aerial parts are harvested by the locals mainly for the digestive properties. Despite its widespread use, few studies have been conducted to date to verify its bioactivity. Aim of the studyThe purpose of the work was to meet the tradition confirming with experimental data the popular belief that the consumption of this species offers beneficial effects to the gastrointestinal system. Materials and methodsUsing Soxhlet apparatus, the dried aerial parts of A. erba-rotta subsp. moschata were successively extracted with petroleum ether (PET), dichloromethane (DCM) and methanol (MeOH). The essential oil (EO) was obtained by hydrodistillation using a Clevenger apparatus while infusion (AE) was prepared following the traditional local recipe. Their chemical characterization was performed by various techniques including SPME-GC/MS, GC/MS and HPLC/MS-MS. An in vitro biological screening was carried out. The influence of AE on lipid digestion was monitored by titration of free fatty acids (FFA) during pancreatic lipase activity with the pH-stat method. For all extracts and EO, the anti-Helicobacter pylori activity was assessed by the broth microdilution method, the influence on cell viability was evaluated against NCI–N87, OE21 and Caco-2 cell lines and a preliminary toxicity evaluation was done using Brine Shrimp lethality (BSL) assay. The anti-inflammatory potential was evidenced by interleukin IL-1- induced IL8 expression on Caco-2 cells. ResultsAE increased by 15% the FFA releasing compared to the pancreatic lipase alone. PET, DCM and MeOH extracts as well as AE and EO were considered active against the growth of both antimicrobial susceptible and resistant strains of H. pylori with MIC values starting from 16 μg/mL.PET and DCM (IC50 = 89 μg/mL and 96 μg/mL, respectively, against Caco-2 cell line) extracts showed the high effect on cell viability while the EO reduced in 50% of cell viability at 1.48 μL/mL (NCI–N87 cells), 1.42 μL/mL (OE21 cells), and 3.44 μL/mL (Caco-2 cells) corroborating the BSL results. In different degrees, all extracts and EO inhibited the IL-1β-stimulated IL-8 production in Caco-2 cells. ConclusionsThe obtained data are encouraging and provide a scientific basis for the traditional use of A. erba-rotta subsp. moschata as a digestive agent although they need to be further corroborated by studies involving the investigation of both the in vivo activities and the role of the compounds detected in the extracts.

Study of the gastroprotective action and healing effects of Kalanchoe pinnata (Lam.) against acidified ethanol- and acetic acid-induced gastric ulcers in rats / Estudo da acção gastroprotectora e dos efeitos curativos de Kalanchoe pinnata (Lam.) contra úlceras gástricas induzidas por etanol acidificado e ácido acético em ratos

Kalanchoe pinnata (Lam.) Pers. (Crassulaceae) is a commonly used species in traditional medicine in Brazil for the treatment of various diseases, including gastric ulcers. This research aims to evaluate the antiulcer aspects of Kalanchoe pinnata leaves. The LD50 value of the hydroethanolic extract (HE) of K. pinnata was 1341.46 mg/kg, after the in vitro cytotoxicity assay. In the phytochemical analysis, several flavonoids were identified in the HE and ethyl acetate fraction (EAF) of K. pinnata. It was verified that the gastroprotective activity of the HE of K. pinnata involved prostaglandins and sulfhydryl compounds. However, the mechanism of gastroprotection of the EAF of K. pinnata is dependent on prostaglandins and nitric oxide. The ulcer healing activity of the HE of K. pinnata was also evaluated. According to the macroscopic results, doses of 200 mg/kg and 400 mg/kg reduced the injury area, with rates of 33% and 39%, respectively, after 7 days of treatment (p <0.05). Histological analysis showed regeneration of the gastric mucosa and re-establishment of the glandular architecture in groups treated with the HE (200 and 400 mg/kg). Antioxidant enzymes (CAT, SOD and GPx) were evaluated in the mechanism of gastric ulcer healing. The results showed that the antiulcerogenic activity was mediated by SOD. The anti-Helicobacter pylori activity was also evaluated; however, the HE did not show anti-H. pylori activity. Analysis of the results suggests that K. pinnata has therapeutic potential against gastric ulcers and that the flavonoids may be linked to the biological effects.

Quercetin -3-O-β-D-glucouronide butyl ester from Vitis vinifera leaves of potent anti-helicobacter pylori activity and impact of its combination with clarithromycin

Quercetin -3-O-β-D-glucouronide butyl ester from Vitis vinifera leaves of potent anti-helicobacter pylori activity and impact of its combination with clarithromycin

2-(Pyridin-4yl)benzothiazole and Its Benzimidazole-Analogue: Biophysical and in silico Studies on Their Interaction with Urease and in vitro Anti-Helicobacter pylori Activities

In this study, the interaction between benzothiazole (BTA, concentration of a drug required for 50% inhibition in vitro (IC50) = 0.77 mM) and benzimidazole (BIA, IC50 = 2.14 mM) with urease was quantitatively assessed, using UV-Vis, molecular fluorescence, and circular dichroism. The results showed that both compounds interact with urease by a static fluorescence quenching mechanism with a non-fluorescent complex formation. The main forces responsible for stabilizing the supramolecular complex between BTA and urease were hydrophobic while, for BIA, van der Waals interactions and hydrogen bonds were the main ones. Urease conformation changes due to the interaction process were analyzed by circular dichroism and synchronous fluorescence. Besides, a competitive assay with substrate and inhibitors was used to evaluate the preferential urease site of interaction with BTA and BIA. Our experimental and theoretical studies supported that both, BTA and BIA, are mixed-inhibitors of ureases with a slight preference to the active site of such enzymes. Finally, both BTA and BIA showed to possess anti-H. pylori (one reference strain and six clinical isolates) activity, presenting minimal inhibitory concentration (MIC) values ranging from 38-150 and 20-164 μM, respectively. The urease inhibitors omeprazole and hydroxyurea showed MIC values in the range of 46-185 μM and 1683-> 3366 μM, respectively.

Screening of Lactic Acid Bacteria with Anti- Helicobacter pylori Activity and Evaluation of Their Probiotic Characteristics

Objective: To screen lactic acid bacteria (LAB) with anti-Helicobacter pylori activity and great probiotic properties from fermented food, dairy products and infant feces. Method: A total of 39 LAB-like strains with stable curd state were screened from 175 samples. 9 Strains with anti-H. pylori activity were initially isolated by agar diffusion assay and H. pylori urease activity test and identified by 16S rDNA sequence analysis. Subsequently, the acid and bile tolerance, antibiotic resistance, antibacterial activity, cell surface hydrophobicity, and cell auto-aggregation of the selected LAB strains were determined. Results: Two probiotic strains with anti-Helicobacter pylori activity were screened: Lactobacillus helveticus GQ1702 and Lactobacillus plantarum D1, and their cell culture supernatants exhibited anti-H. pylori activity equivalent to the anti-H. pylori activity of 0.038 and 0.034 mg/mL metronidazole, respectively. The survival rates of GQ1702 and D1 were above 70% after incubation at pH3 for 3 h, the survival rates of GQ1702 and D1 after incubation at 0.3% bile salt were 0.47% and 1.08%, respectively. Cell surface hydrophobicities of GQ1702 and D1 were 25.10% and 11.79%, respectively. The self-agglutination rate reached 71.18% and 50.78% respectively after 24 hours. The auto-aggregation percentages of GQ1702 and D1 were 61.18% and 57.25%, respectively, after 24 hours. The two LAB strains were not resistant to chloramphenicol, penicillin, erythromycin, ampicillin, or cefazolin, and exhibited antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, E. coli O157:H7, and Salmonella typhimurium. Conclusion: Lactobacillus helveticus GQ1702 and Lactobacillus plantarum D1 with anti-Helicobacter pylori activity were obtained in this experiment, which could provide a source of strains for development and research of functional dairy products.

Characterization of Four Piper Essential Oils (GC/MS and ATR-IR) Coupled to Chemometrics and Their anti-Helicobacter pylori Activity.

Background: Essential oils represent a major class of natural products which are known for their antimicrobial activity. This study aimed to determine the composition of four Piper essential oils by gas chromatography mass spectrometry, attenuated total reflection infrared, and chemometric analysis. Results: Monoterpene was the most predominant class in Piper nigrum and white pepper (87.6 and 80%, respectively) with the dominance of α-pinene, β-pinene, 3-carene, limonene, and β-caryophyllene. Sesquiterpenes represented 50, 19.6, and 12.3% of the essential oils of Piper longum, white pepper, and P. nigrum, respectively. Unlike other species, Piper cubeba oil was found to be rich in aromatics (59%), with eugenol (10.7%) and methyl eugenol (47.4%) representing the major components along with β-myrcene (21.2%) and 1,8-cineole (6.4%). Only P. longum essential oil comprised about 18.2% of alkanes and 13.6% of alkenes. Application of chemometric analysis utilizing GC/MS and ATR-IR data displayed the same segregation pattern where both principal component analysis and hierarchal cluster analysis revealed that white pepper was most closely related to P. nigrum while being completely discriminated from other Piper species. The Piper oils showed promising inhibitory effects on Helicobacter pylori. P. longum oil recorded the most efficient anti-Helicobacter activity [minimum inhibitory concentration (MIC) value of 1.95 μg/ml, which is the same as the MIC of clarithromycin], followed by the oil of white pepper (MIC = 3.90 μg/ml), while P. cubeba and P. nigrum produced the lowest activity (MIC value of 7.81 μg/ml). Conclusion:Piper essential oils can be used as nutritional supplements or therapeutic drugs to protect against H. pylori infection.

 ​Ethanomedicine and Pharmacology of Semal (Bombax ceiba L.)- A Indian Medicinal Plant: A Review

Bombax ceiba L. is valuable herb in the ayurvedic and traditional systems of medicine. In traditional system of drugs various plant parts and exudates are used as medicine. On the basis of literature survey, plant is found to be beneficial as astringent, cooling, stimulant, diuretic, aphrodisiac, demulcent, dysentery, tonic and also useful in the treatment of asthma, diarrhea, wound healing, leucorrhea, anemia and tuberculosis. Apart from these, it is also reported as anti-inflammatory and hepatoprotective, anticancer and anti-HIV activity, anti-helicobacter pylori activity, antiangiogenic activity, analgesic and antioxidant activity, inhibitory effects on tube-like formation of human umbilical venous cells, hypotensive, hypoglycemic activity, cholinesterase and antimicrobial activity. This review is an attempt to discuss the various pharmacognosy, ethnomedicinal, pharmacology and traditional uses along with reported phytochemical and pharmacological activities of Bombax ceiba.

Phytoconstituents, In Vitro Anti-Infective Activity of Buddleja indica Lam., and In Silico Evaluation of its SARS-CoV-2 Inhibitory Potential.

Phytochemical investigation of Buddleja indica Lam. leaves methanol extract (BIT) resulted in the isolation of six known compounds for the first time from the plant, namely, p-hydroxybenzoic acid 1), caffeic acid 2), quercetin 3-O-β-D glucoside-7-O-α-L-rhamnoside 3), kaempferol 3-O-β-D glucoside-7-O-α-L-rhamnoside 4), quercetin 7-O-β-D glucoside 5) and kaempferol 6). BIT extract showed potent antibacterial activity with MIC values ranging between 0.48 and 1.95 μg/ml with Bacillus subtilis was the most susceptible to the BIT effect. It showed a notable antimycobacterial and anti-Helicobacter pylori activity with MIC values of 100 and 80 μg/ml, respectively. Vesicular stomatitis virus (VSV) was more sensitive to the antiviral activity of BIT comparable to herpes simplex virus type 1 (HSV-1), showing 48.38 and 41.85% inhibition of the viral replication at a dose of 50 μg/ml for VSV and HSV-1, respectively. In silico molecular docking of the isolated compounds revealed that caffeic acid 2) showed the highest fitting within the active sites of DNA-gyrase, topoisomerase IV, and SARS-CoV-2 MPro. Quercetin 7-O-β-D glucoside 5) revealed the best fitting in dihydrofolate reductase active site with ∆ G value equals −36.53 Kcal/mol. Kaempferol 6) exhibited the highest fitting towards β-lactamase, SARS-CoV-2PLpro, and SARS-CoV-2 3CLpro active sites. Thus, B. indica Lam. can be considered as a future source of cheap, substantially safe, and credible antibacterial, antifungal, and antiviral candidate of natural origin that could effectively participate in solving the problem of COVID-19 pandemic. These findings provide a scientific consolidation for the ethnomedicinal uses of Buddleja indica Lam. as a topical antiseptic.

Screening of potential probiotics with anti-Helicobacter pylori activity from infant feces through principal component analysis

Helicobacter pylori is considered as the causative agent of gastrointestinal diseases. The large increase of drug-resistant strains caused by the treatment of H. pylori makes it very important to develop new treatment strategies. This study aimed to isolate and select Lactobacillus strains from infant feces and evaluate the inhibitory effects against H. pylori. Six strains were initially screened out of Forty-seven Lactobacillus strains obtained from healthy infants feces through evaluating acid (pH 3.0) and bile salt tolerance (0.3%). Based on the re-screening of the four indexes of transit tolerance, hydrophobicity, self-aggregation and anti-Helicobacter pylori, combined with the comprehensive evaluation of principal component analysis, these both strains of IF-3083 and IF-5014 were obtained. And these two strains were identified as Lactobacillus plantarum using 16S ribosomal RNA gene sequences. Also, the two identified strains showed good adhesion to human gastric adenocarcinoma (AGS) and human colorectal adenocarcinoma (HT-29) cells, γ-hemolytic activity and susceptibility to seven antibiotics. The viable count of H. pylori SS1 was significantly decreased when co-cultured with the live cells (LC) or cell-free supernatants (CFS) of these two strains. These preliminary results suggested that L. plantarum IF-3083 and L. plantarum IF-5014 had the potential to be used as probiotics to prevent H. pylori infection.

Antioxidant and anti-Helicobacter pylori activities of Hericium erinaceus mycelium and culture filtrate

Introduction: Hericium erinaceus is known as a medicinal edible mushroom owing to its antimicrobial, antioxidant, anti-tumor and immunomodulatory effects. Helicobacter pylori infection is one of the major health concerns worldwide due to its high rate in global populations, frequent recurrence, and rapid emergence of drug-resistant strains. The present study aims to investigate antioxidant anti-H. pylori and urease inhibitory activities of solvent fractions from H. erinaceus mycelium and culture filtrate.
 Methods: H. erinaceus mycelium was purely cultured in a liquid medium. A polysaccharide fraction was obtained from the culture filtrate by precipitation with ethanol. The mycelium and culture filtrate were extracted by liquid extraction to obtain solvent-soluble fractions. The antibacterial effects of these fractions were determined using paper disc diffusion and broth microdilution assays. Urease inhibition was determined using the salicylate-hypochlorite method. The antioxidant activity of H. erinaceus was evaluated via 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity.
 Results: The ethyl-acetate (EtOAc) fractions derived from H. erinaceus culture filtrate (fEtOAc Fr.) and mycelium (mEtOAc Fr.) showed the strongest anti-H. pylori activity with MIC (MBC) of 1.25 – 1.5 (5.0 – 7.5) mg/mL and potential urease inhibitory activity with IC50 of 0.34 – 0.35 mg/mL. In addition, fEtOAc Fr. exhibited the greatest antioxidant activity (IC50, 11.83 mg/mL), which was slightly stronger than that of mEtOAc Fr. (IC50, 14.75 mg/mL). Moreover, our study also found that the water fractions from the culture filtrate (fWater Fr.) and the mycelium (mWater Fr.) displayed considerable inhibitory activities against bacterial urease (IC50, 1.26 – 1.40 mg/mL), although they had low or no anti-H. pylori activities and low antioxidant properties.
 Conclusion: The present study revealed that the EtOAC fractions derived from the H. erinaceus mycelium and culture filtrate potentially have anti-H. pylori, anti-urease and antioxidant activities. These results suggest that H. erinaceus mycelium and culture filtrate could be utilized to develop functional foods and nutraceuticals to prevent H. pylori infection. More research is needed to prove the safety of the H. erinaceus mycelium and culture filtrate fractions and their in vivo efficacy in the treatment of H. pylori infection.

Chilean Rhubarb, Gunnera tinctoria (Molina) Mirb. (Gunneraceae): UHPLC-ESI-Orbitrap-MS Profiling of Aqueous Extract and its Anti-Helicobacter pylori Activity.

The full UHPLC-MS metabolome fingerprinting and anti-Helicobacter pylori effect of Gunnera tinctoria (Molina) Mirb. (Nalca) total extract (GTE) and fractions prepared from its edible fresh petioles were evaluated. The activity of G. tinctoria against H. pylori strains ATCC 45504 and J99 was assessed in vitro by means of agar diffusion assay, Minimum Inhibition Concentration (MIC), and Minimum Bactericidal Concentration (MBC), while killing curve and transmission electronic microscopy (TEM) were conducted in order to determine the effect of the plant extract on bacterial growth and ultrastructure. Additionally, the inhibitory effect upon urease was evaluated using both the Jack Bean and H. pylori enzymes. To determine which molecules could be responsible for the antibacterial effects, tentative identification was done by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Q-Orbitrap®-HR-MS). Furthermore, the total G. tinctoria extract was fractionated using centrifugal partition chromatography (CPC), giving four active fractions (1–4). It was determined that the crude extract and centrifugal partition chromatography fractions of G. tinctoria have a bactericidal effect being the lowest MIC and MBC = 32 μg/ml. In the killing curves, fraction one acts faster than control amoxicillin. In the urease assay, F3 exhibited the lowest IC50 value of 13.5 μg/ml. Transmission electronic microscopy showed that crude G. tinctoria extract promotes disruption and separation of the cellular wall and outer membrane detachment on H. pylori causing bacterial cell death.

Structural Insights into New Bi(III) Coordination Polymers with Pyridine-2,3-Dicarboxylic Acid: Photoluminescence Properties and Anti-Helicobacter pylori Activity.

Two novel coordination polymers, [Bi2(2,3pydc)2(2,3pydcH)2(H2O)]n (1) and {(Et3NH)2[Bi(2,3pydc)(2,3pydcH)Cl2]}n (2) were prepared using as a prolinker pyridine-2,3-dicarboxylic acid (2,3pydcH2). The obtained complexes were fully characterized by elemental analysis, TG/DTG, FT-IR, solid-state photoluminescence, DFT calculations and single-crystal X-ray diffraction. The obtained complexes crystallized in the triclinic P-1 space group (1) and comprise dimeric units with two crystallographically different Bi(III) centers (polyhedra: distorted pentagonal bipyramid and bicapped trigonal prism) and monoclinic P21/c space group (2) with a distorted monocapped pentagonal bipyramid of Bi(III) center. The various coordination modes of bridging carboxylate ligands are responsible for the formation of 1D chains with 4,5C10 (1) and 2C1 (2) topology. The photoluminescence quantum yield for polymer 2 is 8.36%, which makes it a good candidate for more specific studies towards Bi-based fluorescent materials. Moreover, it was detected that polymer 1 is more than twice as active against H. pylori as polymer 2. It can be concluded that there is an existing relationship between the structure and the antibacterial activity because the presence of chloride and triethylammonium ions in the structure of complex 2 reduces the antibacterial activity.