scholarly journals Identification and In Silico Characterization of Novel Helicobacter pylori Glucose-6-Phosphate Dehydrogenase Inhibitors

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4955
Author(s):  
Beatriz Hernández-Ochoa ◽  
Gabriel Navarrete-Vázquez ◽  
Rodrigo Aguayo-Ortiz ◽  
Paulina Ortiz-Ramírez ◽  
Laura Morales-Luna ◽  
...  

Helicobacter pylori (H. pylori) is a pathogen that can remain in the stomach of an infected person for their entire life. As a result, this leads to the development of severe gastric diseases such as gastric cancer. In addition, current therapies have several problems including antibiotics resistance. Therefore, new practical options to eliminate this bacterium, and its induced affections, are required to avoid morbidity and mortality worldwide. One strategy in the search for new drugs is to detect compounds that inhibit a limiting step in a central metabolic pathway of the pathogen of interest. In this work, we tested 55 compounds to gain insights into their possible use as new inhibitory drugs of H. pylori glucose-6-phosphate dehydrogenase (HpG6PD) activity. The compounds YGC-1; MGD-1, MGD-2; TDA-1; and JMM-3 with their respective scaffold 1,3-thiazolidine-2,4-dione; 1H-benzimidazole; 1,3-benzoxazole, morpholine, and biphenylcarbonitrile showed the best inhibitory activity (IC50 = 310, 465, 340, 204 and 304 μM, respectively). We then modeled the HpG6PD protein by homology modeling to conduct an in silico study of the chemical compounds and discovers its possible interactions with the HpG6PD enzyme. We found that compounds can be internalized at the NADP+ catalytic binding site. Hence, they probably exert a competitive inhibitory effect with NADP+ and a non-competitive or uncompetitive effect with G6P, that of the compounds binding far from the enzyme’s active site. Based on these findings, the tested compounds inhibiting HpG6PD represent promising novel drug candidates against H. pylori.

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 20
Author(s):  
Maciej Spiegel ◽  
Paweł Krzyżek ◽  
Ewa Dworniczek ◽  
Ryszard Adamski ◽  
Zbigniew Sroka

Helicobacter pylori is one of the most frequent human pathogens and a leading etiological agent of various gastric diseases. As stringent response, coordinated by a SpoT protein, seems to be crucial for the survivability of H. pylori, the main goal of this article was to use in silico computational studies to find phytochemical compounds capable of binding to the active site of SpoT from H. pylori and confirm the ability of the most active candidates to interfere with the virulence of this bacterium through in vitro experiments. From 791 natural substances submitted for the virtual screening procedure, 10 were chosen and followed for further in vitro examinations. Among these, dioscin showed the most interesting parameters (the lowest MIC, the highest anti-biofilm activity in static conditions, and a relatively low stimulation of morphological transition into coccoids). Therefore, in the last part, we extended the research with a number of further experiments and observed the ability of dioscin to significantly reduce the formation of H. pylori biofilm under Bioflux-generated flow conditions and its capacity for additive enhancement of the antibacterial activity of all three commonly used antibiotics (clarithromycin, metronidazole, and levofloxacin). Based on these results, we suggest that dioscin may be an interesting candidate for new therapies targeting H. pylori survivability and virulence.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
María de J. López-López ◽  
Isabel C. Rodríguez-Luna ◽  
Edgar E. Lara-Ramírez ◽  
Marisol López-Hidalgo ◽  
Claudia G. Benítez-Cardoza ◽  
...  

Enolase, which catalyses the conversion of 2-phospho-D-glycerate to phosphoenolpyruvate, is an important enzyme in the classic glycolysis pathway in cells. Enolase is highly conserved in organisms from bacteria to humans, indicating its importance in cells. Thus, enolase is a good target for developing new drugs. In the last decade, new functions of this enzyme have been found. Helicobacter pylori is a common human pathogen that causes gastric diseases and even gastric cancer. In this study, the sequence of H. pylori enolase (HpEno) was analysed; the conservation (at least partial) of binding sites for cofactor, plasminogen, and host extracellular RNA, as well as catalytic site, indicates that HpEno should be capable of performing the functions. Recombinant HpEno was overexpressed and purified from E. coli. Compared to the enolases from other species, HpEno had similar characteristics for its secondary structure. The temperature-induced profiles indicate that HpEno is quite stable to temperature, compared to other homologs. Regarding the kinetics of the unfolding reaction, we found that the activation enthalpy associated with the thermal unfolding reaction is equivalent to the reported activation enthalpy for yeast enolase, indicating a similar scaffold and kinetic stability. Although a wide range of experimental conditions were assayed, it was not possible to detect any enzymatic activity of HpEno. To prove the lack of activity, still a much wider range of experiments should be carried out.


2020 ◽  
Vol 17 ◽  
Author(s):  
Anam Naz ◽  
Tahreem Zaheer ◽  
Hamza Arshad Dar ◽  
Faryal Mehwish Awan ◽  
Ayesha Obaid ◽  
...  

Background: Helicobacter pylori infection and its treatment still remains a challenge to human health worldwide. A variety of antibiotics and combination therapies are currently used to treat H. pylori induced ulcers and carcinoma; however, no effective treatment is available to eliminate the pathogen from the body. Additionally, antibiotic resistance is also one of the main reasons for prolonged and persistent infection. Aim of the study: Until new drugs are available for this infection, vaccinology seems the only alternative opportunity to exploit against H. pylori induced diseases. Methods: Multiple epitopes prioritized in our previous study have been tested for their possible antigenic combinations, and results in 169-mer and 183-mer peptide vaccines containing the amino acid sequences of 3 and 4 epitopes respectively, along with adjuvant (Cholera Toxin Subunit B adjuvant at 5’ end) and linkers (GPGPG and EAAAK). Results: Poly-epitope proteins proposed as potential vaccine candidates against H. pylori include SabAHP0289-Omp16-VacA (SHOV), VacA-Omp16-HP0289-FecA (VOHF), VacA-Omp16-HP0289-SabA (VOHS), VacA-Omp16-HP0289-BabA (VOHB), VacA-Omp16-HP0289-SabA-FecA (VOHSF), VacAOmp16-HP0289-SabA-BabA (VOHSB) and VacA-Omp16-HP0289-BabA-SabA (VOHBS). Structures of these poly-epitope peptide vaccines have been modelled and checked for their affinity with HLA alleles and receptors. These proposed poly-epitope vaccine candidates bind efficiently with A2, A3, B7 and DR1 superfamilies of HLA alleles. They can also form stable and significant interactions with Toll-like receptor 2 and Toll-like receptor 4. Conclusion: Results suggest that these multi-epitopic vaccines can elicit a significant immune response against H. pylori and can be tested further for efficient vaccine development.


2019 ◽  
Vol 19 (3) ◽  
pp. 274-278 ◽  
Author(s):  
Saba Fakhrieh Asl ◽  
Mehrnaz Pourvahedi ◽  
Ali Mojtahedi ◽  
Mohammad Shenagari

Objective:Helicobacter pylori is a Gram-negative bacterium which has a serious effect on up to half of the world’s population and has been related to different gastric diseases. The goal of this study was to assess the frequency of babA, cagE and cagA genotypes among H. pylori strains isolated from gastric biopsies of endoscopic patients in the north of Iran.Methods:The present study was performed on 90 strains of H. pylori isolated from patients with gastric diseases (Gastric ulcer (GU), Duodenal ulcer (DU), Gastritis (G), Non-ulcer dyspepsia (NUD) and Gastric adenocarcinoma (GC)). DNA was extracted from all isolated strains and PCR method was performed to detect the prevalence of babA2, cagE and cagA genes using specific primers.Results:Among 90 samples of H. pylori, babA2, cagE, and cagA genes were detected in 42.2%, 30% and 82.2% of strains respectively. The statistical analysis showed that the prevalence of cagA gene in GU, G, DU, and NUD was significantly higher than other genes. Moreover, cagA, and babA2 genes were significantly more prevalent in GC patients compared to cagE gene. Our isolates exhibited 8 distinct arrangements of virulence patterns. The occurrence of cagA (35.6%) was the most prevalent pattern followed by cagA/babA2 (20%) and cagA/babA2/cagE (14.4%).Conclusion:In summary, as first report from Guilan province in the north of Iran, we showed significant association between the presence of babA2, cagE, and cagA genes in different types of gastric disorders.


1970 ◽  
Vol 4 (3) ◽  
pp. 48-57
Author(s):  
Isabela Maria A. Ribeiro Simões ◽  
Ana Carolina Mauad Coli ◽  
Roseane de Souza Candido Irulegui

Objetivo: Determinar a prevalência de lesões benignas e neoplasia gástrica através do estudo de biópsias realizadas em um Hospital Escola do Sul de Minas Gerais, no período entre 2007 e 2011. Materiais e Métodos: A pesquisa documental foi quantitativa e retrospectiva, baseada na análise dos registros de biópsias e prontuários. Realizou-se o levantamento de dados referentes à idade, gênero, cor, profissão, diagnóstico histopatológico e presença de Helicobacter pylori nas amostras. Resultados: O número total de biópsias gástricas analisadas foi de 1225, cujo perfil populacional encontrado foi: idade média de 56,75 anos, sexo masculino (52%), cor branca (81,9 %), aposentado (30%). Os diagnósticos mais frequentes foram: gastrites (71,9%), pólipos (14,2%), adenocarcinomas (5,9%), úlceras gástricas (6%), linfomas (0,4%), sem alterações (0,4%) e outros (1,2%). Em outros, encontram-se achados de malignidade, metaplasia e xantelasma gástrico. Em relação à presença de Helicobacter pylori nas amostras, o resultado encontrado foi de24% positivas, 46% negativas e 30% não pesquisadas. Conclusão: Os resultados confirmam a alta frequência das doenças gástricas e sua incidência nas diversas faixas etárias, além do envolvimento do H. pylori em tais afecções. É de grande importância a caracterização dos dados epidemiológicos, o que permite prováveis direcionamentos para programas de prevenção e informação para a população. Palavras-chave: biópsia gástrica, gastropatia, perfil epidemiológico.  ABSTRACTObjective: To determine the prevalence of benign lesions and gastric cancer through study of biopsies performed at a school hospital in southern Minas Gerais, in the period between 2007 and 2011.Materials and Methods: The research was quantitative and retrospective, based on analysis of biopsies records and medical records. We conducted the survey data regarding age, sex, color, profession, histopathological diagnosis and the presence of Helicobacter pylori in the samples. Results: The total number of gastric biopsies analyzed was 1225. Population listing was found: mean age of 56.75 years, male (52%), white (81.9%), retired (30%). The most frequent diagnoses were gastritis (71.9%), polyps (14.2%), adenocarcinomas (5.9%), gastric ulcers (6%), lymphoma (0.4%), unchanged (0, 4%) and others (1.2%). In others, there are: findings of malignancy, metaplasia, gastric xanthelasma. Regarding the presence of Helicobacter pylori in the sample, the result was: 24% positive, 46% negative, 30% non searched. Conclusion: The results confirm the high frequency of gastric diseases and their incidence in the various age groups additionally to the involvement of H. pylori in such conditions. It is of great importance to characterize the epidemiological data, allowing probable directions for prevention and information programs for population. Keywords: gastric biopsy, gastropathy, epidemiological profile


2019 ◽  
Vol 77 (9) ◽  
Author(s):  
Narges Dastmalchi ◽  
Seyed Mahdi Banan Khojasteh ◽  
Mirsaed Miri Nargesi ◽  
Reza Safaralizadeh

ABSTRACT Helicobacter pylori infection performs a key role in gastric tumorigenesis. Long non-coding RNAs (lncRNAs) have demonstrated a great potential to be regarded as effective malignancy biomarkers for various gastrointestinal diseases including gastric cancer (GC). The present review highlights the relationship between lncRNAs and H. pylori in GC. Several studies have examined not only the involvement of lncRNAs in H. pylori-associated GC progression but also their molecular mechanisms of action. Among the pertinent studies, some have addressed the effects of H. pylori infection on modulatory networks of lncRNAs, while others have evaluated the effects of changes in the expression level of lncRNAs in H. pylori-associated gastric diseases, especially GC. The relationship between lncRNAs and H. pylori was found to be modulated by various molecular pathways.


2021 ◽  
Vol 22 (5) ◽  
pp. 2695
Author(s):  
Paweł Krzyżek ◽  
Paweł Migdał ◽  
Emil Paluch ◽  
Magdalena Karwańska ◽  
Alina Wieliczko ◽  
...  

Helicobacter pylori, a gastric pathogen associated with a broad range of stomach diseases, has a high tendency to become resistant to antibiotics. One of the most important factors related to therapeutic failures is its ability to change from a spiral to a coccoid form. Therefore, the main aim of our original article was to determine the influence of myricetin, a natural compound with an antivirulence action, on the morphological transformation of H. pylori and check the potential of myricetin to increase the activity of antibiotics against this pathogen. We observed that sub-minimal inhibitory concentrations (sub-MICs) of this compound have the ability to slow down the process of transformation into coccoid forms and reduce biofilm formation of this bacterium. Using checkerboard assays, we noticed that the exposure of H. pylori to sub-MICs of myricetin enabled a 4–16-fold reduction in MICs of all classically used antibiotics (amoxicillin, clarithromycin, tetracycline, metronidazole, and levofloxacin). Additionally, RT-qPCR studies of genes related to the H. pylori morphogenesis showed a decrease in their expression during exposure to myricetin. This inhibitory effect was more strongly seen for genes involved in the muropeptide monomers shortening (csd3, csd6, csd4, and amiA), suggesting their significant participation in the spiral-to-coccoid transition. To our knowledge, this is the first research showing the ability of any compound to synergistically interact with all five antibiotics against H. pylori and the first one showing the capacity of a natural substance to interfere with the morphological transition of H. pylori from spiral to coccoid forms.


2018 ◽  
Vol 7 (5) ◽  
pp. 217-224
Author(s):  
Zouaouia Chama ◽  
Khedoudj Kanoun ◽  
Fatima Zohra Elkadi ◽  
Kara Turqui Douidi ◽  
Noria Harir ◽  
...  

Helicobacter pylori infection concerns half of the world’s population, mainly in developing countries. It causes several gastrodudenal pathologies such as gastritis, ulcer and gastric adenocarcinoma. The aim of our study was to determine the prevalence of H.pylori infection and to assess the impact of different epidemiological factors as well as principal gastric diseases associ-ated to this infection. We underwent a prospective study during 18 months (month 2016-month 2017) which implicated 201 symptomatic patients for gastric fiboptic endoscopy at the level of Sidi Bel Abbes University hospital. We collected patients’ biopsies to perform a histological study and H. pylori culture. H. pylori identification was carried out based on bacteriological and biochemical analysis. The middle age of our population was (47.29 ±15.97ans) and the sex-ratio =0,8. The global prevalence of Helicobacter pylori infection is of 61.2% (123/201). This rate, after a statistic analysis, seems to be significantly related to age. It is particularly high especially for patients belonging to age range (20-30)-(51-60) years. The gender did not affect the infection prevalence that is more frequent in the gastritis case. We noticed also that HP infection prevalence was important in SBA the hospital. The range age (20-30)-(51-60) years had the highest prevalence of H. pylori and of gastritis which might be a risky ground of gastric cancer appearance. The ulcer pathology maximal rate concerned the group of 51 to 60 years. Above this age, this rate dropped whereas the number of patients suffering from gastric cancer, which presents an important rate in our study, increase for the group of 61-70 years.


2019 ◽  
Author(s):  
Alfizah Hanafiah ◽  
Shaza Azlin Razak ◽  
Hui-min Neoh ◽  
Noraziah Mohamad Zin ◽  
Bruno S. Lopes

Abstract Background: Helicobacter pylori is a Gram-negative bacillus that colonises only the mucus layer of the human stomach and is implicated in gastric diseases. Virulent H. pylori harbouring cag-pathogenicity island (cagPAI) which encodes genes for type IV secretion system (T4SS) and CagA protein is one of the major virulence determinants involved in disease development. We examined the entire cagPAI genes in 95 H. pylori isolates from a multiracial population and examined the intactness of cagPAI region with histopathological scores of the gastric mucosa. Results: 95.8% of H. pylori isolates were cagPAI-positive with 23.2% having an intact cagPAI, whereas 72.6% had a partial/rearranged cagPAI. In our study, cag2 and cag4 were found to be significantly higher in H. pylori isolated from Malays, whereas cag4 was predominant in Chinese isolates. We also detected cag24 in significantly high proportion in isolates from the Malays and the Indians compared to the Chinese isolates. The intactness of cagPAI region showed an association with histopathological scores of the gastric mucosa. Significant association was observed between H. pylori harbouring partial cagPAI and higher density of H. pylori and neutrophil activity, whereas strains which lacked cagPAI was associated with higher inflammatory score. Conclusions: The screening of the entire cagPAI genes provides an accurate overview of the cagPAI organisation in H. pylori isolates in a multiracial population. The genotypes of H. pylori strains with various cagPAI rearrangement associated with patients’ ethnicities and histopathological scores might contribute to the pathogenesis of H. pylori infection in a multi-ethnic population.


Author(s):  
Hazim Abdul Rahman Alhit

Editorial: Helicobacter pylori is a micro-aerophilic, helical-form gramnegative aggressive bacteria. Accordingly, the idiom “Helico” intimates its helical appearance, “bacter” symbolizes bacteria, while “pylori” denotes stomach due to the first and common site of this bacteria living. Further, Marshall B. and Warren R. observed and described it in 1982. Then, the followed investigators studied this bacterium in detail with its consequences and complexities [1]. Gastric upset (Indigestion), dyspepsia: means impaired gastric digestion. Accordingly, the patient complains of upper abdominal pain, heartburn, belching, nausea, even feeling earlier gastric fullness than expected while eating. Furthermore, there are many causes of indigestion like gastroesophageal reflux disease, ulcer disease, gastritis, and even gastric cancer. Hence, unexplained recent onset dyspepsia in older people may need additional examinations. Moreover, one of the common causes is Helicobacter pylori infection, which needs laboratory and endoscopic examination [2]. Argument Many theories investigated the etiology and pathogenesis of Helicobacter pylori infection, concerning chronic or acute gastritis. Hence, gastric upset is the main presentation of both types of gastritis. Evidences The genotype is valuable in determining the dominant Helicobacter pylori strains as the isolates were different genetically plus heterogeneous distribution. Accordingly, the vac and cag markers operate a significant function in defining clinical consequences. These virulence agents are present in a subset of Helicobacter pylori strains isolates like cagA, iceA, vacA, and ureC. Moreover, the cagA causes cytotoxins induction by the gastric epithelial cell as Interleukin 8 [3]. The molecular intercommunication researches exhibit that the act of acarus calamus in hindering biofilm formation in Helicobacter pylori is due to the inhibitory impact of phytobio-active component, β-sitosterol, on the quorum sensing molecules-ToxB, PhnB, DnaA, plus Sip. Consequently, this opinion may suggest the molecular mechanism of Helicobacter pylori in producing the acidrelated complaints and gives a clue to a new therapy [4]. Helicobacter pylori infection causes lncRNA risk impression linked to H. pylori in gastric cancer patients and can prognosticate the prediction of these patients [5]. There was a close relationship between raised serum IgE levels in Helicobacter pylori infected patients [6]. Counterargument The laboratory investigations of Helicobacter pylori infection depend on several factors like the fluctuations of serum antibody titers in a time series, the antigene detection in stool tests, the false-positive results of lab tests, or the manner of endoscopic biopsy collection. Furthermore, other factors like the variations in Cytotoxin-Associated Gene A (CagA) in East Asian patients. Moreover, the gastric nodularity or atrophy, the patient’s age, the severity of the gastric mucosal infection are causes of variations in Helicobacter pylori detection at the time of the investigation [7]. Refutation The significant markers of H. pylori, the presence of the vacuolating cytotoxin (vacA), the cytotoxin-associated gene A (cagA), which induced by the direct communication with gastric epithelium factor antigen (iceA gene), and the presence of urease C gene (ureC). Consequently, all these factors play the principal factors in deciding the gastric consequences of Helicobacter infections. Conclusion Helicobacter pylori induce gastric upset by several mechanisms to form numerous Gastric diseases.


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