Proton pump inhibitor‐ and clarithromycin‐based triple therapies for Helicobacter pylori eradication

Effects of some anti-ulcer and anti-inflammatory natural products on cyclooxygenase and lipoxygenase enzymes: insights from in silico analysis

Gastric and duodenal ulcers are increasingly becoming global health burdens. The side effects of conventional treatments such as non-steroid anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPIs), antibiotics, and cytoprotective agents have necessitated the search for new medications. Plants are a rich source of active metabolites and herbal medicines have been used in the treatment of ulcers and cancers. In this study, we used in silico methods like molecular docking and MM-GBSA calculations to evaluate the effects of some anti-ulcer and anti-inflammatory phytochemicals on some key enzymes, cyclooxygenase (COX), and lipoxygenase (LOX), which are implicated in the protection and destruction of the gastric mucosa. The phytochemicals were retrieved from the literature and docked toward the binding sites of the three enzymes (COX-1, COX-2, and 5-LOX). Five compounds, rhamnetin, kaempferol, rutin, rosmarinic acid, and chlorogenic acid were observed to putatively bind to cyclooxygenase 2 (COX-2) and 5-lipoxygenase (5-LOX) but not to cyclooxygenase 1 (COX-1). The interaction mechanisms between these phytochemicals and the target proteins are discussed. The compounds' drug metabolism, pharmacokinetics, and toxicity have been evaluated to assess their suitability as potential next-generation anti-ulcer and anti-inflammatory drugs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00269-2.

Polymorphism of virulence genes and biofilm associated with in vitro induced resistance to clarithromycin in Helicobacter pylori

BACKGROUND

Clarithromycin-containing triple therapy is commonly used to treat Helicobacter pylori infections. Clarithromycin resistance is the leading cause of H. pylori treatment failure. Understanding the specific mutations that occur in H. pylori strains that have evolved antibiotic resistance can help create a more effective and individualised antibiotic treatment plan. However, little is understood about the genetic reprogramming linked to clarithromycin exposure and the emergence of antibiotic resistance in H. pylori. Therefore, this study aims to identify compensatory mutations and biofilm formation associated with the development of clarithromycin resistance in H. pylori. Clarithromycin-sensitive H. pylori clinical isolates were induced to develop clarithromycin resistance through in vitro exposure to incrementally increasing concentration of the antibiotic. The genomes of the origin sensitive isolates (S), isogenic breakpoint (B), and resistant isolates (R) were sequenced. Single nucleotide variations (SNVs), and insertions or deletions (InDels) associated with the development of clarithromycin resistance were identified. Growth and biofilm production were also assessed.

RESULTS

The S isolates with A2143G mutation in the 23S rRNA gene were successfully induced to be resistant. According to the data, antibiotic exposure may alter the expression of certain genes, including those that code for the Cag4/Cag protein, the vacuolating cytotoxin domain-containing protein, the sel1 repeat family protein, and the rsmh gene, which may increase the risk of developing and enhances virulence in H. pylori. Enhanced biofilm formation was detected among R isolates compared to B and S isolates. Furthermore, high polymorphism was also detected among the genes associated with biofilm production.

CONCLUSIONS

Therefore, this study suggests that H. pylori may acquire virulence factors while also developing antibiotic resistance due to clarithromycin exposure.