Anti-Helicobacter pylori Properties of the Ant-Venom Peptide Bicarinalin.

Jesus Guzman,Laila Haddioui-Hbabi,Nathan Téné,Haouaria Belkhelfa,Michel Sauvain,Axel Touchard,Michel Treilhou,Denis Castillo

doi:10.3390/toxins10010021

Abstract

The venom peptide bicarinalin, previously isolated from the ant Tetramorium bicarinatum, is an antimicrobial agent with a broad spectrum of activity. In this study, we investigate the potential of bicarinalin as a novel agent against Helicobacter pylori, which causes several gastric diseases. First, the effects of synthetic bicarinalin have been tested against Helicobacter pylori: one ATCC strain, and forty-four isolated from stomach ulcer biopsies of Peruvian patients. Then the cytoxicity of bicarinalin on human gastric cells and murine peritoneal macrophages was measured using XTT and MTT assays, respectively. Finally, the preventive effect of bicarinalin was evaluated by scanning electron microscopy using an adherence assay of H. pylori on human gastric cells treated with bicarinalin. This peptide has a potent antibacterial activity at the same magnitude as four antibiotics currently used in therapies against H. pylori. Bicarinalin also inhibited adherence of H. pylori to gastric cells with an IC50 of 0.12 μg·mL−1 and had low toxicity for human cells. Scanning electron microscopy confirmed that bicarinalin can significantly decrease the density of H. pylori on gastric cells. We conclude that Bicarinalin is a promising compound for the development of a novel and effective anti-H. pylori agent for both curative and preventive use.

Highlights

Helicobacter pylori is a unique bacteria able to colonize human stomach mucosa [1,2]
Clarithromycin, levofloxacin, metronidazole and amoxicillin are the conventional drugs used in a triple therapy to treat stomach infection by the gram-negative bacteria H. pylori even though the eradication rate is currently less than 80% in most parts of the world
The results show that conventional antibiotics are more efficient with clinical strains except for metronidazole, which has a MIC50 16-fold higher against ATCC strain

Summary

Introduction

Helicobacter pylori is a unique bacteria able to colonize human stomach mucosa [1,2]. This helix-shaped Gram-negative bacteria expresses outer membrane proteins which enable it to bind epithelial gastric cells, and secretes ureases which enable it to overcome stomach acidity. It is estimated that half of the world’s population is infected with H. pylori, making this pathogen one of the most common bacterial infections globally [3,4]. The colonization of stomachs by H. pylori results in gastric inflammation (gastritis), and a persistent colonization is recognized as the leading factor in the development of gastric ulcers and cancers [5,6].

Methods

Results

Discussion

Conclusion