Antibiotics | Bicarinalin Enhances the Antibacterial Activity of Levofloxacin and Clarithromycin Against Helicobacter pylori

This study first demonstrated the antimicrobial synergistic effect of Bicarinalin against Helicobacter pylori, showing its significant enhancement of antibiotic efficacy when used in combination. Through SEM and biochemical leakage analysis, this AMP was confirmed to disrupt bacterial membrane integrity, releasing intracellular proteins and DNA, providing novel insights for H. pylori treatment.

 

Literature Overview
This article titled 'Bicarinalin Enhances the Antibacterial Activity of Levofloxacin and Clarithromycin Against Helicobacter pylori' published in Antibiotics reviews the therapeutic challenges of Helicobacter pylori and explores Bicarinalin's potential as an antimicrobial enhancer. The study evaluates Bicarinalin's antibacterial activity and synergistic effects with antibiotics through in vitro experiments, while investigating its membrane disruption mechanism against H. pylori to provide theoretical foundations for antibiotic enhancement.

Background Knowledge
Helicobacter pylori is a Gram-negative bacterium colonizing the human stomach, associated with gastritis, peptic ulcers, and gastric cancer. Traditional antibiotic therapies face challenges due to its drug resistance and colonization mechanisms, necessitating novel antimicrobial strategies. Antimicrobial peptides (AMPs) have become a research hotspot for their broad-spectrum antimicrobial activity and low resistance-induction potential. Bicarinalin, a newly identified AMP from ant venom, features a stable α-helical structure and low cytotoxicity. Current studies reveal its membrane-disruption and antimicrobial synergistic effects against multiple pathogens. This study focuses on Bicarinalin's enhancement mechanisms in H. pylori treatment, aiming to explore its potential as an antibiotic adjuvant to combat escalating drug resistance.

 

 

Research Methods and Experiments
The study employed agar well diffusion and microdilution assays to evaluate Bicarinalin's antibacterial activity against H. pylori ATCC strains, while testing its synergistic effects with commonly used antibiotics (levofloxacin, clarithromycin, tobramycin). Bacterial membrane disruption was assessed through protein and DNA leakage measurements, complemented by scanning electron microscopy (SEM) to observe morphological changes in H. pylori cells.

Key Conclusions and Perspectives

• Bicarinalin exhibited dose-dependent antibacterial activity, achieving an inhibition zone diameter of 18.3 mm at 32 µg/mL against H. pylori ATCC strains.
• Microdilution assays revealed Bicarinalin's MIC99 at 4.8 µg/mL, with superior antibacterial activity at 15 µg/mL and 30 µg/mL compared to levofloxacin and amoxicillin.
• When combined with levofloxacin or clarithromycin, Bicarinalin significantly enhanced antibiotic efficacy, increasing inhibition zones from 14.2 mm to 20 mm and 7.3 mm to 16 mm, respectively.
• SEM imaging demonstrated membrane rupture and aggregation in H. pylori cells post-Bicarinalin treatment, with severe morphological damage observed.
• Protein and DNA leakage analyses indicated Bicarinalin induced 33.25% protein leakage and 55.10% DNA leakage, substantially exceeding negative control levels.

Research Significance and Prospects
This study systematically evaluates Bicarinalin's antimicrobial enhancement effects and membrane disruption mechanisms against H. pylori, providing theoretical support for developing novel antibacterial agents. Future research should validate its in vivo efficacy and pharmacokinetics in combination therapies to facilitate clinical translation.

 

 

Conclusion
In summary, Bicarinalin, as a novel antimicrobial peptide, significantly enhances levofloxacin and clarithromycin's antibacterial effects against H. pylori through membrane integrity disruption and induction of intracellular protein/DNA leakage. These findings offer new strategies for treating multidrug-resistant H. pylori infections and highlight AMPs' potential in antibiotic synergy. While requiring further in vivo validation, Bicarinalin shows promise as an antibiotic adjuvant to improve therapeutic outcomes and reduce resistance development. This research provides scientific foundations for novel antimicrobial drug development and underscores AMPs' critical role in combating multidrug-resistant infections.

 

Iman Saleh and Pınar Küce Çevik. Bicarinalin Enhances the Antibacterial Activity of Levofloxacin and Clarithromycin Against Helicobacter pylori. Antibiotics.