June 26, 2025 | PLOS One |
Methanolic extracts from Nephelium lappaceum (rambutan) and Hyphaene thebaica (doum palm) were assessed for their antibacterial properties against MDR bacteria in a study carried out by the University of Buea, Cameroon. Target organisms included clinical isolates and resistant strains of Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter aerogenes, and Escherichia coli, which are listed as critical priority pathogens due to their resistance to commonly used antibiotics.
The extracts were tested for minimum inhibitory concentrations (MICs), effects on bacterial cell membrane integrity, and H+-ATPase-mediated proton pumping. Phytochemical analysis confirmed the presence of tannins, phenols, and saponins. Results showed that extracts, particularly from N. lappaceum leaves, exhibited notable antibacterial activity (MIC 128–1024 μg/mL) and were bactericidal, as indicated by MBC/MIC ratios ≤ 4. The extracts disrupted cell membranes and inhibited proton pumping, suggesting potential mechanisms of action.
Importantly, both N. lappaceum (leaves and peels) and H. thebaica (fruits) demonstrated synergistic effects with multiple antibiotics, including tetracycline, vancomycin, imipenem, ciprofloxacin, and cefixime, reducing antibiotic MIC values up to eightfold. No antagonistic interactions were observed. These findings highlight the potential of these plant extracts as alternative antibacterial agents and as adjuvants to restore antibiotic effectiveness against resistant bacteria.
