Evaluation of Olea europaea Leaf extracts as a Natural Antibacterial Agent against Selected Pathogenic Bacteria
DOI:
https://doi.org/10.65419/albahit.v5i3.167Keywords:
Olea europaea, Ultrasonic-Assisted Extraction, Antibacterial activity, Oleuropein, PhytochemicalsAbstract
The rapid emergence of multidrug-resistant bacterial strains poses a critical threat to global public health, driving the search for novel, eco-friendly bioactive agents. Olea europaea (olive tree) leaves are rich in bioactive polyphenols, particularly oleuropein, which exhibit potent antimicrobial properties.
This study aims to evaluate and compare the antibacterial efficacy of aqueous and methanolic extracts of Olea europaea leaves obtained via Ultrasonic-Assisted Extraction (UAE) against five bacterial pathogens.
Olive leaf powder was processed using UAE The crude extracts were concentrated using a rotary evaporator to a nominal stock concentration of 1,000 mg/mL (1 g/mL), from which serial dilutions (100%, 80%, and 60%) were prepared. The antibacterial activity was evaluated using the agar well diffusion method against Staphylococcus aureus, Streptococcus alpha-hemolytic, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa.
UAE demonstrated significantly higher extraction efficiency. Methanolic extracts obtained via UAE exhibited the highest zones of inhibition (ZOI) against all tested clinical isolates.
Overall, Gram-positive bacteria (S. aureus) exhibited higher susceptibility to the extracts compared to Gram-negative strains. The antibacterial effect was concentration-dependent, with the maximum inhibitory activity observed at 100% concentration.
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