| dc.description.abstract | Coleus amboinicus Lour., commonly known in North Sumatra as “daun bangun-bangun,” is an aromatic plant from the Lamiaceae family traditionally used as an anti-infective, anti-inflammatory, and wound-healing agent. Its biological activities are primarily attributed to its secondary metabolite content, including flavonoids, tannins, saponins, alkaloids, phenolics, and essential oils. This study aimed to evaluate the antimicrobial activity of ethanol, ethyl acetate, and n-hexane extracts of C. amboinicus leaves against clinically relevant pathogenic microorganisms, namely Escherichia coli, Staphylococcus aureus, and Candida albicans. Antimicrobial activity was assessed using the disc diffusion method with extract concentrations of 10%, 15%, 20%, and 25% following the Kirby–Bauer procedure. The test microorganisms were clinical pathogens known to exhibit resistance to several commercial antibiotics. The results demonstrated that all extracts were capable of inhibiting microbial growth, with increasing effectiveness at higher extract concentrations. The ethyl acetate extract exhibited the strongest inhibitory activity against all tested microbes, producing larger zones of inhibition compared with the ethanol and n-hexane extracts. The highest antimicrobial effect was observed in the ethanol extract at 25% concentration against the Gram-positive bacterium S. aureus, and in the ethyl acetate extract against C. albicans. The diameter of the inhibition zone increased proportionally with extract concentration. Overall, C. amboinicus leaves possess promising potential as a natural source of antimicrobial agents effective against Gram-positive bacteria, Gram-negative bacteria, and pathogenic fungi. | en_US |
