Melaleuca leucadendron, commonly referred to as Eucalyptus, has been extensively applied in folk remedies and modern therapeutics because of its wide-ranging bioactive effects. This species is rich in various natural compounds that account for its capabilities in reducing inflammation, alleviating pain, regulating blood glucose, and combating cancer cells. The objective of this research was to investigate the antimicrobial effects of extracts obtained from M. leucadendron leaves on microorganisms linked to acne vulgaris. Ground dry leaves from M. leucadendron underwent sequential extraction by maceration in n-hexane, dichloromethane (DCM), and methanol, resulting in the respective fractions designated as MLEH, MLED, and MLEM. The antimicrobial properties of these fractions (MLEH, MLED, and MLEM) were evaluated using the disk diffusion technique on Staphylococcus epidermidis and Propionibacterium acnes at concentrations spanning 1% to 20%. In addition, the chemical profile was determined through gas chromatography–mass spectrometry (GC-MS). The methanolic fraction (MLEM) achieved the maximum yield (11.41%) and confirmed the presence of flavonoids, phenolic compounds, saponins, and terpenoids. The hexane fraction (MLEH) demonstrated antimicrobial effects at 20% concentration, producing inhibition diameters of 11.56 mm against S. epidermidis and 10.36 mm against P. acnes. Greater potency was observed with the DCM fraction (MLED), which formed a 17.41 mm zone against S. epidermidis at 20% and a 12.29 mm zone against P. acnes at 10%. On the other hand, the methanolic fraction (MLEM) only inhibited P. acnes at 20% concentration with a 10.47 mm zone, showing no effect on S. epidermidis. Overall, these results highlight that certain M. leucadendron leaf fractions, notably MLEH and MLED, display significant antimicrobial action toward bacteria involved in acne and could be suitable for creating topical treatments with antibacterial properties.
