Evaluation of the Antibacterial Activity of Dayak Onion Extract (Eleutherine palmifolia L.) against Pathogenic Salmonella spp. and Escherichia coli

Dayak onion extract (Eleutherine palmifolia (L.) Merr) is a traditional medicinal plant widely used by the Dayak tribe in Kalimantan, Indonesia, to treat various diseases. It contains flavonoids and phenolic compounds with potential antibacterial properties. This study aimed to evaluate the antibacterial activity and Minimum Inhibitory Concentration (MIC) of the extract against pathogenic bacteria, while also examining its effects on beneficial bacteria such as Lactobacillus acidophilus ATCC 4356 and Lactobacillus sp. FNCC 0020. Dayak onion powder was extracted using 96 ethanol, and the extract was tested at various concentrations (1, 3, 5, 7, 9, and 11 mL/L) using the Kirby-Bauer method. The results demonstrated that the extract effectively inhibited the growth of the pathogenic bacteria, with the highest concentration (11 ml/L) exhibiting the most substantial inhibition zone diameter. The MIC test revealed that the extract inhibited pathogenic bacteria at concentrations of 11, 5.5, 2.75, and 1.37 mL/L, while Lactobacillus sp. FNCC 0020 was inhibited at 11, 5.5, and 2.75 mL/L. The optimal extract concentration for bacterial inhibition was identified as 1.37 mL/L, as it effectively suppressed the pathogenic bacteria without hindering the growth of the beneficial bacteria. The antibacterial efficacy of the extract is attributed to its flavonoids and phenolic content, as well as the presence of secondary metabolites, including flavonols. These findings suggest that Dayak onion extract has the potential to be utilized as a natural antibacterial agent in food preservation, offering a selective inhibition of pathogenic bacteria while preserving beneficial microorganisms. © (2025), (ResearchersLinks Ltd). All rights reserved.