Antibacterial Potential of Extracts from Allium sativum (Garlic), Allium tuberosum (Ganda), Allium fistulosum (Sebilyeno), Allium ampeloprasum (Leeks) and Allium cepa (Onion)

Abstract

Antimicrobial resistance has encouraged investigation of plant-derived compounds with potential antibacterial activity. This study examined the antibacterial potential of leaf extracts from Allium sativum (Garlic), A. tuberosum (Ganda), A. fistulosum (Sebilyeno), A. ampeloprasum (Leeks), and A. cepa (Onion) to address the escalating global health issue of antibiotic resistance. Over a 12-month period, the research aimed to evaluate these extracts’ phytochemical composition – specifically alkaloids, flavonoids, phenolic compounds, saponins, and tannins – and assess their antibacterial effectiveness against Escherichia coli and Staphylococcus aureus. By comparing the bacterial growth inhibition potential of each plant extract, the study aimed to determine whether their inhibitory effects differed significantly from those of a commercially available antibiotic. Contrary to expectations based on traditional uses and reported bioactive compounds, the study found that none of the tested Allium extracts exhibited a zone of inhibition against either Staphylococcus aureus or Escherichia coli in the assays performed. While phytochemical screening confirmed the presence of flavonoids, phenolic compounds, saponins, and tannins in varying concentrations, these compounds, at the concentrations tested and under the tested conditions, did not demonstrate detectable antibacterial activity. These results suggest that while these Allium species possess various phytochemicals, the specific extraction methods, concentrations, and assay conditions used in this study did not yield antibacterial effects against the tested bacterial strains. This study highlights the need for further research to optimise extraction techniques, explore synergistic effects between compounds, and investigate different bacterial strains to fully understand the potential antibacterial properties of these Allium species.