ANTIMICROBIAL EVALUATION OF VOLATILE OIL OBTAINED FROM OCIMUM BASILICUM
Faculty
Year of Publication
Publication Type
Abstract
This research explored the chemical composition and antimicrobial activity of the essential oil derived from Ocimum basilicum Linn. (Sweet Basil). The oil was obtained through
hydrodistillation using a Clevenger-type apparatus, producing a 0.71% (v/w) average yield of a light-yellow, aromatic extract. Chemical profiling carried out with Gas Chromatography– Mass Spectrometry (GC–MS) revealed nine major constituents, with estragole (46.12%), eucalyptol (16.87%), and linalool (10.45%) as the predominant compounds, supported by smaller amounts of eugenol, thymol, β-caryophyllene, bisabolene, and τ-cadinol. The antimicrobial properties of the oil were assessed using agar well diffusion and minimum inhibitory concentration (MIC) assays against selected bacterial and fungal strains. Results indicated that the oil displayed dose-dependent inhibitory activity, showing marked effects against Staphylococcus aureus (19 mm), Bacillus subtilis (18 mm), Candida albicans (17 mm), and Aspergillus niger (21 mm), while Escherichia coli and Pseudomonas aeruginosa exhibited resistance. The observed antimicrobial efficacy was linked to the synergistic actions of oxygenated monoterpenes and phenylpropanoids in the oil. These findings demonstrate that O. basilicum essential oil exhibits strong antimicrobial potential, especially toward Gram-positive bacterial and fungal organisms, thereby validating its traditional medicinal applications. The dominance of estragole and eucalyptol suggests the Nigerian-grown species belongs to the estragole–eucalyptol chemotype. In summary, the study establishes O. basilicum oil as a viable natural antimicrobial candidate with promising applications in pharmaceutical, nutraceutical, and cosmetic industries, contributing to sustainable strategies against antimicrobial resistance.
hydrodistillation using a Clevenger-type apparatus, producing a 0.71% (v/w) average yield of a light-yellow, aromatic extract. Chemical profiling carried out with Gas Chromatography– Mass Spectrometry (GC–MS) revealed nine major constituents, with estragole (46.12%), eucalyptol (16.87%), and linalool (10.45%) as the predominant compounds, supported by smaller amounts of eugenol, thymol, β-caryophyllene, bisabolene, and τ-cadinol. The antimicrobial properties of the oil were assessed using agar well diffusion and minimum inhibitory concentration (MIC) assays against selected bacterial and fungal strains. Results indicated that the oil displayed dose-dependent inhibitory activity, showing marked effects against Staphylococcus aureus (19 mm), Bacillus subtilis (18 mm), Candida albicans (17 mm), and Aspergillus niger (21 mm), while Escherichia coli and Pseudomonas aeruginosa exhibited resistance. The observed antimicrobial efficacy was linked to the synergistic actions of oxygenated monoterpenes and phenylpropanoids in the oil. These findings demonstrate that O. basilicum essential oil exhibits strong antimicrobial potential, especially toward Gram-positive bacterial and fungal organisms, thereby validating its traditional medicinal applications. The dominance of estragole and eucalyptol suggests the Nigerian-grown species belongs to the estragole–eucalyptol chemotype. In summary, the study establishes O. basilicum oil as a viable natural antimicrobial candidate with promising applications in pharmaceutical, nutraceutical, and cosmetic industries, contributing to sustainable strategies against antimicrobial resistance.
Supervisor(s)
co-supervisor