Evaluating Antibacterial Efficacy And Phytochemical Analysis Of Fennel Seed Oil On Staphylococcus Aureus And Escherichia Coli

Abstract

Fennel (Foeniculum vulgare) is a medicinal plant known for its bioactive compounds and traditional use in treating infections. Increasing resistance to conventional antibiotics has led to growing interest in plant-based alternatives for antibacterial therapy. This study aimed to evaluate the antibacterial efficacy and phytochemical composition of fennel seed oil against Staphylococcus aureus and Escherichia coli. Soxhlet extraction was used to obtain fennel seed oil using n-hexane as the solvent. Qualitative and quantitative phytochemical screening was carried out using standard chemical tests and UV-visible spectrophotometry. Antibacterial activity was assessed using agar well diffusion, while MIC and MBC were determined via broth dilution methods. Data were presented descriptively using tables. Results revealed that phenols (20%) and saponins (19%) were the most abundant phytochemicals, with flavonoids and alkaloids present at 10% each. The oil showed concentration-dependent antibacterial activity, with the highest zone of inhibition recorded at 13.13 mm for S. aureus (200 mg/mL), surpassing that of tetracycline (10.66 mm). MIC and MBC values confirmed stronger susceptibility in S. aureus (0.5–1.0 mg/mL and 1.0–2.0 mg/mL, respectively) compared to E. coli. These findings suggest that fennel seed oil possesses promising antimicrobial properties, particularly against Gram-positive bacteria, and may serve as a potential candidate for developing plant-based therapeutic agents.