Chemical composition and antimicrobial activity of Foeniculum vulgare Mill. essential oil

Abstract

Foeniculum vulgare Mill. (fennel) is a member of the Apiaceae plant family and is used as an antiinflammatory, analgesic, carminative, diuretic, and antispasmodic agent. Nowadays, there is a growing interest in the antioxidant potential and antimicrobial activities of fennel fruit extracts and essential oil [1]. There are many reports on the essential-oil composition of F. vulgare. Previously, the composition and significant antimicrobial activity of the essential oil of F. vulgare from Pakistan was reported with trans-anethole (70.1%) as the main compound [2]. An essential oil of the fruits of F. vulgare, containing trans-anethole (68.5%) and estragole (10.4%), showed antibacterial activity against Staphylococcus albus, Bacillus subtilis, Salmonella typhimurium, Shigella dysenteriae, and Escherichia coli [3]. In the current study, the essential oil of the aerial parts of F. vulgare was obtained by hydrodistillation (3 h). The essential-oil composition was analyzed by means of gas chromatography-mass spectrometry (GC-MS). The main components of the essential oil from the aerial parts were estragole (33.6%), limonene (24.7%), and α-pinene (19.1%). Additionally, the antimicrobial activity of the essential oil was investigated against Gram-negative (Escherichia coli DH5α) and Gram-positive (Staphylococcus aureus) bacteria. The essential oil showed a growth inhibitory activity against E. coli DH5α (69.3%), tested at 80 mg/mL. However, no activity of the oil was detected in the case of Gram-positive bacteria.