Chemical composition and antibacterial activity of the essential oils from flower, leaf and stem of Ferula cupularis growing wild in Iran.

Context: Ferula cupularis (Boiss.) Spalik et S. R. Downie (Apiaceae) is a common plant in Iran that grows in the foothills of Dena Mountain. In traditional folk medicine, this plant has different applications, but there are no studies proving their uses.

Objective: This study is the first attempt to investigate the chemical composition and antibacterial effect of the essential oils of F. cupularis.

Materials And Methods: The essential oils from flower, leaf, and stem of F. cupularis were analyzed by using GC and GC-MS. Antibacterial activity of essential oils was determined by microdilution method against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

Results: The essential oil from flower of F. cupularis contained 15 monoterpene, 13 oxygenated monoterpene, and 2 sesquiterpene hydrocarbons. The leaf essential oil contained 12 monoterpene, 13 oxygenated monoterpene, 2 sesquiterpene, 6 oxygenated sesquiterpene hydrocarbons, and 3 non-terpenoid components. Stem essential oil contained one monoterpene, 23 oxygenated monoterpene, 2 sesquiterpene, and 6 oxygenated sesquiterpene hydrocarbons. The MIC value of stem essential oil was 2.85 mg/mL against both Gram-positive bacteria and Gram-negative bacteria except P. aeruginosa which was inhibited at 22.75 mg/mL. The MIC values of leaf and flower essential oils were higher than 5.69 and 22.75 mg/mL, respectively.

Discussion: This study highlighted the strong antibacterial effect of Ferula cupularis's essential oil which might be due to its high content of oxygenated monoterpene hydrocarbons.

Conclusion: Our results suggested that this plant may be a good candidate for further biological and pharmacological investigations.