Essential oils from Apiaceae as valuable resources in neurological disorders: Foeniculi vulgare aetheroleum

• The anxiolytic and antidepressant effects of the fennel volatile oil were studied.
• Trans-anethole was identified as the major compound, followed by camphor.
• An animal model of Alzheimer was used for pharmacological assessment.
• The biologic activity varied in a dose-dependent manner.

Used as a spice and to improve the palatability of different meat and vegetable dishes, common fennel, Foeniculum vulgare Mill. (Apiaceae), was a traditional remedy for the relief of spasms and colic due to gas accumulation, to stimulate gastrointestinal motility, to alleviate productive coughs as well as for the induction of menstruation and lactation. Fennel essential oil extracted from fennel fruits is used as traditional medicine to improve eyesight, promote courage and mental strength, reduce stress/nervousness and produce calming.Therefore, we wanted to reinforce some of the folk uses with scientific proves. The present study analyzed the anxiolytic and antidepressant of the fennel essential oil in beta-amyloid (1-42) rat model of Alzheimer’s disease (AD). The antioxidant activity of the essential oil was tested in vitro. The anxiolytic- and antidepressant-like effects of the fennel essential oil were studied by means of in vivo (elevated plus-maze and forced swimming tests) approaches. The beta-amyloid (1-42)-treated rats exhibited the following: decrease of the exploratory activity, the percentage of the time spent and the number of entries in the open arm within elevated plus-maze test and decrease of swimming time and increase of immobility time within forced swimming test. Inhalation of the fennel essential oil significantly exhibited anxiolytic- and antidepressant-like effects.Our results suggest that the fennel essential oil inhalation ameliorates beta-amyloid (1-42)-induced anxiety and depression in laboratory rats. Thus, the results of the present study indicate that the fennel essential oil may have potential clinical applications in the management of anxiety and depression related to AD conditions.