Aim of the study: The purpose of the present study was to screen aromatic essential oils that have antidepressant effects to identify the regulatory mechanisms of selected essential oils. Materials and methods: The antidepressant effects of essential oils of Anthemis nobilis (chamomile), Salvia sclarea (clary sage; clary), Rosmarinus officinalis (rosemary), and Lavandula angustifolia (lavender) were assessed using a forced swim test (FST) in rats. Rats were treated with essential oils by intraperitoneal injection or inhalation. Serum levels of corticosterone were assessed by enzyme-linked immunosorbent assay (ELISA). Results: Among the essential oils tested, 5% (v/v) clary oil had the strongest anti-stressor effect in the FST. We further investigated the mechanism of clary oil antidepression by pretreatment with agonists or antagonists to serotonin (5-HT), dopamine (DA), adrenaline, and GABA receptors. The anti-stressor effect of clary oil was significantly blocked by pretreatment with buspirone (a 5-HT1A agonist), SCH-23390 (a D1 receptor antagonist) and haloperidol (a D2, D3, and D4 receptor antagonist). Conclusions: Our findings indicate that clary oil could be developed as a therapeutic agent for patients with depression and that the antidepressant-like effect of clary oil is closely associated with modulation of the DAnergic pathway.
- Forced swim test
- Salvia sclarea