Anxiolytic and antidepressant activities of Pelargonium roseum essential oil on Swiss albino mice: Possible involvement of serotonergic transmission.

The anxiolytic and antidepressant activities of the Reunion Geranium (Pelargonium roseum Willd) essential oil (EO) were evaluated in male Swiss albino mice by intraperitoneal administration of 10, 20, and 50 mg/kg bw using elevated plus maze (EPM), open-field test (OFT), and forced swimming test (FST). Moreover, we evaluated whether the 5-HT1A and GABAA -benzodiazepine receptor systems are involved in the anxiolytic effects through the coadministration of WAY-100635 (a selective 5-HT1A receptor antagonist) and flumazenil (an antagonist of benzodiazepine). GC-MS revealed the monoterpene alcohols citronellol (35.9%) and geraniol (18.5%) as the main components of the P. roseum EO. EO was effective in increasing the total number of entries and time spent in the open arms of EPM whereas number of rearing in OFT was significantly decreased in comparison with the control. In the FST, immobility time decreased in EO treated mice. Pretreatment with WAY-100635, but not Flumazenil, was able to reverse the effects of the EO in the EPM and FST, indicating that the EO activity occurs via the serotonergic but not GABAergic transmission. Overall, results of this work showed significant anxiolytic and antidepressant activity of P. roseum EO and confirmed the traditional uses of Pelargonium species as calming agents.