The essential oil of Abies sibirica (Pinaceae) reduces arousal levels after visual display terminal work

Volatile constituents from natural plants have sometimes been used for the treatment of mental disorders, but the efficacy of many plants has not been determined. Here, we investigated the effects of the essential oil of the Siberian fir tree, Abies sibirica (Pinaceae), on individuals during and after performance of a sustained task on a visual display terminal (VDT). Participants who breathed air containing the essential oil showed prolonged heartbeat intervals and increased theta activity as measured by electroencephalography in the recovery period after the VDT task, but not during the task. The volatile constituents emitted from the essential oil of A. sibirica through the odorant delivery system for 40min were α-pinene (80.4μg), santene (3.1μg), tricyclene (2.4μg), camphene (24.2μg), β-pinene (2.6μg), myrcene (1.0μg), δ-3-carene (14.4μg), limonene (3.8μg), and bornyl acetate (1.0μg). These results show that the essential oil of A. sibirica reduced arousal levels after the VDT task, and might be useful for the prevention of VDT-related mental health disturbance.