Prolonged anxiolytic-like activity of sandalwood (Santalum albumL.) oil in stress-loaded mice

The fragrance of Santalum album L. (sandalwood) has been used as a sedative. However, few reports have investigated the anxiolytic activity of sandalwood fragrance. Therefore, in this study, we examined the anxiolytic-like activity of hexane-extracted sandalwood oil (SAO). Male ICR mice, aged 5 weeks at the start of each experiment, were used. To mimic its clinical use, the effect of SAO after stress loading was investigated. Mice were individually housed in cages for 1 week and subjected to loaded water-immersion stress for 24 h. Next, SAO inhalation (i.h.) was initiated 90 min prior to the elevated plus maze (EPM) test. As a result, significant anxiolytic-like activity was observed at 4 μl/l air SAO i.h. In contrast, anxiolytic-like activity was not observed in non-stressed control mice. Additionally, mice were subjected to SAO i.h prior to water-immersion stress for 24 h in order to investigate its prolonged effect. As a result, significant anxiolytic-like activity was observed at 4 μl/l air SAO i.h. In contrast, anxiolytic-like activity was not observed in non-stressed control mice. The above results indicate that the anxiolytic-like activity of SAO i.h. is revealed under stress conditions and is prolonged for at least 24 h. Since the main components of SAO are (Z)-α-santalol (51.1%) and (Z)-β-santalol (28.5%), it is proposed that they are involved in mediating the characteristic anxiolytic-like activity of SAO. Copyright © 2013 John Wiley & Sons, Ltd.