Prolonged anxiolytic‐like activity of sandalwood (Santalum album L.) oil in stress‐loaded mice

Abstract

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.

Relationship Between Emotional Behavior in Mice and the Concentration of (+)‐α‐Santalol in the Brain

“…Okugawa et al additionally reported that after an intraperitoneal administration, α‐santalol was a strong antagonist of the dopamine D 2 and serotonin 5‐HT 2A receptor binding, although it was less potent than chlorpromazine when used as an antipsychotic agent (Okugawa et al ., ). We further reported that sandalwood oil, for which α‐santalol and β‐santalol are the main components, exhibited a prolonged anxiolytic‐like activity after inhaled administration in mice exposed to water‐immersion stress for 24 h (Satou et al ., ). Our findings suggested that after the inhaled administration, the volatile components produced these anxiolytic effects by neurological and pharmacological transfers.…”

Anxiolytic‐like effects of essential oil from Thymus vulgaris was increased during stress

“…[1][2][3][4][5][6] We recently found that in vivo transferability by inhalation administration varies depending on the type of volatile compounds. It has been reported that essential oils of coniferous trees, juniper, lavender and sandalwood have anxiolytic-like activities, and the chemical components exhibiting these effects are reported to be linalool, linalyl acetate, a-pinene and a-santalo.…”

“…It has been reported that essential oils of coniferous trees, juniper, lavender and sandalwood have anxiolytic-like activities, and the chemical components exhibiting these effects are reported to be linalool, linalyl acetate, a-pinene and a-santalo. [1][2][3][4][5][6] We recently found that in vivo transferability by inhalation administration varies depending on the type of volatile compounds. 7 For example, 1,8-cineole is not readily metabolized from within the brain, even at 30 min after inhalation.…”

A Rare Type of Sesquiterpene and β-Santalol Derivatives from <i>Santalum album</i> and Their Cytotoxic Activities

“…Sandalwood oil is the volatile substance obtained through steam distillation of the heartwood of S. album and is widely used in aromatherapy and traditional medicine. [1][2][3][4] S. album contains a variety of aromatic compounds 5) and sesquiterpenes, [6][7][8] of which α-santalol is a major volatile compound that possesses various biological activities. [9][10][11] However, β-santalol, another major volatile sesquiterpene from S. album with the same bicyclo[2.2.1] heptane skeleton, shows few biological activities, including anti-Helicobacter pylori 12) and antiviral effects.…”

“…These results prompted us to investigate the heartwood of S. album further. In this study, we isolated a rare type of sesquiterpene with a spiro bicyclic system (1), and seven new (2)(3)(4)(5)(6)(7)(8) and four known (9-12) β-santalol derivatives. The structures of these new β-santalol derivatives were determined by analysis of extensive spectroscopic data, including two-dimensional NMR data.…”