Various essential oils from plants and fragrance components such as monoterpenes have been discovered to reduce spontaneous movements in mice; thus, it has been made clear that the odor itself has the sedative activity. In the present study, we examined the sedative activity of the odors of fragrance components added to eye drops; l-menthol, d-camphor, phenylethyl alcohol, and geraniol, which are often used as refreshers or preservatives. Each fragrance component was administered by the inhalation route to mice, and the sedative effects were evaluated using an open field test. The results showed that four components administered via inhalation to mice significantly decreased the amount of spontaneous motor activity in a dose-dependent manner, indicating that all four components have a sedative effect. The optimal concentrations at which l-menthol, d-camphor, phenylethyl alcohol, and geraniol showed the highest sedative activity were 4 × 10^–2 mg per cage, 4 × 10^–4 mg per cage, 4 × 10^–2 mg per cage, and both 4 × 10^–4 and 4 × 10^–2 mg per cage, respectively. The AUC graph of geraniol was represented as a W-shaped curve, suggesting that the sedative action of geraniol was biphasic. The present finding demonstrates a new perspective on a possible pharmacological property of eye drop additives used with no expected pharmacological functions.

已发现来自植物的各种精油和芳香成分（如单萜）可减少小鼠的自发运动。因此，已经清楚的是，气味本身具有镇静活性。在本研究中，我们检查了添加到滴眼液中的香精成分的气味的镇静活性。l-薄荷醇，d-樟脑，苯乙醇和香叶醇，通常用作清爽剂或防腐剂。通过吸入途径将每种香精成分施用于小鼠，并使用开放视野试验评估其镇静作用。结果表明，通过吸入方式对小鼠给药的四种成分以剂量依赖的方式显着降低了自发运动活动的量，表明所有四种成分均具有镇静作用。薄荷醇的最佳浓度 每笼^–2 mg，每笼4×10 ^–4  mg，每笼4×10 ^–2  mg，每笼分别为4×10 ^–4和4×10 ^–2  mg。香叶醇的AUC图表示为W形曲线，表明香叶醇的镇静作用是双相的。本发现证明了在没有预期药理功能的情况下使用的滴眼剂的可能药理特性的新观点。