Kobayashi Yoshinori, Takemoto Hiroaki, Fua Ziqi, Shimizu Emiko, Kinjo Yukitaka
Nat Prod Commun. 2016 Aug;11(8):1175-1178.
Kabuchii (Citrus keraji var. kabuchii hort. ex Tanaka, Rutaceae) is a peculiar Okinawan citrus fruit. Local farmers cultivating various Citrus fruits say that the fragrance of Kabuchii is the most relaxing, but, there are few reports on the biological effects of the essential oil of Kabuchii and its chemical components [1]. In this study, the sedative effects of inhalation of the vaporized Kabuchii essential oil in open field, Rotarod, and pentobarbital sleep tests are compared with diazepam, as a positive control. In the open field test, both Kabuchii essential oil and diazepam decreased the spontaneous motor activity dose-dependently. The reduction in spontaneous motor activity in the 0.3 mg/cage (ca. 0.0278 mg/L) Kabuchii essential oil group was greater than that in the 1 mg/kg diazepam group. In the Rotarod test, Kabuchii did not affect the motor performance, even at the highest dosage tested (3 mg/cage), whereas diazepam decreased it dose- dependently. The effects of the major or characteristic components of Kabuchii, d-limonene, y-terpinene, thymol, and p-cymene, were also evaluated in the- open field and Rotarod tests. y-Terpinene and thymol significantly decreased spontaneous motor activity at a dosage of 0.3 mg/cage, without affecting motor performance. Thus, y-terpinene was estimated to be the main active component. Reduction in spontaneous motor activity by y-terpinene in the open field test was not observed in intranasal zinc sulfate irrigation-induced anosmic mice. In the pentobarbital sleep test, both Kabuchii essential oil and diazepam potentiated pentobarbital-induced loss of the righting reflex (LRR). The LRR duration prolonging effects of both treatments were inhibited by pretreatment with flumazenil, a benzodiazepine receptor antagonist. The LRR latency reducing effect of Kabuchii was not affected by flumazenil, while that of diazepam was suppressed by it. y-Terpinene showed similar potentiating effects on pentobarbital-induced sleep. Thus, vaporized Kabuchii essential oil and its active component, y-terpinene, have sedative effects comparable with diazepam without inducing motor incoordination, which is a well-known side effect of. diazepam.
卡布奇（Citrus keraji var. kabuchii hort. ex Tanaka，芸香科）是冲绳一种独特的柑橘类水果。种植各种柑橘类水果的当地农民表示，卡布奇的香气最令人放松，但是，关于卡布奇精油及其化学成分的生物学效应的报道很少[1]。在本研究中，将在旷场、转棒和戊巴比妥睡眠试验中吸入汽化卡布奇精油的镇静作用与作为阳性对照的地西泮进行比较。在旷场试验中，卡布奇精油和地西泮均剂量依赖性地降低自发运动活性。在0.3 mg/笼（约0.0278 mg/L）卡布奇精油组中自发运动活性降低程度大于1 mg/kg地西泮组。在转棒试验中，即使在测试的最高剂量（3 mg/笼）下，卡布奇也不影响运动表现，而地西泮则剂量依赖性地降低运动表现。还在旷场和转棒试验中评估了卡布奇的主要或特征性成分d-柠檬烯、γ-萜品烯、百里香酚和对伞花烃的作用。γ-萜品烯和百里香酚在剂量为0.3 mg/笼时显著降低自发运动活性，而不影响运动表现。因此，γ-萜品烯被估计为主要活性成分。在经鼻硫酸锌灌洗诱导的嗅觉缺失小鼠中未观察到旷场试验中γ-萜品烯对自发运动活性的降低作用。在戊巴比妥睡眠试验中，卡布奇精油和地西泮均增强戊巴比妥诱导的翻正反射消失（LRR）。两种处理的LRR持续时间延长作用均被苯二氮䓬受体拮抗剂氟马西尼预处理所抑制。卡布奇的LRR潜伏期缩短作用不受氟马西尼影响，而地西泮的该作用则被其抑制。γ-萜品烯对戊巴比妥诱导的睡眠表现出类似的增强作用。因此，汽化的卡布奇精油及其活性成分γ-萜品烯具有与地西泮相当且不引起运动不协调（地西泮的一种众所周知的副作用）的镇静作用。
