Sánchez-Vidaña Dalinda Isabel, Po Kevin Kai-Ting, Fung Timothy Kai-Hang, Chow Jason Ka-Wing, Lau Way Kwok-Wai, So Pui-Kin, Lau Benson Wui-Man, Tsang Hector Wing-Hong
Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China.
Department of Special Education and Counselling, The Education University of Hong Kong, Hong Kong, China.
Neurosci Lett. 2019 May 14;701:180-192. doi: 10.1016/j.neulet.2019.02.042. Epub 2019 Feb 28.
Depression is a major health issue that causes severe societal economic and health burden. Aromatherapy, a practice that uses essential oils for preventive and therapeutic purposes, represents a promising therapeutic alternative for the alleviation of depressive symptoms. Lavender essential oil (LEO) has been the focus of clinical studies due to its positive effect on mood. An animal model of chronic administration of high dose corticosterone to induce depression- and anxiety-like behavior and reduced neurogenesis was used to explore the biological changes brought by aromatherapy. Twenty-four adult male Sprague Dawley rats were randomly assigned into four groups: Control, corticosterone (Cort) group with high dose of corticosterone, LEO group with daily exposure to LEO by inhalation, and LEO + Cort. At the end of the 14-day treatment period, behavioral tests were carried out. Serum samples were collected 2-3 days after the 14-day period treatment and before perfusion to carry out biochemical analyses to measure BDNF, corticosterone and oxytocin. After perfusion, brains were collected for immunohistochemical analysis to detect BrdU and DCX positive cells in the hippocampus and subventricular zone. Results showed that treatment with LEO ameliorated the depression-like behavior induced by the chronic administration of corticosterone as observed in the LEO + Cort group. Cort treatment reduced the number of BrdU positive cells in the hippocampus and the subventricular zone. Treatment with LEO prevented the corticosterone-induced reduction in the number of BrdU positive cells (LEO + Cort group) demonstrating the neurogenic effect of LEO under high corticosterone conditions. Chronic administration of high dose of corticosterone significantly reduced the dendritic complexity of immature neurons. On the contrary, treatment with LEO increased dendritic complexity of immature neurons under high corticosterone conditions (LEO + Cort group). The improved neurogenesis and dendritic complexity observed in the LEO + Cort group demonstrated a clear restorative effect of LEO under high corticosterone conditions. However, 2-3 days after the treatment, the levels of BDNF were upregulated in the LEO and LEO + Cort groups. Furthermore, the concentration of oxytocin in serum, 2-3 days after the treatment, showed to be upregulated in the LEO group alone. The present study has provided evidence of the biological effect of LEO on neuroplasticity and neurogenesis. Also, this study contributes to the understanding of the mechanism of action of LEO in an animal model where depression- and anxiety-like behavior and reduced neurogenesis were induced by high corticosterone administration.
抑郁症是一个重大的健康问题，会造成严重的社会、经济和健康负担。芳香疗法是一种使用精油进行预防和治疗的方法，是缓解抑郁症状的一种有前景的治疗选择。薰衣草精油（LEO）因其对情绪的积极影响而成为临床研究的焦点。使用慢性给予高剂量皮质酮以诱导抑郁和焦虑样行为并减少神经发生的动物模型来探索芳香疗法带来的生物学变化。将24只成年雄性Sprague Dawley大鼠随机分为四组：对照组、高剂量皮质酮的皮质酮（Cort）组、通过吸入每天接触LEO的LEO组和LEO + Cort组。在14天治疗期结束时，进行行为测试。在14天治疗期结束后2 - 3天以及灌注前采集血清样本进行生化分析，以测量脑源性神经营养因子（BDNF）、皮质酮和催产素。灌注后，收集大脑进行免疫组织化学分析，以检测海马体和脑室下区的BrdU和双皮质素（DCX）阳性细胞。结果显示，如在LEO + Cort组中观察到的，LEO治疗改善了慢性给予皮质酮诱导的抑郁样行为。Cort治疗减少了海马体和脑室下区BrdU阳性细胞的数量。LEO治疗防止了皮质酮诱导的BrdU阳性细胞数量减少（LEO + Cort组），证明了在高皮质酮条件下LEO的神经发生作用。慢性给予高剂量皮质酮显著降低了未成熟神经元的树突复杂性。相反，在高皮质酮条件下（LEO + Cort组），LEO治疗增加了未成熟神经元的树突复杂性。在LEO + Cort组中观察到的神经发生和树突复杂性的改善证明了在高皮质酮条件下LEO具有明显的恢复作用。然而，治疗后2 - 3天，LEO组和LEO + Cort组中BDNF水平上调。此外，治疗后2 - 3天，仅LEO组血清中催产素浓度显示上调。本研究提供了LEO对神经可塑性和神经发生的生物学作用的证据。此外，本研究有助于理解在高皮质酮给药诱导抑郁和焦虑样行为以及神经发生减少的动物模型中LEO的作用机制。
