Lavender Oil Reduces Depressive Mood in Healthy Individuals and Enhances the Activity of Single Oxytocin Neurons of the Hypothalamus Isolated from Mice: A Preliminary Study

Keizaburo Ogata; Koji Ataka; Hajime Suzuki; Takakazu Yagi; Ayumi Okawa; Takamasa Fukumoto; Boyang Zhang; Masanori Nakata; Toshihiko Yada; Akihiro Asakawa

doi:10.1155/2020/5418586

Lavender Oil Reduces Depressive Mood in Healthy Individuals and Enhances the Activity of Single Oxytocin Neurons of the Hypothalamus Isolated from Mice: A Preliminary Study

Evid Based Complement Alternat Med. 2020 Jul 14:2020:5418586. doi: 10.1155/2020/5418586. eCollection 2020.

Authors

Keizaburo Ogata^{1

2}, Koji Ataka³, Hajime Suzuki⁴, Takakazu Yagi⁵, Ayumi Okawa⁶, Takamasa Fukumoto², Boyang Zhang⁷, Masanori Nakata^{7

8}, Toshihiko Yada^{7

9

10}, Akihiro Asakawa²

Affiliations

¹ Division of Clinical Psychology, Kitasato University Hospital, 1-15-1, Kitasato, Minami, Sagamihara, Sagamihara 252-0328, Japan.
² Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
³ Department of Pharmacological Sciences of Herbal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
⁴ Department of Oral and Maxillofacial Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
⁵ Department of Orthodontics and Dentofacial Orthopedics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
⁶ Department of Psychology, Faculty of Law, Economics and Humanities, Kagoshima University, 1-21-30, Korimoto, Kagoshima 890-0065, Japan.
⁷ Department of Physiology, Division of Integrative Physiology, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
⁸ Department of Physiology, Wakayama Medical University School of Medicine, 811-1, Kimiidera, Wakayama 641-8509, Japan.
⁹ Kansai Electric Power Medical Research Institute, 1-5-6, Minatojima-Minamimachi, Kobe 650-0047, Japan.
¹⁰ Department of System Neuroscience, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki, Chuo, Kobe 650-0017, Japan.

Abstract

Background: The aim of the present study was to assess the effects of lavender oil inhalation on blood pressure, pulse measurements, cortisol levels, depressive mood, and anxiety in healthy male adults. The mechanism was investigated by the action on oxytocin single neurons in the hypothalamus of rodents.

Methods: The participants (n = 7) were aged 20-40 years. After randomisation, they received an inhaled dose of lavender oil or distilled water for 20 min. They received the other treatment after a washout period of one week. We assessed the outcomes using the Self-Rating Depression Scale, State-Trait Anxiety Inventory, and self-rated unidimensional Visual Analogue Scale for depression; anxiety; and hunger, thirst, and appetite, respectively. Blood pressure, pulse rate, and cortisol concentration in the peripheral blood were assessed before and after inhalation. In the rodent study (n = 4), oxytocin single neurons were isolated from the mouse hypothalamus. Intracellular Ca²⁺ concentration in the oxytocin neurons isolated from the hypothalamus was measured following direct administration of lavender oil.

Results: Seven participants completed the study. Lavender inhalation decreased Self-Rating Depression Scale score and systolic and diastolic blood pressure. Ex vivo administration of lavender oil increased intracellular Ca²⁺ concentration in the hypothalamic oxytocin neurons.

Conclusions: Lavender oil might be a useful therapy for stress relief, and its mechanism of action may include activation of the central oxytocin neurons.