Agarwood essential oil inhalation exerts antianxiety and antidepressant effects via the regulation of Glu/GABA system homeostasis

Canhong Wang; Bao Gong; Yangyang Liu; Deli Chen; Yulan Wu; Jianhe Wei

doi:10.3892/br.2023.1598

Agarwood essential oil inhalation exerts antianxiety and antidepressant effects via the regulation of Glu/GABA system homeostasis

Biomed Rep. 2023 Jan 17;18(2):16. doi: 10.3892/br.2023.1598. eCollection 2023 Feb.

Authors

Canhong Wang^{1

2}, Bao Gong¹, Yangyang Liu¹, Deli Chen¹, Yulan Wu¹, Jianhe Wei^{1

3}

Affiliations

¹ Hainan Branch of The Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Haikou, Hainan 570311, P.R. China.
² Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong, Maoming 525099, P.R. China.
³ Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, P.R. China.

Abstract

Depression and anxiety are common diseases that endanger the physical and mental health of individuals. Agarwood incense inhalation has been used as a traditional Chinese medicine for relaxation and to improve sleep for centuries. In a previous study by the authors it was demonstrated that agarwood essential oil (AEO) injection exerted anxiolytic and antidepressant effects. Therefore the present study further investigated the anxiolytic and antidepressant effects of AEO inhalation on anxiolytic mice induced by M-chlorophenylpiperazine and depressive mice induced by chronic unpredictable mild stress. The results demonstrated that AEO exerted a significant anxiolytic effect, whereby autonomous movements were inhibited during the light dark exploration test and open field test. Furthermore, the tail suspension test and the forced swimming test demonstrated that AEO also exerted an antidepressant effect, whereby the immobility times were decreased. Moreover, AEO was determined to increase the levels of 5-hydroxytryptamine, γ-aminobutyric acid (GABA) A receptor (GABA_A) and glutamate (Glu) in anxiolytic mice and inhibit the levels of GABA_A and Glu in depressive mice. Further investigations into how AEO affected the Glu/GABA system demonstrated that AEO markedly increased the protein expression levels of GABA transaminase (GABAT), glutamate metabotropic receptor 5 (GRM5), glutamate ionotropic receptor AMPA type subunit 1 (GluR1) and vesicular glutamate transporter 1 (VGluT1). Furthermore, AEO reduced the expression levels of GABAT, glutamate ionotropic receptor NMDA type subunit 2B and GRM5, and enhanced the expression levels of GluR1 and VGluT1. These results demonstrated that AEO potentially possesses antianxiety and antidepressant properties. The present study determined that the mechanism was related to the regulation of Glu/GABA neurotransmitter system homeostasis.

Keywords: AEO; Glu/GABA system homeostasis; antianxiety; antidepression; inhalation administration.

Grants and funding

Funding: The present study was supported by the Key Research Project of Hainan Province (grant nos. ZDYF2022SHFZ030 and ZDYF2020111), the National Natural Science Foundation of China (grant no. 82204657), the National Key R&D Program of China (grant no. 2018YFC1706403), the High-level Talents Program of Hainan Province (grant no. 2019RC345), and the CAMS Innovation Fund for Medical Sciences (CIFMS; grant no. 2021-I2M-1-032).