β-asarone prolongs sleep via regulating the level of glutamate in the PVN

• Published in: Biochemical and biophysical research communications 2023-07, Vol.665, p.71-77
• Main Authors: Liu, Haoyu, Zhou, Ruiqing, Yin, Lanxiang, Si, Nana, Yang, Chenglin, Huang, Chengqing, Wang, Rongrong, Chen, Xiangtao
• Format: Article
• Language: English
• Subjects: Animals; Anisoles - pharmacology; gamma-Aminobutyric Acid; Glutamic Acid; Male; Mice; Mice, Inbred C57BL; Non-rapid eye movement sleep; Paraventricular Hypothalamic Nucleus; Paraventricular nucleus of hypothalamus; Sleep; Vesicular glutamate transporters 2; β-asarone
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2023.05.010

People of all ages could suffer from sleep disorders, which are increasingly recognized as common manifestations of neurologic disease. Acorus tatarinowii is a herb that has been used in traditional medicine to promote sleep. β-asarone, as the main component of volatile oil obtained from Acorus tatarinowii, may be the main contributor to the sleeping-promoting efficacy of Acorus tatarinowii. In the study, adult male C57BL/6 mice were administered β-asarone at 12.5 mg/kg, 25 mg/kg, and 50 mg/kg. Behavioral experiments showed that β-asarone at 25 mg/kg could significantly improve sleep duration. It was also observed that the proportion of NREM (Non-Rapid Eye Movement) sleep increased considerably after administration of β-asarone. In the PVN (paraventricular nucleus of hypothalamus) region of the hypothalamus, it was observed that the glutamate content decreased after β-asarone treatment. At the same time, the expression of VGLUT2 (vesicular glutamate transporters 2) decreased while the expression of GAD65 (glutamic acid decarboxylase 65) and GABARAP (GABA Type A Receptor-Associated Protein) increased in the hypothalamus, suggesting that β-asarone may suppress arousal by reducing glutamate and promoting transformation of glutamate to the inhibitory neurotransmitter GABA (γ-aminobutyric acid). This study is the first to focus on the association between β-asarone and sleep, shedding perspectives for pharmacological applications of β-asarone and providing a new direction for future research. •β-asarone prolongs sleep duration in mice.•β-asarone inhibits the activity of glutamatergic neurons in the PVN region.•Glutamate levels in the PVN region are monitored by fiber photometry experiments.