Xi-Dan Zhou1, Dong-Dong Shi2, Zhang-Jin Zhang3. 1. School of Chinese Medicine, LKS Faculty of Medicine, the University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China. 2. Shanghai Mental Health Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. 3. School of Chinese Medicine, LKS Faculty of Medicine, the University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China. Electronic address: zhangzj@hku.hk.
Abstract
BACKGROUND: Menopause is closely associated with the risk of anxiety and depression in a woman's life. Despite the numerous reports on the effects of Radix rehmanniae extract (RRE) on various types of depression, there are few studies exploring the effects of RRE on the menopausal anxiety and depression. PURPOSE: To investigate whether RRE could alleviate the menopausal anxiety and depression in ovariectomized (OVX) mice submitted to chronic unpredictable mild stress (CUMS). METHODS: OVX mice were treated with 2.6 g/kg RRE for 5 weeks. After a series of behavior tests, serum, uterus, and brain tissues were collected for the measurement of neurotransmitters and their related biomarkers, neurotrophins, and estrogen receptor α (ERα) and β (ERβ). RESULTS: RRE showed antidepressant and anxiolytic effects through these behavior tests, but had no effects on the OVX-induced weight gains, uterine shrinkage and drop of serum estrogen level. RRE restored the levels of serotonin (5-HT), dopamine (DA) and its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC), Glutamate (Glu), gamma-Aminobutyric acid (GABA) and their related biomarkers in different brain regions. RRE also reversed OVX-induced decrease in the expression levels of neurotrophins in uterus and brain regions except for uterine nerve growth factor (NGF). Moreover, RRE restored and even enhanced ERβ expression levels in uterus and brain without affecting uterine, hippocampal and cortical ERα. CONCLUSION: This study demonstrated the antidepressant and anxiolytic effects of RRE in OVX mice, which were possibly mediated via their modulation of brain neurotransmitters, and regulation of neurotrophins and activation of ERβ.
BACKGROUND: Menopause is closely associated with the risk of anxiety and depression in a woman's life. Despite the numerous reports on the effects of Radix rehmanniae extract (RRE) on various types of depression, there are few studies exploring the effects of RRE on the menopausal anxiety and depression. PURPOSE: To investigate whether RRE could alleviate the menopausal anxiety and depression in ovariectomized (OVX) mice submitted to chronic unpredictable mild stress (CUMS). METHODS:OVXmice were treated with 2.6 g/kg RRE for 5 weeks. After a series of behavior tests, serum, uterus, and brain tissues were collected for the measurement of neurotransmitters and their related biomarkers, neurotrophins, and estrogen receptor α (ERα) and β (ERβ). RESULTS: RRE showed antidepressant and anxiolytic effects through these behavior tests, but had no effects on the OVX-induced weight gains, uterine shrinkage and drop of serum estrogen level. RRE restored the levels of serotonin (5-HT), dopamine (DA) and its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC), Glutamate (Glu), gamma-Aminobutyric acid (GABA) and their related biomarkers in different brain regions. RRE also reversed OVX-induced decrease in the expression levels of neurotrophins in uterus and brain regions except for uterine nerve growth factor (NGF). Moreover, RRE restored and even enhanced ERβ expression levels in uterus and brain without affecting uterine, hippocampal and cortical ERα. CONCLUSION: This study demonstrated the antidepressant and anxiolytic effects of RRE in OVXmice, which were possibly mediated via their modulation of brain neurotransmitters, and regulation of neurotrophins and activation of ERβ.