Effects of Chailong Jieyu Pill on Behavior, Monoamine Neurotransmitters, and Corticosteroid Receptors in a Rat Model of Anxiety Disorder

Chailong Jieyu Pill (CJP) is composed of Radix Bupleuri, Radix Scutellariae, Rhizoma Pinelliae Preparata, Radix Codonopsis, Radix Glycyrrhizae preparata, keel, Concha Ostreae, Concha Margaritifera Usta, Rhizoma Zingiberis Recens, and Fructus Jujubae. CJP has shown good clinical effects on improving anxiety disorders. However, as the mechanism underlying such benefits remains unclear, the aim of this study was to investigate the mechanism of action for CJP on anxiety-related behaviors in a rat model of anxiety disorder. After establishing a rat model of anxiety disorder using uncertain empty bottle stimulation, rats were divided into control, model, citalopram, low-dose CJP, and high-dose CJP groups. After 1 month of administration, effects of treatments on rat appearance, body weight, and open-field test scores were observed. In addition, hippocampal monoamine neurotransmitter (5-hydroxytryptamine, dopamine, and norepinephrine) contents were measured with an enzyme-linked immunosorbent assay, and mRNA expression of mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) were measured with reverse transcription-polymerase chain reaction. CJP increased rat weight, and this effect was increased in the high-dose CJP group compared with the citalopram group (P < 0.05). CJP also elevated open-field test scores compared with the citalopram group (P < 0.05). While CJP decreased monoamine neurotransmitter contents in rat hippocampus, the regulatory effect of CJP on 5-hydroxytryptamine was reduced compared with citalopram (P < 0.01). CJP upregulated GR mRNA expression in both low-dose (P < 0.05) and high-dose (P < 0.01) CJP groups, but only the latter significantly downregulated MR mRNA expression and showed enhanced effects compared with citalopram (P < 0.05). Thus, CJP likely exerted its significant antianxiety effect by diminishing monoamine neurotransmitters and regulating mRNA expression of MR and GR in the hippocampus of our rat model of anxiety disorder.