Chaihu-Shugan San modulates hippocampal 5-HT2A and BDNF in PSD rats

To investigate the effects of Chaihu-Shugan San (CSS) on the mRNA expression levels of 5-hydroxytryptamine 2A receptor (5-HT2A) and brain-derived neurotrophic factor (BDNF), as well as the amelioration of depressive-like behaviours of PSD rats. Fifty-four healthy male Sprague–Dawley (SD) rats were randomly divided into six groups: blank group (CON group), sham operation group (SHAM group), normal saline group (NS group), medium-dose CSS group (M-CSS group), high-dose CSS group (H-CSS group) and fluoxetine group (FLU group) with nine rats in each group. The rat model of right middle cerebral artery occlusion was made by thread occlusion method, and the post-stroke depression (PSD) model was made by chronic unpredictable mild stimulation (CUMS). After that, the rats were given the drug by intragastric administration once a day for 4 weeks. The body weight of rats in each group was measured, and the behaviour was evaluated. The mRNA levels of serotonin 2A receptor (5-HT2A) and BDNF in hippocampus were detected by fluorescence quantitative PCR (RT-PCR), the number of positive cells of 5-HT2A and BDNF was detected by immunohistochemical staining (IHC), and the protein expression of 5-HT2A and BDNF was detected by Western blotting (WB). CSS alleviated the depressive behaviour of PSD rats induced by CUMS and increased the positive cells of 5-HT2A and BDNF in the hippocampus. The relative gene and protein levels of 5-HT2A and BDNF in hippocampus decreased in CUMS-induced depression model and up-regulated after treatment with CSS. CSS may play an antidepressant role by regulating the relative levels of 5-HT2A and BDNF in the hippocampus.