Compound Chaijin Jieyu Tablets ameliorating insomnia complicated with depression by improving synaptic plasticity via regulating orexin A, melatonin, and acetylcholine contents

To investigate the efficacy and mechanism of action of Compound Chaijin Jieyu Tablets (复方柴金解郁片, CCJJYT) in rats with insomnia complicated with depression. Seventy-two Sprague-Dawley rats were randomly assigned into eight groups: the control, chronic unpredictable mild stress (CUMS), sleep deprivation (SD), CUMS + SD, positive drug (venlafaxine hydrochloride + diazepam), CCJJYT high-dose (CCJJYT˗2×), medium-dose (CCJJYT˗1×), and low-dose (CCJJYT˗0.5×) groups, with nine rats in each group. Depression-like behavior was evaluated by body weight, food intake, and behavioral tests such as the sucrose preference test (SPT), open field test (OFT), forced swimming test (FST), and pentobarbital-induced sleep test (PST). Hematoxylin-eosin (HE) staining and Golgi-Cox staining were used to observe changes in pathological tissue and synaptic morphology, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to detect the contents of orexin-A and acetylcholine. The expression levels of orexin receptor 1 (OXR1), melatonin receptor 1 (MT1A), melatonin receptor 2 (MT1B), acetylcholinesterase (AChE), and choline acetyltransferase (ChAT) were detected by immunohistochemistry and Western blot. In the present study, rats in the model group showed significant behavioral changes as well as a reduction in hippocampal dendritic branch length and synaptic number, along with increasing the content of orexin A and acetylcholine (P< 0.05), and altered expression levels of OX1R, MT1A, MT1B, ChAT, and AChE in the hippocampus and prefrontal cortex after modeling (P < 0.05). CCJJYT can improve depressive insomnia behavior and synaptic plasticity of rats (P < 0.05), which is similar to that of the positive drug group. It can also decrease the content of orexin A and acetylcholine, and reduce the expression levels of OXR1 and ChAT in hippocampus and prefrontal cortex (P < 0.05), and increase the expression levels of MT1A, MT1B, and AChE proteins (P < 0.05). CCJJYT has good antidepressant and insomnia effects, probably through the regu-lation of orexin-A, melatonin, and acetylcholine content in hippocampus and prefrontal cortex of rats, improving synaptic plasticity and thus exerting antidepressant and insomnia effects.