Explore the treatment of depression with Radix Bupleuri from the liver and spleen based on the theory of brain-gut axis.

Objective Taking the brain-gut axis theory as the strating point, it explains the modern scientific connotation of traditional Chinese medicine (TCM) treating depression from the Gan and Pi, explore the mechanism of Radix Bupleuri ¹ realizing co-regulation of the liver and intestines through brain-gut axis in the treatment of depression. Methods By association rules and modern biological information mining methods, analysis the protein expression of depression-related targets in the brain and intestine tissues, as well as the core targets and main mechanisms of Radix Bupleuri antidepressant. Results Depression-related targets had similar protein expression levels in brain and intestinal tissues, and there is a strong relationship in between. The antidepressant TCM belongs to the liver meridian most, followed by the spleen meridian. And there is a close relationship between the two meridians of liver and spleen. Among the antidepression TCM, Radix Bupleuri is the most commonly used one except licorice. It contains active constituents such as flavones, steroids, and terpenes. Mainly through 7 core targets such as MAOA, GSK3B, SLC6A4, etc., regulating 10 pathways such as Serotonergic synapse and Dopaminergic synapse to realize the treatment of depression. Conclusion The role of the brain-gut axis is similar to the physiological function of the Gan and Pi in theoretical system of TCM. This study reveals the mechanism of Radix Bupleuri realizing co-regulation of the liver and intestines through brain-gut axis in the treatment of depression. Provide new ideas and scientific explanations for clinical treatment of depression, and provide data support for the development of new antidepressant drugs.