Objective: To observe changes in the molecular expression of the NLR Family Pyrin Domain Containing Protein 3 (NLRP3) pathway in depressed rats after treatment with Xiaoyaosan, and identify the regulatory mechanism of this compound. Methods: Male Sprague–Dawley rats were randomly divided into five groups with 12 rats in each group, including the control group, model group, Fluoxetine group, Xiaoyaosan group, and MCC950 group. A depression model was generated by chronic immobilization stress (induced by 3 h of restraint immobilization every day...