Guo et al. demonstrated that baicalin (60 mg/kg bodyweight) downregulated the levels of IL-1β, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels, decreased TLR4, and increased upregulated the phosphorylation of phosphatidylinositol 3-kinase (PI3K), Akt1, and Foxo1 in the hippocampus of the chronic unpredictable mild stress (CUMS)-induced depression mouse model. Here, TLR4 is linked to major depressive disorder.