Baicalin significantly reduced the levels of TNF-α, IL-1β, and IL-6 in depression-like hippocampal tissues by upregulating PI3K/AKT/FOXO1 pathway and inhibiting TLR4 expression and so alleviate neuroinflammation-induced depression-like behavior (Guo et al., 2019). This evidence concerns the gene TLR4 and depressive symptom measurement.