CXCL8 and depressive symptom measurement: Animal experimental results also show that Chang-Yu-Xiao-Yao-San inhibits an over-expression of serum IL-6, IL-8, and TNF-α in LPS-induced depression model rats and increased the content of hippocampal 5-HT in rats (Qi et al., 2013; Jing et al., 2015).