TNF-α
12 studies included showed that icariin and its derivatives significantly decreased the level of TNF-α [n = 238, SMD=-6.326, 95%CI (-7.860, -4.791), p = 0.000] (Figurer 5A ). Furthermore, given the significant heterogeneity among studies (I2 = 83.4%, p = 0.000), subgroup analyzes were performed based on dose, duration of treatment, type of disease, animal species and animal sex. Among them, the heterogeneity of the ”0-5 days” subgroup categorized by treatment duration and the ”Local inflammation” and ”Nervous system” subgroups categorized by disease type improved significantly, indicating that treatment duration and disease type are important sources of heterogeneity. Heterogeneity was significantly improved in the ”0-5 days” subgroup based on treatment duration and the ”Local inflammation” and ”Nervous system” subgroups based on disease type, suggesting that treatment duration and disease type are important sources of heterogeneity in this index (Table 2) .