IL-1β
Icariin and its derivatives significantly reduced the level of IL-1β in the 10 studies included [n = 204, SMD =-5.698, 95%CI (-7.307, -4.089), p = 0.000] (Figure 5B ). Given the significant heterogeneity observed across studies (I2 = 84.1%, p = 0.000), subgroup analysis was performed to explore the sources of heterogeneity. In the subgroup analysis by species, the heterogeneity of the ”mice” group was significantly improved. In addition, the heterogeneity of the ”0-5 days” subgroup categorized by treatment duration was also significantly improved. This suggests that species and treatment duration are important sources of heterogeneity in the meta-analysis of IL-1β (Table 3) .