Fig. 4
Subgroup analysis of the effect on the vitro group (a) and the vivo group (b). Experimental variables are used to obtain the weighted standard mean difference along with the corresponding 95% confidence interval (95% CI) followed. However, the reported I2 and P-value was obtained by Q test, with values I2 > 50% or P < 0.1 taken to indicate moderate-to-high heterogeneity