Changes in the testicular Bcl-2 (a), Bax (b), Bax/Bcl-2 ratio (c), and TNF-ɑ (d) gene expression in the control, diabetes, early and late insulin, CM, and DMEM-treated diabetic groups. The BAX, Bcl2, and Bax/Bcl2 data were statistically analyzed using the Kruskal–Wallis nonparametric test and reported as median with IQR. The variable of TNF-ɑ was analyzed by one-way ANOVA (Tukey's HSD test) and presented as mean ± SEM (n = 7). ∗P < 0.05, ∗ ∗P < 0.01, ∗ ∗ ∗P < 0.001 vs. the control group; #P < 0.05, ##P < 0.01 vs. the diabetic group. D-CME, diabetic group receiving early WJMSCs-CM; D-CML, diabetic group receiving late WJMSCs-CM; D-INSE, diabetic group receiving early insulin; D-INSL, diabetic group receiving late insulin; D-DME, diabetic group receiving early DMEM; D-DML, diabetic group receiving late DMEM; early, treatment was started immediately after diabetes induction; late, treatment was started 30 days after diabetes induction.