Figure 2. IGF-Exo inhibited H2O2-induced neural apoptosis in PC12 cells in vitro. (A) Morphology for each experimental group examined by light microscopy (control group: PC12 cells without treatment; H2O2 group: PC12 cells treated with H2O2 for 24h; Nor-Exo group: PC12 cells pretreated with Nor-Exo for 24h followed by H2O2 for 24h; IGF-Exo group: PC12 cells pretreated with IGF-Exo for 24h followed by H2O2 for 24h). (B) Cell viability in each experimental group; (C) TUNEL staining (red) indicating cell apoptosis in each experimental group; nuclear DAPI stain in blue. (D) TUNEL-positive cell numbers per field for each experimental group. (E) Western Blot analysis of apoptotic and anti-apoptotic proteins. (F–I) Relative expression of BAX, Bcl-2, Beclin-1 and Caspase-3. Data are expressed as means ± SD (analysis of variance followed by Student-Newman-Keuls post hoc test). **P < 0.01 vs. control group; ##P < 0.01 vs. H2O2 group.