FIGURE 1.

Irigenin inhibited the proliferation of GBM cells. (A–C) The IC₅₀ of irigenin (IR) was measured by CCK-8 in DBTRG cells (A), C6 cells (B) and astrocytes (C) (n = 3, per group, normalized to the control group). The DBTRG cells, C6 cells and astrocytes were seeded in 96-well plates at 4×10³/well and treated with different concentrations (0, 10, 25, 50, 75, 100 μM) for 24 h or 48 h for CCK-8 assay. (D) The Colony formation assay showed the anti-proliferative activity of 50 μM IR in DBTRG and C6 cells. (E–F) Quantification of the clone numbers in DBTRG cells (D) and C6 cells (E), as shown in (C) (n = 3, per group). (G) Immunofluorescent staining of PH3 (red) in DBTRG and C6 cells treated with 40 μM IR for 24 h (H–I) Quantitative analysis of the percentage of PH3⁺ cells over total DBTRG cells (H) and C6 cells (I) in one field shown in (G) (n = 13, per group). Scale bar, 2 mm in figure (D) and 20 μm in figure (G). Data were shown mean ± SEM. ^* p < 0.05, ^** p < 0.01, ^*** p < 0.001, compared with control group. ^# p < 0.05, ^### p < 0.001, compared with 48 h control group.