Galangin induces apoptosis of glioma cells through Wnt/β-Catenin signal pathway

Abstract

Objective To investigate the effect of galangin on proliferation and apoptosis of glioma cells in vitro. Methods (1) The glioma cells U87 and U251were divided into blank control group, DMSO group, 100, 200, 300 and 400 μmol/L galangin treatment groups. MTT was used to study the effects of drugs on the proliferation of U251 and U87 cells. (2) Hoechest staining was used to observe cell apoptosis in the presence of different concentrations of galangin (0, 100 and 200 μmol/L). (3) Flow cytometry was employed to detect the apoptosis of U251 and U87 cells in the presence of different concentrations of galangin (100 and 200 μmol/L). (4) Western blotting was employed to detect the expressions of apoptosis-related protein β-Catenin, B-cell lymphoma-2 (Bcl-2), Bcl-2 related protein gene (Bax), cleaved-caspase-3, cleaved-caspase-9 and poly (ADP-ribose) polymerase (PARP) in the presence of different concentrations of galangin. Results (1) The proliferation of U251 and U87 cells was obviously inhibited after 100, 200, 300 and 400 μmol/L galangin treatments, and dose-effect relation was noted. The concentrations of galangin at half rate of inhibition (IC50) were 281, 321, 276 and 229 μmol/L in U251 cells, and 289.4, 261.1, 247.4 and 225.3 μmol/L in the U87 cells after 100, 200, 300 and 400 μmol/L galangin treatments for 24 h. (2) Under the action of galangin, corresponding increase in apoptosis rates of U251 and U87 cells was noted following the increase of galangin concentrations (0, 100 and 200 μmol/L), with significant differences (P<0.05). (3) The detection of cell apoptosis by flow cytometry found similar changes. (4) Western blotting results indicated that galangin at the concentration of 0, 100 and 200 μmol/L could significantly decrease the expressions of apoptosis-related protein β-Catenin and Bcl-2, and increase the Bax, cleaved-caspase-3 and cleaved-caspase-9, and cleaved-PARP expressions; significant differences were noted between each two concentrations (P<0.05). Conclusion Galangin can inhibit proliferation of glioma cells U251 and U87, and induce mitochondrial pathway of apoptosis via Wnt/β-Catenin signaling. Key words: Glioma; Wnt/β-Catenin signaling; Galangin; Apoptosis; Mitochondrial pathway