Curcumin induces human lens epithelial cell apoptosis and cell cycle arrest by inhibiting Wnt/β-catenin signaling pathway

Abstract

To investigate the effect of curcumin on cell cycle and apoptosis of human lens epithelial cells and the possible molecular mechanism. Cultured human lens epithelial cell line HLEC-SRA01/04 was treated with 20, 40 and 60 μmol/L curcumin for 24 or 48 h. The cell proliferation inhibition rate was determined using MTT assay, and the changes in cell cycle, mitochondrial membrane potential and apoptosis rate were analyzed with flow cytometry. Western blotting was used to detect the expression levels of caspase-9, caspase-3, Bcl-2, Bax, cyclin B1, CDK1, β-catenin, c-myc, and cyclin D1 in the cells. Curcumin concentration- and time-dependently inhibited the proliferation of in HLEC-SRA01/04 cells as compared with the control cells (P < .05). Flow cytometric analysis showed that curcumin significantly increased apoptosis rate and cell percentage in G2/M phase and lowered mitochondrial membrane potential of HLEC-SRA01/04 cells in a concentrationdependent manner (P < 0.05). The results of Western blotting showed that curcumin also concentration-dependently increased the cellular expressions of caspase-3, caspase-9 and Bax and lowered the expressions of Bcl-2, cyclin B1, CDK1 and β-catenin along with the downstream proteins cyclin D1 and c-myc in the Wnt/β-catenin signaling pathway (P < 0.05). Curcumin inhibits the proliferation of HLEC-SRA01/04 cells possibly by inhibiting the Wnt/β-catenin signaling pathway and causing cell cycle arrest to induce cell apoptosis.