Abstract: Objective To examine the effect of morin on the proliferation and apoptosis of cultured retinoblastoma cells. Design Experimental study. Participants The retinoblastoma cell lines Y79. Methods The retinoblastoma cell lines Y79 were treated with morin in increasing concentrations (0, 50, 100, 150, 250 μM respectively) for 24, 48, and 72 hours and then the cell proliferation rate was measured. Cell cycle was analyzed by flow cytometry, and cell apoptosis rate was measured by TUNEL staining. Main Outcome Measures The percentage of cell survival, the distribution of cell cycle, the percentage of apoptotic cells to total cells. Results After the morin acting on the Y79 cells at the concentrations of 150 μM or 250 μM for 48, 72 h respectively, the percentages of tumor cell survival rate decreased significantly (P<0.05) compared to those at the concentrations of 0, 50 or 100 μM. Correspondingly, the percentage of apoptotic cells to total cells was significantly (P<0.05) higher in the Y79 cells treated by morin at the concentrations of 150 μM or 250 μM than at the concentrations of 0, 50 or 100 μM. In a parallel manner, the cell cycle was significantly (P<0.05) altered in the Y79 cells treated by morin at the concentrations of 150 μM or 250 μM ,with increased percentages of Y79 cells in the G0/G1 arrest and reduced percentages of Y79 cells in the S phase. The morin caused concentration-dependent and time-dependent decreasing in cell proliferation and increasing in cell apoptosis. Conclusion Mrion added to cultures of retinoblastoma cells led to a reduced tumor cell proliferation, and an increased tumor cell apoptosis, which suggests that morin may be a potent drug for the treatment of retinoblastoma.

Key words: morin, retinoblastoma, proliferation, apoptosis