Inhibitory effect of puerarin on proliferation of retinoblastoma cells: An in-vitro study

Purpose: To investigate the anti-proliferative effect of puerarin on retinoblastoma cells. Methods: The effect of puerarin was examined on human retinoblastoma Y79 cells using cell proliferation assays and reverse transcription-polymerase chain reaction (RT-PCR). The effect of puerarin on the cell cycle was also investigated. Western blot and RT-PCR analyses were also performed to identify the putative mechanism of action. Results: The results showed that cell viability was suppressed by puerarin in a concentration-dependent manner with a half-maximal inhibitory concentration (IC50) of 0.184 +/- 0.034 mu mol/L. Moreover, puerarin increased the proportion of cells in G1 phase from 42.6 +/- 3.1 to 62.83 +/- 4.1, 75.76 +/- 3.4 and 91.33 +/- 5.1 % in a concentration-dependent manner at concentrations of 0.1, 0.2, and 0.4 mu mol/L, respectively. The results also indicate that Bmi-1 mRNA and protein levels decreased after puerarin treatment. Additionally, flow cytometry data showed that Bmi-1 knock-down through siRNA resulted in G1-cell cycle arrest. The proportion of cells in G1 were 51.2 +/- 2.5 and 71.4 +/- 4.5 % for control and Bmi-1 siRNA-treated groups, respectively. Conclusions: The results show that puerarin exert suppressive effects on human retinoblastoma Y79 cells and therefore may find application in the treatment of intraocular tumor.