Hypericin and Naringenin Exert no Significant Synergistic Apoptotic Effect on Y79 Retinoblastoma Cell Line.

Background: According to the anti-cancer impact of hypericin and naringenin, we put the main aim of this study to unravel the apoptotic/anti-cancer effect of these compounds on Y79 retinoblastoma cell line.

Materials And Methods: To calculate the 50%inhibitory concentration (IC50) of hypericin for 24 and 48 hours, XTT assay performed. Cytotoxic effect of naringenin investigated by XTT and trypan blue exclusion assay further confirmed the inhibitory impact of these agents on Y79 cells viability. Flow cytometry Annexin V/PI determined the cell death. The mRNAs expression level of Bax and Bcl-2 investigated by real-time PCR in different groups including the control, cells treated with naringenin, hypericin, or concurrent with both compounds.

Results: The 24 and 48 hours IC50 of hypericin, calculated to be 2.5 and 1.25 (μg/ml), respectively. 50 (μg/ml) naringenin induced about 20% and 30% apoptosis in Y79 cells after 24 and 48 hours. Trypan blue staining and flow cytometry confirmed this data. Moreover, flowcytometry results, revealed that the kind cell death occurred in these cells post treatment was mostly apoptosis. Simultaneous treatment with both agents didn't show synergistic effect. Bax/Bcl-2 ratio increased in cells treated with hypericin but in cells treated with narigenin didn't show significant increase in the Bax mRNA level.

Conclusion: Hypericin had more cytotoxic effect in Y79 cells compared with naringenin. Furthermore, hypericin and naringenin didn't have apoptotic synergistic effect in these cells. According to the real-time PCR results, hypericin induces apoptosis in Y79 cells by disrupt the ratio of Bax/Bcl-2.