Plumbagin Induces Cytotoxicity via Loss of Mitochondrial Membrane Potential and Caspase Activation in Metastatic Retinoblastoma.

Background/aim We investigated the cytotoxic effects of plumbagin on metastatic retinoblastoma, using the highly metastatic cell line Y79. Materials and methods Effect of plumbagin on cell growth was assessed with water-soluble tetrazolium 1 (WST-1) cell proliferation assay and automated hemocytometry with trypan blue-exclusion assay. Cell death was studied with acridine orange/ethidium bromide live-dead assay and annexin-V-fluorescein isothiocyanate/propidium iodide microscopy. Loss of mitochondrial membrane potential was studied with JC-10 dye and caspase activation was investigated using CellEvent Caspase-3/7 Green detection reagent. Results Plumbagin highly significantly reduced the growth of Y79 cells treated for 24 h with 2.5 μM or more. Plumbagin also induced significantly high levels of cell death which was associated with loss of mitochondrial membrane potential and caspase activation. Conclusion At very low concentration (2.5 μM), plumbagin potently induced cytotoxicity in metastatic retinoblastoma cells via loss of mitochondrial membrane potential and caspase activation.