Figure 2. Bioactivity of lipofuscin and melanolipofuscin granules

Isolated lipofuscin (LF) and melanolipofuscin (MLF) granules were fed to ARPE-19 cells. Cells that were not fed LF or MLF were used as controls. Cells were then subjected to blue light irradiation (solid bars), or left in the dark (cross-hatched), for 48 h. Cell viability was determined using the Sulforhodamine B assay. Values represent mean of at least four independent measurements, error bars represent standard deviation. The phototoxicity of MLF granules in ARPE-19 cells is at least 72% as potent as that of LF granules, showing that MLF granules have the potential for deleterious affects on RPE cells in the retina.