Figure 3 Effect of lutein on the apoptosis of keratinocytes measured by annexin V-FITC assay. Apoptosis of keratinocyte cell line treated with silk lutein (A) or c-lutein (B) for 24 hours at concentrations ranging from 0.5 to 15 μM. Each bar represents the percentage of cells undergoing apoptosis. Error bars are one standard deviation.