Representative intensity dot plots of (A) un-treated SH-SY5Y cells (the un-treated control group); (B) SH-SY5Y cells co-incubated with 10-hr aged HEWL sample; (C) SH-SY5Y cells co-incubated with 10-hr aged HEWL sample containing 50 mM carnosine. The dotted plots are divided into viable (bottom left quadrants; Annexin V-FITC/PI double negative), early apoptotic (bottom right quadrants; Annexin V-FITC positive, PI negative), and late apoptotic/necrotic cells (top right quadrants; Annexin V-FITC/PI double positive) according to Annexin V-FITC and PI fluorescence. (D) Summary of the effects of carnosine on aged HEWL-induced apoptosis. Results are presented as the percentages of viable cells (Annexin V-FITC/PI double negative), early apoptotic cells (Annexin V-FITC positive, PI negative), and late apoptotic/necrotic cells (Annexin V-FITC FITC/PI double positive) according to the PI fluorescence versus Annexin V-FITC fluorescence dotted plots shown in (A), (B), and (C).