Nicotinamide adenine dinucleotide (NAD) depletion induced by vitamin C-induced H2O2 in MCF7 cells.
(a) Metabolite map of glycolysis. Colors of metabolites indicate significant differences (red, upregulated; green, downregulated). Conversion of GAP to 1,3- BPG mediated by GAPDH. (b) NAD levels were decreased by vitamin C in MCF7 (left) and HT29 cells (right) and were determined using CE-TOFMS. Bar graphs indicate fold changes relative to control sample (None). (c) Effects of NAC on levels of NAD in MCF7 cells. Bar graphs show metabolite levels relative to those of control (None). (d) Effects of NAD on viability of MCF7 (left) and HT29 (right) cells determined by MTT assay in both cell lines treated without or with vitamin C and NAD. Data are presented as means ± SD of triplicate experiments, **P < 0.01.