NADH treatment dose-dependently decreased the number of surviving C6 glioma cells. The cells were treated with 1, 10, 100 and 1000 μM NADH for 24 hrs, and subsequently the number of surviving cells was assessed by LDH assay. N = 25. Data were pooled from 6 independent experiments. **, p < 0.01; ***, p < 0.001.