A The time course of change in the ratio of oxidized to reduced glutathione in lysates of cells treated with HNG (10 nM) (**p = 0.0007, 10 N per experiment, 4 experiments). Both B GPx (**p = 4.0×10−67 N per experiment, 4 experiments) and C catalase (*p = 0.0089, 18 N per experiment, 6 experiments) activities, normalized to total protein, following cell exposure to HNG (10 nM) and lysate prep. D Total cellular SOD activity (normalized to total protein) in lysates from cells exposed to HNG (10 nM) (*p = 0.004, 12 N per experiment, 4 experiments).