Restoration of Glo-1 enzyme activity after ψ-GSH treatment in symptomatic 14-mo-old APP/PS1 mice. Western blot analysis of the prefrontal cortex brain tissue of NTG and APP/PS1 (A/P) mice treated with saline (-) or ψ-GSH (+) for: (a) expression of Glo-1 protein and (b) quantification of Western blot in (a). (c) Endogenous Glo-1 activity was reduced in the cortex and the hippocampus of the vehicle-treated APP/PS1 mice compared to NTG controls. ψ-GSH treatment resuscitated Glo-1 function. (d) Increased MG levels in APP/PS1 mice and reduction in MG levels in ψ-GSH-treated APP/PS1 mice. (e) Levels of the product of the Glo-1 enzymatic reaction, d-lactate, were increased in the APP/PS1- ψ-GSH group compared to the saline controls, confirming in vivo enhancement of the Glo-1 pathway by ψ-GSH. Data are presented as the mean ± S.E.M. NTG, Saline- and ψ-GSH-treated APP/PS1 groups were compared with a one-way ANOVA with Tukey’s post-hoc test for statistical analysis. * p < 0.05, ** p < 0.01.