Fig. 3

Effects of MDD and antidepressant treatment on the antioxidant nuclear factor (erythroid 2-derived)-like 2 (Nrf2) pathway. Subjects with MDD presented a non-significant trend to decrease (− 18%) the Nrf2 activator PI3K expression when compared with controls, being the decrease in the expression more pronounced in the AD-treated group (a, b). Subjects AD-free and AD-treated at death showed a non-significant trend towards a 16–18% increase in the expression of the cytoplasmatic inhibitor of Nrf2 Keap-1 protein when compared with controls (c, d). Subjects with MDD showed a significant decreased nuclear expression of Nrf2 (e). AD-treated group showed a decreased nuclear expression of Nrf2 compared with controls (f). The densitometric data of the band of interest were normalized by beta-actin or GAPDH for the cytoplasmic or nuclear fractions, respectively. Some blots were cropped (black lines) for improving the clarity and conciseness of the presentation. Data are means ± SEM; *p < 0.05 vs. control; unpaired two-tailed t test was performed when comparing controls vs MDD. One-way ANOVA with a Fisher’s LSD post hoc test was used to compare between controls and AD-free and AD-treated MDD groups. See the “Chemicals and statistical analyses” section for more details