Linagliptin suppresses the hippocampal pro-oxidant response and stimulates SIRT1/Nrf2/HO-1 pathway in cadmium-intoxicated rats. Linagliptin lowers the lipid peroxides (A) and replenishes GPx (B), nuclear Nrf2 (C), HO-1 (D), and SIRT1 (E) in the hippocampi of cadmium-intoxicated rats. N = 6 in each group (mean ± standard error of the mean). A p-value of less than 0.05 was significant. ** p < 0.01, *** p < 0.001, or **** p < 0.0001, compared to control; # p < 0.05, ## p < 0.01, compared to cadmium (Tukey’s test for multi-comparisons and one-way ANOVA). Cd, cadmium chloride; GPx, glutathione peroxidase; HO-1, heme oxygenase-1; LIN, linagliptin; Nrf2, nuclear factor erythroid-2-related factor-2.