Fig. 4.

Oltipraz increased the expression of Nrf2 in the spinal cords of PINP rats. a The spinal expression of Nrf2 was significantly increased in PINP rats (*P < 0.05 compared with the vehicle group, n = 6 in each group). Moreover, oltipraz treatment further increased the spinal expression of Nrf2 in PINP rats, which was reversed by the preadministration of trigonelline (*P < 0.05, ***P < 0.001 compared with the vehicle-treated group, ^###P < 0.001 compared with the oltipraz-treated group). b Nrf2 (green) was localized in neurons (as indicated by NeuN, a neuronal marker, red)