Fig. 8
Effect of ML385 on the expression of Nrf2 and its downstream proteins in TNC. A, B Nrf2 protein expression in the nuclear of the TNC was reduced in the NTG+Oil+ML385 group compared to the Control+Oil+ML385 group, and there was no significant change in Nrf2 protein expression in the NTG+NBP+ML385 group compared to the NTG+Oil+ML385 group, whereas Nrf2 protein expression was significantly increased in the NTG+NBP+Vehicle group. C, D, E The expression of HO-1 and NQO-1 proteins in the TNC was reduced in the NTG+Oil+ML385 group compared to the Control+Oil+ML385 group, and there was no significant change in the expression of HO-1 and NQO-1 proteins in the NTG+NBP+ML385 group compared to the NTG+Oil+ML385 group, whereas the expression in the NTG+NBP+Vehicle group was significantly increased. (n = 3–5 in each group; **p < 0.01 and ***p < 0.001 compared with the Control+Oil+ML385 group; ##p < 0.01 and ###p < 0.001 compared with the NTG+NBP+Vehicle group; &&p < 0.01 and &&&&p < 0.0001 compared with the NTG+Oil+ML385 group). F, G Inhibition of Nrf2 by ML385 deprives NBP of protection against mechanical thresholds. The NTG+NBP+ML385 group did not improve the decrease in mechanical thresholds and there was no difference in the NTG+NBP+ML385 group compared to the NTG+Oil+ML385 group. However, the NTG+NBP+vehicle group significantly protected against mechanical nociceptive sensitization compared to the NTG+Oil+ML385 group. (n = 8–10 in each group; &p < 0.05 NTG+NBP+ML385 compared with the NTG+NBP+Vehicle group). As shown in H and I, there was no difference between the NTG+Oil+ML385 group and the NTG+NBP+ML385 group. Photophobic and anxious behaviours were not improved in the NTG+NBP+ML385 group compared with the NTG+NBP+Vehicle group. (n = 8–10 in each group; **p < 0.01, ***p < 0.001 and ****p < 0.0001 compared with the Control+Oil+ML385 group; ##p < 0.01 and ###p < 0.001 compared with the NTG+NBP+Vehicle group; &p < 0.05 and &&p < 0.01 the NTG+NBP+Vehicle group compared with the NTG+Oil+ML385 group)