Fig. 5

Effects of PQQ on levels of Nrf2 and HO-1 in cells treated with siRNA. a Nrf2 knockdown efficiency in cells transfected with three different sequences of Nrf2 siRNA or with NC siRNA. b and c mRNA expression levels of Nrf2 and HO-1 in IPEC-J2 cells transfected with or without Nrf2 siRNA-2. d Western blot analysis of Nrf2 and HO-1 in cells transfected with or without Nrf2 siRNA-2. e Statistical analysis of the data in D. CTRL, cells cultured with basal medium; H₂O₂, cells cultured with 200 μmol/L H₂O₂ for 2 h; PQQ, cells cultured with 10 nmol/L PQQ for 6 h and then incubated with both H₂O₂ (200 μmol/L) and PQQ (10 nmol/L) for another 2 h. NC siRNA, cells transfected with NC siRNA and then pretreated with PQQ for 6 h prior to incubation with both PQQ and H₂O₂ for another 2 h. Nrf2 siRNA, cells transfected with Nrf2 siRNA-2, pretreated with PQQ for 6 h, and then incubated with both PQQ and H₂O₂ for another 2 h. * denotes a significant difference (P < 0.05) with respect to the CTRL group. # denotes a significant difference (P < 0.05) with respect to the H₂O₂ group. n = 3