AU protected the H2O2-caused MG63 cells apoptosis via regulation the Nrf2/HO-1 signaling. (A) AU up-regulated the expression levels of osteoblast differentiation related proteins including Collagen I, Osterix, OPN, BMP2, OCN and P-Smad in MG63 cells exposed to H2O2. (B) AU increased the expression levels of proteins within the Nrf2/HO-1 signaling including P-DPR1, Nrf2, CAT, HO-1, HO-2, SOD-1 and SOD-2 in MG63 cells exposed to H2O2. AU enhanced the expression levels of Nrf2 in both (C) nucleus and (D) cytoplasm of MG63 cells exposed to H2O2. The quantification data of proteins were normalized by corresponding GAPDH, Lamin B, β-actin or total proteins, respectively (n=4). (E) AU increased the mRNA levels of Nrf2 and NQO-1 in MG63 cells exposed to H2O2. Marker size from top to bottom: 1000 bp, 700 bp, 500 bp, 400 bp, 300 bp, 200 bp and 100 bp. The data on quantified mRNA expression were normalized to the levels of β-actin (n=4). Data are expressed as mean ± S.D. and analyzed using a one-way ANOVA. # P<0.05, ## P<0.01 and ### P<0.001 vs. control cells, *P<0.05, **P<0.01 and ***P<0.001 vs. H2O2-exposed cells.