Figure 1.

Effects of methotrexate (MTX) (a) and/or 4-hydroperoxycyclophosphamide (4-HC) (b) on P-glycoprotein (P-gp) levels and cell viability(c) of rheumatoid arthritis fibroblast-like synovial cells (RA-FLSs). Compared with the cell control group, the other medicine groups showed higher levels of P-gp expression and P-gp mRNA-production; the differences were statistically significant (P < 0.05); compared with MTX group, the MTX + 4-HC group showed lower levels of P-gp expression and P-gp mRNA-production; the differences were statistically significant (P < 0.05); after adding pathway inhibitors, P-gp expression and P-gp mRNA-production were lower than the MTX ± 4-HC group, the differences were statistically significant (P < 0.05); comparison between groups showed no differences in cellular inhibitory rates (P > 0.05).