Effect of Sim on oxidative stress (MDA and NO) and antioxidant (GSH, and SOD) markers in the synovium of pristane-induced arthritic mice. Data were expressed as mean ± SEM (n = 5) from the Cnt group (G1). Columns with different letters (a-d) are significantly different at P<0.05. G1, Cnt; G2, Sim; G3, RA; G4, RA+Sim-co; G5, RA+Sim-post group.