Effect of thymoquinone on oxidative stress in SCI rats. Activity levels of (A) SOD, (B) CAT, (C) GSH and (D) MDA were measured using ELISA kits. ##P<0.01 vs. Sham; **P<0.01 vs. Model. SCI, spinal cord injury; Sham, sham surgery group; Model, SCI surgery group; Thymoquinone, SCI + thymoquinone group; SOD, superoxide dismutase; CAT, catalase; GSH, glutathione; MDA, malondialdehyde.