The effect of OR on oxidative stress in the hippocampus of aging mice. Activities of brain (A) SOD and (B) GSH-PX, (C) content of brain MDA, (D) activitys of brain MAO-B, (E) content of brain Lipo. Compared with the young mice group, #P<0.05; compared with the aging mice group, *P<0.05, **P<0.01.