Effect of aspartame (40 mg/kg bwt) on superoxide dismutase (SOD) activity (units/mg of tissue protein) in rat brain discrete regions. CC = cerebral cortex; CB = cerebellum, MB = midbrain; PM = ponsmedulla; HP = hippocampus; HY = hypothalamus. Comparison and analysis were done by the one-way analysis of variance (ANOVA) (n = 6), control group was compared with MTX control group and aspartame MTX group, MTX control group was compared with Aspartame MTX group. Control, MTX control – Methotrexate treated group; Asp + MTX – Aspartame + Methotrexate treated group.The data from various groups for the individual parameters are presented as bar diagram with mean ± SD. significance fixed at P < 0.05, aspartame treated group when compared to control significance is marked as * and MTX treated groups significance is marked as #.