Catalase (CAT) activity

The CAT activity was assayed by the method described previously by Aebi et al. (1975). Briefly, the assay mixture consisted of 2.9 ml H₂O₂ and 0.1 ml brain tissue supernatant in a total volume of 3.0 ml. The observed change in absorbance was recorded spectrophotometrically at 240 nm for 3 min against blank, prepared by addition of 2.9 ml phosphate buffer and 0.1 ml distilled water without H₂O₂ addition. The CAT activity was expressed as μmole H₂O₂ consumed/min/mg protein.