2.3.1. Measurement of catalase activity

Catalase activity was determined in liver and brain homogenate according to method of Aebi (1984) by measuring of the decomposition of H₂O₂ (Aebi, 1984). Briefly, 10 μL of diluted homogenate was added in the quartz cuvette containing 2 ml sodium phosphate buffer (50 mM, pH 7) and 1 ml of H₂O₂ (30 mM). Catalase activity was calculated by determining alteration absorbance at 240 nm for 2 min using extinction coefficient of 39.4 M^-1 cm^-1 and expressed as U/g tissue for brain and liver. One unit of CAT is the amount of enzyme that decomposes 1.0 µmol of H₂O₂ per min at pH 7.0 and 25 °C.