1.5.4.3. Assay of the formation of thiobarbituric acid reactive substance (TBARS)
Lipid peroxidation end product, TBARS, was measured as per the modified method of Buege and Aust (1978) . After the oxidation process with CuSO₄, 0.1ml of EDTA (2mM) was added to the sample mixtures to stop oxidation reaction and the samples (in triplicates) were subjected to quantification of LDL oxidation products. To the samples mixtures, 1ml of trichloroacetic acid (TCA 15%) and 1ml of thiobarbituric acid (TBA 0.67%) in 0.05N NaOH was added and incubated at 90°C for 20 min. After cooling down at room temperature, the samples were centrifuged at 3000rpm for 15 min and the absorbances of the aliquots were recorded in a spectrophotometer at 532 nm. The percentage inhibition of TBARS formation was calculated using the following equation: