and then homogenised by ultra-turrax (ART Miccra RT) for 1.5 min. The resulting mixture was diluted with deionised water to a final volume of 100 mL and then filtered through a Whatman filter paper No. 4. Five millilitre of freshly prepared 0.005 M thiobarbituric acid solution was added to 5 mL of filtrate in a stopper fitted glass tube, mixed by inverting the tube several times, and then kept in the dark for 15 h at room temperature. Finally, the absorbance was measured at 530 nm using a UV visual spectrophotometer (Chebios Optimum-One). Results are expressed as the percentage of malondialdehyde (MDA), which has a molecular weight of 72.06 (Shrestha & Min, 2006).