Attenuated effects of peptides derived from porcine plasma albumin on in vitro lipid peroxidation in the liver homogenate of mice

Porcine plasma albumin was hydrolyzed with alcalase available for industrial application, and attenuated effects of peptides were evaluated using 4-Nitroquiunoline 1-oxide (4-NQO) as an inducing reagent. 4-NQO is a potent oral carcinogen, which has been found to induce lipid peroxidation in vivo and in vitro. Our results indicated that addition of 4-NQO resulted in increase of hydroxyl and superoxide radicals, glutathione peroxidase (GPx) activity and levels of malondialdehyde (MDA), and decrease in activities of superoxide dismutase (SOD) and catalase (CAT) and levels of glutathione (GSH). Simultaneous addition of peptides significantly attenuated lipid peroxidation. The lowermost molecular weight (MW) peptide fractions (<3 kDa) had the highest activity. This study also demonstrated that the attenuated effects of peptides might be due to the protective interactions between cells and peptides rather than the direct inhibition of 4-NQO by peptides. The results of this study showed the potential of utilizing porcine plasma albumin as a source of functional peptides.