Effects of oxidized cooking oil and α-lipoic acid on blood antioxidants: enzyme activities and lipid peroxidation in rats fed a high-fat diet.

The effects of administration of oxidized rapeseed oil and α-lipoic acid on activities of blood antioxidant enzymes and malondialdehyde (MDA) concentration were studied in laboratory rats fed a high-fat diet. Addition of oxidized oil resulted in increased production of oxygen radicals, evidenced by elevated plasma MDA production. Such effect was counteracted by administration of α-lipoic acid. There was an increase of the activities of superoxide dismutase (total and Cu/Zn-SOD) and catalase in rats fed a high-fat diet to which 10% oxidized oil was added. Administration of α-lipoic acid resulted in a decrease of the activities of these enzymes.