Long-term feeding effect of thermally oxidised oils on antioxidant enzymes in rats

Long term feeding effect of thermally oxidised oils on activities of hepatic antioxidant enzymes viz. catalase, glutathione peroxidase (GPX), glutathione-S-transferase (GST) and superoxide dismutase (SOD) at 5 and 20% level for 20 weeks was studied in laboratory rats. Activity of catalase increased in heated and fried oil fed group of rats, whereas activities of GPX, GST and SOD decreased in both heated and fried oil groups. Increase or decrease in activities of these enzymes may be related to several factors like heating and frying conditions, nature of fat, extent of peroxidation, presence of antioxidants, duration of feeding, beside other factors.