Cholesterol is more susceptible to oxidation than linoleates in cultured cells under oxidative stress induced by selenium deficiency and free radicals

Polyunsaturated fatty acids and their esters are known to be susceptible to free-radical mediated oxidation, while cholesterol is more resistant to oxidation. The present study focused on the relative susceptibilities of linoleates and cholesterol in Jurkat cells under oxidative stress induced by selenium deficiency and free radical insult, as assessed by total hydroxyoctadecadienoic acids (MODE) and total 7-hydroxycholesterol (t7-OHCh) measured after reduction and saponification. It was observed that the levels of MODE and t7-OHCh significantly increased by both oxidative insults. The increased amounts of t7-OHCh were higher than those of MODE in both selenium-deficient and free radical-treated cells. These results suggest that, in contrast to plasma oxidation where cholesterol is much more resistant to oxidation than linoleates, cellular cholesterol is more susceptible to oxidation than cellular linoleates. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.