Enhanced capacity of n-3 fatty acid-enriched macrophages to oxidize low density lipoprotein mechanisms and effects of antioxidant vitamins.
We have investigated possible mechanisms by which n-3 fatty acid-enriched macrophages enhance the oxidation of low density lipoprotein (LDL), and the ability of antioxidant vitamins to prevent this. Macrophages were enriched with n-3 fatty acids (eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid) following incubation with fish oil. These macrophages produced large amount of TBARS in medium containing metals, and showed enhanced capacity to oxidize LDL (3-4 fold increase compared to control cells) and to accumulate the modified LDL. 5,8,11,14-eicosatetraynoic acid (ETYA, 15-lipoxygenase inhibitor) and superoxide dismutase (SOD) did not inhibit the enhanced capacity of n-3 fatty acid-enriched cells to oxidize LDL. However antioxidants, (vitamin E-enriched macrophages or vitamin C in the medium), inhibited this enhanced capacity. Medium conditioned by n-3 fatty acid-enriched cells had pro-oxidant effects on metal-initiated LDL oxidation. We conclude that n-3 fatty acid-enriched macrophages display increased oxidant capacity which is not inhibited by ETYA or SOD, and that antioxidant vitamins inhibit the enhanced capacity to oxidize LDL.
Suzukawa
M
M
CSIRO, Division of Human Nutrition, Adelaide, Australia.
Abbey
M
M
Clifton
P
P
Nestel
P J
PJ
D015117:5,8,11,14-Eicosatetraynoic Acid / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D001161:Arteriosclerosis / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D018929:Cell Culture Techniques; D002849:Chromatography, Gas; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology*; D008077:Lipoproteins, LDL / Q000187:drug effects / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D013482:Superoxide Dismutase / Q000494:pharmacology; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014461:Ultracentrifugation
D000975:Antioxidants; D015525:Fatty Acids, Omega-3; D008077:Lipoproteins, LDL; D017392:Thiobarbituric Acid Reactive Substances; D015117:5,8,11,14-Eicosatetraynoic Acid; D013482:Superoxide Dismutase