Effects of n-3 and n-6 fatty acids on the activities and expression of hepatic antioxidant enzymes in autoimmune-prone NZBxNZW F1 mice.
Menhaden fish oil (FO) containing n-3 fatty acids dramatically extends the life span and delays the onset and progression of autoimmune disease in (NZBxNZW)F1 (B/W) female mice as compared to those fed corn oil (CO) rich in n-6 lipids. As an inefficient antioxidant defense system has been linked to autoimmune diseases, the present study was undertaken to determine whether the protective action of n-3 lipids is mediated through their antioxidant defense system. Weanling B/W mice were fed a nutritionally adequate, semipurified diet containing CO or krill oil (KO) or FO at 10% level (w/w) ad libitum until the mice were 6.5 months old. All diets contained the same level of vitamin E (21.5 mg/100 g diet). We compared the effects of feeding n-6 and n-3 lipids on survival, kidney disease, hepatic microsomal lipid composition, peroxidation, and on the activity and mRNA expression of the antioxidant enzymes catalase, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in 6.5-month-old B/W mice. The results showed that when compared to livers from CO-fed mice, livers from KO- and FO-fed mice showed: (i) significantly higher (P < 0.001) activities and expression of CAT, GSH-Px and SOD; (ii) significantly lower (P < 0.001) arachidonic acid (20:4n-6) and linoleic acid (18:2n-6) and higher (P < 0.001) eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) levels in hepatic microsomes; and (iii) significantly lower (P < 0.001) estimated peroxidation indices and thiobarbituric acid reactive substances generation.(ABSTRACT TRUNCATED AT 250 WORDS)
Venkatraman
J T
JT
Department of Medicine, University of Texas Health Science Center, San Antonio 78284-7874.
Chandrasekar
B
B
Kim
J D
JD
Fernandes
G
G
D000818:Animals; D001327:Autoimmune Diseases / Q000201:enzymology*; D001835:Body Weight / Q000502:physiology; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D004198:Disease Susceptibility / Q000276:immunology; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D005979:Glutathione Peroxidase / Q000096:biosynthesis / Q000378:metabolism; D015227:Lipid Peroxidation / Q000502:physiology; D008099:Liver / Q000201:enzymology*; D051379:Mice; D008814:Mice, Inbred NZB; D011507:Proteinuria / Q000378:metabolism; D013482:Superoxide Dismutase / Q000096:biosynthesis / Q000378:metabolism
D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D015500:Chloramphenicol O-Acetyltransferase