Cholesterol synthesis in mice is suppressed but lipofuscin formation is not affected by long-term feeding of n-3 fatty acid-enriched oils compared with lard and n-6 fatty acid-enriched oils.
Hypocholesterolemic activity of dietary polyunsaturated fatty acids is observed after relatively short-term but not long-term feedings, and their long-term feedings are suspected to accelerate aging through tissue accumulation of lipid peroxides and age pigments (lipofuscin). To define the long-term effects of fats and oils in more detail, female mice were fed a conventional basal diet supplemented with lard (Lar), high-linoleic (n-6) safflower oil (Saf), rapeseed oil (Rap), high-alpha-linolenic (n-3) perilla oil (Per), or a mixture of ethyl docosahexaenoate and soybean oil (DHA/Soy) from 17 weeks to 71 weeks of age. The DHA/Soy and Per groups had decreased serum cholesterol levels compared with the Lar and Saf groups, but the difference between the Lar and Saf groups was not significant. The 3-hydroxy-3-methyglutary-CoA (HMG-CoA) reductase activity in the liver was also significantly lower in the Per and DHA/Soy groups. However, no significant difference in lipofuscin contents in the brain and liver was observed among the 5 dietary groups, despite significant differences in peroxidizability indices of the dietary and/or tissue lipids. These results indicate that n-3 fatty acid-rich oils are hypocholesterolemic by suppressing hepatic HMG-CoA reductase activity compared with animal fats and high-linoleic (n-6) oil, but tissue lipofuscin contents are not affected by a long-term feeding of fats and oils with different degree of unsaturation in mice.
Du
Chunyan
C
Department of Preventive Nutraceutical Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan.
Sato
Akira
A
Watanabe
Shiro
S
Wu
Chun-Zheng
CZ
Ikemoto
Atsushi
A
Ando
Ken
K
Kikugawa
Kiyomi
K
Fujii
Yoichi
Y
Okuyama
Harumi
H
D000214:Acyl Coenzyme A / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism; D002784:Cholesterol / Q000096:biosynthesis* / Q000097:blood; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000494:pharmacology*; D005229:Fatty Acids, Monounsaturated; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000494:pharmacology; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000494:pharmacology; D005260:Female; D008062:Lipofuscin / Q000096:biosynthesis*; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010938:Plant Oils / Q000008:administration & dosage / Q000494:pharmacology; D000074262:Rapeseed Oil; D012450:Safflower Oil / Q000008:administration & dosage / Q000494:pharmacology; D013024:Soybean Oil / Q000008:administration & dosage / Q000494:pharmacology; D013997:Time Factors
D000214:Acyl Coenzyme A; D004041:Dietary Fats; D004042:Dietary Fats, Unsaturated; D005229:Fatty Acids, Monounsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D008062:Lipofuscin; D010938:Plant Oils; D000074262:Rapeseed Oil; C008047:3-hydroxy-3-methylglutaryl-coenzyme A; D013024:Soybean Oil; D012450:Safflower Oil; D002784:Cholesterol; C029310:lard