Reduction of hypercholesterolemic atherosclerosis by CDC-flaxseed with very low alpha-linolenic acid.
Flaxseed (Type I flaxseed) with 51-55% alpha-linolenic acid in its oil and richest source of plant lignans, has been shown to reduce hypercholesterolemic atherosclerosis by 46% without lowering serum lipids. Antiatherogenic activity was claimed to be due to its alpha-linolenic acid and/or lignan content. If alpha-linolenic acid component of flaxseed is responsible for antiatherogenic activity, then, CDC-flaxseed (Type II flaxseed) which has similar oil and lignan content but has very little (2-3% of the total oil) alpha-linolenic acid would have no antiatherogenic effect. An investigation, therefore, was made of Type II flaxseed on high cholesterol diet-induced atherosclerosis and serum lipids [total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C)] in rabbits. Rabbits were assigned to four groups: Group I, Control; Group II, Type II flaxseed diet (7.5 g/kg orally daily); Group III, 1% cholesterol diet; Group IV, 1% cholesterol diet supplemented with Type II flaxseed (7.5 g/kg orally daily). Blood samples were collected before (0 time) and after 4 and 8 weeks of experimental diets for measurement of serum lipids. Aorta was removed at the end of 8 weeks for assessment of atherosclerotic plaques. Serum TC, LDL-C, TC/HDL-C, and LDL-C/HDL-C were lower in Group IV as compared to Group III by 14 and 31%, 17 and 32%, 28 and 34% and 24 and 32%, respectively, at 4 and 8 weeks. HDL-C was not affected by Type II flaxseed in hypercholesterolemic rabbit. TG and VLDL-C were markedly increased in Group IV as compared to Group III. Type II flaxseed reduced the development of atherosclerosis by 69%. Histological changes in the atherosclerotic regions were qualitatively similar in Groups III and IV. Results indicate that reduction in hypercholesterolemic atherosclerosis by Type II flaxseed is due to a decrease in serum TC and LDL-C. In conclusion, antiatherogenic activity of Type II flaxseed is not due to alpha-linolenic acid.
Prasad
K
K
Department of Physiology, College of Medicine, University of Saskatchewan and Agriculture and Agrifood Canada, Saskatoon.
Mantha
S V
SV
Muir
A D
AD
Westcott
N D
ND
D000818:Animals; D001011:Aorta / Q000473:pathology; D001161:Arteriosclerosis / Q000150:complications / Q000473:pathology*; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D015243:Cholesterol, VLDL / Q000097:blood; D019597:Flax / Q000737:chemistry; D006937:Hypercholesterolemia / Q000150:complications*; D017705:Lignans / Q000008:administration & dosage; D008055:Lipids / Q000097:blood; D011817:Rabbits; D014280:Triglycerides / Q000097:blood; D017962:alpha-Linolenic Acid / Q000008:administration & dosage* / Q000032:analysis
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D015243:Cholesterol, VLDL; D017705:Lignans; D008055:Lipids; D014280:Triglycerides; D017962:alpha-Linolenic Acid; D002784:Cholesterol