Flax Lignan Complex Slows Down the Progression of Atherosclerosis in Hyperlipidemic Rabbits.

Key Findings:

Flax lignin complex containing secoisolariciresinol diglucoside (SDG; 34% to 38%), cinnamic acid glucoside (15% to 21%), and hydroxymethylglutaric acid (9.6% to 11.0%) was assessed for its ability to scavenge reactive oxygen species (ROS). In a hypercholesterolemic rabbit model, the levels of the oxygen radical malondialdehyde (MDA) increased in aortic tissue MDA content in the aortas of animals fed cholesterol plus flax lignan complex was reduced by 21% which were attributed to the antioxidant activity of flax lignan complex and/or due to a tendency for a normalization of the antioxidant reserve in the aorta. Flax lignan complex decreased the progression of hypercholesterolemic atherosclerosis and may reduce proatherogenic events.

ABSTRACT:

Flax lignan complex suppresses the development of hypercholesterolemic atherosclerosis. However, it is not known whether flax lignan complex would slow down the progression of hypercholesterolemic atherosclerosis. This study was carried out to determine whether flax lignan complex slows down the progression of already developed atherosclerosis, and whether this effect is associated with reductions in serum lipids and oxidative stress. The studies were conducted in 4 groups of rabbits: group I, regular diet (2 months); group II, 0.25% cholesterol diet (2 months); group III, 0.25% cholesterol diet (4 months); group IV, 0.25% cholesterol diet (2 months) followed by 0.25% cholesterol diet plus flax lignan complex (2 months). Serum lipids and oxidative stress parameters (malondialdehyde, antioxidant reserve, white blood cell chemiluminescence) were measured before and at monthly intervals thereafter on their respective diets. Aortas were removed at the end of the protocol for assessment of atherosclerosis and oxidative stress. Atherosclerosis in group II was associated with hyperlipidemia and increased oxidative stress. Significant areas of the aortic intimal surfaces from group II (37.76% + 7.96%), group III (76.6% + 9.04%), and group IV (52.95% + 10.29%) were covered with atherosclerotic plaques. Group IV rabbits had 40% more atherosclerotic lesions than group II but 31% fewer lesions than group III. The flax lignan complex–induced reduction in the progression of atherosclerosis was associated with reductions in oxidative stress. In conclusion, flax lignan complex was effective in slowing down the progression of atherosclerosis by 31%, and this effect was associated with a reduction in oxidative stress. (Authors abstract)