A study on regression of hypercholesterolemic atherosclerosis in rabbits by flax lignan complex

Flax lignan complex (FLC) isolated from flaxseed suppresses the development of hypercholesterolemic atherosclerosis. The objectives of this study were to investigate if FLC produces regression of atherosclerosis and if regression is associated with reductions in serum lipids and oxidative stress. The studies were conducted in 4 groups of rabbits: group I, control diet (2 months); group II, 0.25% cholesterol diet (2 months); group III, 0.25% cholesterol diet (2 months) followed by regular diet (4 months); and group IV, 0.25% cholesterol diet (2 months) followed by regular diet and FLC (4 months). Serum lipids and oxidative stress parameters were measured before and at various intervals thereafter on their respective diets. The aortas were removed at the end of the protocol for assessment of atherosclerotic plaques and oxidative parameters. Atherosclerosis in group II was associated with hyperlipidemia and increased oxidative stress. Atherosclerotic changes were accelerated in group III, and this was associated with reductions in serum lipids and oxidative stress. Atherosclerotic lesions in group IV were similar to group II, but significantly smaller than those in group III, and were associated with reductions in serum lipids and oxidative stress similar to that in group III. These results indicate that FLC does not produce regression but prevents the acceleration of atherosclerosis due to the removal of cholesterol in the diet. These effects of FLC are not associated with reductions in serum lipids and oxidative stress.