Polysaccharides from the green alga Ulva rigida improve the antioxidant status and prevent fatty streak lesions in the high cholesterol fed hamster, an animal model of nutritionally-induced atherosclerosis

We investigated the effects of Ulva in hypercholesterolemic hamsters, before and after processing. Three groups of 12 hamsters were fed a high cholesterol diet for 12 wk (Control) or a high cholesterol diet where cellulose has been replaced for an equivalent fibre weight from Ulva or processed Ulva. Plasma cholesterol, non-HDL cholesterol and specially triglycerides were reduced by Ulva. Liver glutathione peroxidase activity was increased and thiobarbituric acid reactive substances were efficiently reduced by dietary treatments compared with controls, whereas plasma antioxidant capacity was increased and aortic fatty streak area was decreased by 70%. The results show for the first time that chronic consumption of polysaccharides supplied by Ulva prevent the fall of antioxidant defences and the development of atherosclerosis in hamsters. The underlying mechanism is related mainly to increased antioxidant status although improvement of the serum lipid profile was not ruled out.