Antioxidant potential of evening primrose oil administration in hyperlipemic rabbits.

The dietary intake of saturated fatty acids affects arteriosclerosis. We studied the effect of supplementation (15% wt/wt) of a hyperlipemic diet (1.33% cholesterol) with evening primrose oil (EPO) (Oenothera biennis) for 6 weeks in four groups of 10 rabbits each. At the end of this period we determined lipid peroxidation, glutathione content, and glutathione peroxidase, reductase and transferase activities in liver, brain, heart, aorta and platelets. The atherogenic diet increased tissue lipid peroxidation and decreased the protective antioxidant effect of glutathione. Dietary supplementation with EPO reduced tissue lipid peroxidation (61% in liver, 57% in brain, 42% in heart, 24% in aorta, 33% in platelets). Total glutathione was increased, especially in the aorta (90%) and platelets (200%); however, in all tissues the percentage of oxidised glutathione decreased. Evening primrose oil reduced glutathione peroxidase activity and increased the activities of glutathione reductase and transferase. We conclude that in rabbits made hyperlipemic with a diet rich in saturated fatty acids, EPO decreased tissue oxidative stress.