EFFECT OF EVENING PRIMROSE OIL ON PLATELET-AGGREGATION IN RABBITS FEDAN ATHEROGENIC DIET

Evening primrose oil (Oenothera biennis) is a rich source of omega-6 s eries fatty acids. We report here the effects of dietary supplementati on with evening primrose oil (EPO) on platelet aggregation as the main factor in arterial thrombus formation in an experimental model of ath erogenesis in rabbits. A total of 40 male white New Zealand rabbits we re divided into four groups (n = 10 animals/group): 1: normal diet, 2: atherogenic diet (ATD), 3: normal diet enriched with 15% EPO, 4: ATD + EPO. Each group was kept on the diet for 6 weeks. We determined seru m lipid profile, platelet aggregation in whole blood, platelet thrombo xane B-2 production and platelet lipid peroxides. The atherogenic diet increased platelet aggregation (135% when ADP was used, and 185% when collagen was used as the inducer). Evening primrose oil reduced hyper aggregation to the values obtained in rabbits fed with the normal diet . Thromboxane synthesis was increased from 0.18 to 2.28 nmol/10(9) pla telets); EPO reduced this value to 1.38 nmol/10(9) platelets. Lipid pe roxides were increased by ATD from 0.27 to 0.81 nmol/10(9) platelets; EPO prevented this increase (0.35 nmol/10(8) platelets). In conclusion , EPO reduced platelet hyperaggregability in rabbits fed an atherogeni c diet. (C) 1997 Elsevier Science Ltd.