HYPOCHOLESTEROLEMIC EFFECT OF DIETARY EVENING PRIMROSE (OENOTHERA-PARADOXA) CAKE EXTRACT IN RATS

The objective of this study was to determine the effects of dietary ev ening primrose cake extract (E) on the lipid indices and lipid peroxid ation products in growing rats fed cholesterol-free standard diet (S) or diets enriched with 1% cholesterol (C). All animals were divided in to five groups of 10 and were fed during 4 weeks experimental diets: g roup (Gr) I-standard diet (S); Gr 2-S diet supplemented with 1% E (S+1 %E); Gr 3-with 1% C (S+1%C); Gr 4-S + 1%C + 0.5%E and Gr 5-S + 1%C + 1 %E. Dietary E significantly decreased plasma total cholesterol (TC) an d low density lipoprotein cholesterol (LDL-C) but did not change the h igh density lipoprotein cholesterol (HDL-C) either in rats fed cholest erol-free or enriched-in-cholesterol diets. Plasma TC were 98.7, 81.3, 144.6, 114.5 and 99.1 mg 100 ml(-1), whereas LDL-C values were 19.4, 7.6, 77.2, 43.6 and 27.6 mg 100 ml(-1) in Groups 1-5, respectively. Su pplementation of diet with E significantly elevated triglyceride and p hospholipid concentrations in the liver; also 1% E with C (S + 1%C + 1 %E) caused significant TC accumulation in the liver and elevated malon dialdehyde concentrations in plasma and erythrocytes. In conclusion, t his study demonstrates, for the first time, that evening primrose cake extract (E) possesses strong hypocholesterolemic action. Its antioxid ative properties, especially in animals loaded with dietary cholestero l, are less clear and need further studies. (C) 1998 Elsevier Science Ltd. All rights reserved.