DIETARY GINSENOSIDES IMPROVE ENDOTHELIUM-DEPENDENT RELAXATION IN THE THORACIC AORTA OF HYPERCHOLESTEROLEMIC RABBIT

1. Endothelium-dependent relaxation to acetylcholine was impaired in a ortic rings from cholesterol-fed rabbits as compared to rabbits fed wi th a control diet. 2. The dietary treatment of rabbits with ginsenosid es did not affect endothelium-dependent relaxation to acetylcholine bu t did effect the relaxation in cholesterol-fed rabbits. 3. Dietary tre atment of rabbits with ginsenosides did not alter the relaxations to s odium nitroprusside and the contractions to norepinephrine in rings wi thout endothelium from both control and cholesterol-fed rabbits. 4. Gi nsenoside feeding had no significant effect on the plasma lipid levels in both control and cholesterol-fed rabbits. 5. These results suggest that dietary supplementation of rabbits with ginsenosides improve the endothelium-dependent relaxation to acetycholine in the aortic blood vessels in cholesterol-fed rabbits. This beneficial effect of ginsenos ides feeding cannot be explained by a facilitation of the cyclic GMP e ffector pathway in the smooth muscle or by an enhanced cholesterol met abolism but may involve an increased production of nitric oxide by end othelial cells.