Antihypercholesterolemic Activity of β-Sitostanol in Rabbits

The antihypercholesterolemic activity of β-sitosterol and β-sitostanol was compared in male rabbits given a cholesterol-supplemented diet. β-Sitosterol and β-sitostanol were fed to these rabbits at the 0.5 % level with cholesterol (0.5% and 0.2% in experiments I and II, respectively). The serum cholesterol level tended to be lower in rabbits fed β-sitostanol than in the animals fed β-sitosterol even in experiment I. The β-sitostanol exhibited a significantly greater hypocholesterolemic activity in experiment II, LDL-cholesterol being decreased markedly. The liver cholesterol decreased in both groups of rabbits to a similar extent. β-Sitostanol prevented more effectively the formation of dietary cholesterol-induced atheroma in the abdominal aorta than β-sitosterol. It is most likely, together with the data reported previously on rats, that the hypocholesterolemic activity of β-sitostanol results from the significantly greater inhibitory effect on the intestinal absorption of cholesterol than that of β-sitosterol.