EFFECTS OF DIETARY PHYTOSTEROLS ON LIVER LIPIDS AND LIPID-METABOLISM ENZYMES

The effects of dietary phytosterols on lipid metabolism have been assessed through determination of liver lipids (sterols and fatty acids) and lipid metabolism enzymes (acetyl-CoA carboxylase, malic enzyme, glucose-6-phosphate dehydrogenase) in rats fed 12 or 24 mg cholesterol a day and 0-96 mg phytosterols. The results indicate that, provided the dietary phytosterol to Cholesterol ratio is at least 1 and in the presence of a dietary cholesterol excess, phytosterols do exert a regulatory role through decreases of both acetyl-CoA carboxylase and malic enzyme activities. A ratio of 2 enhances this effect. At the same time, liver fatty acids and cholesterol contents significantly decrease.