Guggulsterone, a potent hypolipidaemic, prevents oxidation of low density lipoprotein

The oxidation of low density lipoprotein (LDL) induced by Cu+2 caused marked oxidative changes in the lipid and protein constituents of this lipoprotein in vitro. Guggulsterone prevented the generation of lipid peroxides measured as thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes. This compound protected LDL against depletion of lipid constituents such as cholesterol, cholesterol esters, triglyceride and phospholipids as well as inhibiting the conversion of cholesterol into oxygenated cholesterols. Oxidized LDL containing less apoprotein B with a high protein carbonyl value, was more electronegative, as evidenced by the increase in relative electrophoretic mobility (REM) on agarose gel. Guggulsterone significantly protected LDL apoprotein as measured by reversal of REM after oxidation. The protective action of guggulsterone may be due to its free radical scavenging property as this compound significantly inhibited the generation of hydroxyl radicals in a nonenzymic system. © 1997 John Wiley & Sons, Ltd.