Oral administration of policosanol inhibits in vitro copper ion-induced rat lipoprotein peroxidation

Policosanol, a new cholesterol-lowering agent, is a mixture of higher aliph atic primary alcohols isolated from sugar cane (Saccharum officinarum L.) w ax, which prevents the onset of espontaneously and experimentally induced a therosclerotic lesions in experimental models. Because the oxidation of low -density lipoprotein (LDL) may play a role in the pathogenesis of atheroscl erosis, we investigate the effect of policosanol on copper oxidative suscep tibility of rat lipoprotein fractions (VLDL + LDL). Rats fed normal diet we re treated with policosanol (250-500 mg/kg/day) for up to 4 weeks. EDTA-fre e lipoprotein particles were oxidized in a cell-free system by the addition of copper ions, and conjugated dienes generation was monitored by changes of optical density at 234 nm. Thiobarbituric acid-reactive substances (TBAR S) content and lysine-amino group reactivity were investigated. After admin istration, there was no change in cholesterol, triglycerides, and phospholi pid content of lipoprotein fractions; however, policosanol significantly pr olongs the lag time and reduces the propagation rate of diene generation. A lso, policosanol reduces TEARS content and increases lysine reactivity in l ipoprotein fractions treated with Cu2+. In conclusion, policosanol, in addi tion to its cholesterol-lowering effect, has other properties that enables it to reduce the potential of lipoprotein to undergo lipid peroxidation. Su ch effect can be considered of promissory value in the management of athero sclerosis. (C) 1999 Elsevier Science Inc.