R. Menendez et al., CHOLESTEROL-LOWERING EFFECT OF POLICOSANOL ON RABBITS WITH HYPERCHOLESTEROLEMIA INDUCED BY A WHEAT STARCH-CASEIN DIET, British Journal of Nutrition, 77(6), 1997, pp. 923-932
The effect of policosanol, a mixture of high-molecular-weight aliphati
c alcohols isolated from sugarcane wax, on casein-induced hypercholest
erolaemia in rabbits was studied. When policosanol was administered by
the oral route once daily for 30 d (50 mg/kg) the increases in plasma
total cholesterol and LDL-cholesterol (LDC-C) were significantly redu
ced when compared with the control group. The incorporation of (H2O)-H
-3 into sterols in the liver was significantly depressed, suggesting i
nhibition of hepatic cholesterol biosynthesis. The oral administration
of policosanol raised the rate of removal of I-125-labelled LDL from
serum. Kinetic parameters calculated following injection of [I-125]LDL
showed than in casein-fed rabbits, the terminal half-life (t(1/2)) wa
s significantly decreased after policosanol treatment. The hepatic LDL
-binding activity was increased after policosanol administration which
suggested that the enhanced clearance was due, at least in part, to i
ncreased receptor-mediated uptake of LDL by the liver. Considered toge
ther, these results suggest that policosanol can significantly reduce
the increase of plasma LDL-C in rabbits fed on a wheat starch-casein d
iet by reducing cholesterol biosynthesis in the liver. Such an effect
could account for the enhancement of LDL catabolism through the recept
or-mediated pathway.