Effect of policosanol on intimal thickening in rabbit cuffed carotid artery

We studied the effect of policosanol on smooth muscle cell proliferation in the cuffed carotid artery of the rabbit. Policosanol is a mixture of highe r aliphatic primary alcohols isolated from sugar cane wax, with cholesterol lowering effects proved in experimental models and patients with type II h ypercholesterolemia. It acts by inhibiting cholesterol biosynthesis. The po sitioning of a nonocclusive silicone collar around the rabbit carotid arter y results in the formation of a neointima. We wished to determine whether p olicosanol orally administered prevented intimal thickening. Collars were p laced around the left carotid for 15 days. The contralateral artery was sha m operated. We included three experimental groups: a control received vehic le and two others policosanol at 5 and 25 mg Kg until sacrificed. Samples o f arteries were examined by light and electron microscopy. To evaluate inti mal thickening the cross-sectional area of intima and media were measured. Neointima was significantly reduced in policosanol-treated animals compared with controls. The smooth muscle cell proliferation was studied by the imm unohistochemical detection of proliferating cell nuclear antigen and a sign ificant reduction was observed in policosanol treated rabbits. It is conclu ded that policosanol has a protective effect on the neointima formation in this experimental model. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.