A comparative study of policosanol vs lovastatin on intimal thickening in rabbit cuffed carotid artery

Policosanol is a cholesterol-lowering drug isolated from sugar cane wax, wh ich acts by inhibiting cholesterol biosynthesis. Previous studies have demo nstrated that policosanol inhibited smooth muscle cell (SMC) proliferation in the cuffed carotid artery of the rabbit and in arterial wall damage indu ced by forceps in the central artery of the ear of rabbits. The present stu dy was undertaken to compare the effects of policosanol and lovastatin on S MC proliferation in the cuffed carotid artery of rabbits. Collars were plac ed around the left carotid for 7 and 15 days. The contralateral artery was sham operated. We studied eight experimental groups: two controls groups re ceiving vehicle for 7 and 15 days, respectively, a satellite sham operated control group, four groups treated with policosanol at 5 and 25 mg kg(-1) f or 7 and 15 days and a reference group receiving lovastatin at 20 mg kg(-1) for 15 days. Samples of arteries were examined by light and electron micro scopy. To evaluate intimal thickening the cross-sectional areas of intima a nd media were measured. Neointima was significantly reduced in treated anim als compared with controls, but the reduction in lovastatin animals was sig nificantly lower than in policosanol-treated groups. The SMC proliferation was studied by the immunohistochemical detection of proliferating cell nucl ear antigen and the reduction observed in policosanol-treated rabbits was s ignificantly larger than in lovastatin-treated animals. It is concluded tha t the protective effect of policosanol against neointima formation in this experimental model was slightly better than that of lovastatin. (C) 2001 Ac ademic Press.