Policosanol
DESCRIPTION
Policosanol is the generic term used for a mixture of long-chain primary aliphatic saturated alcohols. These alcohols are derived from the waxes of such plants as sugar cane (Saccharum officinarium) and yams (e.g. Dioscorea opposita). They are also found in beeswax. The main long-chain alcohol in policosanol is the 28 carbon 1-octanosol, and next most abundant is the 30 carbon 1-triacontanol. Other long-chain alcohols present in much lower concentrations are: 1-docosanol (C22), 1-tetracosanol (C24), 1-hexacosanol (C26), 1-heptacosanol (C27), 1-nonacosanol (C29), 1-dotriacontanol (C32) and 1-tetracontanol (C34). These long-chain alcohols are solid waxy substances and are soluble in water. They are known collectively as fatty alcohols.
ACTIONS AND PHARMACOLOGY
ACTIONS
Policosanol may reduce total serum cholesterol and low-density lipoprotein-cholesterol (LDL-C) levels in some.
MECHANISM OF ACTION
The mechanism of action of reported cholesterol-lowering activity is unknown. Some animal studies suggest that policosanol may inhibit cholesterol syntheses in the liver. It is also unclear if the putative cholesterol-lowering activity is due to octacosanol. The long-chain alcohols appear to have different biological activities, and octacosanol by itself may not have the same activities as policosanol. They may work synergistically.
PHARMACOKINETICS
Pharmacokinetic studies have been performed on octacosanol, the major alcohol in policosanol, in experimental animals and human volunteers. The absorption of octacosanol is variable and low. Octacosanol absorption ranges from about 11% in rats and humans to about 28% in rabbits. Octacosanol is absorbed from the small intestine into the lymph and from there enters the blood stream.
Distribution is primarily to the liver digestive tract, skeletal muscle and adipose tissues. Octacosanol may be partly oxidized to the long-chain saturated fatty acid, octacosanoic acid which undergoes beta-oxidation.
Following a single dose of octacosanol in experimental animals, peak plasma levels are seen between 30 minutes to 2 hours. Following a single dose of octacosanol in human volunteers, peak plasma levels are seen at one hour and four hours later. Bile is the main route of excretion. Renal excretion is negligible.
INDICATIONS AND USAGE
Policosanol may be indicated for reducing cholesterol levels. There is preliminary evidence that it can reduce platelet aggregation in both healthy and hypercholesterolemic individuals and that it may be of benefit in individuals with intermittent claudication. Reports that it can boost energy and enhance sexual performance are anecdotal.
RESEARCH SUMMARY
A mixture of higher aliphatic primary alcohols derived from sugar cane wax has become popular in such places as Cuba for its reputed cholesterol-lowering benefits, energizing effects and enhancement of sexual function. It is also the source of another increasingly popular supplement–octacosanol (the primary long-chain alcohol in policosanol).
There are a number of animal studies suggesting that policosanol can lower cholesterol, that it can inhibit experimentally induced atherosclerotic lesions of cerebral ischemia, that it can help prevent the peroxidation of lipoprotein and inhibit platelet aggregation.
Human studies have been increasing. In one recent study, patients with LDL-cholesterol greater than 160 mg/dl were randomized in double-blind fashion to receive policosanol (10 milligrams daily), lovastatin (20 milligrams daily) or simvastatin (10 milligrams daily). After eight weeks of therapy, LDL-cholesterol was reduced 24% in the policosanol groups, 22% in the lovastatin group and 15% with simvastatin. HDL-cholesterol increased significantly in the policosanol group but not in the other two groups. Policosanol was judged to be “a safe and effective cholesterol reducing agent.”
In another recent double-blind study of policosanol’s possible effects in hypercholesterolemia, patients received 5 milligrams of policosanol or placebo daily for 12 weeks followed by 10 milligrams of policosanol or placebo for a subsequent 12 weeks. Policosanol (5 and 10 milligrams daily) appeared to significantly reduce LDL-cholesterol (18.2% and 25.6% respectively) and reduce cholesterol (13% and 17.4%). It appeared to raise HDL-cholesterol (15.5% and 28.4%). Triglycerides were unchanged in the first 12-week period but were significantly reduced (5.2%) by the end of the second 12-week period. Side effects were few and minor. There were 11 serious (7 of these were vascular) adverse events among those taking policosanol.
Policosanol appears to significantly reduce platelet aggregation in both healthy and hypercholesterolemic individuals, apparently proving as effective (at 20 milligrams daily doses) as aspirin (100 milligrams per day). The substance also appears to demonstrate beneficial effect in patients with intermittent claudication. Long-term therapy (20 months) using 5 milligrams of policosanol twice a day resulted in significant improvement in treadmill exercise performance and exercise — ECG responses in a group of coronary heart disease patients. The addition of 125 milligrams of aspirin daily further enhanced these results. It is hoped that others will confirm these very promising, largely Cuban studies.
Policosanol’s reputed efficacy in boosting energy and enhancing sexual function, particularly male sexual function, is entirely anecdotal.
CONTRAINDICATIONS, PRECAUTIONS, ADVERSE REACTION
CONTRAINDICATIONS
Hypersensitivity to any component of policosanol.
PRECAUTIONS
Policosanol is not recommended for children, pregnant women and nursing mothers. Because of possible antithrombotic activity, those taking warfarin and hemophliacs should exercise caution in the use of policosanol. Policosanol supplementation should be stopped before any surgery.
ADVERSE REACTIONS
Mild gastrointestinal side effects, skin rash, headache, insomnia and weight loss have been reported. The incidence of these adverse reactions is low. Policosanol is generally well tolerated.
Except for possible lowering of serum total cholesterol and LDL-cholesterol, policosanol does not appear to affect any other laboratory test results.
INTERACTIONS
Aspirin: Policosanol showed a synergism with the antithrombotic properties of aspirin in different experimental models.
No adverse interactions have been found with policosanol use in combination with beta-blockers, diuretics, calcium-channel blockers, NSAIDs, anxiolytics, oral hypoglycemic agents, digoxin, nitroglycerin, neuroleptics or anti-depressants.
No known adverse interactions with nutritional supplements, herbs or foods.
OVERDOSAGE
There are no reports of overdosage. A single dose of 1 gram (50 times the maximum recommended dose) was well tolerated by healthy volunteers. Oral LD50 in mice, rats and rabbits is higher than 5 grams per kilogram. Policosanol did not induce genotoxic changes in somatic or germ cells, and it does not act as a mutagenic agent. Teratogenic and carcinogenic testing to date have been negative.
DOSAGE AND ADMINISTRATION
The recommended starting dose of policosanol is 5 milligrams daily taken once a day at dinner time. An effect may take up to 12 weeks to be observed. The dose can be doubled to 5 milligrams twice a day, taken at lunch and dinner time. A dose of 20 milligrams daily should not be exceeded.
LITERATURE
Arruzazabala, ML, Carbajal D, Mas R, et al. Cholesterol-lowering effects of policosanol in rabbits. Biol Res. 1994; 27:205-208.
Arruzazabala ML, Mas R, Molina V, et al. Effect of policosanol on platelet aggregation in type II hypercholesterolemic patients. Int J Tissue React. 1998; 20:119-124.
Arruzazabala ML, Valdes S, Mas R, et al. Comparative study of policosanol, aspirin and the combination therapy policosanol-aspirin on platelet aggregation in healthy volunteers. Pharmacol Res. 1997; 36:293-297.
Castano G, Mas R, Roca J, et al. A double-blind, placebo-controlled study of the effects of policosanol in patients with intermittent claudication. Angiology. 1999; 50:123-130.
Hernandez F, Illnait J, Mas R, et al. Effect of policosanol on serum lipids and lipoproteins in healthy volunteers. Current Therap Res. 1992; 52:568-575.
Mas R, Castano G, Illnait J, et al. Effects of policosanol in patients with type II hypercholesterolemia and additional coronary risk factors. Clin Pharmaco Ther. 1999; 64:439-447.
Menendez R, Frago V, Amor GM, et al. Oral administration of policosanol inhibits in vitro copper ion-induced rat lipoprotein peroxidation. Physiol Behav. 1999; 67: 1-7.
Prat H, Roman O, Piro E. Comparative effects of policosanol and two HMG-CoA reductase inhibitors on type II hypercholesterolemia. Rev Med Chil. 1999; 127:286-294.
Stusser R, Batista J, Padron R, et al. Long-term therapy with policosanol improves treadmill exercise- ECG testing performance of coronary heart disease patients. Int J Clin Pharmacol Ther. 1998; 36:469-473.
Torres O, Agramante AJ, Illnait J, et al. Treatment of hypercholesterolemia in NIDDM with policosanol. Diabet Care. 1995; 18:393-396.