Nutraceuticals (3) Octacosanol
The Pharmaceutical Journal Vol 265 No 7107p170-171
July 29, 2000 Articles
By Lisa Rapport, BPharm, MRPharmS, and Brian Lockwood, PhD, MRPharmS
An increasingly popular supplement, octacosanol is often used by athletes. Although research is still in its infancy, octaconasol may also have a gastroprotective and lipid lowering role. This article reviews the evidence.
Octacosanol is an example of a nutraceutical. It is a 28-carbon chain alcohol which is present in the superficial layers of fruit, leaves and skin of many plants as well as whole grains.1 Most studies investigating this compound have used either a wheat germ oil extract, or policosanol. Policosanol is a natural mixture of primary alcohols purified from sugar cane wax, whose main component is octacosanol.
It is well known that athletes use anabolic steroids and amphetamines in order to enhance their performance. Alternatively, if an athlete manages to reduce his body weight by a small amount each day, he may be able to compete in a lower body weight category, increasing his chances of winning. Many athletes are realising that apart from being illegal, many of these substances are harmful to health and they are therefore turning to more natural products to enhance performance.2
Octacosanol is now being advertised in Australia and America as such a product. However, it is often difficult to assess these products as any increased performance may also be due to improved training or diet. A study was carried out using 33 male student athletes to test these claims.3 Of these, 20 students were used as controls and 13 consumed two "paks" daily (each "pak" contained 29 supplements, including 2,000µg of octacosanol). After eight weeks, all the supplemented subjects showed a decrease in body fat compared to only one in the control group. The supplemented subjects also showed a significant increase in muscle girth measurements, indicating the formation of lean body mass. This study was not a blind study, and the diet of the subjects was not monitored. Also, since the "paks" contained many other supplements besides octacosanol, no conclusions can be made without further studies on the isolated product.
Another study using 16 subjects (students of and lecturers in physical education), measured grip and chest strength (as an indication of body strength), and reaction time to both auditory and visual stimuli.4 Results showed that only reaction time to a visual stimulus and grip strength were improved after 1,000µg of octacosanol was taken for eight weeks. The authors conclude that there are some benefits to supplementation with octacosanol, but these do not appear to be as widespread as advertised.
However, an experimental procedure carried out on mice showed that octacosanol enhanced swimming endurance, possibly by converting lipids into energy.5 More human studies are therefore necessary before claims for the ergogenic properties of octacosanol can be substantiated.
Motor neurone disease
A small controlled study was carried out to assess the effects of octacosanol in Parkinson's patients.6 The 12-week, double-blind, crossover trial involved 10 patients with mild to moderate Parkinson's disease. One tablet of octacosanol 5mg, or equivalent placebo, was taken for six weeks, three times a day with meals. Three patients improved, and another was himself able to identify the octacosanol period, although the results were not statistically significant. Side effects were minimal, and the results supported benefit from octacosanol in patients with mild symptoms. However, a much larger patient population is needed before clinically significant conclusions can be reached.
Another disease state studied was amyotrophic lateral sclerosis (ALS). This degenerative motor neurone disease is a group of chronic neurological disorders affecting the spinal cord and lower brain stem. It typically results in painless weakness and atrophy of the hands with spasticity and reflex hyperactivity of the legs.7 The disease is progressive, with death within three years in 50 per cent of patients, but it can be prolonged and may stabilise after some years of progression or, rarely, reverse.8
A placebo-controlled, double-blind, crossover trial was carried out in which ALS patients received either 40mg of active drug or placebo for three months and then the groups were crossed over.9,10 Eleven patients completed the trial. The mean results showed no difference between octacosanol and placebo.
The cholesterol lowering effects of policosanol were studied in the rabbit, as this animal is a useful model for lipid metabolism and lipid lowering drugs.11 Three groups of seven rabbits received 5, 50 and 200mg/kg of policosanol and the control group of 10 animals received only placebo. The normal cholesterol diet was similar in all groups as was weight gain during the study. All doses significantly reduced total cholesterol and low density lipoprotein cholesterol (LDL-C) in a dose-dependent way, whereas high density lipoprotein cholesterol (HDL-C) was unchanged.
Another study on the effect of octacosanol in a high-fat diet was carried out in three parts.1 One experiment looked at the effect of supplementation with octacosanol on four groups of six rats. A significant decrease in weight of perirenal adipose tissue was found. Two further experiments examined the effect of octacosanol on the enzymes involved in lipid metabolism and on the rate of total fatty acid oxidation in two groups of 10 rats. The activities of the enzymes were affected by the fat content of the diet, but octacosanol had no effect. However, the rate-limiting step in the esterification of fatty acid into triacylglycerol was decreased by octacosanol, suggesting that a step in the biosynthesis of cholesterol had been inhibited.
When policosanol was given to human volunteers, there were no significant side effects,12 and human subjects were therefore used to test the lipid effects of policosanol. A double-blind study was carried out in 38 healthy volunteers, who were given placebo, 10mg policosanol twice daily or 20mg twice daily. After four weeks, serum cholesterol levels were significantly lowered in a dose-dependent manner. As in the animal experiments, these effects were related to the reduction of LDL-C.
Another study, in which 26 elderly hypercholesterolaemic patients13 received placebo, policosanol 1mg, or policosanol 2mg each evening for 24 weeks, also showed promising results. Again, serum total cholesterol was significantly reduced, suggesting that policosanol is an effective drug for elderly, hypercholesterolaemic patients with a safe profile for a long duration of treatment.
To test the effect of successive doses on the lipid profile and tolerability of treatment, a double-blind study was carried out on 33 outpatients with primary hypercholesterolaemia.14 For six weeks the test subjects received two policosanol 5mg tablets daily, and then for a further six weeks they took two tablets twice daily. Patients treated with the lower dose showed a significant reduction in total cholesterol and LDL-C, and the subsequent dose further reduced these levels.
In non-insulin-dependent diabetes mellitus (NIDDM), increased LDL levels are a major coronary artery disease risk factor. In one study,15 32 patients with stable glycaemic control were given policosanol 5mg twice a day for 12 weeks, or a placebo. Both cholesterol and LDL-C were significantly reduced in the test group and showed a non-significant upward trend in the placebo group. Side effects were mild and, at week 12, no side effects were reported in the policosanol group. This study shows the possible place of policosanol as a cholesterol lowering drug in patients with controlled NIDDM.
In a study using 48 rats, the effect of oral pre-treatment with policosanol, two hours before isoprenaline-induced myocardial infarction, was investigated.16 Policosanol reduced the size of the myocardial injury and decreased the number of polymorphonuclear neutrophils (PMN) and mast cells in the damaged areas. These cells play an important role in cardiac cell damage, so in the case of less damage there are fewer PMN and mast cells. The authors concluded that more work was necessary to determine the clinical value of their findings.
D-002, a mixture of higher primary alcohols containing 17.49 per cent octacosanol, was used in the investigation of anti-ulcer activity.17 Ten rats were treated with 5, 25 or 50mg/kg D-002, or 25mg/kg cimetidine. One hour later ulceration was induced with indomethacin or 60 per cent ethanol. D-002 showed similar results to cimetidine in significantly preventing both indomethacin-induced and ethanol-induced ulcers. One of the main factors in the formation of these ulcers is the presence of gastric acid but, in a further experiment, D-002 was shown to be independent of gastric acid.
The possible role of D-002 as a cytoprotective agent, where the mechanism is not dependent on gastric acid was further investigated.18 The results suggest the possible role of prostaglandins in the gastroprotective effects of D-002, rather than the inhibition of gastric acid, as in the case of cimetidine.
Since some lipid-lowering drugs also have an effect on platelet aggregation, this possibility was investigated for policosanol.19 Groups of 10 rats were used in a controlled study, which found that policosanol had an anti-aggregation effect on platelets. Policosanol at a dose of 200mg/kg also significantly reduced mortality in cerebral infarction in gerbils.20
Aspirin is the most commonly used drug for cerebral ischaemia and thrombosis, and the synergistic effect of co-administering policosanol was investigated and found significantly to protect the experimental animals. Both of these studies indicate the involvement of policosanol in prostaglandin and thromboxane pathways.
Octacosanol is a useful supplement in certain circumstances, such as in the area of lipid metabolism and cholesterol lowering. However, many claims, such as in improving athletic performance, have yet to be proved. With continued study in this field it may be that octacosanol will be shown to be a useful supplement in gastric ulceration and motor neurone disease, but it is too early to predict. At least no side effects were found in any of the studies so there is no reason not to continue this work into the usefulness of this nutraceutical.
The authors are from the School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester M13 9PL. Lisa Rapport is also a practising community pharmacist. Correspondence to Dr Lockwood (e-mail Lockwood@fs1.pa.man.ac.uk)
Citation: The Pharmaceutical Journal URI: 20002347
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