Effect of policosanol on cerebral ischemia in Mongolian gerbils: role of prostacyclin and thromboxane A2

Octacosanol and policosanol prevent high-fat diet-induced obesity and metabolic disorders by activating brown adipose tissue and improving liver metabolism

Brown adipose tissue (BAT) is an attractive therapeutic target for treating obesity and metabolic diseases. Octacosanol is the main component of policosanol, a mixture of very long chain aliphatic alcohols obtained from plants. The current study aimed to investigate the effect of octacosanol and policosanol on high-fat diet (HFD)-induced obesity. Mice were fed on chow, or HFD, with or without octacosanol or policosanol treatment for four weeks. HFD-fed mice showed significantly higher body weight and body fat compared with chow-fed mice. However, mice fed on HFD treated with octacosanol or policosanol (HFDo/p) showed lower body weight gain, body fat gain, insulin resistance and hepatic lipid content. Lower body fat gain after octacosanol or policosanol was associated with increased BAT activity, reduced expression of genes involved in lipogenesis and cholesterol uptake in the liver, and amelioration of white adipose tissue (WAT) inflammation. Moreover, octacosanol and policosanol significantly increased the expression of Ffar4, a gene encoding polyunsaturated fatty acid receptor, which activates BAT thermogenesis. Together, these results suggest that octacosanol and policosanol ameliorate diet-induced obesity and metabolic disorders by increasing BAT activity and improving hepatic lipid metabolism. Thus, these lipids represent promising therapeutic targets for the prevention and treatment of obesity and obesity-related metabolic disorders.

Modulation of platelet functions by crude rice (Oryza sativa) bran policosanol extract

Background

Rice bran is bioactive-rich and has proven health benefits for humans. Moreover, its source, the brown rice has antioxidant, hypolipidemic and other functional properties that are increasingly making it a nutritional staple especially in Asian countries. This study investigated the antiplatelet aggregation mechanisms of crude hexane/methanolic rice bran extract, in which policosanol was the targeted bioactive. Platelets play a vital role in pathogenesis of atherosclerosis and cardiovascular diseases, and their increased activities could potentially cause arterial thrombus formation or severe bleeding disorders. Thus, in this study, platelet aggregation and adhesion of platelets to major components of basal lamina were examined in vitro. In addition, cellular protein secretion was quantified as a measurement of platelet activation.

Methods

Adenosine diphosphate (ADP), collagen, and arachidonic acid (AA)-induced aggregation were studied using the microtiter technique. Rat platelets were pre-treated with various concentrations of policosanol extract, and the adhesion of platelets onto collagen- and laminin-coated surface (extracellular matrix) was studied using the acid phosphatase assay. The effect of crude policosanol extract on released proteins from activated platelets was measured using modified Lowry determination method.

Results

Rice bran policosanol extract significantly inhibited in vitro platelet aggregation induced by different agonists in a dose dependent manner. The IC₅₀ of ADP-, collagen-, and AA-induced platelet aggregation were 533.37 ± 112.16, 635.94 ± 78.45 and 693.86 ± 70.57 μg/mL, respectively. The present study showed that crude rice bran policosanol extract significantly inhibited platelet adhesion to collagen in a dose dependent manner. Conversely, at a low concentration of 15.625 μg/mL, the extract significantly inhibited platelet adhesion to laminin stimulated by different platelet agonists. In addition to the alteration of cell adhesive properties, cellular protein secretion of the treated platelets towards different stimulants were decreased upon crude extract treatment.

Conclusion

Our results showed that crude rice bran policosanol extract could inhibit in vitro platelet adhesion, aggregation and secretion upon activation using agonists. These findings serve as a scientific platform to further explore alternative therapies in cardiovascular diseases related to platelet malfunction.

Effects of policosanol on borderline to mildly elevated serum total cholesterol levels: a prospective, double-blind, placebo-controlled, parallel-group, comparative study

BACKGROUND

Hypercholesterolemia is a major risk factor for coronary heart disease. Clinical studies have shown that lowering elevated serum cholesterol levels, particularly low-density lipoprotein cholesterol (LDL-C), is beneficial for patients with borderline to mildly elevated serum total cholesterol (TC) levels (5.0-6.0 mmol/L). Policosanol is a cholesterol-lowering drug made from purified sugar cane wax. The therapeutic range of policosanol is 5 to 20 mg/d.

OBJECTIVE

This study investigated the efficacy and tolerability of policosanol 5 mg/d in patients with borderline to mildly elevated serum TC levels.

METHODS

This 14-week, single-center, prospective, double-blind, placebo-controlled, parallel-group, comparative study was conducted in men and women aged 25 to 75 years with a serum TC level ≥4.8 to <6.0 mmol/L. After a 6-week run-in period in which patients were placed on therapeutic lifestyle changes, in particular a cholesterol-lowering diet, patients were randomly assigned to receive policosanol 5-mg tablets or placebo tablets once daily with the evening meal for 8 weeks, and the diet was continued throughout the study. Lipid profile variables, safety indicators, adverse events (AEs), and compliance with study medications were assessed.

RESULTS

One hundred patients (71 women, 29 men; mean [SD] age, 52 [10] years) entered the study after the dietary run-in period. After 8 weeks of treatment, the mean (SD) serum LDL-C level decreased significantly in the policosanol group (P<0.001 vs baseline and placebo) from 3.57 (0.30) mmol/L to 2.86 (0.41) mmol/L (change, -19.9%). Significantly more patients in the policosanol group (42 patients [84%]) achieved a ≥15% decrease in serum LDL-C than in the placebo group (2 patients [4%]) (P<0.001). Also in the policosanol group, the mean (SD) serum TC level decreased significantly, from 5.20 (0.22) mmol/L to 4.56 (0.44) mmol/L (P<0.001 vs baseline and placebo) (change, -12.3%); the mean (SD) triglyceride (TG) level decreased significantly, from 1.59 (0.57) mmol/L to 1.48 (0.57) mmol/L (P<0.01 vs baseline; P<0.05 vs placebo) (change, -6.9%); and the mean (SD) high-density lipoprotein cholesterol (HDL-C) level increased significantly from 1.05 (0.18) mmol/L to 1.16 (0.21) mmol/L (P<0.001 vs baseline and placebo) (change, +10.5%). The percentage changes were significantly different between the policosanol and placebo groups for serum LDL-C, TC, and HDL-C levels (P<0.001, P<0.001, and P<0.05, respectively), but not for TG. In the placebo group, changes in lipid profile variables from baseline were not significant. Policosanol did not significantly impair any safety indicator and was well tolerated. Three patients (3%) (1 patient [2%] in the policosanol group; 2 patients [4%] in the placebo group) withdrew from the trial, none because of AEs. Two patients (1 patient [2%] each in the policosanol and placebo groups) withdrew from the study because of an unwillingness to return for follow-up; 1 patient (2%) in the placebo group had a change of address and could not be followed up. Overall, 4 patients (4%) (1 patient [2%] in the policosanol group; 3 [6%], placebo) reported AEs; all were mild. Of the patients who received placebo and reported AEs, all 3 (6%) experienced heartburn, and 1 (2%) also experienced dry skin, while the policosanol-treated patient (2%) who reported an AE experienced headache.

CONCLUSIONS

In this study of patients with borderline to mildly elevated serum TC levels, based on the criterion that ≥70% of policosanol-treated patients reached the LDL-C goal of a decrease ≥15% from baseline whenever this proportion was different with respect to placebo, 8 weeks of treatment with policosanol 5 mg/d was effective. The decreased LDL-C, TC, and TG levels, increased HDL-C level, and good tolerability found with this treatment support its use in such patients.

Policosanol, alpha-tocopherol, and moisture content as a function of timing of harvest of Switchgrass (Panicum virgatum L.)

Using switchgrass ( Panicum virgatum L.) as a cellulosic feedstock for the production of ethanol could lead to the extraction of co-products prior to the pretreatment step, thereby adding value to the ethanol conversion process. Policosanols, registered as 142583-61-7, are present in Poaceae and are a mixture of long-chained primary alcohols. Policosanols are composed mainly of docosanol (C(22)), tetracosanol (C(24)), hexacosanol (C(26)), octacosanol (C(28)), triacontanol (C(30)), and dotriacontanol (C(32)). This study determined changes in moisture, policosanol, and alpha-tocopherol concentrations of Cave-in-Rock and Blackwell switchgrass cultivars during maturation from July to December in Arkansas and Oklahoma. Moisture content on a dry weight basis declined from 150 to 50% with progressive harvests. The total policosanol concentration ranged between 89 mg/kg for July harvested Cave-in-Rock switchgrass from Arkansas and 182 mg/kg for August harvested Cave-in-Rock switchgrass for Oklahoma, and these values remained relatively constant throughout the season. This is the first report on the presence of policosanols in switchgrass. Total switchgrass policosanol concentrations were lower than those typically reported for sorghum grains; however, switchgrass-extracted policosanols contained different policosanol ratios, wherein C(30) and C(32) alcohol ranges were 36-41 and 43-50%, respectively. alpha-Tocopherol extracted from both switchgrass cultivars varied between 320 and 400 mg/kg but decreased in the October harvest after frost.

Protective Effect of Policosanol on Endothelium and Intimal Thickness Induced by Forceps in Rabbits

Policosanol is a cholesterol-lowering drug isolated from sugar cane wax with concomitant antiplatelet effects that prevents lipofundin-induced atherosclerotic lesions in rabbits and rats, including foam cell formation, and also reduces foam cell formation in carrageenan-induced granulomas in rats, while it inhibits proliferation of smooth muscle cells induced in rabbit cuffed artery. This study was undertaken to determine whether policosanol prevents endothelium damage and increase in arterial wall thickness in rabbits with arterial walls damaged with a forceps. Artery forceps were placed over the central artery of the right ear of all rabbits, and each artery was injured eight times. Animals were randomly distributed into four groups: a positive control group treated with Tween 20/H2O vehicle, two groups treated with policosanol (5 and 25 mg/kg, respectively), and a group treated with aspirin (8 mg/kg). Treatments were given for 30 days. Damaged arteries were examined by light and electron (transmission and scanning) microscopy. To evaluate intimal thickening, areas of intima were measured, and a significant reduction in policosanol-treated animals was observed. The endothelial surface, studied with scanning electron microscopy, revealed several types of damage. In control group, the endothelial surface was severely damaged. De-endothelialized areas were reduced in policosanol-treated animals. Platelet adhesion to subendothelium was seen in all animals of the control group, whereas policosanol-treated groups exhibited significantly reduced platelet adhesion. Policosanol also reduced, dose-dependently, the platelet sequestration induced in the damaged vessel wall, partially preventing the reduction in platelet count. It is concluded that policosanol prevents endothelium injury and reduces significantly intimal thickness of rabbit arteries damaged with forceps.

Effects of Policosanol on Patients with Ischemic Stroke: A Pilot Open Study

Stroke is a major health problem worldwide. Its pharmacological management includes thrombolytic therapy for the acute phase and antiplatelet drugs for stroke recovery and prevention. Statins can help in the acute phase and in preventing stroke in secondary prevention patients. Policosanol is a cholesterol-lowering drug with concomitant antiplatelet effects, with protective effects in stroke models. This observational study investigated the effects of policosanol (20 mg/day) administered during the acute phase and for 5 years later on the neurological recovery of patients with ischemic stroke treated with antiplatelets and vitamins. After hospital discharge, patients were followed up every 3 (first year) and 6 (thereafter) months. Neurological improvement was assessed with the modified Canadian Neurological Scale. Adverse events were recorded. Fifty patients were included; all completed the study. Neurological score improved throughout the study. No patient died, and most [40 (80.0%)] did not experience new vascular events; only one (2.0%) suffered a new stroke, and two (4.0%) suffered more than one transient ischemic attack. The time to the first recurrent event was 46.2 months. Policosanol persistently lowered serum total cholesterol, with such reduction correlating with the neurological improvement (R = 0.995253301). Triglycerides were unchanged. Treatment was well tolerated. Policosanol administered to patients suffering ischemic stroke treated with aspirin and vitamins showed good results on neurological outcomes and recurrent events. This study, however, has limitations, since it was open and uncontrolled, and patients also consumed aspirin and vitamins. New randomized, controlled studies are needed to assess the usefulness of policosanol in stroke management.

Effects of combination treatment with policosanol and omega-3 fatty acids on platelet aggregation: A randomized, double-blind clinical study

BACKGROUND

Policosanol is a mixture of long-chain primary aliphatic alcoholspurified from sugar cane wax that has cholesterol lowering and antiplatelet effects. Omega-3 fatty acids (FA) have triglyceride lowering and antiplatelet effects. Combination treatment with policosanol and omega-3 FA (Ω23FA) has been associated with significant inhibition of platelet aggregation in rabbits compared with either drug alone.

OBJECTIVE

The aim of this study was to investigate the effects of combination treatment with Ω3FA (1 g/d) and policosanol (Ω3FA+Poli) compared with Ω3FA (1 g/d) plus placebo (Ω3FA+Pla) on platelet aggregation in human patients with hypercholesterolemia.

METHODS

This randomized, double-blind, clinical study at the Surgical Medical Research Center (Havana City, Cuba) recruited outpatients from lipid clinics, with some atherosclerotic risk factors. Outpatients of both sexes aged 20 to 75 years with serum total cholesterol (TC) levels ≥5 and <6 mmol/L were eligible to enroll. They were included in the study at the end of a 4-week diet stabilization period if their platelet aggregation to arachidonic acid (AA) was ≥50% and serum TC level remained ≥5 mmol/L. Patients were then evenly randomized to receive Ω3FA (1 g/d) + placebo or Ω3FA (1 g/d) + policosanol (10 mg/d) to be taken PO with the evening meal for 21 days. Treatment was assigned according to a randomization code using balanced blocks and a 1:1 allocation ratio. Inhibition of platelet aggregation to AA was the primary efficacy variable, while effects on platelet aggregation to collagen and epinephrine and on lipid profile were secondary variables. Drug compliance and adverse events (AEs) were monitored. Tolerability was assessed using physical examinations and laboratory test results.

RESULTS

Sixty-four subjects were initially enrolled. Fifty-four patients (30 women, 24 men; mean [SD] age, 58.4 [12] years, [range, 40-70 years]) met the inclusion criteria and were randomized to treatment; 2 groups of 27. After 21 days, platelet aggregation to AA was significantly inhibited in the 2 groups. Ω3FA+Poli inhibited platelet aggregation to all agonists by ≥20%. Platelet aggregation to AA 1.0 and 1.5 mM was inhibited with combination treatment (39.6% and 33.9%, respectively; both P < 0.001 vs baseline; P < 0.001 and P < 0.01, respectively, vs Ω3FA+Pla) and with Ω3FA+Pla (11.0% and 13.3%; both, P < 0.001). Combination treatment was more effective in inhibiting platelet aggregation to AA 1.0 and 1.5 mM in 28.6% (P < 0.001) and 20.6% (P < 0.01), respectively. Platelet aggregation to collagen 1 μg/mL was significantly inhibited with combination treatment and with Ω3FA+Pla compared with baseline (43.2% and 15.1%, respectively; both, P < 0.001), but the effects of combination treatment were significantly greater (P < 0.01). Platelet aggregation to epinephrine 0.1 mM was inhibited with Ω3FA+Poli and Ω3FA+Pla (34.8% and 20.1%; both, P < 0.001), with similar results for both groups. Bleeding time did not change significantly for either group and Ω3FA+Pla did not significantly change the lipid profile. Combination treatment did significantly reduce levels of low-density lipoprotein cholesterol (LDL-C) (17.4%; P < 0.001 vs baseline, P < 0.05 vs Ω3FA+Pla) and TC (10.1%; P < 0.001 vs baseline, P < 0.05 vs Ω3FA+Pla), increase high-density lipoprotein cholesterol (HDL-C) levels (18.0%; P < 0.001 vs baseline), but did not significantly change triglyceride levels. Three patients (2 from the Ω3FA+Poli group and 1 from the Ω3FA+Pla group) withdrew from the trial, though none were due to AEs. Two patients receiving combination treatment reported mild AEs (headache). All treatments were well tolerated.

CONCLUSIONS

In these patients, policosanol (10 mg/d) administered concomitantly with Ω3FA (1 g/d) enhanced the inhibition of platelet aggregation to AA and collagen, but not to epinephrine, compared with Ω3FA+Pla, without significantly affecting bleeding time. Concomitant treatment was also associated with reduced levels of LDL-C and TC and raised HDL-C levels. All treatments were well tolerated.

Protective Effect of Policosanol on Atherosclerotic Plaque on Aortas in Monkeys

BACKGROUND

Policosanol is a cholesterol-lowering drug isolated from sugar cane wax with concomitant antiplatelet effects. Previous studies have shown that policosanol prevents lipofundin-induced atherosclerotic lesions in rabbits and rats, including foam cell formation, as well as the development of foam cells in carrageenan-induced granulomas in rats. Policosanol also inhibits smooth muscle cells proliferation induced on rabbit cuffed artery and on forceps-induced arterial wall damage. Furthermore, policosanol administered long term lowered serum cholesterol and prevented the development of atherosclerotic lesions in Macaca arctoides monkeys. The present study was undertaken to determine whether policosanol could change some characteristic features of atherosclerotic lesions, such as macrophage number and immunohistochemical localization of apoA-1 and apoB in aortas of M. arctoides monkeys.

METHODS

Fourteen adult male monkeys weighing 6-10 kg and receiving a low fat, protein-rich diet were randomly distributed in three groups: control group (six monkeys) and two other groups (four monkeys/group) treated with policosanol (2.5 and 25 mg/kg) for 54 weeks. Samples of arteries were examined by light microscopy. Monoclonal antibodies were used to evaluate the presence of macrophage, apoA-1 and apoB.

RESULTS

Policosanol reduced the presence of macrophages and the occurrence of apoB, whereas increased apoA-1 localization in aortic atherosclerotic lesions compared with control monkeys.

CONCLUSIONS

These results suggest the policosanol potential benefit on plaque composition and stability and could explain the protective effects of policosanol on atherosclerosis development.

Policosanol has no antioxidant activity in human low-density lipoprotein but increases excretion of bile acids in hamsters

Policosanol is a group of long chain primary alcohols and has been shown to reduce blood cholesterol levels and to inhibit the oxidation of low-density lipoprotein (LDL). The present study examined (i) the effect of policosanol supplementation in the diet on the fecal excretion of neutral and acidic sterols in hamsters and (ii) the antioxidant activity of policosanol in human LDL. Golden Syrian hamsters were divided into four groups (n = 12/each) fed one of the four diets containing 0 (control), 0.38, 0.75, and 1.50 g kg(-1) policosanol for 6 weeks. It was found that hamsters given 0.38-1.5 g kg(-1) diets had a serum total cholesterol level lowered by 15-25% and had a high-density lipoprotein cholesterol elevated by 7-16.8%. It was found that policosanol increased the excretion of acidic sterols by 25-73%. Contrary to that in previous reports, policosanol had no apparent anti-LDL oxidation activity when 1-tetracosanol, 1-hexacosanol, and 1-octacosanol were incubated in human LDL. Policosanol also possessed no scavenging activity on the free radical2,2-diphenyl-1-picrylhydrazyl. These data provide evidence that in addition to the effect of HMG-CoA reductase, the cholesterol-lowering activity of policosanol is partially mediated by its inhibition on the absorption of bile acids, but these data disprove the claim that policosanol is an antioxidant.

Effects of Concurrent Therapy with Policosanol and Omega-3 Fatty Acids on Lipid Profile and Platelet Aggregation in Rabbits

BACKGROUND

Policosanol is a mixture of high-molecular-weight aliphatic primary alcohols isolated from sugarcane wax with cholesterol-lowering and antiplatelet effects. Omega-3 fatty acids (FA) from fish oil can protect against coronary disease. An antiarrhythmic mechanism is emerging as the most convincing explanation for omega-3 FA cardiovascular protection, but triglyceride (TG)-lowering effects and inhibition of platelet function could play a role. In view of the effects of policosanol and omega-3 FA on lipid profile and platelet function, potential benefits of combined therapy were expected.

OBJECTIVE

To investigate whether combined therapy with policosanol and omega-3 FA would offer some benefit, compared with policosanol or omega-3 FA alone, on serum lipid profile and platelet aggregation in rabbits.

METHODS

Male rabbits were randomly distributed in four groups (n = 9 per group). A control group received vehicle, one group was treated with policosanol 5 mg/kg and one with omega-3 FA (eicosapentaenoic acid; EPA [47.0%], docosahexaenoic acid; DHEA [41%]) 250 mg/kg, and the fourth received policosanol 5 mg/kg + omega-3 FA 250 mg/kg. Treatments were orally administered for 60 days. Bodyweight, food consumption and animal behaviour were performed at baseline and study completion.

RESULTS

Policosanol significantly lowered low-density lipoprotein cholesterol (LDL-C) [42.7%; p < 0.01] and total cholesterol (TC) [29.4%; p < 0.05], increased high-density lipoprotein (HDL-C) [15.4%; p < 0.05], but left TG levels unchanged. Omega-3 FA significantly lowered TG (47.1%; p < 0.05), but left TC, LDL-C and HDL-C unchanged. Combined therapy decreased LDL-C (38.7%; p < 0.05). Changes in TC, LDL-C and HDL-C obtained with combined therapy were greater (p < 0.05) than those with omega-3 FA, but similar to those with policosanol, whereas the opposite applied to TG reduction. No significant changes in lipid profile were observed in the control group. Policosanol and omega-3 FA significantly (p < 0.05) but moderately inhibited platelet aggregation induced with arachidonic acid (13.3% and 12.4%, respectively); combined therapy achieved greater inhibition (23.9%; p < 0.05). All groups showed similar food consumption and bodyweight gain. No toxic signs were observed in any animal.

CONCLUSIONS

Concurrent therapy with policosanol 5 m/kg and omega-3 FA 250 mg/kg lowered LDL-C, TC and TG and increased HDL-C. All treatments inhibited platelet aggregation, but better effects were observed with policosanol + omega-3 FA compared with either treatment alone. Combined therapy was well tolerated. These results suggest that treatment with policosanol + omega-3 FA could be useful for regulating lipid profile and inhibiting platelet aggregation, but conclusive demonstration of such effects requires further experimental and clinical studies.

A pharmacological surveillance study of the tolerability of policosanol in the elderly population

BACKGROUND

Policosanol is a drug derived from sugar cane wax that has cholesterol-lowering and antiplatelet properties. Randomized, controlled studies are the gold standard for demonstrating drug efficacy, safety, and tolerability, but postmarketing surveillance studies are encouraged for corroborating drug effects. A valid proof of the safety of a drug is a well-documented, good tolerability profile in older individuals, since this population is more prone to drug-related adverse events (AEs).

OBJECTIVE

This study investigated the tolerability of policosanol in the elderly population by monitoring the incidence and nature of AEs occurring in older Cuban patients treated with policosanol in routine clinical practice.

METHODS

All patients aged > or =60 years treated with policosanol at 7 major medical centers from January 2000 to May 2003 were included. Policosanol (5, 10, or 20 mg/d) was prescribed to patients eligible to receive cholesterol-lowering and/or antiplatelet drugs, with the dosage recommended according to their individual atherosclerotic risk. Patients had follow-up visits approximately every 6 months. Data on AEs and other relevant information, including changes in policosanol treatment, concomitant medications, and discontinuations, were recorded on individual case-report forms.

RESULTS

This study included 2252 patients (1306 women, 946 men): 647 (28.7%), 244 (10.8%), and 173 (7.7%) patients had coronary, cerebrovascular, and peripheral artery disease, respectively. A total of 1485 patients had hypercholesterolemia (65.9%), 1322 (58.7%) had hypertension, and 323 (14.3%) had diabetes mellitus. Of the enrolled patients, 1123 (49.9%), 644 (28.6%), and 485 (21.5%) received policosanol 5, 10, and 20 mg/d, respectively. Treatment duration varied: 2169 (96.3%), 1861 (82.6%), 1116 (49.6%), and 412 (18.3%) patients were treated for 6, 12, 24, and 36 months, respectively. Thirty-one patients (1.4%) experienced serious AEs, 18 of them fatal. Death was most often due to vascular events: myocardial infarction (4 patients), sudden cardiac arrest (1), ventricular arrhythmia (2), ischemic stroke (1), lung thromboembolism (1), cancer (5), pneumonia (1), peritonitis (1), lung edema (1), and dehydration (1). Another 13 patients (0.6%) were hospitalized, and 61 (2.7%) reported moderate or mild AEs. Overall, 21 patients (0.9%) discontinued prematurely from the study, 18 of them due to a fatal serious AE.

CONCLUSIONS

Long-term tolerability of policosanol in elderly patients at high vascular risk was very good, as assessed under conditions of routine clinical practice. These results are consistent with those obtained in randomized, double-blind clinical studies of older patients treated with policosanol.

D-003 and warfarin interaction on the bleeding time and venous thrombosis experimentally induced in rats

D-003 is a mixture of higher aliphatic primary acids isolated and purified from sugarcane wax, the main component of which is octacosanoic acid. D-003 exhibits a cholesterol-lowering effect as well as antiplatelet and antithrombotic effects in experimental models. Warfarin is a coumarin derivative with anticoagulant activity that acts as a vitamin K antagonist. Since in clinical practice warfarin and D-003 could be administered together, the objective of this study was to evaluate the effects of the simultaneous administration of both drugs on the bleeding time and the venous thrombosis experimentally induced in rats. The combined therapy of minimally effective doses of D-003 and warfarin produced an antithrombotic effect significantly higher than those produced by each monotherapy. Likewise, the prolongation of bleeding time induced by warfarin was increased by the simultaneous administration with D-003, showing a synergistic effect between both drugs.

Complementary and alternative medicine in cardiovascular disease: a review of biologically based approaches

BACKGROUND

The use of complementary and alternative medical (CAM) practices in the United States is growing rapidly. In this manuscript, we review some of the most commonly used biologically based approaches, including herbs, supplements, and other pharmacological therapies, that are encountered in caring for patients with cardiovascular disease, focusing on potential effects, adverse effects, and treatment interactions.

METHODS

Between November 2002 and April 2003, we searched Medline and the National Center for Complementary and Alternative Medicine (NCCAM) web site and its various references and several complementary medicine text books. The key words used were: "cardiovascular diseases," "coronary disease," "heart failure, congestive," "complementary and alternative medicine," "complementary therapies," "drug interactions," and "plants, medicinal." A keyword search of each individual supplement identified was also performed. Additionally, we relied on expert opinion in the field.

RESULTS

Potentially serious adverse effects and interactions with conventional cardiovascular therapies exist for many herbs and supplements. There are currently scarce mechanistic data and very limited data on the effect of CAM therapies on clinical outcomes.

CONCLUSIONS

Randomized clinical trials with adequate power to detect effects of CAM therapies on clinical outcomes and safety are needed. Until these data are available, clinicians must be aware of the increasing use of CAM approaches by their patients and the potential for interactions with conventional therapies and should focus on treatment with proven, evidence-based strategies.

Effect of D-003 on isoproterenol-induced myocardial necrosis in rats

D-003 is a mixture of high-molecular-weight aliphatic primary acids purified from sugar cane wax with antiplatelet and cholesterol-lowering effects. Cardiac lesions induced by isoproterenol (ISO) are characterized by myocardial necrosis and exudative infiltration. The objective of this study was to determine whether D-003 shows protective effects against ISO-induced myocardial necrosis in rats. Effects of orally administered single doses of D-003 (25-400 mg/kg) and acetylsalicylic acid (ASA, 30 mg/kg), as well as repeated doses of D-003 (5-200 mg/kg), on characteristic markers of ISO-induced myocardial necrosis in rats were investigated. D-003 administered as single doses dose-dependently decreased necrosis area, percent of infarct area, and the presence of polymorphonuclear cells (PMNs) in myocardial tissue, but only the reductions induced by 200 and 400 mg/kg were significant. Oral acute treatment with ASA also decreased necrosis area and percent of infarct area, but the occurrence of PMNs was unchanged. D-003 administered repeatedly for 10 days also decreased all myocardial necrosis indicators in a dose-dependent manner, with results effective from 25 mg/kg to the highest dose tested, indicating that the repeated dose scheme was more effective to prevent the damage. It is concluded that D-003 shows a protective effect on the myocardial necrosis induced by ISO in rats.

Effect of policosanol on carbon tetrachloride-induced acute liver damage in Sprague-Dawley rats

BACKGROUND

Policosanol is a cholesterol-lowering drug purified from sugarcane (Saccharum officinarum, L.) wax. Beneficial pleiotropic effects of policosanol, such as inhibition of the susceptibility of low density lipoprotein to lipid peroxidation, have been shown. Policosanol has a good safety profile and well tolerated and, to date, no drug-related adverse effects have been demonstrated. Specifically, policosanol has not been shown to affect liver function or to increase liver enzyme levels in experimental or clinical studies.

AIM

This study was conducted to determine whether policosanol prevents liver damage induced by carbon tetrachloride (CCl4) in rats, since this model has been associated with an increased rate of lipid peroxidation.

METHODS

Male Sprague-Dawley rats were randomised to four experimental groups: negative controls (no CCl4 or policosanol, group 1); positive controls (CCl4 but no policosanol, group 2); policosanol 25 mg/kg (group 3) and policosanol 100 mg/kg (group 4). Acute liver injury was induced in groups 2, 3 and 4 by CCl4 suspended in olive oil and administered at a dose of 1590 mg/kg via intraperitoneal injection. Eighteen hours after CCl4 dosing, the rats were anaesthetised and their livers removed for histopathological studies.

RESULTS

Policosanol 25 and 100 mg/kg dose dependently and significantly (p < 0.01) decreased the percentage of ballooned cells and hepatocytes with lipid inclusions and increased the percentage of normal hepatocytes compared with positive controls. The percentage inhibition of the occurrence of ballooned cells and hepatocytes with lipids was marked, reaching 71 and 49%, respectively, with the higher dose (100 mg/kg). The percentage of swollen hepatocytes was unchanged by policosanol compared with positive controls. No histological alterations in liver sections were found in the negative control group. Necrotic areas and inflammatory infiltrates were observed in the liver of seven of eight (87.5%) animals in the positive control group. However, only one of eight (12.5%) animals treated with policosanol 25 mg/kg and none (0%) treated with the higher dose (100 mg/kg) showed such a pattern.

CONCLUSIONS

Policosanol protected against the histological changes characteristic of CCl(4)-induced hepatic injury in rats, a model of hepatotoxicity in which the process of lipid peroxidation plays a role. Further studies aimed at demonstrating the connection between such hepatoprotective and antioxidant effects of policosanol must be initiated.

Synergistic effect of D-003 and aspirin on experimental thrombosis models

D-003 is a mixture of higher primary aliphatic saturated acids purified from sugarcane wax, with antiplatelet and antithrombotic effects experimentally demonstrated. Octacosanoic acid is the main component of D-003, followed by triacontanoic, dotriacontanoic, and tetracontanoic acids, while other acids are minor components. This work investigates the effects of combination therapy D-003+aspirin (ASA) on arachidonic acid (AA)-induced sudden death in mice and bleeding time in rats. In addition, the effects of D-003 on serum levels of two metabolites of AA: thromboxane A(2) and prostacyclin, assessed through the measurement of their stable metabolites: thromboxane B(2) (TxB(2)) and 6 keto PgF1alpha by radioimmunoassay kits, were also investigated. Combination therapy of D-003 (50mg/kg) and ASA (3mg/kg) significantly increased bleeding time in rats in a synergistic manner compared with D-003 or ASA alone. Moreover, the combined treatment of D-003 (200mg/kg) and ASA (5mg/kg) in mice protected against AA-induced sudden death (83% survivors) in a synergistic manner which was compared with each treatment alone (33% survivors). These results indicate that antiplatelet effects of D-003 are not mediated by a cyclooxygenase inhibition. D-003 and ASA monotherapies reduced serum TxB(2) levels, whereas D-003, but not ASA, significantly increased 6 keto PgF1alpha levels.

In Vivo Genotoxic Evaluation of D-003, a Mixture of Very Long Chain Aliphatic Acids

D-003 is a mixture of very long chain aliphatic acids purified from sugar cane wax with cholesterol-lowering effects. The present study was undertaken to investigate the in vivo cytotoxic and genotoxic potential of D-003 using three established assays: bone marrow micronucleus, sperm morphology, and single cell gel electrophoresis (Comet) assay. In a first experimental series, CEN/NMRI mice (6-8 animals per sex per group) were administered D-003 by gastric gavage at 5, 50, or 500 mg/kg for 90 days, then sacrificed 24 hours after the last administration. The effects on bone marrow micronucleus were evaluated only in female mice. D-003 (5-500 mg/kg) did not increase the frequency of micronucleated polychromatic erythrocytes, nor the ratio of polychromatic to normochromatic erythrocytes, compared with the controls. The assessment of the effects on sperm morphology showed that D-003 did not change the sperm count or the frequency of all types of abnormal head shapes, compared with the controls. In a second series, the micronucleus assay was performed in mice of both sexes given 2,000 mg/kg for 6 days. Likewise, in this series, neither cytotoxic nor genotoxic effects were found. Finally, five male Sprague-Dawley rats were treated with D-003 (1,250 mg/kg) by oral gavage for 90 days, and Comet assay on liver cells was performed. No single-strand breaks or alkali-labile site induction on DNA was observed. These results indicate that D-003 does not show evidence of cytotoxic or genotoxic activity on either somatic or germ cells in rodents.

Pharmacological Interaction Between Policosanol and Nitroprusside in Rats

Policosanol is a natural mixture of higher aliphatic primary alcohols isolated from sugar cane wax (Saccharum officinarum L.). It has cholesterol-lowering effects demonstrated in experimental models and in patients with type II hypercholesterolemia, with positive pleiotropic properties such as inhibition of platelet aggregation and lipid peroxidation. Policosanol reduced thromboxane A(2) and malondialdehyde (MDA) serum levels in animals and human beings. Because nitric oxide (NO) can be destroyed by oxygen-derived radicals and policosanol possesses an antioxidant effect, the purpose of this study was to determine the putative interaction between policosanol and nitroprusside (an NO-containing substance) on platelet aggregation and arterial blood pressure in rats. The percentage of inhibition of adenosine diphosphate-induced aggregation (preincubation with nitroprusside) was higher in platelet-rich plasma of policosanol-treated animals than in control animals. Pretreatment with single doses of policosanol significantly increased the nitroprusside-induced hypotensive effect.

Effects of policosanol on older patients with hypertension and type II hypercholesterolaemia

OBJECTIVE

This study was conducted to investigate the effects of policosanol administered for 12 months on the lipid profile of older patients with hypertension and type II hypercholesterolaemia and no history of coronary heart disease (CHD) or cerebrovascular disease.

PATIENTS AND PARTICIPANTS

589 older male and female patients with hypertension and type II hypercholesterolaemia and no history of CHD or cerebrovascular disease were included.

METHODS

This was a prospective, randomised, double-blind, placebo-controlled study in parallel groups treated with policosanol (5 to 10 mg/day) for 1 year. After 6 weeks on a standard step I cholesterol-lowering diet, 589 patients were randomised to policosanol (5 mg) or placebo tablets, to be taken once daily for 12 months. The dosage was doubled to 10 mg/day if total cholesterol values were > 6.1 mmol/L after 6 months of therapy.

RESULTS

Policosanol significantly (p < 0.00001) lowered serum low-density lipoprotein-cholesterol (LDL-C) [20.5%], total cholesterol (TC) [15.4%], triglycerides (11.9%), LDL-C/high-density lipoprotein-cholesterol (HDL-C) ratio [22.2%] and TC/HDL-C ratio (20.1%), and increased (p < 0.0001) HDL-C (12.7%). The frequency of vascular and all-cause serious adverse events (SAEs) was lower (p < 0.05) in the policosanol recipients (two vascular SAEs, 0.7%; five all-cause SAEs, 1.7%) than in the placebo recipients (six vascular SAEs, 2.0%; 12 all-cause SAEs, 4.1%). Similarly, total adverse events (AEs) were less frequent in the policosanol-treated group (29; 9.8%) compared with the placebo group (52; 17.7%) [p < 0.01]. Three placebo recipients and no policosanol recipents died during the study as a result of myocardial infarction (two patients) and sudden cardiac arrest (one). Policosanol was well tolerated, and no drug-related disturbances in safety indicators were found. Policosanol significantly decreased systolic blood pressure (BP) compared with baseline and placebo, which could be an additional advantage in this population at high coronary risk.

CONCLUSIONS

Policosanol administered long term is effective in lowering LDL-C and TC as well as increasing HDL-C levels in older patients with hypertension and type II hypercholesterolaemia without a history of CHD or cerebrovascular disease. In addition, policosanol treatment also shows benefits in the occurrence of SAEs of vascular aetiology, on the general AE profile and the reduction of BP in treated patients compared with baseline.

Antiplatelet effects of policosanol (20 and 40 mg/day) in healthy volunteers and dyslipidaemic patients

1. The present study was undertaken to compare the effects of a higher dose of policosanol, a cholesterol-lowering drug, (40 mg/day) with the effects of 20 mg/day policosanol on platelet aggregation in healthy volunteers and type II hypercholesterolaemic patients. 2. Study subjects were randomized to receive, under double-blind conditions, placebo or policosanol (20 or 40 mg/day) for 30 days once a day. Blood sampling was performed at baseline and after 30 days on therapy. 3. Platelet aggregation was induced with three aggregating agents: arachidonic acid (AA), collagen and low doses of ADP. 4. Policosanol (20 and 40 mg/day) moderately yet significantly reduced platelet aggregation, but no differences were observed in the effects produced by either dose of policosanol. In healthy volunteers, policosanol at 20 and 40 mg/day inhibited aggregation induced by 2 mmol/L AA (28.2 and 24.9%, respectively), 1 micro g/mL collagen (21.1 and 20.2%) and 1 micro mol/L ADP (30.9 and 29.1%). Changes that occurred following the administration of placebo were not significant, although an upward trend for collagen- and ADP-induced aggregation occurred in normal and hypercholesterolaemic subjects, respectively, thus partially masking the effects of policosanol on these responses. 5. The antiplatelet effects of policosanol at 20 and 40 mg/day in hypercholesterolaemic patients were also similar, so that both doses inhibited aggregation induced by 1.5 mmol/L AA (20.1 and 33.0%, respectively), 0.5 micro g/mL collagen (22.7 and 21.1%) and 1 micro mol/L ADP (40.5 and 34.7%). 6. In addition, after 30 days of therapy, 20 and 40 mg/day policosanol significantly (P < 0.01) reduced low-density lipoprotein-cholesterol (15.9 and 17.0%, respectively) and total cholesterol (12.4 and 12.3%, respectively; P < 0.05), yet increased high-density lipoprotein-cholesterol values by 5% in both groups (P < 0.05). 7. Triglycerides were decreased compared with baseline, but not with respect to the placebo. 8. We conclude that the antiplatelet effects induced by 40 mg/day policosanol administered for 30 days to healthy volunteers and to hypercholesterolaemic patients were similar to the effects induced by 20 mg/day policosanol. Thus, no enhancement of the response was achieved with the use of a higher dose of policosanol in study patients.

Policosanol safely down-regulates HMG-CoA reductase - potential as a component of the Esselstyn regimen

Many of the wide-ranging health benefits conferred by statin therapy are mediated, not by reductions in LDL cholesterol, but rather by inhibition of isoprenylation reactions essential to the activation of Rho family GTPases; this may be the mechanism primarily responsible for the favorable impact of statins on risk for ischemic stroke, senile dementia, and fractures, as well as the anti-hypertensive and platelet-stabilizing actions of these drugs. Indeed, the extent of these benefits is such as to suggest that most adults would be wise to take statins; however, owing to the significant expense of statin therapy, as well as to the potential for dangerous side effects that mandates regular physician follow-up, this strategy appears impractical. However, policosanol, a mixture of long-chain aliphatic alcohols extractable from sugar cane wax, has shown cholesterol-lowering potency comparable to that of statins, and yet appears to be devoid of toxic risk. Recent evidence indicates that policosanol down-regulates cellular expression of HMG-CoA reductase, and thus has the potential to suppress isoprenylation reactions much like statins do. Consistent with this possibility, the results of certain clinical and animal studies demonstrate that policosanol has many effects analogous to those of statins that are not likely explained by reductions of LDL cholesterol. However, unlike statins, policosanol does not directly inhibit HMG-CoA reductase, and even in high concentrations it fails to down-regulate this enzyme by more than 50% - thus likely accounting for the safety of this nutraceutical. In light of the fact that policosanol is quite inexpensive and is becoming available as a non-prescription dietary supplement, it may represent a practical resource that could enable the general public to enjoy health benefits comparable to those conferred by statins. In a long-term clinical study enrolling patients with significant symptomatic coronary disease, Esselstyn has demonstrated that a low-fat, whole-food vegan diet, coupled with sufficient statin therapy to maintain serum cholesterol below 150 mg/dL, can stop the progression of coronary disease and virtually eliminate further risk for heart attack. A comparable regimen, in which policosanol is used in place of statins, may represent a practical strategy whereby nearly everyone willing to commit to health-protective eating can either prevent coronary disease, or prevent pre-existing coronary disease from progressing to a life-threatening event.

Policosanol: clinical pharmacology and therapeutic significance of a new lipid-lowering agent

BACKGROUND

Policosanol is a mixture of higher primary aliphatic alcohols isolated from sugar cane wax, whose main component is octacosanol. The mixture has been shown to lower cholesterol in animal models, healthy volunteers, and patients with type II hypercholesterolemia.

METHODS

We reviewed the literature on placebo-controlled lipid-lowering studies using policosanol published in peer-reviewed journals as well as studies investigating its mechanism of action and its clinical pharmacology.

RESULTS

At doses of 10 to 20 mg per day, policosanol lowers total cholesterol by 17% to 21% and low-density lipoprotein (LDL) cholesterol by 21% to 29% and raises high-density lipoprotein cholesterol by 8% to 15%. Because higher doses have not been tested up to now, it cannot be excluded that effectiveness may be even greater. Daily doses of 10 mg of policosanol have been shown to be equally effective in lowering total or LDL cholesterol as the same dose of simvastatin or pravastatin. Triglyceride levels are not influenced by policosanol. At dosages of up to 20 mg per day, policosanol is safe and well tolerated, as studies of >3 years of therapy indicate. There is evidence from in vitro studies that policosanol may inhibit hepatic cholesterol synthesis at a step before mevalonate generation, but direct inhibition of the hydroxy-methylglutaryl-coenzyme A reductase is unlikely. Animal studies suggest that LDL catabolism may be enhanced, possibly through receptor-mediated mechanisms, but the precise mechanism of action is not understood yet. Policosanol has additional beneficial properties such as effects on smooth muscle cell proliferation, platelet aggregation, and LDL peroxidation. Data on efficacy determined by clinical end points such as rates of cardiac events or cardiac mortality are lacking.

CONCLUSIONS

Policosanol seems to be a very promising phytochemical alternative to classic lipid-lowering agents such as the statins and deserves further evaluation.

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, which acts by inhibiting cholesterol biosynthesis. Previous studies have demonstrated that policosanol inhibited smooth muscle cell (SMC) proliferation in the cuffed carotid artery of the rabbit and in arterial wall damage induced by forceps in the central artery of the ear of rabbits. The present study was undertaken to compare the effects of policosanol and lovastatin on SMC proliferation in the cuffed carotid artery of rabbits. Collars were placed around the left carotid for 7 and 15 days. The contralateral artery was sham operated. We studied eight experimental groups: two controls groups receiving 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)for 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 microscopy. To evaluate intimal thickening the cross-sectional areas of intima and media were measured. Neointima was significantly reduced in treated animals compared with controls, but the reduction in lovastatin animals was significantly lower than in policosanol-treated groups. The SMC proliferation was studied by the immunohistochemical detection of proliferating cell nuclear antigen and the reduction observed in policosanol-treated rabbits was significantly larger than in lovastatin-treated animals. It is concluded that the protective effect of policosanol against neointima formation in this experimental model was slightly better than that of lovastatin.

Acute and oral subchronic toxicity of D-003 in rats

D-003 is a mixture of higher aliphatic primary acids purified from sugar cane wax (Saccharum officinarum) with cholesterol-lowering and antiplatelet effects experimentally proven. The present work reports the results of two studies investigating the acute and subchronic oral toxicity of D-003 in rats. Oral acute toxicity of D-003 (2000 mg/kg) was investigated according to the Acute Toxic Class (ATC) method (an alternative for the classical LD(50) test), which was performed in Wistar rats. The results obtained in this study defined D-003 oral acute toxicity as unclassified. In the subchronic study, rats of both sexes were orally treated with D-003 at 50, 200 and 1250 mg/kg for 90 days. At this time, animals were sacrificed. No evidence of treatment-related toxicity was detected during the study. Thus, data analysis of body weight gain, food consumption, clinical observations, blood biochemical, haematology, organ weight ratios and histopathological findings did not show significant differences between control and treated groups. It is concluded that D-003 orally administered to rats was safe and that no drug-related toxicity was detected even at the highest doses investigated in both acute (2000 mg/kg) and subchronic (1250 mg/kg) studies.

Antiplatelet and antithrombotic effect of D-003

D-003 is a mixture of higher primary aliphatic saturated acids purified from sugar cane wax whose main component is octacosanoic acid followed by triacontanoic, dotriacontanoic, and tetratriacontanoic acids. The aim of this study was to evaluate the effects of D-003 on: ex vivo platelet aggregation, arterial thrombosis and bleeding time in rats. In addition, time course of antiplatelet effects of D-003 was also investigated on ex vivo platelet aggregation in guinea-pigs. D-003 (25-200 mg kg(-1)) orally administered at single or repeated doses (3 days) inhibited platelet aggregation induced by collagen (2.2 microg ml(-1)) and ADP (2 micromol l(-1)) in rats, and collagen (0.25 microg ml(-1)) induced aggregation in guinea-pigs in a dose-dependent manner. Single doses of D-003 (5-500 mg kg(-1)) administered orally 2 h before induction of arterial thrombosis significantly inhibited the reduction of rectal temperature. D-003 administered at a single dose (50-200 mg kg(-1)) 2 h before the experiment significantly increased the bleeding time in a dose-dependent manner. The time-course effects of D-003 on platelet aggregation, arterial thrombus formation, and bleeding time showed no effect 0.5 h after dosing, and maximal effects exhibited 1-2 h after treatment, whereas no significant effects were found 4 h after treatment.

Effect of policosanol on cerebral ischemia in Mongolian gerbils

Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane wax, whose main component is octacosanol. An inhibitory effect of policosanol on platelet aggregation and cerebral ischemia in animal models has been reported. Thus, the objective of the present study was to evaluate the effect of policosanol on cerebral ischemia induced by unilateral carotid ligation and bilateral clamping and recirculation in Mongolian gerbils. Policosanol (200 mg/kg) administered immediately after unilateral carotid ligation and at 12- or 24-h intervals for 48 h significantly inhibited mortality and clinical symptoms when compared with controls, whereas lower doses (100 mg/kg) were not effective. Control animals showed swelling (tissue vacuolization) and necrosis of neurons in all areas of the brain studied (frontal cortex, hippocampus, striatum and olfactory tubercle), showing a similar injury profile. In the group treated with 200 mg/kg policosanol swelling and necrosis were significantly reduced when compared with the control group. In another experimental model, comparison between groups showed that the brain water content of control gerbils (N = 15) was significantly higher after 15 min of clamping and 4 h of recirculation than in sham-operated animals (N = 13), whereas policosanol (200 mg/kg) (N = 19) significantly reduced the edema compared with the control group, with a cerebral water content identical to that of the sham-operated animals. cAMP levels in the brain of control-ligated Mongolian gerbils (N = 8) were significantly lower than those of sham-operated animals (N = 10). The policosanol-treated group (N = 10) showed significantly higher cAMP levels (2.68 pmol/g of tissue) than the positive control (1.91 pmol/g of tissue) and similar to those of non-ligated gerbils (2.97 pmol/g of tissue). In conclusion, our results show an anti-ischemic effect of policosanol administered after induction of cerebral ischemia, in two different experimental models in Mongolian gerbils, suggesting a possible therapeutic effect in cerebral vascular disorders.

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 higher aliphatic primary alcohols isolated from sugar cane wax, with cholesterol lowering effects proved in experimental models and patients with type II hypercholesterolemia. It acts by inhibiting cholesterol biosynthesis. The positioning of a nonocclusive silicone collar around the rabbit carotid artery results in the formation of a neointima. We wished to determine whether policosanol orally administered prevented intimal thickening. Collars were placed around the left carotid for 15 days. The contralateral artery was sham operated. We included three experimental groups: a control received vehicle and two others policosanol at 5 and 25 mg Kg until sacrificed. Samples of arteries were examined by light and electron microscopy. To evaluate intimal 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 immunohistochemical detection of proliferating cell nuclear antigen and a significant reduction was observed in policosanol treated rabbits. It is concluded that policosanol has a protective effect on the neointima formation in this experimental model.

Effect of policosanol on platelet aggregation and serum levels of arachidonic acid metabolites in healthy volunteers

Policosanol is a cholesterol-lowering drug with hypocholesterolemic effects demonstrated in experimental models, healthy volunteers and patients with type II hypercholesterolemia. In addition, antiplatelet effects of policosanol have been shown in experimental models and healthy volunteers. This study reports the results of a 2-week, randomized, double-blind, placebo-controlled trial investigating the effects of policosanol on platelet aggregation and thromboxane B2 and prostacyclin (6 keto PGF1alpha) production after stimulation with collagen in healthy volunteers. The volunteers were on a placebo-baseline period for 7 days and thereafter they received randomly, under double-blind conditions, placebo or policosanol (10 mg/day) for 15 days. Platelet aggregation was determined at baseline and after 15 days of treatment. Significant reductions of arachidonic acid and collagen-induced platelet aggregation were observed. Thromboxane, but not prostacyclin, generation induced by collagen was also inhibited by policosanol.

Effect of policosanol on circulating endothelial cells in experimental models in Sprague-Dawley rats and in rabbits

The effect of policosanol on circulating endothelial cells has been studied in different experimental models with endothelium damage. Oral administration of 25 mg kg-1 policosanol to Sprague-Dawley rats resulted in significant protection of the endothelial lining against the desquamating effect of citrate. Oral administration of 5 mg kg-1 policosanol to spontaneously hypertensive rats (SHR) resulted in a significant reduction of circulating endothelial cells compared with controls. Moreover, comparison between groups revealed a lower frequency of aortic lesions in policosanol-treated animals than in controls. On the other hand, administration of 5 mg kg-1 policosanol to rabbits with intimal hyperplasia induced by cuff placement in the carotid artery resulted in levels of circulating endothelial cells significantly lower than in controls. These results demonstrate the protective effect of policosanol in different experimental models and suggest its potential for endothelial protection.

Carcinogenicity of policosanol in mice: an 18-month study

Policosanol (trade name Ateromixol) is a new cholesterol-lowering drug that has been isolated and purified from sugar cane wax. The effects of policosanol (50-500 mg/kg) administered orally for 18 months to male and female Swiss mice were investigated. No differences in daily clinical observations, weight gain, food consumption and mortality (survival analysis) between groups were found. Histopathological study showed that the frequency of neoplastic (benign and malignant) lesions was similar in the control and policosanol-treated groups. The lesions observed were similar to the spontaneous lesions in Swiss mice reported in previous studies. As no drug-related increase in the occurrence of malignant or benign neoplasm was found, nor acceleration in tumour growth in any specific group observed, this study shows no evidence of policosanol-induced carcinogenicity in Swiss mice.

Effect of policosanol on experimental thrombosis models

Policosanol is a natural product, obtained from sugar cane wax (Saccharum officinarum L.) with which cholesterol-lowering effects have been demonstrated in experimental models, healthy volunteers and hypercholesterolemic patients. The effects of policosanol on experimental venous and arterial thrombosis in rats were investigated. Policosanol (25 mg/kg) significantly decreased the thrombus weight, in the venous thrombosis models, the protective effect persisting until 4 h after its oral administration. Policosanol (25 mg/kg single dose) was able to reduce rectal temperature variation induced by arterial thrombosis. Also at the same dose policosanol increased 6-keto-PGF1 alpha serum levels in rats.