Effect of policosanol on experimental thrombosis models

Assessment of the effect of bioactive nutrients and probiotic microorganisms on the parameters of lipid metabolism in the body

The aim of the work is a comparative study of the effect of vegetable nutrients - wheat germ oil (WGO), flour from wheat germ cake (WGC), and animal - concentrated tissue fish oil, origin on lipid metabolism indicators of students and university teachers, as well as an assessment of the probiotic factor in increasing the effectiveness of the target biologically active substances. The data obtained confirm the relation between the nutritional sufficiency of the body and the increase in lipid metabolism effectiveness and atherosclerosis risk reduction in students and teachers of an engineering university with the daily use of bioactive nutrients: WGO, WGCF, CTFO and their combinations with the biomass of lactobacilli and bifidobacteria consortium. The lipid metabolism was evaluated based on the analysis of indicators of the total cholesterol (TC) concentrations, high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides (TG), atherogenic index (AI). The values of these indicators were recorded before and after daily consuming the study foods for 30 days. The data obtained were analyzed for 3 age groups: 16 – 24, 25 – 44, and 45 – 65. It was found that WGO has the most effective antiatherosclerotic effect; the decrease in the TC level was 6.4%, the increase in the HDL concentration was 13.7%, the decrease in the LDL concentration was 11.3%, the decrease in the TG concentration was 17.1%, and the AI decreased by 22.6%, respectively. With WGCF, the changes in the studied parameters were 6.0, 12.3, 13.1, 13.1, and 22.1%, respectively. Together with probiotics WGO effectiveness increased in terms of the reduced TC level (1.9%), increased HDL concentration (8.2%), decreased LDL concentration (2.5%), reduced TG concentration (5.7%), and decreased AI (6.3%) for CTFO by 9.1, 26.1, 14.7, 24.1 and 31.2%, respectively. Thus, the dynamics of lipid metabolism indices objectively testifies to the positive effect of bioactive nutrients on human health indicators.

Attenuation of Thrombosis by Crude Rice (Oryza sativa) Bran Policosanol Extract: Ex Vivo Platelet Aggregation and Serum Levels of Arachidonic Acid Metabolites

Background. Vascular occlusion or thrombosis was often attributed to uncontrolled platelet activation. Influence of sugarcane policosanol extract on platelet was reported but little was known of rice bran policosanol, particularly its mechanisms of actions on platelet activities. Objective. Antiplatelet mechanisms of rice bran policosanol extract (RBE) were studied using hyperlipidemic Sprague Dawley rats. Ex vivo platelet aggregation, platelet count (PC), bleeding time (BT), and coagulation time were assayed. Serum eicosanoids and other aggregation-related metabolites levels were quantified. Design. Rats were divided into 6 groups for comparisons (vehicle control Tween 20/H₂O, high dose policosanol 500 mg/kg, middle dose policosanol 250 mg/kg, low dose policosanol 100 mg/kg, and positive control aspirin 30 mg/kg). Results. Low dose 100 mg/kg of RBE inhibited aggregation by 42.32 ± 4.31% and this was comparable with the effect of 30 mg/kg aspirin, 43.91 ± 5.27%. Results showed that there were no significant differences in PC, BT, and coagulation time among various groups after RBE treatment. Serum thromboxane A₂ was attenuated while prostacyclin level increased upon RBE treatment. Conclusions. RBE reduced ex vivo ADP-induced platelet aggregation without giving adverse effects. No changes in full blood count suggested that rice bran policosanol did not disturb biological blood cell production and destruction yet it reduced aggregation through different mechanisms.

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.

Decichine enhances hemostasis of activated platelets via AMPA receptors

INTRODUCTION

Dencichine, one of the non-protein amino acids present in the roots of Panax notoginseng, has been found to shorten bleeding time of mice and increase the number of platelets. However, the exact underlying mechanisms have not been elucidated yet. This study was aimed to identify the hemostatic effect of dencichine and uncover its mechanisms.

MATERIALS AND METHODS

Hemostatic effect was assessed by measuring tail bleeding time and coagulation indices of rats. PT, APTT, TT and FIB concentration were measured using a Sysmex CA-1500 plasma coagulation analyzer. Platelet aggregation rate was determined by using a platelet aggregometer. Concentration of cyotosolic calcium was evaluated by Fluo-3 and levels of cyclic adenosine monophosphate (cAMP) and thromboxane A₂ (TXA₂) were measured by ELISA method.

RESULTS AND CONCLUSION

Dencichine administered orally shortened tail bleeding time, reduced APTT and TT but increased the concentration of FIB in plasma in a dose-dependent manner. When induced with trap, dencichine could elevate the cytoplasmic concentration of calcium, and secretion of TXA₂ as well as the ratio of TXA₂ to PGI₂ from platelets. Meanwhile, it decreased the level of intracellular cAMP. However, CNQX could block the enhanced hemostatic effect of dencichine. These results suggested that dencichine exerted hemostatic function via AMPA receptors on platelets, therefore, facilitated coagulation cascade in a paracrine fashion by control of platelet cytosolic calcium influx, cAMP production and TXA₂ release. Current study may contribute to its clinical use in therapy of hemorrhage.

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.

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.

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.

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: 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.

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.

Effects of policosanol on postmenopausal women with type II hypercholesterolemia

This randomized, double-blind, placebo-controlled study was conducted to investigate the efficacy, safety and tolerability of policosanol, a cholesterol-lowering drug purified from sugar-cane wax, in postmenopausal women with type II hypercholesterolemia. A total of 244 women who had experienced the menopause and showed elevated serum total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels despite 6 weeks on a standard lipid-lowering diet were randomized to receive placebo or policosanol 5 mg/day for 12 weeks, after which the dose was doubled to 10 mg/day for the next 12 weeks. Policosanol (5 and 10 mg/day) significantly lowered LDL-C levels (17.7% and 25.2%, respectively) and total cholesterol (12.6% and 16.7%, respectively), as well as the ratios of LDL-C to high-density lipoprotein cholesterol (HDL-C) (17.0% and 29.3%, respectively) and total cholesterol to HDL-C (16.7% and 27.2%, respectively), compared to the baseline and placebo; at the same time, policosanol significantly raised HDL-C levels by 16.5% and 29.3%, respectively. The drug was safe and well tolerated. No drug-related adverse events were observed, and even the extent of adverse events was less in the policosanol group than in the placebo group. Four serious adverse events occurred in the placebo group (one myocardial infarction, two cases of hypertensive status and one surgical intervention) compared to none in the policosanol group. In conclusion, policosanol is effective, safe and well tolerated in hypercholesterolemic postmenopausal women.

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 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.