ubiquinone and Arteriosclerosis

All animal cells synthesize sufficient amounts of coenzyme Q (CoQ) and the cells also possess the capacity to metabolize the lipid. The main product of the metabolism is an intact ring with a short carboxylated side chain which glucuronidated in the liver and excreted mainly into the bile (Nakamura et al., Biofactors 9 (1999), 111-119). In other cells CoQ is phosphorylated, transferred into the blood and excreted through the urine. The biosynthesis of this lipid is regulated by nuclear receptors. PPARalpha is not required for the biosynthesis, or induction upon cold exposure, but it is necessary for the elevated CoQ synthesis during peroxisomal induction. RXRalpha is involved in the basal synthesis of CoQ and also in the increased synthesis upon cold treatment but is not required for peroxisomal induction. Dietary CoQ in human appear in the blood and it is taken up by mononuclear but not polynuclear cells. The former cells display a specific phospholipid modification, an increase of arachidonic acid content. In monocytes the CoQ administration leads to a significant decrease of the beta2-integrin CD11b and the complement receptor CD35. CD11b is one of the adhesion factors regulating the entry of these cells into the arterial wall which demonstrates that the anti-atherogenic effect of CoQ is mediated by other mechanisms beside its antioxidant protection.

Topics: Animals; Arteriosclerosis; Bile; CD18 Antigens; Dietary Supplements; Homeostasis; Humans; Liver; Monocytes; Phosphorylation; Receptors, Retinoic Acid; Retinoid X Receptors; Transcription Factors; Ubiquinone

Substantial evidence implicates oxidative modification of low density lipoprotein (LDL) as an important event contributing to atherogenesis. As a result, the elucidation of the molecular mechanisms by which LDL is oxidized and how such oxidation is prevented by antioxidants has been a significant research focus. Studies on the antioxidation of LDL lipids have focused primarily on alpha-tocopherol (alpha-TOH), biologically and chemically the most active form of vitamin E and quantitatively the major lipid-soluble antioxidant in extracts prepared from human LDL. In addition to alpha-TOH, plasma LDL also contains low levels of ubiquinol-10 (CoQ10H2; the reduced form of coenzyme Q10). Recent studies have shown that in oxidizing plasma lipoproteins alpha-TOH can exhibit anti- or pro-oxidant activities for the lipoprotein's lipids exposed to a vast array of oxidants. This article reviews the molecular action of alpha-TOH in LDL undergoing "mild" radical-initiated lipid peroxidation, and discusses how small levels of CoQ10H2 can represent an efficient antioxidant defence for lipoprotein lipids. We also comment on the levels alpha-TOH, CoQ10H2 and lipid oxidation products in the intima of patients with coronary artery disease and report on preliminary studies examining the effect of coenzyme Q10 supplementation on atherogenesis in apolipoprotein E knockout mice.

Topics: Animals; Antioxidants; Arteriosclerosis; Coenzymes; Free Radicals; Humans; Lipoproteins, LDL; Mice; Models, Chemical; Ubiquinone; Vitamin E

The oxidation of low density lipoprotein (LDL) is now commonly regarded as an important early event in atherogenesis. As such there is considerable interest in the ability of antioxidant supplementation to attenuate LDL oxidation and hence atherosclerosis. A majority of studies on LDL antioxidation have focused on alpha-tocopherol (alpha-TOH), biologically and chemically the most active form of vitamin E and quantitatively the major lipid-soluble antioxidant in extracts prepared from human LDL. In addition to alpha-TOH, circulating LDL also contains low levels of ubiquinol-10 (CoQ10H2; the reduced form of coenzyme Q). Recent studies have shown that in intact, isolated LDL, alpha-TOH can act as either an anti- or prooxidant for the lipoprotein's lipids. This article reviews the molecular action of alpha-TOH in LDL undergoing radical-initiated oxidation, and how the presence of CoQ10H2 suppresses the pro-oxidant or complements the antioxidant activity of the vitamin. We also comment on the plasma and intimal levels of alpha-TOH and CoQ10H2 in patients suffering from coronary artery disease and discuss the potential implications of these results for atherogenesis.

Topics: Antioxidants; Arteriosclerosis; Coronary Artery Disease; Diet; Humans; Lipid Peroxidation; Lipoproteins, LDL; Models, Biological; Oxidation-Reduction; Peroxides; Ubiquinone; Vitamin E

The very extensive research into atherogenesis carried out in recent years has yielded new knowledge of the importance of oxidation by free radicals of low-density lipoproteins and lipids, for instance in endothelial cell membrane. This has provided greater insight into the potential benefit of preventive measures using anti-oxidants to inhibit atherogenesis, and the results of clinical trials carried out so far would seem to confirm this. Prospective, controlled epidemiological trials are still lacking, but this will probably be remedied within the next 2-3 decades. The most clinically interesting antioxidants are vitamins C and E, beta-carotene, the ubiquinones, and the trace element selenium, substances that are naturally integrated components of the complex biochemistry of the human organism. The review is intended to clarify the scientific rationale for an increased intake of such anti-oxidants with a view to reducing the incidence of ischaemic vascular disorders.

Topics: Antioxidants; Arteriosclerosis; Ascorbic Acid; beta Carotene; Carotenoids; Clinical Trials as Topic; Free Radicals; Humans; Ubiquinone; Vitamin E

In a randomized, double-blind, controlled trial, the effects of oral treatment with coenzyme Q10 (CoQ10, 120 mg/day), a bioenergetic and antioxidant cytoprotective agent, were compared for 1 year, on the risk factors of atherosclerosis, in 73 (CoQ, group A) and 71 (B vitamin group B) patients after acute myocardial infarction (AMI). After 1 year, total cardiac events (24.6 vs. 45.0%, p < 0.02) including non-fatal infarction (13.7 vs. 25.3%, p < 0.05) and cardiac deaths were significantly lower in the intervention group compared to control group. The extent of cardiac disease, elevation in cardiac enzymes, left ventricular enlargement, previous coronary artery disease and elapsed time from symptom onset to infarction at entry to study showed no significant differences between the two groups. Plasma level of vitamin E (32.4 +/- 4.3 vs. 22.1 +/- 3.6 umol/L) and high density lipoprotein cholesterol (1.26 +/- 0.43 vs. 1.12 +/- 0.32 mmol/L) showed significant (p < 0.05) increase whereas thiobarbituric acid reactive substances, malondialdehyde (1.9 + 0.31 vs. 3.1 + 0.32 pmol/L) and diene conjugates showed significant reduction respectively in the CoQ group compared to control group. Approximately half of the patients in each group (n = 36 vs. 31) were receiving lovastatin (10 mg/day) and both groups had a significant reduction in total and low density lipoprotein cholesterol compared to baseline levels. It is possible that treatment with CoQ10 in patients with recent MI may be beneficial in patients with high risk of atherothrombosis, despite optimal lipid lowering therapy during a follow-up of 1 year. Adverse effect of treatments showed that fatigue (40.8 vs. 6.8%, p < 0.01) was more common in the control group than CoQ group.

Topics: Adult; Antioxidants; Arteriosclerosis; Cholesterol, HDL; Coenzymes; Double-Blind Method; Female; Humans; Male; Malondialdehyde; Middle Aged; Myocardial Infarction; Risk Factors; Thiobarbituric Acid Reactive Substances; Ubiquinone; Vitamin E

The purpose of this article is to summarise our studies, in which the main determinants and absorption of plasma coenzyme Q10 (Q10, ubiquinone) have been assessed, and the effects of moderate dose oral Q10 supplementation on plasma antioxidative capacity, lipoprotein oxidation resistance and on plasma lipid peroxidation investigated. All the supplementation trials carried out have been blinded and placebo-controlled clinical studies. Of the determinants of Q10, serum cholesterol, serum triglycerides, male gender, alcohol consumption and age were found to be associated positively with plasma Q10 concentration. A single dose of 30 mg of Q10, which is the maximum daily dose recommended by Q10 producers, had only a marginal elevating effect on plasma Q10 levels in non-Q10-deficient subjects. Following supplementation, a dose-dependent increase in plasma Q10 levels was observed up to a daily dose of 200 mg, which resulted in a 6.1-fold increase in plasma Q10 levels. However, simultaneous supplementation with vitamin E resulted in lower plasma Q10 levels. Of the lipid peroxidation measurements, Q10 supplementation did not increase LDL TRAP, plasma TRAP, VLDL+LDL oxidation resistance nor did it decrease LDL oxidation susceptibility ex vivo. Q10 with minor vitamin E dose neither decreased exercise-induced lipid peroxidation ex vivo nor muscular damage. Q10 supplementation might, however, decrease plasma lipid peroxidation in vivo, as assessed by the increased proportion of plasma ubiquinol (reduced form, Q10H2) of total Q10. High dose vitamin E supplementation decreased this proportion, which suggests in vivo regeneration of tocopheryl radicals by ubiquinol.

Topics: Absorption; Administration, Oral; Aged; Antioxidants; Arteriosclerosis; Cholesterol; Coenzymes; Creatine Kinase; Cytoprotection; Dietary Supplements; Dose-Response Relationship, Drug; Double-Blind Method; Exercise; Female; Humans; Lipid Peroxidation; Lipoproteins, LDL; Lipoproteins, VLDL; Male; Middle Aged; Oxidative Stress; Running; Ubiquinone; Vitamin E

Inflammation and oxidative stress are processes that mark early metabolic abnormalities in vascular diseases.. We explored the effects of a high-fat, high-cholesterol (HFHC) diet on vascular responses in baboons and the potential response-attenuating effects of vitamin E and coenzyme Q(10) (CoQ(10)) supplementation.. We used a longitudinal design by subjecting 21 baboons (Papio hamadryas) to sequential dietary challenges.. After being maintained for 3 mo on a baseline diet (low in fat and cholesterol), 21 baboons were challenged with an HFHC diet for 7 wk. The serum C-reactive protein (CRP) concentrations did not change. Subsequent supplementation of the HFHC diet with the antioxidant vitamin E (250, 500, or 1000 IU/kg diet) for 2 wk reduced serum CRP concentrations from 0.91 +/- 0.02 to 0.43 +/- 0.06 mg/dL. Additional supplementation with CoQ(10) (2 g/kg diet) further reduced serum CRP to approximately 30% of baseline (0.28 +/- 0.03 mg/dL; P = 0.036 compared with the HFHC diet). Introduction of the HFHC diet itself significantly decreased serum P-selectin (from 48.8 +/- 7.2 to 32.9 +/- 3.7 ng/dL, P = 0.02) and von Willebrand factor (from 187.0 +/- 10.1 to 161.9 +/- 9.0%, P = 0.02) concentrations. However, neither vitamin E alone nor vitamin E plus CoQ(10) significantly altered the serum concentrations of P-selectin or von Willebrand factor.. Dietary supplementation with vitamin E alone reduces the baseline inflammatory status that is indicated by the CRP concentration in healthy adult baboons. Cosupplementation with CoQ(10), however, significantly enhances this antiinflammatory effect of vitamin E.

Topics: alpha-Tocopherol; Analysis of Variance; Animals; Antioxidants; Arteriosclerosis; Biomarkers; C-Reactive Protein; Cholesterol, Dietary; Coenzymes; Dietary Fats; Dietary Supplements; Dose-Response Relationship, Drug; Drug Synergism; Female; Inflammation; Longitudinal Studies; Male; Oxidative Stress; P-Selectin; Papio; Random Allocation; Ubiquinone; Vitamin E; von Willebrand Factor

The oxidative modification of low density lipoprotein (LDL) is thought to play an important role in atherogenesis. Drugs of beta-hydroxy-beta-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) family are usually used as a very effective lipid-lowering preparations but they simultaneously block biosynthesis of both cholesterol and ubiquinone Q10 (coenzyme Q), which is an intermediate electron carrier in the mitochondrial respiratory chain. It is known that reduced form of ubiquinone Q10 acts in the human LDL as very effective natural antioxidant. Daily per os administration of HMG-CoA reductase inhibitor simvastatin to rats for 30 day had no effect on high-energy phosphates (adenosin triphosphate, creatine phosphate) content in liver but decreased a level of these substances in myocardium. We study the Cu2+-mediated susceptibility of human LDL to oxidation and the levels of free radical products of LDL lipoperoxidation in LDL particles from patients with atherosclerosis after 3 months treatment with natural antioxidants vitamin E as well as during 6 months administration of HMG-CoA reductase inhibitors such as pravastatin and cerivastatin in monotherapy and in combination with natural antioxidant ubiquinone Q10 or synthetic antioxidant probucol in a double-blind placebo-controlled trials. The 3 months of natural antioxidant vitamin E administration (400 mg daily) to patients did not increase the susceptibility of LDL to oxidation. On the other hand, synthetic antioxidant probucol during long-time period of treatment (3-6 months) in low-dose (250 mg daily) doesn't change the lipid metabolism parameters in the blood of patients but their high antioxidant activity was observed. Really, after oxidation of probucol-contained LDL by C-15 animal lipoxygenase in these particles we identified the electron spin resonance signal of probucol phenoxyl radical that suggests the interaction of LDL-associated probucol with lipid radicals in vivo. We observed that 6 months treatment of patients with pravastatine (40 mg daily) or cerivastatin (0.4 mg daily) was followed by sufficiently accumulation of LDL lipoperoxides in vivo. In contrast, the 6 months therapy with pravastatin in combination with ubiquinone Q10 (60 mg daily) sharply decreased the LDL initial lipoperoxides level whereas during treatment with cerivastatin in combination with probucol (250 mg daily) the LDL lipoperoxides concentration was maintained on an invariable level. Therefore, antioxida

Topics: Animals; Antioxidants; Arteriosclerosis; Coenzymes; Dose-Response Relationship, Drug; Double-Blind Method; Enzyme Inhibitors; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lipid Peroxidation; Lipoproteins, LDL; Liver; Male; Middle Aged; Oxidation-Reduction; Pravastatin; Probucol; Pyridines; Rats; Time Factors; Ubiquinone; Vitamin E

This study evaluates the effect of a Curcuma longa extract on the development of experimental atherosclerosis (fatty streak) in rabbits and its interaction with other plasmatic antioxidants.. Two experimental groups of male New Zealand White rabbits, a control group and a curcuma-extract (CU) group, were fed an atherogenic diet. Additionally, the CU group received an oral curcuma hydroalcoholic extract. Six animals from each experimental group were killed after 10, 20, and 30 days. Compared with the CU group, the control group showed significantly higher plasma lipid peroxide at all experimental times (10, 20, and 30 days) and significantly lower alpha-tocopherol and coenzyme Q levels at 20 and 30 days. Histological results for the fatty streak lesions revealed damage in the thoracic and abdominal aorta that was significantly lower in the CU group than in the control group at 30 days.. Supplementation with Curcuma longa reduces oxidative stress and attenuates the development of fatty streaks in rabbits fed a high cholesterol diet.

Topics: alpha-Tocopherol; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Aortic Diseases; Arteriosclerosis; Coenzymes; Coumaric Acids; Curcuma; Curcumin; Diarylheptanoids; Diet, Atherogenic; Dietary Supplements; Lipid Peroxides; Lipoproteins, LDL; Male; Oxidative Stress; Plant Extracts; Rabbits; Ubiquinone; Vitamin A

Antioxidants may prevent atherosclerosis by interfering with endothelial activation, which involves the expression of endothelial adhesion molecules. The aim of this study was to explore the relationship between plasma levels of some lipid-soluble antioxidants (gamma-tocopherol, alpha-tocopherol, lycopene, beta-carotene, and ubiquinone), carotid maximum intima-media thickness (IMTmax), an index of atherosclerotic extension/severity, and soluble adhesion molecules (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion molecule-1 [ICAM-1], and E-selectin), which are taken as a reflection of vascular cell expression of adhesion molecules.. We studied 11 healthy control subjects, 11 patients with uncomplicated hypertension (UH), and 11 patients with essential hypertension plus peripheral vascular disease (PVD) who were matched for age, sex, smoking habit, and body mass index.. Patients with PVD had elevated IMTmax (2.7 [1.1-3.1] mm, median [range]) compared with both patients with UH(1.2 [0.8-2.4] mm) and control subjects (1.0 [0.6-2] mm). In patients with PVD, soluble (s)VCAM-1 and sICAM-1 were also significantly higher than in the 2 other categories. Plasma levels of lycopene had a trend toward lower values in patients with PVD compared with other groups (P =.13). A statistically significant correlation was found between lycopene and IMTmax (r = 0.42, P =.014) at univariate analysis, which persisted at multivariate analysis (P <.05) and was independent of low-density lipoprotein cholesterol, creatinine clearance, and plasma insulin. Plasma lycopene did not significantly correlate with any of the soluble adhesion molecules tested.. We conclude that the inverse relationship of plasma lycopene with IMTmax is compatible with a protective role of this natural dietary antioxidant in atherosclerosis, although the mechanism of protection does not apparently involve a decrease in endothelial activation measured through soluble adhesion molecules.

Topics: alpha-Tocopherol; Analysis of Variance; Antioxidants; Arteriosclerosis; beta Carotene; Biomarkers; Carotenoids; Carotid Artery Diseases; E-Selectin; Female; gamma-Tocopherol; Humans; Hypertension; Intercellular Adhesion Molecule-1; Lycopene; Male; Middle Aged; Peripheral Vascular Diseases; Ubiquinone; Vascular Cell Adhesion Molecule-1

Oxidative modification of lipoproteins may trigger and maintain atherogenesis. We compared the effects of different antioxidants (alpha-tocopherol, probucol, ubiquinone-10) at doses similar to those used in humans in Watanabe Heritable Hyperlipidemic (WHHL) rabbits for 12 months. Aortic lesions were analyzed for their extent and cellular composition of lesions, mean thickness of fibrous caps and density of smooth muscle cells therein, content of antioxidants, non-oxidized and oxidized lipids. Compared to controls, probucol significantly lowered the extent and macrophage content of lesions and increased the existence and smooth muscle cell density of fibrous caps. alpha-Tocopherol supplementation increased the aortic content of vitamin E, but had no decreasing effect on either the accumulation of macrophage-specific antigen in the aorta or lesion size. Nevertheless, both probucol and alpha-tocopherol significantly decreased in vitro LDL oxidizability, measured under typically strong oxidative conditions. Ubiquinone-10 supplement increased lesion size and the fraction of lesions containing fibrous caps; however, LDL oxidizability remained unaffected by ubiquinone-10 treatment. None of the antioxidants tested lowered oxidized lipids within aortic tissue; however, long-term treatment with probucol provided the most effective anti-atherosclerotic effect, while alpha-tocopherol may be pro-atherogenic and ubiquinone-10 exerts ambivalent effects. Our data suggest that (i) widely used oxidation measures, such as ex-vivo LDL oxidizability, do not reflect the degree of atherosclerosis; and (ii) long-term beneficial effects of relatively low doses of antioxidants may be outweighed by high levels of plasma cholesterol in WHHL rabbits.

Topics: alpha-Tocopherol; Animals; Antioxidants; Aorta; Arteriosclerosis; Coenzymes; Disease Models, Animal; Female; Humans; Lipids; Lipoproteins, LDL; Male; Probucol; Rabbits; Ubiquinone; Vitamin E

The oxidation hypothesis of atherosclerosis implies that antioxidants are able to inhibit lipoprotein oxidation in the arterial wall and thereby retard atherogenesis. Since most of the animal studies performed have used very high doses of antioxidants, it is to date unknown whether antioxidants are effective antiatherosclerotic agents when given in pharmacological doses. Here we addressed this question using homozygous Watanabe heritable hyperlipidaemic (WHHL) rabbits as an animal model of atherosclerosis. The rabbits were divided into four groups, each consisting of ten animals. They received either a standard diet or a diet containing 4.3 mg ubiquinone-10, or 4.3 mg vitamin E or 15 mg probucol/kg body weight daily. After 12 months, the extent of aortic atherosclerosis was assessed as the intima thickness, media thickness and intima-to-media ratio in 14 cross sections equally distributed over the whole aorta. To evaluate the antioxidant effects of the diet, lipophilic and hydrophilic antioxidants, lipids, fatty acids and plasma oxidizability were measured after 0, 3 and 6 months of feeding. We found that supplementation with probucol significantly decreased aortic intima-to-media ratio compared to controls. The antiatherosclerotic action of probucol was accompanied by its beneficial action on plasma oxidizability and some plasma antioxidants. No decrease in aortic atherosclerosis was measured in ubiquinone-10- and vitamin E-supplemented rabbits, despite the fact that both antioxidants decreased plasma oxidizability and ubiquinone-10 increased the plasma levels of antioxidants. Taken together, these data suggest that pharmacological doses of probucol retard atherogenesis in WHHL rabbits by an antioxidant mechanism, while ubiquinone-10 and vitamin E at these dosages are ineffective in this highly hyperlipidaemic model. The measurement of some oxidation-related parameters in plasma, such as lipophilic antioxidants, polyunsaturated fatty acids and lipoprotein oxidizability, may be useful in assessing the risk of atherogenesis in humans.

Topics: Administration, Oral; Animals; Anticholesteremic Agents; Antidotes; Antioxidants; Aorta; Arteriosclerosis; Diet; Dose-Response Relationship, Drug; Fatty Acids, Unsaturated; Hyperlipidemias; Lipoproteins; Oxidation-Reduction; Probucol; Rabbits; Tunica Intima; Ubiquinone; Vitamin E

Intimal oxidation of LDL is considered an important early event in atherogenesis, and certain antioxidants are antiatherogenic. Dietary coenrichment with vitamin E (VitE) plus ubiquinone-10 (CoQ(10), which is reduced during intestinal uptake to the antioxidant ubiquinol-10, CoQ(10)H(2)) protects, whereas enrichment with VitE alone can increase oxidizability of LDL lipid against ex vivo oxidation. In the present study, we tested whether VitE plus CoQ(10) cosupplementation is more antiatherogenic than either antioxidant alone, by use of apolipoprotein E-deficient (apoE-/-) mice fed a high-fat diet without (control) or with 0.2% (wt/wt) VitE, 0.5% CoQ(10), or 0.2% VitE plus 0.5% CoQ(10) (VitE+CoQ(10)) for 24 weeks. None of the supplements affected plasma cholesterol concentrations, whereas in the VitE and CoQ(10) groups, plasma level of the respective supplement increased. Compared with control, plasma from CoQ(10) or VitE+CoQ(10) but not VitE-supplemented animals was more resistant to ex vivo lipid peroxidation induced by peroxyl radicals. VitE supplementation increased VitE levels in aorta, heart, brain, and skeletal muscle, whereas CoQ(10) supplementation increased CoQ(10) only in plasma and aorta and lowered tissue VITE: All treatments significantly lowered aortic cholesterol compared with control, but only VitE+CoQ(10) supplementation significantly decreased tissue lipid hydroperoxides when expressed per parent lipid. In contrast, none of the treatments affected aortic ratios of 7-ketocholesterol to cholesterol. Compared with controls, VitE+CoQ(10) supplementation decreased atherosclerosis at the aortic root and arch and descending thoracic aorta to an extent that increased with increasing distance from the aortic root. CoQ(10) significantly inhibited atherosclerosis at aortic root and arch, whereas VitE decreased disease at aortic root only. Thus, in apoE-/- mice, VitE+CoQ(10) supplements are more antiatherogenic than CoQ(10) or VitE supplements alone and disease inhibition is associated with a decrease in aortic lipid hydroperoxides but not 7-ketocholesterol.

Topics: Animals; Antioxidants; Aorta; Aortic Diseases; Apolipoproteins E; Arteriosclerosis; Cholesterol, VLDL; Coenzymes; Dietary Fats; Disease Models, Animal; Lipids; Mice; Mice, Inbred C57BL; Mice, Knockout; Ubiquinone; Vitamin E

The effects of the administration of coenzyme Q10 (3 mg/kg per day) (group A, n=10) and placebo (aluminum hydroxide, 3 mg/kg per day) (group B, n=10) were compared over 24 weeks in a randomized, single-blind, controlled trial. There were two groups of rabbits receiving a trans fatty acid (TFA)-rich diet (5-8 g/day) for 36 weeks. Oxidized rabbit chow with vitamin C plus ferric chloride was administered for 4 weeks in all rabbits. Intervention with coenzyme Q10 after feeding of TFA-rich diet was associated with a significant decline in thiobarbituric acid reactive substances (TBARS), diene conjugates and malondialdehyde, and an increase in plasma levels of vitamin E in the coenzyme Q group compared to placebo group. These changes, which were indicators of a decrease in oxidative damage, were independent of lipid lowering. The aortic and coronary artery plaque sizes, coronary atherosclerosis index, aortic and coronary atherosclerosis scores were significantly lower in the coenzyme Q group than placebo group. Aortic and coronary plaque frequencies, as well as frequencies of ulceration, thrombosis or hemorrhage, and cracks and fissures, were also significantly lower in the coenzyme Q group, indicating a better quality of atheroma compared to those in the control group. Aortic cholesterol, triglycerides and sudanophilia were significantly lower and vitamin E significantly higher in the coenzyme Q group in comparison to the placebo group indicating that coenzyme Q10 can have beneficial effect on the chemical composition of atheroma. The findings suggest that antioxidant therapy with coenzyme Q10 may be used as an adjunct to lipid lowering for additional beneficial effects related to chemical composition and quality of atheroma independent of hypolipidemic agents.

Topics: Animals; Antioxidants; Aorta; Arteriosclerosis; Cholesterol; Coenzymes; Coronary Vessels; Rabbits; Thiobarbituric Acid Reactive Substances; Triglycerides; Ubiquinone; Vitamin E

Oxidation of low-density lipoprotein (LDL) lipid is implicated in atherogenesis and certain antioxidants inhibit atherosclerosis. Ubiquinol-10 (CoQ10H2) inhibits LDL lipid peroxidation in vitro although it is not known whether such activity occurs in vivo, and, if so, whether this is anti-atherogenic. We therefore tested the effect of ubiquinone-10 (CoQ10) supplemented at 1% (w/w) on aortic lipoprotein lipid peroxidation and atherosclerosis in apolipoprotein E-deficient (apoE-/-) mice fed a high-fat diet. Hydroperoxides of cholesteryl esters and triacylglycerols (together referred to as LOOH) and their corresponding alcohols were used as the marker for lipoprotein lipid oxidation. Atherosclerosis was assessed by morphometry at the aortic root, proximal and distal arch, and the descending thoracic and abdominal aorta. Compared to controls, CoQ10-treatment increased plasma coenzyme Q, ascorbate, and the CoQ10H2:CoQ10 + CoQ10H2 ratio, decreased plasma alpha-tocopherol (alpha-TOH), and had no effect on cholesterol and cholesterylester alcohols (CE-OH). Plasma from CoQ10-supplemented mice was more resistant to ex vivo lipid peroxidation. CoQ10 treatment increased aortic coenzyme Q and alpha-TOH and decreased the absolute concentration of LOOH, whereas tissue cholesterol, cholesteryl esters, CE-OH, and LOOH expressed per bisallylic hydrogen-containing lipids were not significantly different. CoQ10-treatment significantly decreased lesion size in the aortic root and the ascending and the descending aorta. Together these data show that CoQ10 decreases the absolute concentration of aortic LOOH and atherosclerosis in apoE-/- mice.

Topics: Animals; Antioxidants; Aorta; Apolipoproteins E; Arteriosclerosis; Coenzymes; Diet, Atherogenic; Dietary Supplements; Gene Deletion; Lipid Metabolism; Lipid Peroxidation; Lipid Peroxides; Lipids; Lipoproteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Peroxides; Ubiquinone

Oxidation of lipoproteins is thought to be an early event in atherogenesis. To evaluate whether aortic lipoprotein lipid (per)oxidation contributes to atherosclerosis, we investigated the time-dependent changes to lipids and antioxidants in plasma and aortas of apolipoprotein E gene knockout (apoE-/-) mice receiving a high fat diet, and compared these changes with lesion development. Circulating buoyant lipoproteins and associated cholesterol (C), cholesteryl esters (CE), and alpha-tocopherol (alpha-TOH) increased within 1 month then remained largely constant up to 6 months. Coenzyme Q (CoQ) remained unchanged for the first 3 months and increased marginally after 6 months. With increasing duration of the diet, plasma lipids showed an increased propensity to undergo peroxyl radical-induced (per)oxidation. Absolute concentrations of aortic C, hydroperoxides and hydroxides of CE (CE-O(O)H) and alpha-TOH increased gradually while aortic CE increased more markedly with changes to cholesteryl linoleate being most pronounced. Aortic CoQ remained largely unchanged. Overall, the extent of aortic CE (per)oxidation remained low (

Topics: Animals; Antioxidants; Aorta; Apolipoproteins E; Arteriosclerosis; Cholesterol Esters; Chromatography, High Pressure Liquid; Dietary Fats; Kinetics; Lipid Metabolism; Lipid Peroxidation; Lipids; Lipoproteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Peroxides; Ubiquinone; Vitamin E

Total CoQ10 levels were evaluated in whole blood and in plasma obtained from a group of 83 healthy donors. Extraction with light petroleum ether/methanol was more efficient, for whole blood, than the extraction which is often used for plasma and serum, i.e., ethanol hexane. An excellent correlation was present between plasma CoQ10 and whole blood CoQ10. CoQ10 is mainly associated with plasma rather than with cellular components. Positive, significant correlations were found between the LDL-chol/CoQ10 ratio and the total-chol/HDL-chol ratio, which is usually considered a risk factor for atherosclerosis. The proportion of CoQ10 carried by LDL was 58 +/- 10%, while the amount carried by HDL was 26 +/- 8%. In VLDL + IDL CoQ10 was 16 +/- 8%. The content of CoQ10 in single classes of lipoproteins is strictly correlated with CoQ10 plasma concentration. In a parallel study conducted on a population of diabetic patients (one IDDM group and one NIDDM) CoQ10 plasma levels were generally higher compared to the control group, also when normalised to total cholesterol. In particular the LDL fraction showed a CoQ10/chol ratio higher in NIDDM but not in IDDM patients, compared to controls. The CoQ10/triglycerides ratio was lower in NIDDM respect to controls and even lower in IDDM patients.

Topics: Aged; Antioxidants; Arteriosclerosis; Ascorbic Acid; beta Carotene; Biomarkers; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Coenzymes; Female; Fructosamine; Humans; Lipoproteins; Male; Middle Aged; Reference Values; Risk Factors; Ubiquinone; Vitamin A; Vitamin E

Greenlanders (Eskimos) have low prevalence of ischaemic heart disease, partly explained by a lower extent of atherosclerosis and a low n-6/n-3 ratio of polyunsaturated fatty acids. As atherosclerosis is also a result of oxidative stress, the total antioxidative readiness could have a substantial impact. From a health survey we chose the subpopulation from the most remote area, where the traditional Greenlandic diet with high intake of sea mammals and fish predominates. The mean (SD) of S-CoQ10 in males was 1.495 (0.529) nmol/ml and 1.421 (0.629) nmol/ml in females, significantly higher (p < 0.001) compared to a Danish population. In a linear multiple regression model the S-CoQ10 level is significantly positively associated with age and S-selenium in males, and S-total cholesterol in females. The high level of CoQ10 in Greenlanders probably reflects diet, since no bioaccumulation takes place, and it could probably be a substantial part of the antioxidative defense.

Topics: Adult; Aged; Aging; Antioxidants; Arteriosclerosis; Asian People; Biomarkers; Cholesterol; Coenzymes; Denmark; Female; Greenland; Humans; Inuit; Male; Middle Aged; Myocardial Ischemia; Pilot Projects; Prevalence; Risk Factors; Selenium; Sex Factors; Ubiquinone; White People

Oxidative modification of low-density lipoprotein (LDL), regarded an early event in atherogenesis, is associated with the depletion of the lipoprotein's antioxidants. We tested whether the levels of major lipophilic antioxidants in the blood of patients with advanced atherosclerosis are different to those in age-matched controls. On average, plasma ubiquinol-10, total coenzyme Q and coenzyme Q redox status were slightly lower whereas the levels of alpha-tocopherol were slightly higher in patients (63 +/- 11 years, n = 32) than controls (64 +/- 10 years, n = 24). However, these differences were not statistically significant (p > 0.05). The levels of antioxidants in LDL isolated from a subset of patients (n = 20) and controls (n = 15) were also indifferent, and hydroperoxides of cholesteryl esters were undetectable (detection limit 10 nM) in plasma of patients (n = 11) and controls (n = 10). The data suggests that plasma and LDL levels of lipophilic antioxidants are not depleted in patients suffering from severe atherosclerosis, and that neither parameter serves as a useful diagnostic indicator for this disease.

Topics: Aged; Aging; Antioxidants; Arteriosclerosis; Case-Control Studies; Chromatography, High Pressure Liquid; Coenzymes; Female; Humans; Lipoproteins, LDL; Male; Middle Aged; Oxidation-Reduction; Ubiquinone; Vitamin E

The development of the atherosclerosis is mediated by the accumulation of oxidized lipids in the arterial wall. There is a relationship between average intake of dietary fat, its quality, and incidence of atherosclerosis. The goal of this work was to study the effect of different dietary fats on the coenzyme Q10 and hydroperoxide content of liver mitochondria in rabbits affected by an induced atherosclerosis. The results show that the induction of experimental atherosclerosis leads to a significant increase in hydroperoxides of rabbit liver membrane mitochondria and to a significant drop in the content of CoQ10. Furthermore, treatment of atherosclerotic rabbits with different diets resulted in an increase of membrane hydroperoxides in the group fed sunflower oil whereas the increase was significantly lower for animals fed virgin olive oil and fish oil stabilized with vitamin E (1 g/kg). CoQ10 levels only recovered partially in all groups; however, values in the sunflower oil were significantly lower as compared to corresponding values of the other groups. The use of either virgin olive oil or vitamin E stabilized fish oil in the dietary treatment of atherosclerosis appears to be a valid alternative for maintaining adequate levels of CoQ10 and hydroperoxides in liver mitochondria.

Topics: Animals; Arteriosclerosis; Cholesterol, Dietary; Coenzymes; Diet, Atherogenic; Dietary Fats; Fish Oils; Hydrogen Peroxide; Lipid Peroxidation; Male; Mitochondria, Liver; Olive Oil; Plant Oils; Rabbits; Sunflower Oil; Ubiquinone; Vitamin E

We measured serum ubiquinone and dolichol concentrations in 13 men while they abused anabolic androgenic steroids (AAS) and during the following withdrawal period. Serum total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol and triglycerides were also determined. AAS administration increased serum ubiquinone by 68% (P < .001) and decreased serum dolichol by 30% (P < .002). Both nonsterol isoprenoid levels in plasma correlated with the AAS dose, ubiquinone positively (P < .001) and dolichol negatively (P < .002). When the subjects were taking steroids, the ubiquinone to LDL ratio was 42% higher than during the withdrawal period. In conclusion, our study suggests that AAS have an influence on the by-products of the mevalonate pathway.

Topics: Adult; Anabolic Agents; Arteriosclerosis; Cholesterol, HDL; Cholesterol, LDL; Dolichols; Humans; Male; Mevalonic Acid; Substance-Related Disorders; Ubiquinone

The conjugated polyene fatty acid parinaric acid (PnA) undergoes a stoichiometric loss in fluorescence upon oxidation and can be used to directly monitor peroxidative stress within lipid environments. We evaluated the course of potentially atherogenic oxidative changes in low density lipoproteins (LDL) by monitoring the oxidation of PnA following its incorporation into buoyant (p = 1.026-1.032 g/ml) and dense (p = 1.040-1.054 g/ml) LDL subfractions. Copper-induced oxidation of LDL-associated PnA exhibited an initial lag phase followed by an increased rate of loss until depletion. Increased PnA oxidation occurred immediately after the antioxidants ubiquinol-10 and alpha-tocopherol were consumed but before there were marked elevations in conjugated dienes. Despite differences in sensitivity to early oxidation events, PnA oxidation and conjugated diene lag times were correlated (r = 0.582; P = 0.03), and both indicated a greater susceptibility of dense than buoyant LDL in accordance with previous reports. The greater susceptibility of PnA in dense LDL was attributed to reduced levels of ubiquinol-10 and alpha-tocopherol, which were approximately 50% lower than in buoyant LDL (mol of antioxidant/mol of LDL) and together accounted for 80% of the variation in PnA oxidation lag times. These results suggest that PnA is a useful probe of LDL oxidative susceptibility and may be superior to conjugated dienes for monitoring the initial stages of LDL lipid peroxidation. Differences in oxidative susceptibility among LDL density subfractions are detected by the PnA assay and are due in large part to differences in their antioxidant content.

Topics: Adult; Antioxidants; Arteriosclerosis; Fatty Acids, Unsaturated; Female; Fluorescent Dyes; Humans; Lipid Peroxidation; Lipoproteins, LDL; Male; Oxidation-Reduction; Ubiquinone; Vitamin E

Topics: Age Factors; Animals; Aorta; Arteries; Arteriosclerosis; Carnitine; Chromatography, Paper; Coenzyme A; Coenzymes; Creatine; Cytochrome c Group; Dipeptides; DNA; Glutathione; Guinea Pigs; Humans; Nucleotides; Oxidation-Reduction; Pulmonary Artery; RNA; Spectrophotometry; Thioctic Acid; Ubiquinone

Topics: Adolescent; Adult; Aged; Aging; Animals; Aorta; Arteries; Arteriosclerosis; Cattle; Chromatography, Paper; Coronary Vessels; Humans; Middle Aged; Pulmonary Artery; Species Specificity; Spectrophotometry; Ubiquinone