Coenzyme Q10 concentrations in coronary artery disease

Gas-Phase Fragmentation of Coenzyme Q10 Radical Anion Generated by APCI: A Study by High/Low-Resolution Tandem/Sequential Mass Spectrometry

Coenzyme Q10 (CoQ10) and closely related compounds with varying isoprenoid tail lengths (CoQn, n = 6-9) are biochemical cofactors involved in many physiological processes, playing important roles in cellular respiration and energy production. Liquid chromatography (LC) coupled with single or tandem mass spectrometry (MS) using electrospray (ESI) or atmospheric pressure chemical ionization (APCI) is considered the gold standard for the identification and quantification of CoQ10 in food and biological samples. However, the characteristic fragmentation exhibited by the CoQ10 radical anion ([M]•-, m/z 862.684), the prevailing ion generated by APCI in negative polarity, has not been studied in detail. In this work, a systematic study was carried out to clarify this issue, using higher collisional energy dissociation (HCD) with high-resolution tandem FTMS and collision-induced dissociation-low-resolution sequential mass spectrometry (CID-MSn, n = 2-4). Various fragmentation pathways were successfully interpreted, with some structures proposed for product ions checked using density functional theory (DFT) calculations. Besides the already-known detachments of methyl radicals occurring directly from the CoQ10 radical anion and leading to ions like [M - CH3]- and [M - 2CH3]•-, the homolytic cleavage of C-C bonds along the oligo-isoprenoid side chain was tentatively proposed to explain some of the observed fragmentations. As a result, the generation of uncommon yet potentially stable distonic biradical anions was hypothesized, with some of them likely undergoing intramolecular cyclization to generate ions without unpaired electrons. Diagnostic product ions emerged from the fragmentation processes of CoQ10 and were found to be common also to the radical anions of other CoQn derivatives (n = 7-9), facilitating their identification in extracts of edible Brassicaceae plant microgreens by reversed-phase liquid chromatography (RPLC)-APCI-FTMS.

Cardiovascular and haematological pathology in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A role for viruses

ME/CFS is a debilitating chronic condition that often develops after viral or bacterial infection. Insight from the study of Long COVID/Post Acute Sequelae of COVID-19 (PASC), the post-viral syndrome associated with SARS-CoV-2 infection, might prove to be useful for understanding pathophysiological mechanisms of ME/CFS. Disease presentation is similar between the two conditions, and a subset of Long COVID patients meet the diagnostic criteria for ME/CFS. Since Long COVID is characterized by significant vascular pathology - including endothelial dysfunction, coagulopathy, and vascular dysregulation - the question of whether or not the same biological abnormalities are of significance in ME/CFS arises. Cardiac abnormalities have for a while now been documented in ME/CFS cohorts, with recent studies demonstrating major deficits in cerebral blood flow, and hence vascular dysregulation. A growing body of research is demonstrating that ME/CFS is accompanied by platelet hyperactivation, anomalous clotting, a procoagulant phenotype, and endothelial dysfunction. Endothelial damage and dysregulated clotting can impair substance exchange between blood and tissues, and result in hypoperfusion, which may contribute to the manifestation of certain ME/CFS symptoms. Here we review the ME/CFS literature to summarize cardiovascular and haematological findings documented in patients with the condition, and, in this context, briefly discuss the potential role of previously-implicated pathogens. Overall, cardiac and haematological abnormalities are present within ME/CFS cohorts. While atherosclerotic heart disease is not significantly associated with ME/CFS, suboptimal cardiovascular function defined by reduced cardiac output, impaired cerebral blood flow, and vascular dysregulation are, and these abnormalities do not appear to be influenced by deconditioning. Rather, these cardiac abnormalities may result from dysfunction in the (autonomic) nervous system. Plenty of recently published studies are demonstrating significant platelet hyperactivity and endothelial dysfunction in ME/CFS, as well as anomalous clotting processes. It is of particular importance to determine to what extent these cardiovascular and haematological abnormalities contribute to symptom severity, and if these two systems can be targeted for therapeutic purposes. Viral reservoirs of herpesviruses exist in ME/CFS, and most likely contribute to cardiovascular and haematological dysfunction directly or indirectly. This review highlights the potential of studying cardiac functioning, the vasculature, and coagulation system in ME/CFS.

Coenzyme Q10 Supplementation and Oxidative Stress Parameters: An Updated Systematic Review and Meta-analysis of Randomized Controlled Clinical Trials

Background: Oxidative stress (OS) contributes to the development of some disorders, including malignancies, metabolic diseases, Alzheimer's disease, and Parkinson's disease. Objectives: The effects of coenzyme Q10 (CoQ10) supplementation on OS parameters have been assessed through an updated systematic review and meta-analysis. Methods: SCOPUS, PubMed, Cochrane Library, EMBASE, and Web of Sciences were used for article searching. Standardized mean difference (SMD) and its standard error were calculated using a random-effects DerSimonian and Laird model. All analyses were done using the STATA software version 16.0 (StataCorp, College Station, TX). Results: Based on twenty-five studies which remained to be incorporated in the meta-analysis, a statistically significant decrease in malondialdehyde (MDA) (SMD -2.74; 95% CI -3.89, -1.58; I2 = 96.9%) as well as nitric oxide (NO) (SMD -5.16; 95% CI -7.98, 2.34; I2 = 92.5%) was associated with CoQ10 supplementation, and a significant increase in total antioxidant capacity (TAC) (SMD 3.40; 95% CI 1.98, 4.83; I2 = 97.4%) and superoxide dismutase (SOD) activity (SMD 1.22; 95% CI 0.32, 2.12; I2 = 94.32%). Conclusions: The results showed no significant effect of CoQ10 supplementation on glutathione peroxidase (GPx), catalase (CAT) activities, and glutathione (GSH) levels. CoQ10 supplementation significantly reduced MDA and NO concentrations and increased TAC and SOD activity.

The Use of Coenzyme Q10 in Cardiovascular Diseases

CoQ10 is an endogenous antioxidant produced in all cells that plays an essential role in energy metabolism and antioxidant protection. CoQ10 distribution is not uniform among different organs, and the highest concentration is observed in the heart, though its levels decrease with age. Advanced age is the major risk factor for cardiovascular disease and endothelial dysfunction triggered by oxidative stress that impairs mitochondrial bioenergetic and reduces NO bioavailability, thus affecting vasodilatation. The rationale of the use of CoQ10 in cardiovascular diseases is that the loss of contractile function due to an energy depletion status in the mitochondria and reduced levels of NO for vasodilatation has been associated with low endogenous CoQ10 levels. Clinical evidence shows that CoQ10 supplementation for prolonged periods is safe, well-tolerated and significantly increases the concentration of CoQ10 in plasma up to 3–5 µg/mL. CoQ10 supplementation reduces oxidative stress and mortality from cardiovascular causes and improves clinical outcome in patients undergoing coronary artery bypass graft surgery, prevents the accumulation of oxLDL in arteries, decreases vascular stiffness and hypertension, improves endothelial dysfunction by reducing the source of ROS in the vascular system and increases the NO levels for vasodilation.

Plasma coenzyme Q10 concentration, antioxidant status, and serum N-terminal pro-brain natriuretic peptide concentration in dogs with various cardiovascular diseases and the effect of cardiac treatment on measured variables

OBJECTIVE To determine the plasma total antioxidant capacity, erythrocyte superoxide dismutase activity, whole blood glutathione peroxidase activity, and plasma coenzyme Q₁₀ (CoQ₁₀) concentration in dogs with various stages of cardiovascular diseases and in healthy dogs; assess the influence of cardiac treatment on the levels of antioxidant variables, plasma CoQ₁₀ concentration, and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, and determine any correlation between the disease severity (NT-proBNP concentration) and antioxidant variables or CoQ₁₀ concentration. ANIMALS 43 dogs with various types and stages of cardiovascular diseases (congenital and acquired) and 29 healthy dogs. PROCEDURES Blood samples were collected from all dogs for spectrophotometric assessment of antioxidant variables. Plasma CoQ₁₀ concentration was determined with a high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry method. Serum NT-proBNP concentration was measured with an ELISA. RESULTS Values for antioxidant variables did not differ among groups of dogs with cardiovascular diseases, regardless of disease stage or treatment. Plasma CoQ₁₀ concentration was significantly increased in treated dogs with congestive heart failure (CHF), compared with untreated patients. However, plasma CoQ₁₀ concentration did not differ among heart failure classes. A significant, negative correlation between serum NT-proBNP and plasma CoQ₁₀ concentrations was identified in treated CHF-affected dogs, suggesting that low plasma CoQ₁₀ concentration may be associated with increased severity of CHF. CONCLUSIONS AND CLINICAL RELEVANCE The antioxidant variables evaluated were not altered in dogs with CHF, regardless of cardiac disease stage or treatment. Further investigation into the possible effects of CoQ₁₀ supplementation in dogs with advanced stages of CHF is warranted.

Genotoxicity evaluation of HMG CoA reductase inhibitor rosuvastatin

The genotoxic potential of rosuvastatin as one of the statin drugs was assessed by chromosomal aberrations (CAs), micronucleus (MN) and DNA damage by comet assay in the human peripheral blood lymphocytes. Rosuvastatin was used at concentrations of 0.0625, 0.125, 0.25, 0.5 and 1 µg/mL for these in vitro assays. In all assays, a negative and positive control were also included. CA frequencies were significantly increased in all concentrations at 24 hours and significantly increased in all concentrations except 0.0625 µg/mL at 48 hours, compared to the negative control. Rosuvastatin has a decreased mitotic index (MI) at 0.5- and 1-µg/mL concentrations at 24 hours and at 0.25, 0.5 and 1 µg/mL at 48 hours. A significant increase was observed for induction of MN in all treatments, compared to the negative control. Cytokinesis-block proliferation indices were not affected by treatments with rosuvastatin. In the comet assay, significant increases in comet tail length and tail moment were observed at 0.0625-, 0.5- and 1-µg/mL concentrations. Comet intensity was significantly increased in all concentrations except 0.0625 µg/mL. According to these results, rosuvastatin is cytotoxic and clastogenic/aneugenic in human peripheral lymphocytes. Further studies should be conducted in other test systems to evaluate the full genotoxic potential of rosuvastatin.

Aged garlic extract and coenzyme Q10 have favorable effect on inflammatory markers and coronary atherosclerosis progression: A randomized clinical trial

Background:

Aged garlic extract (AGE) and coenzyme Q10 (CoQ10) have been shown to affect multiple cardiovascular risk factors. The current study evaluates the effect of AGE combined with CoQ10 on inflammatory markers and progression of coronary atherosclerosis compared with placebo.

Methods and Results:

In this placebo-controlled, double-blind, randomized trial, 65 intermediate risk firefighters (age 55 ± 6 years) were treated with a placebo capsule or a capsule containing AGE and CoQ10 (AGE+CoQ10, 1200 and 120 mg, respectively) daily for 1 year. All participants underwent coronary artery calcium (CAC) scanning and C-reactive protein (CRP) at baseline and at 12 months. At 1 year, mean CAC progression was significantly lower in AGE+CoQ10 (32 ± 6 vs. 58 ± 8, P = 0.01) than placebo. Similarly, CRP were significantly decreased in AGE+CoQ10 compared with placebo (-0.12 ± 0.24 vs. 0.91 ± 0.56 mg/L, P < 0.05). After adjustment for age, gender, conventional cardiac risk factors, and statin therapy, AGE+CoQ10 was associated with 3.99 fold (95% 1.3–12.2, P = 0.01) lack of CAC progression compared with the placebo.

Conclusion:

AGE+CoQ10 are associated with beneficial effects on inflammatory markers and reduced progression of coronary atherosclerosis.

The relationship between coenzyme Q10, oxidative stress, and antioxidant enzymes activities and coronary artery disease

A higher oxidative stress may contribute to the pathogenesis of coronary artery disease (CAD). The purpose of this study was to investigate the relationship between coenzyme Q10 concentration and lipid peroxidation, antioxidant enzymes activities and the risk of CAD. Patients who were identified by cardiac catheterization as having at least 50% stenosis of one major coronary artery were assigned to the case group (n = 51). The control group (n = 102) comprised healthy individuals with normal blood biochemical values. The plasma coenzyme Q10, malondialdehyde (MDA) and antioxidant enzymes activities (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx)) were measured. Subjects with CAD had significant lower plasma coenzyme Q10, CAT and GPx activities and higher MDA and SOD levels compared to those of the control group. The plasma coenzyme Q10 was positively correlated with CAT and GPx activities and negatively correlated with MDA and SOD. However, the correlations were not significant after adjusting for the potential confounders of CAD with the exception of SOD. A higher level of plasma coenzyme Q10 (≥0.52 μmol/L) was significantly associated with reducing the risk of CAD. Our results support the potential cardioprotective impact of coenzyme Q10.

Reduced coenzyme Q(10) in female smokers and its association with lipid profile in a young healthy adult population

INTRODUCTION

Cigarette smoking has a negative effect on body reserve of antioxidants and cholesterol metabolism. Coenzyme Q(10) (CoQ(10)), a potent antioxidant synthesized as part of the cholesterol pathway, is a potential biomarker for systemic oxidative stress. We aimed to investigate gender variation in plasma lipid profile and CoQ(10) concentrations in healthy non-smokers and in smokers.

MATERIAL AND METHODS

The study included 55 cigarette smokers (25 females and 30 males) and 51 non-smokers (25 females and 26 males) with the age range from 21 to 45 years, and who had no history of alcohol abuse or chronic diseases such as diabetes mellitus or obesity. Coenzyme Q(10) plasma concentrations were measured by reverse-phase high performance liquid chromatography (HPLC) with ultraviolet detection. Fasting plasma glucose and lipid levels were determined by standard colorimetric methods.

RESULTS

Our results showed that CoQ(10) concentrations were significantly decreased in smokers, especially in females, than their non-smoker counterparts. Female smokers also exhibited a significant decrease in plasma concentrations of total cholesterol (TC), HDL-C, LDL-C, and atherogenic ratios HDL-C/TC and CoQ(10)/LDL-C than male counterparts. Plasma triglyceride concentrations were increased in smokers irrespective of gender. Plasma CoQ(10) was relatively more associated with TC and LDL-C in female smokers than male smokers.

CONCLUSIONS

The adverse effects of smoking on body reserve of antioxidants and cholesterol metabolism are greater in females than in males, partially as a result of decreased CoQ(10) plasma concentrations, HDL-C and total-cholesterol and abnormal atherogenicity indices.

Hormonal influence on coenzyme Q(10) levels in blood plasma

Coenzyme Q₁₀ (CoQ₁₀), also known as ubiquinone for its presence in all body cells, is an essential part of the cell energy-producing system. However, it is also a powerful lipophilic antioxidant protecting lipoproteins and cell membranes. Due to these two actions, CoQ₁₀ is commonly used in clinical practice in chronic heart failure, male infertility, and neurodegenerative disease. However, it is also taken as an anti-aging substance by healthy people aiming for long-term neuroprotection and by sportsmen to improve endurance. Many hormones are known to be involved in body energy regulation, in terms of production, consumption and dissipation, and their influence on CoQ₁₀ body content or blood values may represent an important pathophysiological mechanism. We summarize the main findings of the literature about the link between hormonal systems and circulating CoQ₁₀ levels. In particular the role of thyroid hormones, directly involved in the regulation of energy homeostasis, is discussed. There is also a link with gonadal and adrenal hormones, partially due to the common biosynthetic pathway with CoQ₁₀, but also to the increased oxidative stress found in hypogonadism and hypoadrenalism.

Coenzyme Q(10) in male infertility: physiopathology and therapy

Both the bioenergetic and the antioxidant role of CoQ(10) suggest a possible involvement in sperm biochemistry and male infertility. CoQ(10) can be quantified in seminal fluid, where its concentration correlates with sperm count and motility. It was found that distribution of CoQ(10) between sperm cells and seminal plasma was altered in varicocele patients, who also presented a higher level of oxidative stress and lower total antioxidant capacity. The effect of vericocelectomy on partially reversing these biochemical abnormalities is discussed. The redox status of coenzyme Q(10) in seminal fluid was also determined: an inverse correlation was found between ubiquinol/ubiquinone ratio and hydroperoxide levels and between this ratio and the percentage of abnormal sperm forms. After the first in vitro observations CoQ(10) was administered to infertile patients affected by idiopathic asthenozoospermia, originally in an open label study and then in three randomized placebo-controlled trials; doses were around 200-300 mg/day and treatment lasted 6 months. A significant increase in the concentration of CoQ(10) was found, both in seminal plasma and sperm cells. Treatment also led to a certain improvement in sperm motility. In one of the studies there was also a decrease in plasma levels of follicle stimulating horhone (FSH) and luteinizine horhone (LH). Administration of CoQ(10) may play a positive role in the treatment of asthenozoospermia, possibly related to not only to its function in the mitochondrial respiratory chain but also to its antioxidant properties. Further studies are needed in order to determine whether there is also an effect on fertility rate.

Multiple aberrations in shared inflammatory and oxidative & nitrosative stress (IO&NS) pathways explain the co-association of depression and cardiovascular disorder (CVD), and the increased risk for CVD and due mortality in depressed patients

There is evidence that there is a bidirectional relationship between major depression and cardiovascular disorder (CVD): depressed patients are a population at risk for increased cardiac morbidity and mortality, and depression is more frequent in patients who suffer from CVD. There is also evidence that inflammatory and oxidative and nitrosative stress (IO&NS) pathways underpin the common pathophysiology of both CVD and major depression. Activation of these pathways may increase risk for both disorders and contribute to shared risk. The shared IO&NS pathways that may contribute to CVD and depression comprise the following: increased levels of pro-inflammatory cytokines, like interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-12, tumor necrosis factor-α, and interferon-γ; T cell activation; increased acute phase proteins, like C-reactive protein, haptoglobin, fibrinogen and α1-antitrypsin; complement factors; increased LPS load through bacterial translocation and subsequent gut-derived inflammation; induction of indoleamine 2,3-dioxygenase with increased levels of tryptophan catabolites; decreased levels of antioxidants, like coenzyme Q10, zinc, vitamin E, glutathione and glutathione peroxidase; increased O&NS characterized by oxidative damage to low density lipoprotein (LDL) and phospholipid inositol, increased malondialdehyde, and damage to DNA and mitochondria; increased nitrosative stress; and decreased ω3 polyunsaturated fatty acids (PUFAs). The complex interplay between the abovementioned IO&NS pathways in depression results in pro-atherogenic effects and should be regarded as a risk factor to future clinical CVD and due mortality. We suggest that major depression should be added as a risk factor to the Charlson "comorbidity" index. It is advised that patients with (sub)chronic or recurrent major depression should routinely be assessed by serology tests to predict if they have an increased risk to cardiovascular disorders.

Evaluation of antioxidant systems in pituitary-adrenal axis diseases

The role of adrenal steroids in antioxidant regulation is not known. Previously, we demonstrated some Coenzyme Q(10) (CoQ(10)) alterations in pituitary diseases, which can induce complex pictures due to alterations of different endocrine axes. Therefore we determined CoQ(10) and Total Antioxidant Capacity (TAC) in pituitary-dependent adrenal diseases: 6 subjects with ACTH-dependent adrenal hyperplasia (AH); 19 with secondary isolated hypoadrenalism (IH), 19 with associated hypothyroidism (multiple pituitary deficiencies, MPH). CoQ(10) was assayed by HPLC; TAC by the system metmyoglobin-H(2)O(2), which, interacting with the chromogenous 2,2(I)-azinobis-(3-ethylbenzothiazoline-6-sulphonate), generates a spectroscopically revealed radical compound after a latency time (Lag) proportional to the antioxidant content. CoQ(10) levels were significantly lower in IH than AH and MPH, with a similar trend when adjusted for cholesterol. Also TAC was lower in IH than in AH and MPH, suggesting that adrenal hormones can influence antioxidants. However, since thyroid hormones modulate CoQ(10) levels and metabolism, when thyroid deficiency coexists it seems to play a prevalent influence.

Hormones and antioxidant systems: role of pituitary and pituitary-dependent axes

Oxidative stress, a condition defined as unbalancing between production of free radicals and antioxidant defenses, is an important pathogenetic mechanism in different diseases. Despite the abundant literature, many aspects of hormone role in regulating antioxidant synthesis and activity still remain obscure. Therefore, we reviewed experimental data, in vivo and in vitro, about the effects of the different pituitary- dependent axes on antioxidant levels, trying to give a broad view from hormones which also have antioxidant properties to the classic antioxidants, from the lipophilic antioxidant Coenzyme Q10, strictly related to thyroid function, to total antioxidant capacity, a measure of non-protein non-enzymatic antioxidants in serum and other biological fluids. Taken together, these data underline the importance of oxidative stress in various pituitary-dependent disorders, suggesting a possible clinical usefulness of antioxidant molecules.

Evaluation of antioxidant systems (coenzyme Q10 and total antioxidant capacity) in morbid obesity before and after biliopancreatic diversion

Biliopancreatic diversion (BPD) is a surgical procedure performed in patients with untreatable obesity and insulin resistance. The demonstrated metabolic and hormonal results of this procedure include the reversal of insulin resistance; an increase in diet-induced thermogenesis; and modifications of gut hormones, such as gastrin, enteroglucagon, neurotensin, and cholecystokinin. On the other hand, obesity is a condition of increased oxidative stress; however, few studies have investigated antioxidant systems in obese persons with BPD. To evaluate the metabolic status and antioxidant systems in such patients, we studied a group of 11 morbidly obese patients, aged 28 to 62 years, with a mean body mass index (BMI) of 54.71 +/- 2.52 kg/m(2), before and after successful BPD (mean post-BPD BMI, 44.68 +/- 1.51 kg/m(2)). A control group composed of 10 slightly overweight women, with a mean BMI of 28.5 +/- 0.72 kg/m(2), was also studied. Coenzyme Q(10) (CoQ(10)) levels (also normalized for cholesterol levels) and total antioxidant capacity in blood plasma were assessed in these populations. The most striking datum was the extremely low level of CoQ(10) in postoperative period (0.34 +/- 0.16 vs 0.66 +/- 0.09 mug/mL, P = .04); also, the data corrected for cholesterol levels presented the same pattern, with a more marked significance (152.46 +/- 11.13 vs 186.4 +/- 17.98 nmol/mmol, P = .001). This could be due to lipid malabsorption after surgery. In fact, the pre-BPD data present all the metabolic and hormonal characteristics of severe obesity; and after BPD, there was a net improvement in the metabolic parameters. The first pathophysiologic phenomenon seems to be lipid malabsorption that has been argued to be the cause of insulin resistance reversion. This metabolic interpretation is also confirmed by the absence of significant variations of total antioxidant capacity (57.5 +/- 5.3 vs 66 +/- 5.3). The mechanisms of these phenomena remain to be established. These data suggest the importance of correcting postsurgical metabolic complications, in these clinical populations, with CoQ(10) supplementation.

Determination of coenzyme Q10 and Q9 in vegetable oils

A new sensitive and selective method has been developed for the quantification of the total coenzyme Q9 (CoQ9) and coenzyme Q10 (CoQ10) concentration in vegetable oil samples. The coenzyme Q fraction is isolated by solid-phase extraction (SPE) on amino phase eluting with a mixture of heptane:ethyl ether. The organic solvent is evaporated under nitrogen, and the residue is dissolved in a mixture of acetonitrile:tetrahydrofuran and finally is analyzed by reverse-phase high-performance liquid chromatography with a mass detector. The sensitivity of the method is based on the high efficient formation of the radical anions [M (-.)] of CoQ9 and CoQ10 by negative atmospheric pressure ionization. Interferences are minimized by using mass detection of the [M (-.)] ions ( m/ z = 797.5 for CoQ9 and m/ z = 862.5 for CoQ10) in selective reaction monitoring mode ( m/ z = 797.5 --> m/ z = 779.5 and m/ z = 862.5 --> m/ z = 847.5) using a triple-quadrupole mass spectrometer. The method was successfully applied to sunflower, soybean, and rapeseed oils, with a limit of quantification of 0.025 mg/kg for both compounds.

Environmental contaminants and redox status of coenzyme Q10 and vitamin E in Inuit from Nunavik

The Inuit are heavily exposed to potentially prooxidant contaminants such as methylmercury (MeHg) and polychlorinated biphenyls (PCB) through their traditional diet. This diet is also an abundant source of n-3 polyunsaturated fatty acids (n-3 PUFA), selenium, and antioxidants, which might reduce cardiovascular risk. Although Inuit from Nunavik have low concentrations of plasma oxidized low-density lipoprotein (OxLDL) and elevated glutathione-related antioxidant defenses, the variance in OxLDL was predicted by PCB and blood glutathione, leaving the issue of contaminant-associated oxidative stress unresolved. The objective of the study was to assess oxidative stress in these Inuit by measuring the plasma concentrations and redox states of alpha-tocopherol and coenzyme Q10 (CoQ10), 2 sensitive biomarkers of oxidative stress, in relation to exposure. Plasma lipophilic antioxidants were determined by high-performance liquid chromatography-coupled electrochemical detection; and their relations to PCB, MeHg, n-3 PUFA, selenium, and OxLDL were assessed by multivariate analyses. Ubiquinol-10, ubiquinone-10, and ubiquinone-10 to CoQ10(total) ratio were elevated as compared with white populations but showed no associations with PCB, MeHg, or n-3 PUFA. Ubiquinol-10 (beta = .23, P = .007) and CoQ10(total) (beta = .27, P = .009) were predicted by blood selenium; and alpha-tocopherol, by PCB (beta = 4.12, P = .0002), n-3 PUFA (beta = 9.16, P = .02), and OxLDL (beta = 3.04, P = .05). Unexpectedly, the alpha-tocopheryl quinone to alpha-tocopherol ratio, in the reference range, was negatively predicted by PCB (beta = -0.41, P = .02). Using sensitive biomarkers of redox alterations, we found no evidence for MeHg- or PCB-associated oxidative stress in these Inuit. However, despite robust blood antioxidant defenses, the unusually elevated ubiquinone-10 to CoQ10(total) ratio (0.21 +/- 0.11) suggests some form of oxidative stress of unknown origin.

Seasonal mercury exposure and oxidant-antioxidant status of James Bay sport fishermen

The effects of a moderate seasonal exposure to methylmercury on plasma low-density lipoprotein (LDL) oxidation and cardiovascular risk indices are not known. The objective of the study was to assess the effects of a seasonal exposure to mercury at similar dose reported to increase cardiovascular risk through fish consumption. Effects on lipoprotein cholesterol and fatty acid profiles, LDL oxidation, and blood oxidant-antioxidant balance were to be assessed in sport fishermen presenting normal blood selenium and omega-3 fatty acid contents. Thirty-one healthy James Bay sport fishermen were assessed for within-subject longitudinal seasonal variations in hair and blood mercury, plasma oxidized LDL, lipophilic antioxidants, homocysteine, blood selenium, and glutathione peroxidase and reductase activities determined before and after the fishing season and compared by matched-pair tests. Hair mercury doubled during the fishing season (2.8+/-0.4 microg/g, P<.0001). Baseline blood selenium, homocysteine, and erythrocyte fatty acid profiles did not change. Plasma high-density lipoprotein cholesterol increased (+5%, P=.05), whereas very low-density lipoprotein cholesterol and oxidized LDL decreased (-8%, P=.05; -18%, P=.008). Blood glutathione peroxidase (+9.7%, P=.001), glutathione reductase (+7.2%, P<.0001), and total glutathione (+45% P<.0001) increased during the fishing season. Plasma total coenzyme Q10 (+13%, P=.02), ubiquinone-10 (+67%, P=.03), and beta-carotene (+46%, P=.01) also increased, whereas vitamin E status was unaffected. Pairwise correlations revealed no association between mercury exposure and any of the biomarkers investigated. In contrast, strong predictors of cardiovascular risk such as high-density lipoprotein cholesterol, oxidized LDL, and glutathione peroxidase improved during the fishing season despite elevated methylmercury exposure. The beneficial effects of seasonal fishing activity and fish consumption on cardiovascular health may suppress detrimental effects of concomitant moderate methylmercury exposure.

Continuous counter current extraction, isolation and determination of solanesol in Nicotiana tobacum L. by non-aqueous reversed phase high performance liquid chromatography

A method of continuous counter current extraction in a large-scale production of solanesol from tobacco leaves was developed. The crude extract containing 15-20% solanesol was subjected to a series of steps, viz., saponification, solvent recrystallization and column chromatography. The pure material was characterized by FT-IR, ESI-MS, 1H NMR and 13C NMR spectrometry. The analysis was carried out by a simple and rapid non-aqueous reversed-phase high performance liquid chromatographic method on a Hypersil BDS C18 column (250 mm x 4.6mm, particle size 5 microm) with isopropyl alcohol-methanol (60:40, v/v) as mobile phase and detection at 215 nm. The product purity was between 95 and 98% (w/w) as determined by HPLC.

Antiangiogenic and hypolipidemic activity of coenzyme Q10 supplementation to breast cancer patients undergoing Tamoxifen therapy

Tamoxifen, a non-steroidal anti-estrogen is now widely used and has led to an increase in both disease-free and overall survival of women after primary surgery. Tamoxifen therapy is found to cause hypertriglyceridemia by reducing activity of lipolytic enzymes on triglycerides, and thereby increasing the risk of cardiovascular disease. Angiogenesis promotes local tumour progression and invasion and enables tumour cell dissemination and metastasis formation. Our study has found that co-administration of Coenzyme Q10 (100 mg) along with tamoxifen (10 mg, twice a day) to breast cancer patients reduced the level of angiogenesis markers and lipid levels.

Coenzyme Q10 protect against ischemia/reperfusion induced biochemical and functional changes in rabbit urinary bladder

PURPOSE

Ischemia, reperfusion, and free radical generation have been recently implicated in the progressive bladder dysfunction. Coenzyme Q10 (CoQ10) is a pro-vitamin like substance that appears to be efficient for treatment of neurodegenerative disorders and ischemic heart disease. Our goal was to investigate the potential protective effect of CoQ10 in a rabbit model of in vivo bilateral ischemia and ischemia/reperfusion (I/R).

MATERIAL AND METHODS

Six groups of four male New Zealand White rabbits each were treated with CoQ10 (3 mg/kg body weight/day-dissolved in peanut oil) (groups 1-3) or vehicle (peanut oil) (groups 4-6). Groups 1 and 4 (ischemia-alone groups) had clamped bilateral vesical arteries for 2 h; in groups 2 and 5 (I/R groups), bilateral ischemia was similarly induced and the rabbits were allowed to recover for 2 weeks. Groups 3 and 6 were controls (shams) and were exposed to sham surgery. The effects on contractile responses to various stimulations and biochemical studies such as citrate synthase (CS), choline acetyltransferase (ChAT), superoxide dismutase (SOD), and catalase (CAT) were evaluated. The protein peroxidation indicator, carbonyl group, and nitrotyrosine contents were analyzed by Western blotting.

RESULTS

Ischemia resulted in significant reductions in the contractile responses to all forms of stimulation in vehicle-fed rabbits, whereas there were no reductions in CoQ10-treated rabbits. Contractile responses were significantly reduced in vehicle-treated I/R groups, but significantly improved in CoQ10-treated rabbits. Protein carbonylation and nitration increased significantly in ischemia-alone and I/R bladders; CoQ10 treatment significantly attenuated protein carbonylation and nitration. CoQ10 up-regulated SOD and CAT activities in control animals; the few differences in CoQ10-treated animal in SOD and CAT after ischemia and in general increase CAT activities following I/R.

CONCLUSIONS

CoQ10 supplementation provides bladder protection against I/R injury. This protection effect improves mitochondrial function during I/R by repleting mitochondrial CoQ10 stores and potentiating their antioxidant properties.

Augmented antioxidant status in Tamoxifen treated postmenopausal women with breast cancer on co-administration with Coenzyme Q10, Niacin and Riboflavin

BACKGROUND

Reactive oxygen species (ROS) such as superoxide anion, hydrogen peroxide (H(2)O(2)), hydroxyl radical have been implicated in pathogenesis of various diseases including cancer and metastasis. Tamoxifen (TAM) is a non-steroidal anti-estrogen drug most widely used as an adjuvant hormonal therapy in breast cancer. TAM also has estrogenic activity on liver and endometrium causing severe oxidative stress and hypertriglycerdemia. Coenzyme Q(10) (CoQ(10)), Niacin and Riboflavin are well-known potent antioxidants and protective agents against many diseases including cancer. In this context, this study was undertaken to find if co-administration of CoQ(10), Niacin and Riboflavin along with TAM could augment the antioxidant (AO) status in postmenopausal women with breast cancer.

METHODS

The vitamin supplementation with Tamoxifen was given for a period of 90 days. Blood samples were collected at the base line, 45th and 90th day during the course of treatment. Plasma lipids, lipid peroxides and various circulating enzymatic and non-enzymatic antioxidants were estimated in 78 untreated, sole TAM treated and combinatorial treated group along with 46 age- and sex-matched controls.

RESULTS

Enhanced oxidative stress as evidenced by increased lipids and lipid peroxides with decreased AO levels in untreated breast cancer patients was observed. Adjuvant TAM-treated group had a limited impact on the increased oxidative stress with decreased AO status. Severe hypertriglycerdemia was observed in TAM-treated group when compared to untreated and control subjects. Combinatorial therapy (CT) of CoQ(10), Niacin and Riboflavin along with TAM decreased the oxidative stress and increased the AO status.

CONCLUSION

The antioxidant defense system is compromised in breast cancer patients. There is a shift in the oxidant / antioxidant balance in favor of lipid peroxidation (LPO), which could lead to tumour promotion observed in the disease. CT of CoQ(10), Niacin and Riboflavin along with TAM significantly increased the AO status, while decreasing lipid and lipid peroxides. The results suggest the necessity of therapeutic co-administration of antioxidants along with conventional drug to such patients. However, due to limited number of cases included in this study, more studies may be required to substantiate the results and arrive at a definitive conclusion, in terms of safety and efficacy of adding an AO therapy in treatment of breast cancer.

Rapid and quantitative determination of solanesol in Nicotiana tabacum by liquid chromatography-tandem mass spectrometry

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with multiple reaction monitoring (MRM) was developed for the determination of solanesol in Nicotiana tabacum. Sample preparation was performed by ultrasonic extraction with methanol for 20 min and then supernatant was extracted with hexane. The method used atmospheric pressure chemical ionization (APCI) detection in positive-ion mode. The separation of solanesol was performed on a Symmetry Shield RP18 column with a mixture of acetonitrile and isopropanol (1:1, v/v) containing 2mM ammonium acetate as mobile phase. Quantification of solanesol was performed by the standard addition method. The limit of quantification (LOQ) and limit of detection (LOD) of solanesol were, respectively, 5.0 ng/ml (S/N=10) and 1.5 ng/ml (S/N=3). The relative standard deviations of peak area were 0.89 and 1.12% for intra-day and inter-day, respectively. The recoveries of solanesol ranged from 97.72 to 99.67% and the corresponding R.S.D.s were less than 2.7%. Analysis took 5 min, making the method suitable for rapid determination of solanesol in N. tabacum. The proposed method has been successfully applied to the analysis of solanesol in various organs of N. tabacum.

Ubiquinol-10/lipids ratios in consecutive patients with different angiographic findings

OBJECTIVE

Information concerning un-supplemented plasma concentrations of ubiquinol-10 in coronary artery disease patients is still controversial. The aim of this study is to determine the levels of plasma ubiquinol-10 and ratios of ubiquinol-10 to plasma lipids in consecutive patients with different angiographic findings.

SUBJECTS AND METHODS

Thirty-six consecutive patients who underwent coronary angiography were split in two groups with different atherosclerotic changes. These patients were un-supplemented with antioxidants and were not treated by lipid-lowering medication. We have measured a plasma level of ubiquinol-10 using high-performance liquid chromatography with coulometric detection. Conventional plasma lipids, markers of oxidative stress and other widely accepted risk factors of atherosclerosis have been determined too.

RESULTS

Plasma ubiquinol-10 to low-density lipoprotein cholesterol (LDL-C) ratios in patients with different angiographic findings have been found as 180+/-69 and 132+/-43, respectively (p=0.020). The ubiquinol-10/LDL-C ratio was significantly lower in angiographically positive patients. There were also significant differences in ubiquinol-10 per total cholesterol (109+/-47 and 80+/-26, respectively; p=0.031), per triglycerides (426+/-191 and 237+/-86, respectively; p=0.002) and per the sum of triglycerides and total cholesterol (86+/-35 and 61+/-20, respectively; p=0.013).

CONCLUSIONS

There have not been found any significant differences between levels of widely accepted risk factors for genesis and progress of atherosclerotic changes in these two groups of patients. Only the level of triglycerides and the total cholesterol minus high-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio were significantly higher in patients with stenosis. This ratio correlated with the ubiquinol-10/LDL-C ratio, which was significantly lower in patients with stenosis. Our results indicate that the ratio of ubiquinol-10/LDL-C is likely to be a risk factor for atherogenesis.

Ameliorating effect of coenzyme Q10, riboflavin and niacin in tamoxifen-treated postmenopausal breast cancer patients with special reference to lipids and lipoproteins

OBJECTIVES

Tamoxifen (TAM), a non-steroidal anti-estrogen that is widely used in adjuvant therapy for all stages of breast carcinomas and in chemoprevention of high-risk group. The hepatic estrogenic effect of TAM induces hypertriglyceridemia by reduced activity of lipolytic enzymes (LPL) on triglycerides. Coenzyme Q10 (Co Q10), riboflavin and niacin are proved to be potent antioxidant and protective agents against many diseases including cancer and cardiovascular diseases (CVD). In this context, the objective of the study is to find the effect of the combined modality of Co Q10 (100 mg), riboflavin (10 mg) and niacin (50 mg) with TAM (10 mg twice a day) on serum lipids and lipoprotein levels in postmenopausal women with breast cancer.

DESIGN AND METHODS

The vitamin supplementation with tamoxifen was given for a period of 90 days. Blood samples were collected at the base line, 45th and 90th day during the course of treatment. Plasma total cholesterol (TC), free cholesterol (FC), ester cholesterol (EC), phospholipids (PL), triglycerides (TGL), free fatty acids (FFA), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and very low density cholesterol (VLDL-C) were estimated in 78 untreated, only TAM-treated and combinatorialy treated group along with 46 age- and sex-matched controls.

RESULTS

Serum TGL and VLDL-C (p<0.001) were found to be significantly elevated and LDL-C (p<0.01), significantly reduced among TAM-treated patients as compared to the untreated breast cancer subjects. All the lipids and lipoprotein levels were found to be significantly altered in the untreated breast cancer patients when compared to their normal counterparts. All the lipid and lipoprotein abnormalities were reverted back to near normal levels on 90 days of treatment on combinatorial therapy.

CONCLUSION

The study figures the altered lipid and lipoprotein levels in the untreated and TAM-treated breast cancer patients. On combination therapy with Co Q10, riboflavin and niacin, it counteracts the tamoxifen-induced hyperlipidemia to normal levels.

Determination of coenzyme Q10 in human seminal plasma by high-performance liquid chromatography and its clinical application

A high-performance liquid chromatographic (HPLC) method for the analysis of coenzyme Q10 (CoQ10) in human seminal plasma was developed and applied to investigate its clinical significance as a reference index relating to oxidative stress and infertile status of spermatozoa. After precipitation of proteins in seminal plasma with methanol, CoQ10 and coenzyme Q9 (CoQ9; internal standard) were extracted with hexane. The supernatant after centrifugation was evaporated to dryness with nitrogen at 45 degrees C. The residue was re-dissolved in isopropanol. HPLC separation of the sample solution was performed on a Lichrospher C(18) column with a mobile phase composed of isopropanol-methanol-tetrahydrofuran in the ratio of 55:39:6 (v/v/v) at a flow rate of 1.0 mL/min. Under the chromatographic conditions described, the CoQ10 and CoQ9 had retention times of approximately 5.83 and 4.97 min, respectively. The peaks were detected at UV 275 nm. Good separation and detectability of CoQ10 in human seminal plasma were obtained. The method was linear in the range 0.01-10.00 microg/mL. The relative standard deviations within- and between-assay for CoQ10 analysis were 0.85 and 1.86%, respectively. The average recoveries were 94.1-99.0% for the human seminal plasma samples. The CoQ10 levels in seminal plasma of 195 patients and 23 control subjects were studied. CoQ10 concentrations in the two populations were: 37.1 +/- 12.2 ng/mL in the fertile group and 48.5 +/- 20.4 ng/mL in the infertile group. The large difference (p < 0.01) between the fertile and infertile populations is evident.

Coenzyme Q10 evaluation in pituitary-adrenal axis disease: preliminary data

In previous works we have demonstrated plasma CoQ10 alterations in pituitary diseases, such as acromegaly or secondary hypothyroidism. However, pituitary lesions can induce complex clinical pictures due to alterations of different endocrine axes controlled by pituitary itself. A further rationale for studying CoQ10 in pituitary-adrenal diseases is related to the common biosynthetic pathway of cholesterol and ubiquinone. We have therefore assayed plasma CoQ10 levels in different conditions with increased or defective activity of pituitary-adrenal axis (3 subjects with ACTH-dependent adrenal hyperplasia, 2 cases of Cushing's disease and 1 case of 17-alpha-hydroxylase deficiency; 10 subjects with secondary hypoadrenalism, including three subjects with also secondary hypothyroidism). CoQ10 levels were significantly lower in isolated hypoadrenalism than in patients with adrenal hyperplasia and multiple pituitary deficiencies (mean +/- SEM: 0.57 +/- 0.04 vs 1.08 +/- 0.08 and 1.10 +/- 0.11 microg/ml, respectively); when corrected for cholesterol levels, the same trend was observed, but did not reach statistical significance. These preliminary data indicate that secretion of adrenal hormones is in some way related to CoQ10 levels, both in augmented and reduced conditions. However, since thyroid hormones have an important role in modulating CoQ10 levels and metabolism, when coexistent, thyroid deficiency seems to play a prevalent role in comparison with adrenal deficiency.

The Effect of HMG-CoA Reductase Inhibitors on Coenzyme Q10

The HMG-CoA reductase inhibitors, also known as statins, have an enviable safety profile; however, myotoxicity and to a lesser extent hepatotoxicity have been noted in some patients following treatment. Statins target several tissues, depending upon their lipophilicity, where they competitively inhibit HMG-CoA reductase, the rate-limiting enzyme for mevalonic acid synthesis and subsequently cholesterol biosynthesis. HMG-CoA reductase is also the first committed rate-limiting step for the synthesis of a range of other compounds including steroid hormones and ubidecarenone (ubiquinone), otherwise known as coenzyme Q(10) (CoQ(10)). Recent interest has focused on the possible role CoQ(10) deficiency may have in the pathophysiology of the rare adverse effects of statin treatment. Currently, there is insufficient evidence from human studies to link statin therapy unequivocally to pathologically significantly decreased tissue CoQ(10) levels. Although statin treatment has been reported to lower plasma/serum CoQ(10) status, few human studies have assessed tissue CoQ(10) status. The plasma/serum CoQ(10) level is influenced by a number of physiological factors and, therefore, has limited value as a means of assessing intracellular CoQ(10) status. In those limited studies that have assessed the effect of statin treatment upon tissue CoQ(10) levels, none have shown evidence of a fall in CoQ(10) levels. This may reflect the doses of statins used, since many appear to have been used at doses below those recommended for their maximum therapeutic effects. Moreover, the poor bioavailability in those peripheral tissues tested may not reflect the effects the agents are having in liver and muscle, the tissues commonly affected in those patients who do not tolerate statins. This article reviews the biochemistry of CoQ(10), its role in cellular metabolism and the available evidence linking possible CoQ(10) deficiency to statin therapy.