Decreased levels of coenzyme Q(10) in patients with bronchial asthma

The effect of coenzyme Q10 as a part of standard therapy on plasma concentrations of ubiquinol, ubiquinone, total CoQ10 and its redox state in patients with ischemic heart disease

BACKGROUND

Despite CoQ10 being a powerful antioxidant and its redox state that may characterize the body's antioxidant system, the latter remains unstudied in patients with cardiovascular diseases.

OBJECTIVE

This prospective case-control study aimed to investigate the concentrations of ubiquinol, ubiquinone, total CoQ10 and its redox state in patients with ischemic heart disease (IHD) and arterial hypertension (AH) during standard therapy and with the additional prescription of CoQ10.

METHODS

The study included 54 healthy individuals and 26 patients, who were divided into a control group receiving standard therapy and a test group receiving CoQ10 in addition to standard therapy. Quantitative determination of COQ10, ubiquinone and ubiquinol was carried out by HPLC-MS/MS.

RESULTS

It was found that the CoQ10 level in patients was significantly lower than in healthy individuals (on average -32Δ%). In the test group, after treatment, the concentrations of ubiquinol (+53 Δ%), ubiquinone (-28 Δ%), total CoQ10 (+27 Δ%) and redox state (+112 Δ%) were significantly different from the baseline, while in the control group no significant differences were noticed. In the test group after treatment, the levels of total CoQ10 (+25 Δ%), ubiquinol (+43 Δ%), and redox state (+86 Δ%) were statistically significantly higher than in the control group and total CoQ10 concentration did not significantly differ from that in healthy individuals (-12 Δ%).

CONCLUSION

The additional prescription of CoQ10 for patients with IHD significantly increases the level of total CoQ10, which leads to the increase of body antioxidant potential .

The effect of Co-Q10 on allergic rhinitis and allergic asthma

Background

Allergic asthma is an inflammatory disease resulting from continued or intermittent allergen exposure, and allergic rhinitis can be trigger of asthma. The main mechanism of these disease is allergic reaction and immune response dysregulation. Co-Q10 is an enzyme cofactor in mitochondria can control asthma and allergic rhinitis symptoms. In the present study, we determined that the CoQ10-induced anti-allergic effects were mediated by up-regulation of Nrf2.

Methods

Animal models of allergic rhinitis and allergic asthma were produced and treated with Co-Q10, Co-Q10 and O-3, Co-Q10 and Mg-S. Bronchoalveolar lavage fluid was collected from animal models, and IL-4, 5, 13, INF-y, Eicosanoids, IgE, EPO, and histamine production were measured. Also, COX-2, CCL24, CCL11, Nrf2, Eotaxin, Cytb, COX1 and ND1 genes expressions and histopathology were studied. BALf's cells were collected by tracheostomy and used in slide producing by cytospine. Cytokines, Eicosanoids, IgE, EPO, and histamine were measured by ELISA method. Gene expression was done by Real-time PCR.

Results

Co-Q10 with two supplementation (Mg-S and O-3) modulate MRC, BALf eosinophils, eosinophilic inflammation related genes (eotaxin, CCL11 and CCL24), peribronchial and perivascular inflammation, EPO, type 2 cytokines (IL-4, 5 and 13), IgE, histamine, Cyc-LT and LTB4 as main allergic bio-factors. Importantly, Co-Q10 treatment increased Nrf2 expression and Nrf2 induced antioxidant genes, glutathione redox and inhibited inflammation, oxidative stress injury, Th2 cytokines production and attenuated allergic inflammatory responses.

Conclusion

Nrf2 is activated in response to allergen, induces resistance against the rhinitis and asthma development and plays an essential role in broncho-protection. Co-Q10 increases the Nrf2 expression and the Nrf2 over-expression has strong effect in control of type2 cytokines, allergic mediators and inflammatory factors that lead to harnessing of allergy and asthma.

Graphic abstract

Coenzyme Q10 in COPD: An Unexplored Opportunity?

COPD represents a major cause of mortality and morbidity worldwide, is linked to systemic inflammation and tends to coexist with a variety of comorbidities. Inflammation, oxidative stress and protease-antiprotease imbalance represent the pathogenic triad of COPD. Even though oxidative stress and mitochondrial dysfunction is a well-studied phenomenon in COPD and there is a variety of studies that aim to counteract its effect, there is limited data available on the use of coenzyme Q10 in COPD. The aim of the current review is to analyze the current data on the use of coenzyme Q10 in the management of COPD and frequently encountered comorbidities.

Oxidative Stress and Bronchial Asthma in Children-Causes or Consequences?

Bronchial asthma is one of the most common chronic inflammatory diseases of the airways. In the pathogenesis of this disease, the interplay among the genes, intrinsic, and extrinsic factors are crucial. Various combinations of the involved factors determine and modify the final clinical phenotype/endotype of asthma. Oxidative stress results from an imbalance between the production of reactive oxygen species and reactive nitrogen species and the capacity of antioxidant defense mechanisms. It was shown that oxidative damage of biomolecules is strongly involved in the asthmatic inflammation. It is evident that asthma is accompanied by oxidative stress in the airways and in the systemic circulation. The oxidative stress is more pronounced during the acute exacerbation or allergen challenge. On the other hand, the genetic variations in the genes for anti-oxidative and pro-oxidative enzymes are variably associated with various asthmatic subtypes. Whether oxidative stress is the consequence of, or the cause for, chronic changes in asthmatic airways is still being discussed. Contribution of oxidative stress to asthma pathology remains at least partially controversial, since antioxidant interventions have proven rather unsuccessful. According to current knowledge, the relationship between oxidative stress and asthmatic inflammation is bidirectional, and genetic predisposition could modify the balance between these two positions-oxidative stress as a cause for or consequence of asthmatic inflammation.

Genome-Wide Association Study Identification of Novel Loci Associated with Airway Responsiveness in Chronic Obstructive Pulmonary Disease

Increased airway responsiveness is linked to lung function decline and mortality in subjects with chronic obstructive pulmonary disease (COPD); however, the genetic contribution to airway responsiveness remains largely unknown. A genome-wide association study (GWAS) was performed using the Illumina (San Diego, CA) Human660W-Quad BeadChip on European Americans with COPD from the Lung Health Study. Linear regression models with correlated meta-analyses, including data from baseline (n = 2,814) and Year 5 (n = 2,657), were used to test for common genetic variants associated with airway responsiveness. Genotypic imputation was performed using reference 1000 Genomes Project data. Expression quantitative trait loci (eQTL) analyses in lung tissues were assessed for the top 10 markers identified, and immunohistochemistry assays assessed protein staining for SGCD and MYH15. Four genes were identified within the top 10 associations with airway responsiveness. Markers on chromosome 9p21.2 flanked by LINGO2 met a predetermined threshold of genome-wide significance (P < 9.57 × 10(-8)). Markers on chromosomes 3q13.1 (flanked by MYH15), 5q33 (SGCD), and 6q21 (PDSS2) yielded suggestive evidence of association (9.57 × 10(-8) < P ≤ 4.6 × 10(-6)). Gene expression studies in lung tissue showed single nucleotide polymorphisms on chromosomes 5 and 3 to act as eQTL for SGCD (P = 2.57 × 10(-9)) and MYH15 (P = 1.62 × 10(-6)), respectively. Immunohistochemistry confirmed localization of SGCD protein to airway smooth muscle and vessels and MYH15 to airway epithelium, vascular endothelium, and inflammatory cells. We identified novel loci associated with airway responsiveness in a GWAS among smokers with COPD. Risk alleles on chromosomes 5 and 3 acted as eQTLs for SGCD and MYH15 messenger RNA, and these proteins were expressed in lung cells relevant to the development of airway responsiveness.

Coenzyme Q 10 – its biochemical and related aspects

This review analyses the findings of biochemical and related pharmacotherapeutical aspects of coenzyme Q10. Its important role in the respiratory chain is presented. Furthermore, the article presents administration of coenzyme Q10 as a supplement within preventative measures in medicine, its pharmacotherapeutical aspects and effects in a number of diseases of various aetiologies. Concurrently, it presents the issue of mutual interactions of coenzyme Q10 and its efficacy in combining supplementation with conservative therapy of selected aetiologies.

Vitamin E isoforms as modulators of lung inflammation

Asthma and allergic diseases are complex conditions caused by a combination of genetic and environmental factors. Clinical studies suggest a number of protective dietary factors for asthma, including vitamin E. However, studies of vitamin E in allergy commonly result in seemingly conflicting outcomes. Recent work indicates that allergic inflammation is inhibited by supplementation with the purified natural vitamin E isoform α-tocopherol but elevated by the isoform γ-tocopherol when administered at physiological tissue concentrations. In this review, we discuss opposing regulatory effects of α-tocopherol and γ-tocopherol on allergic lung inflammation in clinical trials and in animal studies. A better understanding of the differential regulation of inflammation by isoforms of vitamin E provides a basis towards the design of clinical studies and diets that would effectively modulate inflammatory pathways in lung disease.

Isoforms of Vitamin E Differentially Regulate PKC α and Inflammation: A Review

Vitamin E regulation of disease has been extensively studied but most studies focus on the α-tocopherol isoform of vitamin E. These reports indicate contradictory outcomes for anti-inflammatory functions of the α-tocopherol isoform of vitamin E with regards to animal and clinical studies. These seemingly disparate results are consistent with our recent studies demonstrating that purified natural forms of vitamin E have opposing regulatory functions during inflammation. In this review, we discuss that α-tocopherol inhibits whereas γ-tocopherol elevates allergic inflammation, airway hyperresponsiveness, leukocyte transendothelial migration, and endothelial cell adhesion molecule signaling through protein kinase Cα. Moreover, we have demonstrated that α-tocopherol is an antagonist and γ-tocopherol is an agonist of PKCα through direct binding to a regulatory domain of PKCα. In summary, we have determined mechanisms for opposing regulatory functions of α-tocopherol and γ-tocopherol on inflammation. Information from our studies will have significant impact on the design of clinical studies and on vitamin E consumption.

Oxidative stress status and plasma trace elements in patients with asthma or allergic rhinitis

INTRODUCTION

This study was conducted to evaluate the oxidant/antioxidant balance (oxidative stress status) and plasma essential trace element levels in patients with bronchial asthma or allergic rhinitis.

METHODS

A total of 94 individuals consisting of 19 allergic asthmatics; 17 non-allergic asthmatics; 22 patients with allergic rhinitis; and 36 healthy control people were enrolled into this study. Superoxide dismutase (CuZnSOD) and glutathione peroxidase (GSH-Px) activity as antioxidant defence mechanism parameters, along with malondialdehyde (MDA) as a marker of lipid peroxidation, were determined in erythrocytes of patient groups and controls. Plasma copper and zinc levels were also determined in all groups.

RESULTS

CuZnSOD activity was significantly lower in all groups of patients (p<0.001 for allergic asthmatics, p=0.008 for allergic rhinitis patients, and p<0.001 for non-allergic asthmatics) when compared to those of controls. Erythrocyte GSH-Px enzyme activity was not different when compared to that of the control group. Similarly, the patient groups had no difference from those of the controls with respect to erythrocyte MDA levels. While plasma Cu levels in all asthmatic patients were not different from those of the controls, allergic rhinitis patients had significantly elevated (p<0.001) Cu levels compared to those of the controls. No statistically significant difference was established between patient groups and controls with respect to plasma zinc levels.

CONCLUSION

While defective CuZnSOD activity observed in all patients groups was expected to cause an increase in lipid peroxidation indicated by high MDA levels in these patients groups, the fact that MDA levels were not different from those of controls in all patient groups indicates that other components of anti-oxidant defence system preserve their functions in these patients. On the other hand, statistically significant difference between all patients groups and controls with respect to trace elements was only observed in allergic rhinitis patients who had higher levels of Cu than those of controls.

Isoforms of vitamin E differentially regulate inflammation

Vitamin E regulation of disease has been extensively studied in humans, animal models and cell systems. Most of these studies focus on the α-tocopherol isoform of vitamin E. These reports indicate contradictory outcomes for anti-inflammatory functions of the α-tocopherol isoform of vitamin E, especially with regards to clinical studies of asthma and atherosclerosis. These seemingly disparate clinical results are consistent with recently reported unrecognized properties of isoforms of vitamin E. Recently, it has been reported that physiological levels of purified natural forms of vitamin E have opposing regulatory functions during inflammation. These opposing regulatory functions by physiological levels of vitamin E isoforms impact interpretations of previous studies on vitamin E. Moreover, additional recent studies also indicate that the effects of vitamin E isoforms on inflammation are only partially reversible using physiological levels of a vitamin E isoform with opposing immunoregulatory function. Thus, this further influences interpretations of previous studies with vitamin E in which there was inflammation and substantial vitamin E isoforms present before the initiation of the study. In summary, this review will discuss regulation of inflammation by vitamin E, including alternative interpretations of previous studies in the literature with regards to vitamin E isoforms.

Coenzyme Q10: Clinical Update and Bioavailability

Coenzyme Q10 (CoQ 10) supplementation has been reported to be beneficial in treating a variety of health conditions and diseases, with more than 200 clinical trials investigating its use as a drug or dietary supplement. Numerous reviews of the safety and clinical potential of CoQ10 have been published. Successful treatment and efficacy is dependent on the bioavailability of CoQ 10, which is well known to be poor because of its lipophilic nature and large molecular weight. A number of recent clinical trials on CoQ 10 have investigated new formulations of CoQ10 for improvements in absorption and bioavailability. This review provides an update of clinical efficacy trials using CoQ10 and describes recent advances in formulation technology to improve the bioavailability of CoQ10. The authors also discuss a new method to improve the standards of reporting the bioavailability results of such advanced CoQ10 formulations to help clinicians and consumers make informed decisions.

Mitochondrial Dysfunction and Oxidative Stress in Asthma: Implications for Mitochondria-Targeted Antioxidant Therapeutics

Asthma is a complex, inflammatory disorder characterized by airflow obstruction of variable degrees, bronchial hyper-responsiveness, and airway inflammation. Asthma is caused by environmental factors and a combination of genetic and environmental stimuli. Genetic studies have revealed that multiple loci are involved in the etiology of asthma. Recent cellular, molecular, and animal-model studies have revealed several cellular events that are involved in the progression of asthma, including: increased Th2 cytokines leading to the recruitment of inflammatory cells to the airway, and an increase in the production of reactive oxygen species and mitochondrial dysfunction in the activated inflammatory cells, leading to tissue injury in the bronchial epithelium. Further, aging and animal model studies have revealed that mitochondrial dysfunction and oxidative stress are involved and play a large role in asthma. Recent studies using experimental allergic asthmatic mouse models and peripheral cells and tissues from asthmatic humans have revealed antioxidants as promising treatments for people with asthma. This article summarizes the latest research findings on the involvement of inflammatory changes, and mitochondrial dysfunction/oxidative stress in the development and progression of asthma. This article also addresses the relationship between aging and age-related immunity in triggering asthma, the antioxidant therapeutic strategies in treating people with asthma.

Acquired coenzyme Q10 deficiency in children with recurrent food intolerance and allergies

The current study evaluated 23 children (ages 2-16 years) with recurrent food intolerance and allergies for CoQ10 deficiency and mitochondrial abnormalities. Muscle biopsies were tested for CoQ10 levels, pathology, and mitochondrial respiratory chain (MRC) activities. Group 2 (age >10 years; n = 9) subjects had significantly decreased muscle CoQ10 than Group 1 (age <10 y; n = 14) subjects (p = 0.001) and 16 controls (p<0.05). MRC activities were significantly lower in Group 2 than in Group 1 (p<0.05). Muscle CoQ10 levels in study subjects were significantly correlated with duration of illness (adjusted r(2) = 0.69; p = 0.012; n = 23). Children with recurrent food intolerance and allergies may acquire CoQ10 deficiency with disease progression.

Consumption of pasteurized human lysozyme transgenic goats' milk alters serum metabolite profile in young pigs

Nutrition, bacterial composition of the gastrointestinal tract, and general health status can all influence the metabolic profile of an organism. We previously demonstrated that feeding pasteurized transgenic goats' milk expressing human lysozyme (hLZ) can positively impact intestinal morphology and modulate intestinal microbiota composition in young pigs. The objective of this study was to further examine the effect of consuming hLZ-containing milk on young pigs by profiling serum metabolites. Pigs were placed into two groups and fed a diet of solid food and either control (non-transgenic) goats' milk or milk from hLZ-transgenic goats for 6 weeks. Serum samples were collected at the end of the feeding period and global metabolite profiling was performed. For a total of 225 metabolites (160 known, 65 unknown) semi-quantitative data was obtained. Levels of 18 known and 4 unknown metabolites differed significantly between the two groups with the direction of change in 13 of the 18 known metabolites being almost entirely congruent with improved health status, particularly in terms of the gastrointestinal tract health and immune response, with the effects of the other five being neutral or unknown. These results further support our hypothesis that consumption of hLZ-containing milk is beneficial to health.

Redox control of asthma: molecular mechanisms and therapeutic opportunities

An imbalance in reducing and oxidizing (redox) systems favoring a more oxidative environment is present in asthma and linked to the pathophysiology of the defining symptoms and signs including airflow limitation, hyper-reactivity, and airway remodeling. High levels of hydrogen peroxide, nitric oxide ((*)NO), and 15-F(2t)-isoprostane in exhaled breath, and excessive oxidative protein products in lung epithelial lining fluid, peripheral blood, and urine provide abundant evidence for pathologic oxidizing processes in asthma. Parallel studies document loss of reducing potential by nonenzymatic and enzymatic antioxidants. The essential first line antioxidant enzymes superoxide dismutases (SOD) and catalase are reduced in asthma as compared to healthy individuals, with lowest levels in those patients with the most severe asthma. Loss of SOD and catalase activity is related to oxidative modifications of the enzymes, while other antioxidant gene polymorphisms are linked to susceptibility to develop asthma. Monitoring of exhaled (*)NO has entered clinical practice because it is useful to optimize asthma care, and a wide array of other biochemical oxidative and nitrative biomarkers are currently being evaluated for asthma monitoring and phenotyping. Novel therapeutic strategies that target correction of redox abnormalities show promise for the treatment of asthma.

High plasma levels of CD40 are associated with low coenzyme Q and vitamin E content of low‐density lipoprotein in healthy men

OBJECTIVE

There is a growing body of evidence to suggest that low-density lipoprotein (LDL) cholesterol, inflammation and oxidative stress are pivotal in the development of cardiovascular disease, but their interconnections are not well known. The objective of this study was to determine whether immunological activation, reflected by the plasma levels of soluble CD40 (sCD40), interleukin (IL)-1beta, tumor necrosis factor-alpha and IL-6 are associated with the antioxidant potential of LDL particles or with common lipid, immunological or thrombotic markers in 51 young healthy men.

MATERIAL AND METHODS

We determined the coenzyme Q level from an oxidized LDL fraction, obtaining the concentration for ubiquinone, which indicates total coenzyme Q levels.

RESULTS

The plasma level of sCD40 was negatively correlated with LDL ubiquinone (r=-0.45, p=0.001) and E vitamin (r=-0.37, p=0.008) and positively correlated with plasma concentration of plasminogen activator inhibitor-1 (PAI-1, r=0.52, p=0.002) and caspase-1 (r=0.40, p=0.004). No correlation was detected between sCD40 and plasma lipid or C-reactive protein concentrations. As sCD40 was strongly correlated with the content of LDL ubiquinone and vitamin E, their values were compared according to groups formed by sCD40 tertiles. Analysis of variance showed that there were significant differences in LDL ubiquinone (p<0.0001) and vitamin E (p=0.004) concentrations between sCD40 tertiles.

CONCLUSIONS

The data indicate that increased activation of the CD40 system is related to low levels of LDL ubiquinone and vitamin E. This suggests that chronic or increased immunological activation may consume the antioxidant potential of LDL particles.

Kinetics of hypobromous acid-mediated oxidation of lipid components and antioxidants

Hypohalous acids are generated from the oxidation of halide ions by myeloperoxidase and eosinophil peroxidase in the presence of H2O2. These oxidants are potent antibacterial agents, but excessive production can result in host tissue damage, with this implicated in a number of human pathologies. Rate constants for HOCl with lipid components and antioxidants have been established. Here, the corresponding reactions of HOBr have been examined to determine whether this species shows similar reactivity. The second-order rate constants for the reaction of HOBr with 3-pentenoic acid and sorbate, models of unsaturated lipids, are 1.1x10(4) and 1.3x10(3) M(-1) s(-1), respectively, while those for reaction of HOBr with phosphoryl-serine and phosphoryl-ethanolamine are ca. 10(6) M(-1) s(-1). The second-order rate constants (M(-1) s(-1)) for reactions of HOBr with Trolox (6.4x10(4)), hydroquinone (2.4x10(5)), and ubiquinol-0 (2.5x10(6)) were determined, as models of the lipid-soluble antioxidants, alpha-tocopherol, and ubiquinol-10; all of these rate constants are ca. 50-2000-fold greater than for HOCl. In contrast, the second-order rate constants for the reaction of HOBr with the water-soluble antioxidants, ascorbate and urate, are ca. 10(6) M(-1) s(-1) and closer in magnitude to those for HOCl. Kinetic models have been developed to predict the sites of HOBr attack on low-density lipoproteins. The data obtained indicate that HOBr reacts to a much greater extent with fatty acid side chains and lipid-soluble antioxidants than HOCl; this has important implications for HOBr-mediated damage to cells and lipoproteins.

Elevated plasma glutathione peroxidase concentration in acute severe asthma: comparison with plasma glutathione peroxidase activity, selenium and malondialdehyde

OBJECTIVE

To investigate plasma glutathione peroxidase concentration, glutathione peroxidase activity, plasma selenium and oxidative stress in acute severe asthma.

MATERIAL AND METHODS

The study was case-control in design, with cases presenting to the emergency department with acute severe asthma and controls randomly selected from a larger cross-sectional study. Plasma malondialdehyde (MDA) was used as a measure of oxidative stress and plasma selenium was measured using ICP-MS. Glutathione peroxidase (GPx) activity was analysed using a colorimetric GPx assay and plasma GPx level was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Fifteen cases [mean (range) predicted peak expiratory flow rate (PEFR) of 43% (20-69)] and 15 matched controls were recruited. MDA levels (mean+/-SD) were higher in acute asthma subjects (1.30+/-0.56 micromol/L) than in controls (0.86+/-0.53 micromol/L; p<0.05). There were no differences between cases and controls for selenium (99+/-34 microg/L versus 109+/-17 microg/L) or for GPx activity (39+/-25 nmol min(-1) mL(-1) versus 38+/-24 nmol min(-1) mL(-1)), however, GPx plasma levels measured by ELISA were higher in cases than controls (22.5+/-10.8 mg/L versus 13.8+/-7.3 mg/L; p<0.05).

CONCLUSIONS

Patients with acute severe asthma demonstrated increased MDA levels but no differences in plasma selenium levels or GPx activity. GPx levels measured by ELISA were elevated in severe asthma. These results are consistent with an adaptive up-regulation of GPx to protect against oxidative stress.

Effects of oral alpha-tocopherol on lung response in rat model of allergic asthma

OBJECTIVE AND BACKGROUND

Asthma is a chronic inflammatory disease in which an oxidant/antioxidant imbalance plays an important role. d-alpha-tocopherol (biologically the most active form of vitamin E) has redox properties and by scavenging the free radicals can act as an antioxidant. The aim of this study was to examine the effects of orally administered alpha-tocopherol in a rat model of allergic asthma.

METHODOLOGY

Actively sensitized rats (OA) were treated with alpha-tocopherol (400 mg/kg/day for 10 days) or vehicle; 1 h after the last dose, they were challenged with antigen aerosol. The antigen-induced airway hyperresponsiveness to direct bronchoconstrictor (serotonin), the inflammatory cell infiltrate and histological changes were determined 1 or 24 h after the antigen challenge.

RESULTS

Alpha-tocopherol pretreatment was not significantly effective at reducing the studied parameters when compared with controls, even though there was a tendency to a reduction in bronchial responsiveness and in eosinophil and neutrophil infiltration.

CONCLUSION

Alpha-tocopherol when administered in the chosen study design in an animal model of asthma had no major effect on airway inflammation. The effect of antioxidants deserves further evaluation.

Coenzyme Q10 supplementation reduces corticosteroids dosage in patients with bronchial asthma

Bronchial asthma is a chronic inflammatory disease of respiratory system, with disturbances in the dynamic balance of oxidant-antioxidant capacity of the lungs. Long-term administration of corticosteroids has been shown to result in mitochondrial dysfunction and oxidative damage of mitochondrial and nuclear DNAs. We previously documented decreased coenzyme Q(10) (CoQ(10)) and alpha-tocopherol concentrations in plasma and blood in corticosteroid-dependent bronchial asthma patients. In the present study we demonstrate that CoQ(10) supplementation reduces the dosage of corticosteroids in these patients.

PATIENTS AND METHODS

This was an open, cross-over, randomized clinical study with 41 bronchial asthma patients (13 males, 28 females), ages 25-50 years. All patients suffered from persistent mild to moderate asthma. The patients were divided into two groups, one group receiving standard antiasthmatic therapy and clinically stabilized, and the second group receiving, in addition, antioxidants consisting of CoQ(10) as Q-Gel (120 mg) + 400 mg alpha-tocopherol + 250 mg vitamin C a day. The groups were crossed over at 16 weeks for a total duration of 32 weeks.

RESULTS AND CONCLUSIONS

Data show that patients with corticosteroid-dependent bronchial asthma have low plasma CoQ(10) concentrations that may contribute to their antioxidant imbalance and oxidative stress. A reduction in the dosage of corticosteroids required by the patients following antioxidant supplementation was observed, indicating lower incidence of potential adverse effects of the drugs, decreased oxidative stress. This study also demonstrates the significant uptake of CoQ(10) by lung tissue in a rat model using hydrosoluble CoQ(10) (Q-Gel).

Age-related changes in plasma coenzyme Q10 concentrations and redox state in apparently healthy children and adults

BACKGROUND

Coenzyme Q10 (CoQ) is an endogenous enzyme cofactor, which may provide protective benefits as an antioxidant. Because age-related CoQ changes and deficiency states have been described, there is a need to establish normal ranges in healthy children. The objectives of this study are to determine if age-related differences in reduced CoQ (ubiquinol), oxidized CoQ (ubiquinone), and CoQ redox state exist in childhood, and to establish reference intervals for these analytes in healthy children.

METHODS

Apparently healthy children (n=68) were selected from individuals with no history of current acute illness, medically diagnosed disease, or current medication treatment. Self-reported healthy adults (n=106) were selected from the ongoing Princeton Follow-up Study in greater Cincinnati. Participants were assessed for lipid profiles, ubiquinol concentration, ubiquinone concentration, total CoQ concentration, and CoQ redox ratio.

RESULTS

Mean total CoQ and ubiquinol concentrations are similar in younger children (0.2-7.6 years) and adults (29-78 years); however, lipid-adjusted total CoQ concentrations are significantly increased in younger children. Also CoQ redox ratio is significantly increased in younger and older children compared with adults.

CONCLUSIONS

Elevated CoQ and redox ratios in children may be an indication of oxidative stress effects, which are associated with early development of coronary heart disease.

Plasma coenzyme Q10 reference intervals, but not redox status, are affected by gender and race in self-reported healthy adults

BACKGROUND

Abnormal concentrations of coenzyme Q(10) have been reported in many patient groups, including certain cardiovascular, neurological, hematological, neoplastic, renal, and metabolic diseases. However, controls in these studies are often limited in number, poorly screened, and inadequately evaluated statistically. The purpose of this study is to determine the reference intervals of plasma concentrations of ubiquinone-10, ubiquinol-10, and total coenzyme Q(10) for self-reported healthy adults.

METHODS

Adults (n=148), who were participants in the Princeton Prevalence Follow-up Study, were identified as healthy by questionnaire. Lipid profiles, ubiquinone-10, ubiquinol-10, and total coenzyme Q(10) concentrations were measured in plasma. The method used to determine the reference intervals is a procedure incorporating outlier detection followed by robust point estimates of the appropriate quantiles.

RESULTS

Significant differences between males and females were present for ubiquinol-10 and total coenzyme Q(10). Blacks had significantly higher Q(10) measures than whites in all cases except for the ubiquinol-10/total Q(10) fraction.

CONCLUSIONS

The fraction of ubiquinol-10/total coenzyme Q(10) is a tightly regulated measure in self-reported healthy adults, and is independent of sex and racial differences. Different reference intervals for certain coenzyme Q(10) measures may need to be established based upon sex and racial characteristics.

Hepatocyte metabolism of coenzyme Q1 (ubiquinone-5) to its sulfate conjugate decreases its antioxidant activity

Previous studies on the metabolism of coenyzme Q (CoQ) have focused on products found in the urine, bile or feces. However, the metabolites found in these samples were end products from a multitude of catabolic processes which did not necessarily reflect CoQ intracellular metabolism (e.g. in the liver, the major site of CoQ synthesis or metabolism). Using isolated rat hepatocytes, we have found that the sulfation of coenzyme Q1 (CoQ1) was the initial and dominant step following its reduction to the hydroquinone. This metabolic process is important as conjugation may occur on the hydroquinone metabolites of any coenzyme10 scission product retaining the quinone ring. By using rat liver cytosol, we were able to identify the monosulfated metabolite of CoQ1. The CoQ1 sulfate conjugate was identified by mass spectrometry followed by tandem mass spectrometry. The rate of formation of the CoQ1 sulfate conjugate was markedly increased by the addition of NADH and was prevented by dicumarol, a DT-diaphorase (NQO1) inhibitor. CoQ1 sulfate conjugate formation catalysed by cytosol was inhibited by the sulfotransferase 1A (SULT1A) inhibitor, pentachlorophenol (PCP) suggesting that sulfation was carried out by the SULT 1A isoform. CoQ1 sulfation in isolated hepatocytes and inversely CoQ1 hydroquinone formation were dependent on the concentration of inorganic sulfate in the media. Intracellular sulfation also decreased CoQ1 antioxidant and cytoprotective activity towards cumene hydroperoxide (CHP) induced cell death. Sulfotransferases may therefore play a significant role in endogenous CoQ metabolism following its degradation to short chain products.