Effect of coenzyme Q10 supplementation on mitochondrial function after myocardial ischemia reperfusion

Dynamic changes in the mouse hepatic lipidome following warm ischemia reperfusion injury

Liver failure secondary to metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most common cause for liver transplantation in many parts of the world. Moreover, the prevalence of MASLD not only increases the demand for liver transplantation, but also limits the supply of suitable donor organs because steatosis predisposes grafts to ischemia-reperfusion injury (IRI). There are currently no pharmacological interventions to limit hepatic IRI because the mechanisms by which steatosis leads to increased injury are unclear. To identify potential novel mediators of IRI, we used liquid chromatography and mass spectrometry to assess temporal changes in the hepatic lipidome in steatotic and non-steatotic livers after warm IRI in mice. Our untargeted analyses revealed distinct differences between the steatotic and non-steatotic response to IRI and highlighted dynamic changes in lipid composition with marked changes in glycerophospholipids. These findings enhance our knowledge of the lipidomic changes that occur following IRI and provide a foundation for future mechanistic studies. A better understanding of the mechanisms underlying such changes will lead to novel therapeutic strategies to combat IRI.

Cardio-Oncology: Mechanisms, Drug Combinations, and Reverse Cardio-Oncology

Chemotherapy, radiotherapy, targeted therapy, and immunotherapy have brought hope to cancer patients. With the prolongation of survival of cancer patients and increased clinical experience, cancer-therapy-induced cardiovascular toxicity has attracted attention. The adverse effects of cancer therapy that can lead to life-threatening or induce long-term morbidity require rational approaches to prevention and treatment, which requires deeper understanding of the molecular biology underpinning the disease. In addition to the drugs used widely for cardio-protection, traditional Chinese medicine (TCM) formulations are also efficacious and can be expected to achieve “personalized treatment” from multiple perspectives. Moreover, the increased prevalence of cancer in patients with cardiovascular disease has spurred the development of “reverse cardio-oncology”, which underscores the urgency of collaboration between cardiologists and oncologists. This review summarizes the mechanisms by which cancer therapy induces cardiovascular toxicity, the combination of antineoplastic and cardioprotective drugs, and recent advances in reverse cardio-oncology.

Pathogenetic rationale for using an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase and an antioxidant coenzyme Q₁₀ in the treatment and prevention of cardiovascular disease

The review discusses atherosclerosis-related mechanisms of car-diovascular disease development, as well as the optimization of their prevention and treatment methods. Recent experimental and clinical studies have shown the important role of vascular endothelium in the development and progression of atherosclerosis. Myocardial ischemia, activation of free-radical processes and impaired bioenergetics initiate a decrease in production of nitric oxide, which plays major vasodilator role. In this regard, the scientists is interested in the search for new drugs that can affect the main pathogenetic links of coronary artery disease. Statins are currently the drugs of choice. However, they are not always effective and have an ambiguous effect on oxidative potential of myocardial cells and endothelial function. Moreover, inhibition of mevalonic pathway for cholesterol synthesis is accompanied by a deficiency of coenzyme Q10, which is the central cellular antioxidant that protects phospholipids of cell membranes from free radicals. Rationale of using coenzyme Q10 in the complex treatment and secondary prev ention of cardiovascular diseases, including coronary artery di sease, is discussed.

Combating Ischemia-Reperfusion Injury with Micronutrients and Natural Compounds during Solid Organ Transplantation: Data of Clinical Trials and Lessons of Preclinical Findings

Although extended donor criteria grafts bear a higher risk of complications such as graft dysfunction, the exceeding demand requires to extent the pool of potential donors. The risk of complications is highly associated with ischemia-reperfusion injury, a condition characterized by high loads of oxidative stress exceeding antioxidative defense mechanisms. The antioxidative properties, along with other beneficial effects like anti-inflammatory, antiapoptotic or antiarrhythmic effects of several micronutrients and natural compounds, have recently emerged increasing research interest resulting in various preclinical and clinical studies. Preclinical studies reported about ameliorated oxidative stress and inflammatory status, resulting in improved graft survival. Although the majority of clinical studies confirmed these results, reporting about improved recovery and superior organ function, others failed to do so. Yet, only a limited number of micronutrients and natural compounds have been investigated in a (large) clinical trial. Despite some ambiguous clinical results and modest clinical data availability, the vast majority of convincing animal and in vitro data, along with low cost and easy availability, encourage the conductance of future clinical trials. These should implement insights gained from animal data.

Therapeutic targeting of oxidative stress with coenzyme Q10 counteracts exaggerated diabetic cardiomyopathy in a mouse model of diabetes with diminished PI3K(p110α) signaling

Diabetes-induced cardiac complications include left ventricular (LV) dysfunction and heart failure. We previously demonstrated that LV phosphoinositide 3-kinase p110α (PI3K) protects the heart against diabetic cardiomyopathy, associated with reduced NADPH oxidase expression and activity. Conversely, in dominant negative PI3K(p110α) transgenic mice (dnPI3K), reduced cardiac PI3K signaling exaggerated diabetes-induced cardiomyopathy, associated with upregulated NADPH oxidase. The goal was to examine whether chronic supplementation with the antioxidant coenzyme Q(10) (CoQ(10)) could attenuate LV superoxide and diabetic cardiomyopathy in a setting of impaired PI3K signaling. Diabetes was induced in 6-week-old nontransgenic and dnPI3K male mice via streptozotocin. After 4 weeks of diabetes, CoQ(10) supplementation commenced (10 mg/kg ip, 3 times/week, 8 weeks). At study end (12 weeks of diabetes), markers of LV function, cardiomyocyte hypertrophy, collagen deposition, NADPH oxidase, oxidative stress (3-nitrotyrosine), and concentrations of CoQ(9) and CoQ(10) were determined. LV NADPH oxidase (Nox2 gene expression and activity, and lucigenin-enhanced chemiluminescence), as well as oxidative stress, were increased by diabetes, exaggerated in diabetic dnPI3K mice, and attenuated by CoQ(10). Diabetes-induced LV diastolic dysfunction (prolonged deceleration time, elevated end-diastolic pressure, impaired E/A ratio), cardiomyocyte hypertrophy and fibrosis, expression of atrial natriuretic peptide, connective tissue growth factor, and β-myosin heavy chain were all attenuated by CoQ(10). Chronic CoQ(10) supplementation attenuates aspects of diabetic cardiomyopathy, even in a setting of reduced cardiac PI3K protective signaling. Given that CoQ(10) supplementation has been suggested to have positive outcomes in heart failure patients, chronic CoQ(10) supplementation may be an attractive adjunct therapy for diabetic heart failure.

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.

Screening of effective pharmacological treatments for MELAS syndrome using yeasts, fibroblasts and cybrid models of the disease

BACKGROUND AND PURPOSE

MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) is a mitochondrial disease most usually caused by point mutations in tRNA genes encoded by mitochondrial DNA (mtDNA). Approximately 80% of cases of MELAS syndrome are associated with a m.3243A > G mutation in the MT-TL1 gene, which encodes the mitochondrial tRNALeu (UUR). Currently, no effective treatments are available for this chronic progressive disorder. Treatment strategies in MELAS and other mitochondrial diseases consist of several drugs that diminish the deleterious effects of the abnormal respiratory chain function, reduce the presence of toxic agents or correct deficiencies in essential cofactors.

EXPERIMENTAL APPROACH

We evaluated the effectiveness of some common pharmacological agents that have been utilized in the treatment of MELAS, in yeast, fibroblast and cybrid models of the disease. The yeast model harbouring the A14G mutation in the mitochondrial tRNALeu(UUR) gene, which is equivalent to the A3243G mutation in humans, was used in the initial screening. Next, the most effective drugs that were able to rescue the respiratory deficiency in MELAS yeast mutants were tested in fibroblasts and cybrid models of MELAS disease.

KEY RESULTS

According to our results, supplementation with riboflavin or coenzyme Q(10) effectively reversed the respiratory defect in MELAS yeast and improved the pathologic alterations in MELAS fibroblast and cybrid cell models.

CONCLUSIONS AND IMPLICATIONS

Our results indicate that cell models have great potential for screening and validating the effects of novel drug candidates for MELAS treatment and presumably also for other diseases with mitochondrial impairment.

Preparation of coenzyme Q10 liposomes using supercritical anti-solvent technique

Coenzyme Q(10) (CoQ(10)) proliposomes were prepared using the supercritical anti-solvent (SAS) technique to encapsulate CoQ(10). The mixture of cholesterol and soya bean phosphatidylcholine (PC) was chosen as wall materials. The effects of operation conditions (temperature, pressure and components) on the recovery of CoQ(10) and the CoQ(10) loading in CoQ(10) proliposomes were studied. At the optimum conditions of pressure of 8.0 MPa, temperature of 35°C, the weight ratio of 1/10 between CoQ(10) and PC, and the weight ratio of 1/3 between cholesterol and PC, the CoQ(10) loading reached 8.92%. CoQ(10) liposomes were obtained by hydrating CoQ(10) proliposomes and the entrapment efficiency of CoQ(10) reached 82.28%. The morphologies of CoQ(10) proliposomes were characterized by scanning electron microscope, and their solid states were characterized by X-ray diffractometer. The structures of CoQ(10) liposomes were characterized by transmission electron microscope. The particle size distribution of CoQ(10) liposomes was determined by dynamic light scattering instrument. The results indicate that CoQ(10) liposomes with particle sizes about 50 nm can be easily obtained from hydrating CoQ(10) proliposomes prepared by SAS technique.

Middle age aggravates myocardial ischemia through surprising upholding of complex II activity, oxidative stress, and reduced coronary perfusion

Aging compromises restoration of the cardiac mechanical function during reperfusion. We hypothesized that this was due to an ampler release of mitochondrial reactive oxygen species (ROS). This study aimed at characterising ex vivo the mitochondrial ROS release during reperfusion in isolated perfused hearts of middle-aged rats. Causes and consequences on myocardial function of the observed changes were then evaluated. The hearts of rats aged 10- or 52-week old were subjected to global ischemia followed by reperfusion. Mechanical function was monitored throughout the entire procedure. Activities of the respiratory chain complexes and the ratio of aconitase to fumarase activities were determined before ischemia and at the end of reperfusion. H(2)O(2) release was also evaluated in isolated mitochondria. During ischemia, middle-aged hearts displayed a delayed contracture, suggesting a maintained ATP production but also an increased metabolic proton production. Restoration of the mechanical function during reperfusion was however reduced in the middle-aged hearts, due to lower recovery of the coronary flow associated with higher mitochondrial oxidative stress indicated by the aconitase to fumarase ratio in the cardiac tissues. Surprisingly, activity of the respiratory chain complex II was better maintained in the hearts of middle-aged animals, probably because of an enhanced preservation of its membrane lipid environment. This can explain the higher mitochondrial oxidative stress observed in these conditions, since cardiac mitochondria produce much more H(2)O(2) when they oxidize FADH(2)-linked substrates than when they use NADH-linked substrates. In conclusion, the lower restoration of the cardiac mechanical activity during reperfusion in the middle-aged hearts was due to an impaired recovery of the coronary flow and an insufficient oxygen supply. The deterioration of the coronary perfusion was explained by an increased mitochondrial ROS release related to the preservation of complex II activity during reperfusion.

Triple nutrient supplementation improves survival, infarct size and cardiac function following myocardial infarction in rats

BACKGROUND AND AIM

We evaluated the impact of triple nutrient supplementation (TNS: carnitine, taurine and coenzyme Q(10)) vs. carnitine alone (CARN) or placebo on survival, infarct size, cardiac function and metabolic gene expression using a model of myocardial infarction (MI) in rats.

METHODS AND RESULTS

Male Wistar rats were randomized to three groups divided in two independent studies prior to ligation of the left anterior descending coronary artery (LAD): TNS vs. Placebo and TNS vs. CARN. Nutrient supplementation [L-carnitine (300 mg/day), coenzyme Q(10) (15 mg/kg body weight/day) and taurine (0.1M)] was administered daily for four weeks prior to and for 10 days after MI. At that time, cardiac function and infarct size were measured. Metabolic gene (mRNA) expression in the peri-infarct tissue of left ventricle from TNS, placebo or corresponding time-control rats (TNS or placebo without LAD ligation) was measured 10 days after MI. When compared to placebo, TNS significantly improved survival (60% vs. 34%, p<0.02), cardiac function, and reduced infarct size (30+/-7% vs. 42+/-9%, p<0.001). Although CARN improved survival like TNS (45% vs. 50%, not significant), it did not reduce infarct size (32+/-14% vs. 19+/-10%, p<0.05) or delay myocardial remodeling. In the placebo group, MI was associated with a significantly altered pattern of metabolic gene expression (glucose transporter 1, liver carnitine palmitoyl transferase 1, medium-chain acyl-CoA dehydrogenase; p<0.01 for all three) in the left ventricle peri-infarct tissue. In contrast, gene expression was normalized in the group receiving TNS.

CONCLUSIONS

Our results support the potential cardioprotective impact of TNS during myocardial ischemia. In contrast to carnitine supplementation alone, TNS improved survival as well as cardiac function, gene expression and delayed remodeling.

The beneficial effect of coenzyme Q10 and lipoic acid on obstructive bladder dysfunction in the rabbit

PURPOSE

Recent evidence indicates that ischemia and reperfusion are major etiological factors in the bladder dysfunction that occurs after partial bladder outlet obstruction. Coenzyme Q10 and alpha-lipoic acid are found naturally in mitochondria and act as potent antioxidants. We investigated the beneficial effects of coenzyme Q10 plus alpha-lipoic acid in a rabbit model of bladder outlet obstruction.

MATERIALS AND METHODS

Twenty male rabbits were divided into 5 groups. Group 1 served as control and group 2 received three weeks of coenzyme Q10 plus alpha-lipoic acid supplementation. Rabbits in group 3 underwent surgical partial bladder outlet obstruction for duration of four weeks and groups 4 and 5 were obstructed for seven weeks. In group 5, coenzyme Q10 plus alpha-lipoic acid supplementation was given following 4 weeks obstruction and continued till the end of the seven weeks. The contractile responses to various agents were determined. The protein nitration and carbonylation levels were studied by immunoblotting. Nerve function was determined by choline acetyltransferase activity and nerve density.

RESULTS

The contractile responses to different forms of stimulations, including field stimulation, ATP, carbachol and KCl all showed decreases following 4 and 7 weeks obstruction. Treatment with coenzyme Q10 plus alpha-lipoic acid significantly restored contractile responses to all forms of stimulation. Treatment also had mitochondrial and neuronal effects and reduced protein nitration and carbonylation. Histologically there was less detrusor muscle hypertrophy.

CONCLUSIONS

The current study clearly demonstrates that coenzyme Q10 and alpha-lipoic acid supplementation can improve bladder function after outlet obstruction.

Effect of co-enzyme Q10 and alpha-lipoic acid on response of rabbit urinary bladder to repetitive stimulation and in vitro ischemia

OBJECTIVES

To determine the efficacy of coenzyme Q10 (CoQ10) and alpha-lipoic acid (alpha-LA), either alone or in combination, to protect the contractile responses of the rabbit urinary bladder from damage caused by repetitive stimulation in the presence or absence of in vitro ischemia.

METHODS

Four groups of New Zealand white rabbits (4 per group) were treated with vehicle (group 1), CoQ10 (group 2), alpha-LA (group 3), or CoQ10 plus alpha-LA (group 4) for 2 weeks. At the end of the treatment period, eight longitudinal strips from each rabbit bladder body were placed in oxygenated Tyrode's solution with glucose (normal physiologic medium). The strips were stimulated by field stimulation, carbachol, and KCl, and the responses were recorded. One half of the strips were switched for 1 hour to Tyrode's solution with no glucose equilibrated with nitrogen (ischemia medium). Simultaneously, all strips were subjected to 1 h of repetitive field stimulation followed by 1 hour of recovery in normal physiologic medium, and the responses to all stimuli were recorded again.

RESULTS

CoQ10 showed no protective effect. Alpha-LA resulted in increased contractile responses of the control bladder and showed a moderate protective effect for all forms of stimulation. The combination, however, showed a significantly greater increase in the contraction of the control bladder and a greater protective effect than alpha-LA alone.

CONCLUSIONS

The combination of alpha-LA and CoQ10 treatment enhanced the contractile response in normal medium and diminished the contractile dysfunction induced by repetitive field stimulation and ischemia.

Ischemic preconditioning modulates mitochondrial respiration, irrespective of the employed signal transduction pathway

We tested in the in vivo rat heart the hypothesis that although ischemic preconditioning can employ different signal transduction pathways, these pathways converge ultimately at the level of the mitochondrial respiratory chain. Infarct size produced by a 60-min coronary artery occlusion (69%+/-2% of the area at risk) was limited by a preceding 15-min coronary occlusion (48%+/-4%). Cardioprotection by this stimulus was triggered by adenosine receptor stimulation, which was followed by protein kinase C and tyrosine kinase activation and then mitochondrial K(+)(ATP)-channel opening. In contrast, cardioprotection by 3 cycles of 3-min coronary occlusions (infarct size 27%+/-5% of the area at risk) involved the release of reactive oxygen species, which was followed by protein kinase C and tyrosine kinase activation, but was independent of adenosine receptor stimulation and K(+)(ATP)-channel activation. However, both pathways decreased respiratory control index (RCI; state-3/state-2, using succinate as complex-II substrate) from 3.1+/-0.2 in mitochondria from sham-treated hearts to 2.4+/-0.2 and 2.5+/-0.1 in hearts subjected to a single 15-min and triple 3-min coronary occlusions, respectively (both P<0.05). The decreases in RCI were due to an increase in state-2 respiration, whereas state-3 respiration was unchanged. Abolition of cardioprotection by blockade of either signal transduction pathway was paralleled by a concomitant abolition of mitochondrial uncoupling. These observations are consistent with the concept that mild mitochondrial uncoupling contributes to infarct size limitation by various ischemic preconditioning stimuli, despite using different signal transduction pathways. In conclusion, in the in vivo rat heart, different ischemic preconditioning (IPC) stimuli can activate highly different signal transduction pathways, which seem to converge at the level of the mitochondria where they increase state-2 respiration.

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.

Protective effect of coenzyme Q10-loaded liposomes on the myocardium in rabbits with an acute experimental myocardial infarction

PURPOSE

We assessed whether the infusion of Coenzyme Q10-loaded liposomes (CoQ10-L) in rabbits with an experimental myocardial infarction can result in increased intracellular delivery of CoQ10 and thus limit the fraction of the irreversibly damaged myocardium.

METHODS

CoQ10-L, empty liposomes (EL), or Krebs-Henseleit (KH) buffer were administered by intracoronary infusion, followed by 30 min of occlusion and 3 h of reperfusion. Unisperse Blue dye was used to demarcate the net size of the occlusion-induced ischemic zone ("area at risk") while nitroblue tetrazolium staining was used to detect the final fraction of the irreversibly damaged myocardium within the total area at risk.

RESULTS

The total size of the area at risk in all experimental animals was approx. 20% wt. of the left ventricle (LV). The final irreversible damage in CoQ10-L-treated animals was only ca. 30% of the total area at risk as compared with ca. 60% in the group treated with EL (p < 0.006) and ca. 70% in the KH buffer-treated group (p < 0.001).

CONCLUSIONS

CoQ10-L effectively protected the ischemic heart muscle by enhancing the intracellular delivery of CoQ10 in hypoxic cardiocytes in rabbits with an experimental myocardial infarction as evidenced by a significantly decreased fraction of the irreversibly damaged heart within the total area at risk. CoQ10-L may provide an effective exogenous source of the CoQ10 in vivo to protect ischemic cells.

Effect of Coenzyme Q10 Incorporation on the Characteristics of Nanoliposomes

Coenzyme Q(10) (CoQ(10)) is incorporated in nanoliposomes composed of egg yolk phospholipid, cholesterol, and Tween 80. Atomic force microscopy, performed to characterize vesicle surface topology, shows some visible influence of CoQ(10) on the nanoliposomal structure. CoQ(10) incorporation can suppress the increase of the z-average diameter of nanoliposomes during storage for 8 months at 4 degrees C. The liposomal lipid peroxidation caused by Fe(III)/ascorbate is also significantly inhibited. Perturbation of acyl chain motion of lipids due to the presence of CoQ(10) in the bilayer is examined by fluorescence probe diphenyl-hexatriene and Raman spectroscopy. Fluorescence probe studies indicate that CoQ(10) incorporation results in the microviscosity increase of nanoliposomes. The steric structure of nanoliposomes reflected by Raman spectroscopy changes obviously and shows CoQ(10) content dependency. The order parameters for the lateral interaction between chains increase. The trans conformation decrease and the gauche conformation increase as the weight contents of CoQ(10) incorporation are at 1%, 5%, 10%, and 32.5%. However, the order parameters for the longitudinal interaction in chains was higher than that of pure nanoliposomes as the weight content of CoQ(10) is at 25%. Results suggest that CoQ(10)might intercalate between lipid molecules and perturb the bilayer structure.

Lifestyle and nutrition, caloric restriction, mitochondrial health and hormones: scientific interventions for anti-aging

Aging is a universal process to all life forms. The most current and widely accepted definition for aging in humans is that there is a progressive loss of function and energy production that is accompanied by decreasing fertility and increasing mortality with advancing age. The most obvious and commonly recognised consequence of aging and energy decline is a decrease in skeletal muscle function which affects every aspect of human life from the ability to play games, walk and run to chew, swallow and digest food. There is hence a recognised overall decline of an individuals' fitness for the environment that they occupy. In Westenised countries this decline is gradual and the signs become mostly noticeable after the 5th decade of life and henceforth, where the individual slowly progresses to death over the next three to four decades. Given that the aging process is slow and gradual, it presents with opportunities and options that may ameliorate and improve the overall functional capacity of the organism. Small changes in function may be more amenable and likely to further slow down and possibly reverse some of the deleterious effects of aging, rather, than when the incremental changes are large. This overall effect may then translate into a significant compression of the deleterious aspects of human aging with a resultant increase in human life expectancy.

Oxidative stress : relationship with exercise and training

Free radicals are reactive compounds that are naturally produced in the human body. They can exert positive effects (e.g. on the immune system) or negative effects (e.g. lipids, proteins or DNA oxidation). To limit these harmful effects, an organism requires complex protection - the antioxidant system. This system consists of antioxidant enzymes (catalase, glutathione peroxidase, superoxide dismutase) and non-enzymatic antioxidants (e.g. vitamin E [tocopherol], vitamin A [retinol], vitamin C [ascorbic acid], glutathione and uric acid). An imbalance between free radical production and antioxidant defence leads to an oxidative stress state, which may be involved in aging processes and even in some pathology (e.g. cancer and Parkinson's disease). Physical exercise also increases oxidative stress and causes disruptions of the homeostasis. Training can have positive or negative effects on oxidative stress depending on training load, training specificity and the basal level of training. Moreover, oxidative stress seems to be involved in muscular fatigue and may lead to overtraining.

Optimization in the preparation of coenzyme Q10 nanoliposomes

The optimal formulation of coenzyme Q10 (CoQ10) nanoliposomes and the feasibility of production in a pilot scale were investigated. The nanoliposomes were prepared by ethanol injection and sonication techniques for a desired vesicle size in the laboratory. Optimization of formulation in the preparation of CoQ10 nanoliposomes was achieved by an orthogonal array design. The best formulation was found to be phospholipid/CoQ10/cholesterol/Tween 80 (2.5:1.2:0.4:1.8, w/w) with phosphate buffer solution (pH 7.4, 0.01 M) as the hydration media. The z-average diameter (D(z)) was about 68 nm. The encapsulation efficiency was greater than 95% with a retention ratio higher than 90% and a particle size change lower than 10% after storage at 4 degrees C in the dark for 90 days. CoQ10 incorporation resulted in a dramatic increase of the microviscosity of nanoliposomes and inhibited the peroxidation of phospholipid. The D(z) of CoQ10 nanoliposomes produced in a pilot scale was about 67 nm. Results suggest that the technology developed by this investigation is practical to produce the CoQ10 nanoliposomes with the expected encapsulation quality and stability not only in the laboratory but also in a pilot scale.

Pre-operative Preparation for Cardiac Surgery Utilising a Combination of Metabolic, Physical and Mental Therapy

Cardiac surgery represents major metabolic, physical and mental stresses associated with an increased production of reactive oxygen species. These stresses may hamper post-operative recovery, increasing hospitalisation times and operative mortality. We conducted a quality assurance and feasibility study to evaluate and monitor the safety and efficacy of a new program of combined pre-operative metabolic (enhanced antioxidant), physical and mental therapy to counter these stresses prior to cardiac surgery.

METHODS

Sixteen cardiac surgery patients received metabolic therapy consisting of the antioxidants coenzyme Q(10) (CoQ(10)) (300 mg) and alpha-lipoic acid (300 mg), combined with magnesium orotate (1200 mg), and omega-3 fatty acids (3g) given daily for a mean 36+/-7 days up until the day of operation. Patients also received a regimen of physical therapy incorporating non-exhaustive, light exercise and stretching techniques. Mental therapy in the form of stress reduction, relaxation and music was also provided. Blood levels of CoQ(10) and malondialdehyde (MDA) were measured and a quality of life (QoL) questionnaire (SF-36) was administered before, after the program and 1 month after surgery. A patient satisfaction survey was conducted at six weeks post-operatively.

RESULTS

During the pre-operative period, treated patients (n=16) showed significant improvements in QoL composite scores, physical (33.5+/-4.1 to 41.0+/-4.5, p=0.005) and mental (44.3+/-4.5 to 54.1+/-5.3, p=0.006). CoQ(10) levels increased from 725.6+/-96.1 nmol/l to 3019.9+/-546.4 nmol/l (p=0.006), MDA levels decreased from 2.2+/-0.9 microM to 1.4+/-0.7 microM (p=0.013) and systolic blood pressure decreased from 140+/-4.0 mmHg to 132+/-3.0 mmHg (p=0.002). One month after surgery the treated group (n=14) demonstrated significant improvements from pre-operative baseline in QoL composite scores, physical (38.9+/-4.0 to 57.9+/-5.4, p=0.01) and mental (50.3+/-5.6 to 69.3+/-4.8, p=0.03) compared to a previously reported similar group of cardiac surgery patients (n=74) whose physical and mental scores decreased from 43.0 to 42.8 (p=0.05) and 53.8 to 49.8, respectively (p=0.05).

CONCLUSION

These preliminary results suggest that a program of combined metabolic, physical and mental preparation before cardiac surgery is safe, feasible and may improve quality of life, lower systolic blood pressure, reduce levels of oxidative stress and thus has the potential to enhance post-operative recovery.

Targeting cellular energy production in neurological disorders

The concepts of energy dysregulation and oxidative stress and their complicated interdependence have rapidly evolved to assume primary importance in understanding the pathophysiology of numerous neurological disorders. Therefore, neuroprotective strategies addressing specific bioenergetic defects hold particular promise in the treatment of these conditions (i.e., amyotrophic lateral sclerosis, Huntington's disease, Parkinson's disease, Friedreich's ataxia, mitochondrial cytopathies and other neuromuscular diseases), all of which, to some extent, share 'the final common pathway' leading to cell death through either necrosis or apoptosis. Compounds such as creatine monohydrate and coenzyme Q(10) offer substantial neuroprotection against ischaemia, trauma, oxidative damage and neurotoxins. Miscellaneous agents, including alpha-lipoic acid, beta-OH-beta-methylbutyrate, riboflavin and nicotinamide, have also been shown to improve various metabolic parameters in brain and/or muscle. This review will highlight the biological function of each of the above mentioned compounds followed by a discussion of their utility in animal models and human neurological disease. The balance of this work will be comprised of discussions on the therapeutic applications of creatine and coenzyme Q(10).

A review of free radicals and antioxidants for critical care nurses

In the critical care setting, nurses frequently care for patients with acute and chronic diseases that affect multiple body systems. Many of these medical conditions have been associated with an imbalance between oxidizing chemicals called free radicals and antioxidants. Free radical damage is now assumed to be a contributing factor in all major diseases. In order to provide the most current and comprehensive care, critical care nurses need to be well informed about how free radicals cause damage and the antioxidant compounds that neutralize their destructive effects. This article provides an overview of oxygen free radicals and antioxidants and how they impact different clinical illnesses familiar to critical care nurses.

Coenzyme Q10 Levels in Maternal Plasma and Cord Blood:Correlations with Mode of Delivery

BACKGROUND

Oxygen (O2) plays a critical role in the O2-reduction reactions indispensable for life, but can produce free radicals that are involved in many diseases. Coenzyme Q10 (CoQ10), acting as a redox carrier in the respiratory chain, occupies a central position in the energy metabolism and oxidative defence. Neonates seem to be very subjected to oxidative stress because of their deficient antioxidant systems.

DESIGN/METHODS

The aim of the study was to verify whether the mode of delivery may affect CoQ10 levels in the mother and neonate, and thus influence the risk of oxidative damage in the newborn. We measured CoQ10 levels in maternal plasma and cord blood at birth after three different modes of delivery (45 term healthy pregnancies): (1) vaginal in room air (VD) (n = 15); (2) elective caesarean section with general anaesthesia (50% O2 and 50% N2O) (CSg) (n = 15), and (3) elective caesarean section with spinal anaesthesia without O2 (CSs) (n = 15). Our results showed higher levels of Q10 in mothers and neonates with VD (1.29 +/- 0.43 and 0.15 +/- 0.06 microg/ml, respectively) or CSs (1.15 +/- 0.28 and 0.24 +/- 0.06 microg/ml, respectively) when compared to CSg (0.74 +/- 0.28 and 0.07 +/- 0.03 microg/ml, respectively) (p < 0.01).

CONCLUSIONS

These data demonstrate that the mode of delivery may affect CoQ(10) levels in mothers and neonates, and thus influence the risk of oxidative damage in the newborn.

Effects of dichloroacetate and ubiquinone infusions on glycolysis activity and thermal sensitivity during sepsis

Energy-metabolism disturbances during sepsis are characterized by enhanced glycolytic fluxes and reduced mitochondrial respiration. However, it is not known whether these abnormalities are the result of a specific mitochondrial alteration, decreased pyruvate dehydrogenase (PDH) complex activity, depletion of ubiquinone (CoQ(10); electron donor for the mitochondrial complex III), or all 3. In this study we sought to specify metabolism disturbances in a murine model of sepsis, using either a PDH-activator infusion (dichloroacetate, DCA) or CoQ(10) supplementation. After anesthesia, Sprague-Dawley rats received intravenous saline solution (control; n = 5), DCA (n = 5; 20 mg/100 g), or CoQ(10) (n = 5; 1 mg/100 g), before the induction of sepsis. Increased plasma lactate levels and increased muscle glucose content were observed after 4 hours in the control group. In the DCA group, a decrease in the muscle content of lactate (P <.05) and an increase in muscle glucose content (P <.05) were observed at 4 hours, but no lactatemia variation was noted. In the CoQ(10) group, only increased plasma lactate levels were observed. Increased muscle glycolysis fluxes were observed after 4 hours in the control group, but to a slighter degree in both the DCA and CoQ(10) groups. Only DCA restored a normal temperature sensitivity in the hyperthermia range, but we noted no differences in survival time. In conclusion, only DCA infusion restores normal glycolysis function.

Diabetes induces metabolic adaptations in rat liver mitochondria: role of coenzyme Q and cardiolipin contents

Several studies have been carried out to evaluate the alterations in mitochondrial functions of diabetic rats. However, results are sometimes controversial, since experimental conditions diverge, including age and strain of used animals. The purpose of this study was to evaluate the metabolic modifications in liver mitochondria, both in the presence of severe (STZ-treated rats) and mild hyperglycaemia [Goto-Kakizaki (GK) rats], when compared with control animals of similar age. Moreover, metabolic alterations were evaluated also at initial and advanced stages of the disease. We observed that both models of diabetes (type 1 and type 2) presented a decreased susceptibility of liver mitochondria to the induction of permeability transition (MPT). Apparently, there is a positive correlation between the severity of diabetes mellitus (and duration of the disease) and the decline in the susceptibility to MPT induction. We also found that liver mitochondria isolated from diabetic rats presented some metabolic adaptations, such as an increase in coenzyme Q and cardiolipin contents, that can be responsible for the observed decrease in the susceptibility to multiprotein pore (MPTP) opening.

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.

High-Glucose Induced Protective Effect against Hypoxic Injury Is Associated with Maintenance of Mitochondrial Membrane Potential

Our previous report has showed that the treatment of 48 h with 22 mM glucose prevents hypoxia-induced cardiac cell death. In the present study, we investigated whether high glucose affects the mitochondrial death pathway during hypoxia, and if it does, what relates to the high glucose induced cardioprotection. Heart-derived H9c2 cells were incubated in low (5.5 mM) or high (22 mM) glucose medium for 48 h, then transferred to a normoxic or hypoxic condition. The hypoxia-induced reduction of mitochondrial redox potential, assessed by MTT assay, was inhibited in high glucose treated cells. The mitochondrial membrane potential was significantly decreased by hypoxia in low glucose treated cells, but not in high glucose treated cells. The hypoxia-induced cytoplasmic accumulation of cytochrome c, released from the mitochondria, was blocked by a treatment of high glucose. High glucose did not induce the expression of an antiapoptotic protein Bcl-2, nor did it reduce a proapoptotic protein Bax, but it did inhibit a hypoxia-induced downregulation of Bcl-2. The cellular ATP contents were not changed by the treatment of high glucose for 48 h, and the hypoxia-induced decline of intracellular ATP level was observed in high glucose treated cells and in low glucose. A glycolytic inhibitor, 2-deoxyglucose, did not reverse the high glucose induced reduction of LDH release. The elevation of [ROS](i) induced by hypoxia was inhibited in high glucose treated cells. These results suggest that high glucose induced cardioprotection may be accounted for in part by the preservation of MMP and the maintenance of a basal level of [ROS](i) during hypoxia.