Effect of coenzyme Q10 on experimental atherosclerosis and chemical composition and quality of atheroma in rabbits

Coenzyme Q10 in atherosclerosis

Atherosclerotic disease is a chronic disease that predominantly affects the elderly and is the most common cause of cardiovascular death worldwide. Atherosclerosis is closely related to processes such as abnormal lipid transport and metabolism, impaired endothelial function, inflammation, and oxidative stress. Coenzyme Q10 (CoQ10) is a key component of complex Ⅰ in the electron transport chain and an important endogenous antioxidant that may play a role in decelerating the progression of atherosclerosis. Here, the different forms of CoQ10 presence in the electron transport chain are reviewed, as well as its physiological role in regulating processes such as oxidative stress, inflammatory response, lipid metabolism and cellular autophagy. It was also found that CoQ10 plays beneficial effects in atherosclerosis by mitigating lipid transportation, endothelial inflammation, metabolic abnormalities, and thrombotic processes from the perspectives of molecular mechanisms, animal experiments, and clinical evidence. Besides, the combined use of CoQ10 with other drugs has better synergistic therapeutic effects. It seems reasonable to suggest that CoQ10 could be used in the treatment of atherosclerotic cardiovascular diseases while more basic and clinical studies are needed.

Sub-chronic exposure to hexaconazole affects the lipid metabolism of rats through mTOR-PPAR-γ/SREBP1 signaling pathway mediated by oxidative stress

Hexaconazole (Hex) is a widely used and high frequency detected triazole fungicide in agricultural products and environment which may pose potential toxicity to the nontargeted organisms. Hex had been reported to affect lipid homeostasis while the mechanism was undefined. This study aims to explore the characteristic lipidomic profiles and clarify the underlying signaling pathways of Hex-induced lipid metabolism disorder in rat liver. The results showed that sub-chronic exposure to environmental related concentrations of Hex caused histopathological changes, oxidative stress, fat accumulation, lipid biochemical parameter increase in rats. Moreover, the untargeted lipidomic analysis showed that the levels of TAG, PC, and PE and the pathway of glycerophospholipid metabolism were heavily altered by Hex. We further analyzed the lipid metabolism related genes and proteins which revealed that Hex exposure increased amount of lipogenesis by activating oxidative stress-mediated mTOR-PPAR-γ/SREBP1 signaling pathways. The imbalance of lipid homeostasis induced by Hex exposure might further lead to obesity, cardiovascular diseases (CVDs), and hyperlipidemia. Our results provided systematic and comprehensive evidence for the mechanism of Hex-induced lipid metabolism disorder at environmental concentrations and supplied a certain basis for its health risks assessment.

Modulation of NRF2/KEAP1 Signaling in Preeclampsia

Placentation is a key and tightly regulated process that ensures the normal development of the placenta and fetal growth. Preeclampsia (PE) is a hypertensive pregnancy-related disorder involving about 5-8% of all pregnancies and clinically characterized by de novo maternal hypertension and proteinuria. In addition, PE pregnancies are also characterized by increased oxidative stress and inflammation. The NRF2/KEAP1 signaling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. ROS activate NRF2, allowing its binding to the antioxidant response element (ARE) region present in the promoter of several antioxidant genes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase that neutralize ROS, protecting cells against oxidative stress damages. In this review, we analyze the current literature regarding the role of the NRF2/KEAP1 pathway in preeclamptic pregnancies, discussing the main cellular modulators of this pathway. Moreover, we also discuss the main natural and synthetic compounds that can regulate this pathway in in vivo and in vitro models.

The influence of dietary Coenzyme Q10 on growth performance, antioxidant capacity and resistance against Aeromonas hydrophila of juvenile European eel (Anguilla anguilla)

The present study was conducted to investigate the effects of dietary Coenzyme Q10 (CoQ10) on the growth performance, body composition, digestive enzyme activity, antioxidant capacity, intestinal histology, immune-antioxidant gene expression and disease resistance of juvenile European eel (Anguilla anguilla). Fish were fed a diet supplemented with CoQ10 at concentrations of 0, 40, 80 and 120 mg/kg for 56 days. The results indicated that dietary CoQ10 supplementation did not significantly affect final body weight (FBW), survival rate (SR), weight gain (WG), feed rate (FR), viscerosomatic index (VSI) or hepatosomatic index (HSI) among all experimental groups. However, the highest FBW, WG and SR were found in the 120 mg/kg CoQ10 group. Dietary 120 mg/kg CoQ10 markedly improved feed efficiency (FE) and the protein efficiency ratio (PER). The crude lipids in the body and triglycerides (TG) and total cholesterol (TC) in serum were obviously lower in the 120 mg/kg CoQ10 group than in the control group. For digestive enzymes, protease activity in the intestine was markedly boosted in the 120 mg/kg CoQ10 group. The serum activities of SOD, CAT and GST in the 120 mg/kg CoQ10 group were significantly higher than those in the control group. Dietary 120 mg/kg CoQ10 efficiently enhanced superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities in the liver, while the malondialdehyde (MDA) content was significantly decreased. No significant histological changes in the liver were identified in any group. Dietary supplementation with 120 mg/kg CoQ10 improved antioxidant capacity and immunity by upregulating the expression of cyp1a, sod, gst, lysC, igma1, igmb1 and irf3 in the liver. Furthermore, the cumulative survival rate of juvenile European eel against challenge with Aeromonas hydrophila was significantly elevated in the 80 and 120 mg/kg CoQ10 supplemented groups. Conclusively, our study suggested that supplementing the diet of juvenile European eel with CoQ10 at a concentration of 120 mg/kg could promote their feed utilization, fat reduction, antioxidant capacity, digestibility, immune-antioxidant gene expression and resistance to Aeromonas hydrophila without negative effects on fish health status.

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.

Influence of statin-potency on the risk of kidney disease - A nationwide cohort study using laboratory data

PURPOSE

To estimate the risk of kidney disease in high-potency statin users compared to those treated with low-potency statins without history of kidney disease at statin initiation, linking the Swedish national healthcare registers and laboratory data.

METHODS

Incident users of statins, ≥40 years of age, with estimated Glomerular Filtration Rate (eGFR) >60 ml/min/1.73 m² and no diagnosis of kidney disease at treatment initiation were identified between 2006 and 2007 and then followed for 2-years. The outcome was the incidence of kidney disease identified by the presence of the diagnostic code in the healthcare registers or eGFR <60 ml/min/1.73 m² . We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) with adjusted and propensity score (PS)-matched Cox proportional hazards models.

RESULTS

A total of 27 385 patients were identified, 25.2% of which treated with a high-potency statin. During the follow-up, 68 (0.25%) patients were identified with a diagnosis of kidney disease from the registers. The number increased to 2498 (9.1%) when the criteria of eGFR <60 ml/min/1.73 m² was added. The adjusted HR of kidney disease in high-potency statin users was 1.14 (95%CI 1.03-1.25) compared to low-potency users; the result was unchanged after the PS approach.

CONCLUSIONS

Adding information from laboratory data to those from the national health registers, a slightly increased risk for kidney disease was found in high-potency statin users without pre-existing kidney disease at treatment initiation compared to those treated with low-potency statins.

CoQ10 exerts hepatoprotective effect in fructose-induced fatty liver model in rats

BACKGROUND

Excess dietary sugar is associated with deleterious metabolic effects, liver injury, and coenzyme-Q10 (CoQ10) deficiency. This study investigates the ability of CoQ10 to protect against fructose-induced hepatic damage.

METHODS

Rats were fed tap water or 30% fructose for 12 weeks with or without CoQ10 (10 mg/kg, po). An additional group of rats were allowed to feed on either water or 30% fructose for 12 weeks, followed by four weeks of treatment with either the vehicle or CoQ10.

RESULTS

Fructose-fed rats showed lower CoQ10 levels, increased systolic pressure, increased body weight, higher liquid consumption, decreased food intake and hyperglycemia. Fructose-fed rats also showed deteriorated serum and liver lipid profiles, impaired liver function tests and oxidative status, and lower expression of adiponectin receptor 1 and 2 along with higher GLUT-2 levels. Furthermore, following fructose treatment, tyrosine kinase-PI3K pathway was inhibited. Additionally, there was an increase in the levels of apoptotic markers and serum visfatin and a decrease in the levels of adiponectin and soluble receptor of the advanced glycated end product. Consequently, several histopathological changes were detected in the liver. Concurrent or three months post-exposure administration of CoQ10 in fructose rats significantly reversed or attenuated all the measured parameters and hepato-cytoarchitecture alterations.

CONCLUSION

This study suggests CoQ10 supplement as a possible prophylaxis or treatment candidate for fructose-induced liver injury.

Coenzyme Q10 Supplementation Prevents Iron Overload While Improving Glycaemic Control and Antioxidant Protection in Insulin-Resistant Psammomys obesus

This study investigated the anti-diabetic preventive activity of coenzyme Q10 (CoQ10) in a murine model of diet-induced insulin resistance (IR), Psammomys obesus (Po). IR was induced by feeding a standard laboratory diet (SD). CoQ10 oil suspension was orally administered at 10 mg/kg body weight (BW)/day along with SD for 9 months. Anthropometric parameters, namely, total body weight gain (BWG) and the relative weight of white adipose tissue (WAT) were determined. Blood glucose, insulin, quantitative insulin sensitivity check index (QUICKI), total antioxidant status (TAS), iron, malondialdehyde (MDA) and nitrite (NO2 (-)) were evaluated. NO2 (-) level was also assessed in peripheral blood mononuclear cells (PBMCs) culture supernatants. Our results show that CoQ10 supplementation significantly improved blood glucose, insulin, QUICKI, TAS, iron and MDA, but influenced neither NO2 (-) levels nor the anthropometric parameters. These findings support the hypothesis that CoQ10 would exert an anti-diabetic activity by improving both glycaemic control and antioxidant protection. The most marked effect of CoQ10 observed in this study concerns the regulation of iron levels, which may carry significant preventive importance.

Is there a place for coenzyme Q in the management of metabolic disorders associated with obesity?

Coenzyme Q (CoQ), a lipophilic cofactor of the electron transport chain in the mitochondria, can be synthesized endogenously or provided by food. The aim of this review is to summarize the in vitro cell culture studies, the in vivo animal studies, and the human studies investigating the impact of CoQ supplementation on the occurrence of obesity and related disorders (diabetes, hypertension, lipemia, and atherosclerosis). The antioxidative properties of CoQ have been observed in different experimental models of atherosclerosis, obesity, and diabetes. The recent discovery of the anti-inflammatory effect of CoQ, mostly described in vitro, has generated increased interest in CoQ supplementation, but it needs to be confirmed in vivo in pathological situations. CoQ intervention studies in humans failed to show reproducible effects on body weight, fat mass, or glycemia, but CoQ supplementation does seem to have an antihypertensive effect. The molecular mechanism to explain this effect has only recently been discovered.

Actions of "antioxidants" in the protection against atherosclerosis

This review addresses the role of oxidative processes in atherosclerosis and its resulting cardiovascular disease by focusing on the outcome of antioxidant interventions. Although there is unambiguous evidence for the presence of heightened oxidative stress and resulting damage in atherosclerosis, it remains to be established whether this represents a cause or a consequence of the disease. This critical question is complicated further by the increasing realization that oxidative processes, including those related to signaling, are part of normal cell function. Overall, the results from animal interventions suggest that antioxidants provide benefit neither generally nor consistently. Where benefit is observed, it appears to be achieved at least in part via modulation of biological processes such as increase in nitric oxide bioavailability and induction of protective enzymes such as heme oxygenase-1, rather than via inhibition of oxidative processes and lipid oxidation in the arterial wall. Exceptions to this may be situations of multiple/excessive stress, the relevance of which for humans is not clear. This interpretation is consistent with the overall disappointing outcome of antioxidant interventions in humans and can be rationalized by the spatial compartmentalization of cellular oxidative signaling and/or damage, complex roles of oxidant-producing enzymes, and the multifactorial nature of atherosclerosis.

Plasma coenzyme Q10 is increased during gestational diabetes

OBJECTIVES

To determine plasma CoQ(10) concentration in the course of gestational diabetes mellitus.

STUDY DESIGN

The assessment was provided longitudinally during the third trimester of pregnancy in 40 women with gestational diabetes mellitus (GDM) and 40 normal controls. CoQ(10) was measured with the HPLC method. CoQ(10) results were also normalized to plasma cholesterol concentration (nmoles/mmoles). Plasma samples were collected longitudinally throughout the third trimester.

RESULTS

No statistically significant difference of plasma CoQ(10)/cholesterol levels between GDM patients and controls at 28-32 and 32-36 weeks of gestation, this difference was significant in late pregnancy (36-40 weeks), similarly, in the same gestational period, there was an increased level of HOMA-IR as index of insulin resistance ORAC as index of oxidative stress.

CONCLUSIONS

Since coenzyme Q(10) is believed to be an important cellular antioxidant defence, higher levels of CoQ(10) in GDM patients may be a compensatory mechanism, in response to an activated oxidative stress, probably associated to hyperglycaemia and insulin resistance.

Experimental schistosomal hepatitis: protective effect of coenzyme-Q10 against the state of oxidative stress

Schistosoma mansoni (S. mansoni) eggs trapped in the host liver elicit a chain of oxidative processes that may be, at least in part, responsible for the pathology and progression of fibrosis associated with schistosomal hepatitis. This study was designed to assess the protective effect of the antioxidant coenzyme-Q10 (Co-Q10) against experimental S. mansoni-induced oxidative stress in the liver, and its potential role as an adjuvant to praziquantel (PZQ) therapy. The oxidative stress and overall liver function were improved under Co-Q10 therapy as evidenced by significant reduction in oxidative stress markers and preservation of antioxidant factors. Liver fibrosis was also reduced with a positive impact on liver function. Moreover, addition of Co-Q10 to PZQ therapy caused: significant reduction of liver egg load, significant improvement of the redox status, and lastly decreased liver fibrosis.

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.

Dietary antioxidants in preventing atherogenesis

Several naturally occurring constituents have received considerable attention because of their potential antioxidant activity. Consuming a diet rich in natural antioxidants has been associated with prevention from and/or treatment of atherosclerosis. Bioactive components of food, which are of special interest, include the Vitamins E and C, polyphenols, carotenoids-mainly lycopene and beta-carotene, and coenzyme Q10, featured by antioxidant properties. Antioxidant therapy is supposed to be effective in the early stages of atherosclerosis by preventing LDL oxidation and the oxidative lesion of endothelium. This review focuses on the effect of dietary antioxidants pertained to LDL oxidation and to the vascular endothelial dysfunction. Now that the human genome has been completely sequenced, genetic factors involved in oxidation may open new horizons to identify persons at risk for cardiovascular disease, allowing effective dietary intervention strategies to recover normal homeostasis and to prevent diet-related implications. On this basis, current studies on the action of selected antioxidant nutraceuticals on the activity of transcription factors, such as final targets in the signal transduction cascade and gene regulation, may emerge into new treatment concepts.

Placental CoQ10 levels in HELLP syndrome

Oxidative stress is considered a key factor in HELLP syndrome, a severe complication of preeclampsia in pregnancy. In the present study we analysed the content of Coenzyme Q(10) (CoQ(10)), a fundamental component of the mitochondrial respiratory chain and recognized lipophilic antioxidant, in placentas from women affected by HELLP syndrome and compared them with the relative controls. Twenty-eight patients with HELLP syndrome and twenty-eight age-matched healthy pregnant controls were enrolled. Two aliquots of placental tissue were taken immediately after delivery and placed into liquid nitrogen. Thawed samples were homogenised by Ultra-Turrax; total protein and CoQ(10) concentration were thereafter analysed. CoQ(10) concentration was 0.162 +/- 0.07 microg/mg protein in HELLP syndrome versus 0.87 +/- 0.003 microg/mg protein in controls, the difference being highly significant. A positive correlation, within the placentas from HELLP, was found between the weight of the new-born and CoQ(10)/protein ratio. A significant positive correlation was also present between CoQ(10)/protein ratio and Apgar at 1st and 5th minute as well as between CoQ(10)/protein ratio and the median cerebral artery pulsatility index. The increase in placental CoQ(10) in this syndrome might derive from a compensatory mechanism in a situation of increased oxidative stress.

Coenzyme Q10 and diabetic endotheliopathy: oxidative stress and the 'recoupling hypothesis'

Increased oxidative stress in diabetes mellitus may underlie the development of endothelial cell dysfunction by decreasing the availability of nitric oxide (NO) as well as by activating pro-inflammatory pathways. In the arterial wall, redox imbalance and oxidation of tetrahydrobiopterin (BH4) uncouples endothelial nitric oxide synthase (eNOS). This results in decreased production and increased consumption of NO, and generation of free radicals, such as superoxide and peroxynitrite. In the mitochondria, increased redox potential uncouples oxidative phosphorylation, resulting in inhibition of electron transport and increased transfer of electrons to molecular oxygen to form superoxide and other oxidant radicals. Coenzyme Q10 (CoQ), a potent antioxidant and a critical intermediate of the electron transport chain, may improve endothelial dysfunction by 'recoupling' eNOS and mitochondrial oxidative phosphorylation. CoQ supplementation may also act synergistically with anti-atherogenic agents, such as fibrates and statins, to improve endotheliopathy in diabetes.

MRI of coronary artery atherosclerosis in rabbits: Histopathology-MRI correlation and atheroma characterization

BACKGROUND AND OBJECTIVES: We report in vivo magnetic resonance imaging (MRI) characteristics and histopathology correlation of the thrombus formation in atherosclerosis the rabbit animal model. DESIGN AND METHODS: Atherosclerosis was induced in white male rabbits with vegetable ghee followed oxidized diet. Baseline MRI of atherosclerosis-recruited rabbits was done and later animals were used for atheroma histopathology characterization. Contiguous cross-sectional T2-weighted fast spin echo MRI images were compared by coronary histopathology. In all animals, coronary aortic wall thickening and atheroma size was measured using MRI. RESULTS: MRI images and digitized histological sections confirmed intraluminal thrombus in 6 (67%) of the 9 animals. MRI data showed correlation with the histopathology for aortic wall thickness (R2 = 0.82, P < 0.0001), lumen area (R2 = 0.88, P < 0.0001) and plaque size (R2 = 0.77, P < 0.0001). Optimized TE and TR parameters and multicontrast enhancement generated better MRI visibility of vulnerable plaque components. The MRI data evaluated % stenosis, plaque burden. Frequency of plaques, plaque height in aorta and coronary artery atheroma was also assessed by histology. In vivo, MRI determined the presence and size of the thrombus in this animal model of atherosclerosis and histopathology defined the plaque disruption. CONCLUSION: The combination of in vivo MRI and comparison with histopathology images of rabbit coronary thrombus may be a research tool for understanding of the pathogenesis of acute coronary plaques.

Relative bioavailability and antioxidant potential of two coenzyme q10 preparations

Coenzyme Q10 (CoQ10) is synthesized by the human body and found in certain foods. Daily supplementation of CoQ10 could protect against heart disease but the bioavailability of CoQ10 supplements depends on the formulation taken. We compared the bioavailability and antioxidant properties of two commercial CoQ10 formulations, a commercial grade CoQ10 powder (commercial grade CoQ) and a new BT-CoQ10 BIO-TRANSFORMED (BT-CoQ10) obtained by fermentation of a soy-based, CoQ10-rich media with baker's yeast. Eleven healthy individuals participated in a randomized two-way crossover trial, with a 3-week washout period. Capsules containing 300 mg of either BT-CoQ10 or commercial grade CoQ10 were given daily for 1 week and multiple blood samples were taken for CoQ10, glutathione and glutathione peroxidase (GPx) determination. In 3 subjects, baseline plasma CoQ10 levels were lower prior to BT than prior to commercial grade CoQ treatment. In the remaining participants, ingestion of BT vs. commercial grade CoQ significantly increased maximum plasma CoQ10 concentration (+126%, p = 0.04) and tended to increase CoQ10 area under the curve from 0 to 24 h (+160%, p = 0.07). One week of treatment with each formulation increased plasma CoQ10 but did not alter plasma glutathione or GPx activity. The enhanced bioavailability of the BT product might be due to its predominantly reduced, hydrophilic membrane-complex form.

Free radical mediated peroxidative damage in systemic lupus erythematosus

Free radicals and damage caused by these molecular species are implicated in the pathogenesis of a variety of diseases, including autoimmune. Here we have examined oxidative damage, SOD activity and autoantibodies against SOD in systemic lupus erythematosus (SLE), a multifactorial disease with autoantibody production as an universal feature. We found significantly increased amounts of conjugated dienes in the SLE patients compared to normals (mean value of 0.917 vs 0.627, p = 0.0001) and MDA formation (6.96 vs 4.17 nmoles/microl, p = 0.0006) as well as decreased SOD activity. In addition, we found autoantibodies binding SOD by both ELISA and immunoblot. The presence of anti-SOD antibodies was associated with increased free radical damage in SLE patients. Heat inactivated anti-SOD autoantibodies were able to inhibit the activity of the enzyme. We propose that the inhibition of SOD by autoantibodies is, in part, responsible for the increased free radical damage seen in the disease.

Can coenzyme Q10 improve vascular function and blood pressure? Potential for effective therapeutic reduction in vascular oxidative stress

Coenzyme Q10 (CoQ) is an endogenously synthesised compound that acts as an electron carrier in the mitochondrial electron transport chain. The presence of adequate tissue concentrations of CoQ may be important in limiting oxidative and nitrosative damage in vivo. Oxidative and nitrosative stress are likely to be elevated in conditions such as diabetes and hypertension. In these conditions elevated oxidative and nitrosative stress within the arterial wall may contribute to increased blood pressure and vascular dysfunction. The major focus of this review is the potential of CoQ to improve vascular function and lower blood pressure. Although there is substantial indirect support for the putative mechanism of effect of CoQ on the vascular system, to date there is little direct support for an effect of CoQ on in vivo markers of oxidative or nitrosative stress. The limited data available from studies in animal models and from human intervention studies are generally consistent with a benefit of CoQ on vascular function and blood pressure. The observed effects of CoQ on these endpoints are potentially important therapeutically. However, before any firm clinical recommendations can be made about CoQ supplementation, further intervention studies in humans are needed to investigate the effects of CoQ on vascular function, blood pressure and cardiovascular outcomes. The particularly relevant groups of patients for these studies are those with insulin resistance, type 2 diabetes, hypertension and the metabolic syndrome.

Dietary cosupplementation with vitamin E and coenzyme Q(10) inhibits atherosclerosis in apolipoprotein E gene knockout mice

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