Life-long supplementation with a low dosage of coenzyme Q10 in the rat: effects on antioxidant status and DNA damage

Effects of idebenone and coenzyme Q10 on NLRP3/caspase-1/IL-1β pathway regulation on ethanol-induced hepatotoxicity in rats

Chronic and excessive alcohol consumption leads to liver toxicity. There is a need to investigate effective therapeutic strategies to alleviate alcohol-induced liver injury, which remains the leading cause of liver-related morbidity and mortality worldwide. Therefore here, we looked into and evaluated how ethanol-induced hepatotoxicity was affected by coenzyme Q10 (CoQ10) and its analog, idebenone (IDE), on the NLRP3/caspase-1/IL-1 pathway. Hepatotoxicity induced in rats through the oral administration of gradually increasing dosages of ethanol (from 2 to 6 g/kg/day) over 30 days and the effect of CoQ10 (10 or 20 mg/kg) and IDE (50 or 100 mg/kg) were evaluated. Serum hepatotoxicity markers (ALT, AST, GGT, ALP, and TBIL), tissue oxidative stress markers and the mRNA expressions of IL-1β, IL-18, TGF-β, NF-κB, NLRP3, and caspase-1 were evaluated. Masson's trichrome staining was also used to visualize fibrosis in the liver tissue. The results indicated that ethanol exposure led to hepatotoxicity as well as considerable NLRP3/caspase-1/IL-1β pathway activation. Moreover, CoQ10 or IDE treatment reduced measured parameters in a dosage-dependent manner. Thus, by inhibiting the NLRP3/caspase-1/IL-1 pathway, CoQ10 and IDE can prevent the hepatotoxicity caused by ethanol, although CoQ10 is more effective than IDE. This study will provide insight into new therapeutic avenues that take advantage of the anti-inflammatory and antioxidant properties of CoQ10 and IDE in ethanol-induced liver diseases.

Dietary antioxidants and lifespan: Relevance of environmental conditions, diet, and genotype of experimental models

The rise of life expectancy in current societies is not accompanied, to date, by a similar increase in healthspan, which represents a great socio-economic problem. It has been suggested that aging can be manipulated and then, the onset of all age-associated chronic disorders can be delayed because these pathologies share age as primary underlying risk factor. One of the most extended ideas is that aging is consequence of the accumulation of molecular damage. According to the oxidative damage theory, antioxidants should slow down aging, extending lifespan and healthspan. The present review analyzes studies evaluating the effect of dietary antioxidants on lifespan of different aging models and discusses the evidence on favor of their antioxidant activity as anti-aging mechanisms. Moreover, possible causes for differences between the reported results are evaluated.

Coenzyme Q-related compounds to maintain healthy mitochondria during aging

Mitochondrial dysfunction is one of the main factors that affects aging progression and many age-related diseases. Accumulation of dysfunctional mitochondria can be driven by unbalanced mito/autophagy or by decrease in mitochondrial biosynthesis and turnover. Coenzyme Q is an essential component of the mitochondrial electron transport chain and a key factor in the protection of membrane and mitochondrial DNA against oxidation. Coenzyme Q levels decay during aging and this can be considered an accelerating factor in mitochondrial dysfunction and aging progression. Supplementation with coenzyme Q is successful for some tissues and organs but not for others. For this reason, the role of coenzyme Q in systemic aging is a complex picture that needs different strategies depending on the organ considered the main objective to be addressed. In this chapter we focus on the different effects of coenzyme Q and related compounds and the probable strategies to induce endogenous synthesis to maintain healthy aging.

Coenzyme Q10 in aging and disease

Coenzyme Q10 (CoQ10) is an essential component of the electron transport chain. It also acts as an antioxidant in cellular membranes. It can be endogenously produced in all cells by a specialized mitochondrial pathway. CoQ10 deficiency, which can result from aging or insufficient enzyme function, has been considered to increase oxidative stress. Some drugs, including statins and bisphosphonates, often used by older individuals, can interfere with enzymes responsible for endogenous CoQ10 synthesis. Oral supplementation with high doses of CoQ10 can increase both its circulating and intracellular levels and several clinical trials observed that its administration provided beneficial effects on different disorders such as cardiovascular disease and inflammation which have been associated with low CoQ10 levels and high oxidative stress. Moreover, CoQ10 has been suggested as a promising therapeutic agent to prevent and slow the progression of other diseases including metabolic syndrome and type 2 diabetes, neurodegenerative and male infertility. However, there is still a need for further studies and well-designed clinical trials involving a large number of participants undergoing longer treatments to assess the benefits of CoQ10 for these disorders.

The Many Roles Mitochondria Play in Mammalian Aging

Significance: Aging is a natural process that affects most living organisms, resulting in increased mortality. As the world population ages, the prevalence of age-associated diseases, and their associated health care costs, has increased sharply. A better understanding of the molecular mechanisms that lead to cellular dysfunction may provide important targets for interventions to prevent or treat these diseases. Recent Advances: Although the mitochondrial theory of aging had been proposed more than 40 years ago, recent new data have given stronger support for a central role for mitochondrial dysfunction in several pathways that are deregulated during normal aging and age-associated disease. Critical Issues: Several of the experimental evidence linking mitochondrial alterations to age-associated loss of function are correlative and mechanistic insights are still elusive. Here, we review how mitochondrial dysfunction may be involved in many of the known hallmarks of aging, and how these pathways interact in an intricate net of molecular relationships. Future Directions: As it has become clear that mitochondrial dysfunction plays causative roles in normal aging and age-associated diseases, it is necessary to better define the molecular interactions and the temporal and causal relationship between these changes and the relevant phenotypes seen during the aging process. Antioxid. Redox Signal. 36, 824-843.

Coenzyme Q at the Hinge of Health and Metabolic Diseases

Coenzyme Q is a unique lipidic molecule highly conserved in evolution and essential to maintaining aerobic metabolism. It is endogenously synthesized in all cells by a very complex pathway involving a group of nuclear genes that share high homology among species. This pathway is tightly regulated at transcription and translation, but also by environment and energy requirements. Here, we review how coenzyme Q reacts within mitochondria to promote ATP synthesis and also integrates a plethora of metabolic pathways and regulates mitochondrial oxidative stress. Coenzyme Q is also located in all cellular membranes and plasma lipoproteins in which it exerts antioxidant function, and its reaction with different extramitochondrial oxidoreductases contributes to regulate the cellular redox homeostasis and cytosolic oxidative stress, providing a key factor in controlling various apoptosis mechanisms. Coenzyme Q levels can be decreased in humans by defects in the biosynthesis pathway or by mitochondrial or cytosolic dysfunctions, leading to a highly heterogeneous group of mitochondrial diseases included in the coenzyme Q deficiency syndrome. We also review the importance of coenzyme Q levels and its reactions involved in aging and age-associated metabolic disorders, and how the strategy of its supplementation has had benefits for combating these diseases and for physical performance in aging.

Effect of mitophagy in oocytes and granulosa cells on oocyte quality†

Mitophagy is the process by which cells selectively remove supernumerary or damaged mitochondria through autophagy, and is crucial for mitochondrial homeostasis and cell survival. Mitochondria play vital roles in determining the developmental competence of oocytes. During the early stages of oogenesis, aberrant mitochondria can be removed by mitophagy. After oocyte formation, mitophagy is not actively initiated to clear damaged mitochondria despite the presence of mitophagy regulators in oocytes, which leads to the transmission of dysfunctional mitochondria from the oocyte to the embryo. However, granulosa cells around oocytes can improve mitochondrial function through mitophagy, thereby improving oocyte developmental capacity. Furthermore, this review discusses recent work on the substances and environmental conditions that affect mitophagy in oocytes and granulosa cells, thus providing new directions for improving oocyte quality during assisted reproductive technology treatment.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.

The effects of coenzyme Q10 supplement on blood lipid indices and hepatic antioxidant defense system in SD rats fed a high cholesterol diet

A total of 24 SD rats were allotted to four treatment groups such as the control (CON), 1% of cholesterol diet (CHO), 0.5% of coenzyme Q₁₀ (COQ) and 1% of cholesterol plus 0.5% of coenzyme Q₁₀ (CHCQ) groups to determine the effects of coenzyme Q₁₀ (CoQ₁₀) on the antioxidant defense system in rats. The body weight, weight gain, liver weight and abdominal fat pads were unaffected by 0.5% of CoQ₁₀ supplement in the rats. The level of triglyceride and HDL-cholesterol levels in the blood was significantly increased (p < 0.05) by the 1% of cholesterol supplement (CHO), whereas 0.5% of CoQ₁₀ supplement (COQ) did not alter these blood lipid indices. In the mRNA expression, there was a significant effect (P < 0.05) of the CoQ₁₀ supplement on the mRNA expression of superoxide dismutase (SOD), although the mRNA expression of glutathione peroxidase (GPX) and glutathione S-transferase (GST) was unaffected by cholesterol or the CoQ₁₀ supplement. Similar to mRNA expression of SOD, its activity was also significantly increased (P < 0.05) by CoQ₁₀, but not by the cholesterol supplement effect. The activities hepatic GPX and GST were unaffected by CoQ₁₀ and cholesterol supplements in rats. Lipid peroxidation in the CHO group resulted in a significant (p < 0.05) increase compared with that in the other groups, indicating that the CoQ₁₀ supplement to 1% of cholesterol-fed rats alleviated the production of lipid peroxidation in the liver. In conclusion, 0.5% of the CoQ₁₀ supplement resulted in positive effects on the hepatic antioxidant defense system without affecting blood lipid indices in 1% of cholesterol fed rats.

Ubiquinol-10 delays postovulatory oocyte aging by improving mitochondrial renewal in pigs

Ubiquinol-10, the reduced form of coenzyme Q10, protects mammalian cells from oxidative damage and enhances mitochondrial activity. However, the protective effect of ubiquinol-10 on mammalian oocytes is not well understood. In this study, we investigated the effect of ubiquinol-10 on porcine oocytes during postovulatory aging. Metaphase II oocytes were selected as fresh oocytes and further cultured for 48 h with different concentrations of ubiquinol-10 (0–400 μM) in vitro as a postovulatory aging model. After choosing the optimal concentration of ubiquinol-10 (100 μM) that maintained oocyte morphology and developmental competence during the progression of aging, the oocytes were randomly divided into five groups: fresh, control-24 h, ubiquinol-24 h, control-48 h, and ubiquinol-48 h. The results revealed that ubiquinol-10 significantly prevented aging-induced oxidative stress, GSH reduction, cytoskeleton impairment, apoptosis, and autophagy. Mitochondrial biogenesis (SIRT1 and PGC-1α) and mitophagy (PINK1 and PARKIN)-related proteins were decreased during aging. Addition of ubiquinol-10 prevented the aging-induced reduction of these proteins. Consequently, although mitochondrial content was decreased, the number of active mitochondria and ATP level were significantly increased upon treatment with ubiquinol-10. Thus, ubiquinol-10 has beneficial effects on porcine postovulatory aging oocytes owing to its antioxidant properties and ability to promote mitochondrial renewal.

The Paradox of Coenzyme Q10 in Aging

Coenzyme Q (CoQ) is an essential endogenously synthesized molecule that links different metabolic pathways to mitochondrial energy production thanks to its location in the mitochondrial inner membrane and its redox capacity, which also provide it with the capability to work as an antioxidant. Although defects in CoQ biosynthesis in human and mouse models cause CoQ deficiency syndrome, some animals models with particular defects in the CoQ biosynthetic pathway have shown an increase in life span, a fact that has been attributed to the concept of mitohormesis. Paradoxically, CoQ levels decline in some tissues in human and rodents during aging and coenzyme Q₁₀ (CoQ₁₀) supplementation has shown benefits as an anti-aging agent, especially under certain conditions associated with increased oxidative stress. Also, CoQ₁₀ has shown therapeutic benefits in aging-related disorders, particularly in cardiovascular and metabolic diseases. Thus, we discuss the paradox of health benefits due to a defect in the CoQ biosynthetic pathway or exogenous supplementation of CoQ₁₀.

CoQ10 and Aging

The aging process includes impairment in mitochondrial function, a reduction in anti-oxidant activity, and an increase in oxidative stress, marked by an increase in reactive oxygen species (ROS) production. Oxidative damage to macromolecules including DNA and electron transport proteins likely increases ROS production resulting in further damage. This oxidative theory of cell aging is supported by the fact that diseases associated with the aging process are marked by increased oxidative stress. Coenzyme Q10 (CoQ₁₀) levels fall with aging in the human but this is not seen in all species or all tissues. It is unknown whether lower CoQ₁₀ levels have a part to play in aging and disease or whether it is an inconsequential cellular response to aging. Despite the current lay public interest in supplementing with CoQ₁₀, there is currently not enough evidence to recommend CoQ₁₀ supplementation as an anti-aging anti-oxidant therapy.

Dietary intervention with a specific micronutrient combination for the treatment of patients with cardiac arrhythmias: the impact on insulin resistance and left ventricular function

Background

Cardiac arrhythmias (CA) are very common and may occur with or without heart disease. Causes of these disturbances can be components of the metabolic syndrome (MetS) or deficits of micronutrients especially magnesium, potassium, B vitamins and coenzyme Q10. Both causes may also influence each other. Insulin resistance (IR) is a risk factor for diastolic dysfunction. One exploratory outcome of the present pilot study was to assess the impact of a dietary intervention with specific micronutrients on the lowering of IR levels in patients with CA with the goal to improve the left ventricular (LV) function.

Methods

This was a post hoc analysis of the randomized double blind, placebo-controlled pilot study in patients with CA (VPBs, SVPBs, SV tachycardia), which were recruited using data from patients who were 18–75 years of age in an Outpatient Practice of Cardiology. These arrhythmias were assessed by Holter ECG and LV function by standard echocardiography. Glucose metabolism was measured by fasting glucose, fasting insulin level and the Homeostasis Model Assessment of IR (HOMA-IR) at baseline and after 6 weeks of dietary supplementation.

Results

A total of 54 randomized patients with CA received either a specific micronutrient combination or placebo. Dietary intervention led to a significant decrease in fasting insulin ≥58 pmol/l (p = 0.020), and HOMA-IR (p = 0.053) in the verum group after 6 weeks. At the same time, parameters of LV diastolic function were improved after intervention in the verum group: significant reduction of LV mass index (p = 0.003), and in tendency both a decrease of interventricular septal thickness (p = 0.053) as well as an increase of E/A ratio (p = 0.051). On the other hand, the premature beats (PBs) were unchanged under verum.

Conclusions

In this pilot study, dietary intervention with specific micronutrient combination as add-on to concomitant cardiovascular drug treatment seems to improve cardio metabolic health in patients with CA. Further studies are required.

Study registration

The study was approved by the Freiburg Ethics Commission International and was retrospectively registered with the U.S. National Institutes of Health Clinical Trials gov ID NCT 02652338 on 16 December 2015.

Coenzyme Q10 in Cardiovascular and Metabolic Diseases: Current State of the Problem

The burden of cardiovascular and metabolic diseases is increasing with every year. Although the management of these conditions has improved greatly over the years, it is still far from perfect. With all of this in mind, there is a need for new methods of prophylaxis and treatment. Coenzyme Q10 (CoQ10) is an essential compound of the human body. There is growing evidence that CoQ10 is tightly linked to cardiometabolic disorders. Its supplementation can be useful in a variety of chronic and acute disorders. This review analyses the role of CoQ10 in hypertension, ischemic heart disease, myocardial infarction, heart failure, viral myocarditis, cardiomyopathies, cardiac toxicity, dyslipidemia, obesity, type 2 diabetes mellitus, metabolic syndrome, cardiac procedures and resuscitation.

Effects of coenzyme Q10 on the antioxidant system in SD rats exposed to lipopolysaccharide-induced toxicity

The study was performed to see the effects of coenzyme Q₁₀ (CoQ₁₀) on blood biochemical components and hepatic antioxidant system in rats exposed to lipopolysaccharide (LPS)-induced toxicity. A total of 24 rats were allocated to four groups: control (CON), 100 mg/kg BW of LPS (LPS), 100 mg of CoQ₁₀/kg BW with LPS (LCQI) and 300 mg of CoQ₁₀/kg BW with LPS (LCQII). The LPS and LCQI groups showed a significant (P<0.05) increase in the relative spleen weight compared with the CON group without affecting body and liver weights. The blood alanine aminotransferase (ALT) level in the LPS group was significantly (P<0.05) greater than that in the CON group, while supplementation with 100 or 300 mg CoQ₁₀ to rats injected with LPS normalized the ALT level in the CON group. In antioxidant systems, the LPS group showed a significantly (P<0.05) higher mRNA and activity of superoxide dismutase (SOD) than the CON group. The supplementation with CoQ₁₀ to the LPS-treated group normalized the level of SOD, which was comparable to the level of the CON group. Both the mRNA expression and activity of glutathione peroxidase in the LCQI and LCQII groups were higher (P<0.05) than that of the LPS group. However, administration of LPS or CoQ₁₀ unaffected the level of catalase and total antioxidant power. The level of lipid peroxidation in the LCQII group was lower (P<0.05) than that in the LPS group. In conclusion, CoQ₁₀ exerted its favorable effect against liver damage by modulation of antioxidant enzymes in LPS treated rats.

Does Swimming at a Moderate Altitude Favor a Lower Oxidative Stress in an Intensity-Dependent Manner? Role of Nonenzymatic Antioxidants

Casuso, Rafael A., Jerónimo Aragón-Vela, Gracia López-Contreras, Silvana N. Gomes, Cristina Casals, Yaira Barranco-Ruiz, Jordi J. Mercadé, and Jesus R. Huertas. Does swimming at a moderate altitude favor a lower oxidative stress in an intensity-dependent manner? Role of nonenzymatic antioxidants. High-Alt Med Biol. 18:46-55, 2017.-we aimed to describe oxidative damage and enzymatic and nonenzymatic antioxidant responses to swimming at different intensities in hypoxia. We recruited 12 highly experienced swimmers who have been involved in competitive swimming for at least 9 years. They performed a total of six swimming sessions carried out at low (LOW), moderate (MOD), or high (HIGH) intensity at low altitude (630 m) and at 2320 m above sea level. Blood samples were collected before the session (Pre), after the cool down (Post), and after 15 minutes of recovery (Rec). Blood lactate (BL) and heart rate were recorded throughout the main part of the session. Average velocities did not change between hypoxia and normoxia. We found a higher BL in response to MOD intensity in hypoxia. Plasmatic hydroperoxide level decreased at all intensities when swimming in hypoxia. This effect coincided with a lower glutation peroxidase activity and a marked mobilization of the circulating levels of α-tocopherol and coenzyme Q10 in an intensity-dependent manner. Our results suggest that, regardless of the intensity, no oxidative damage is found in response to hypoxic swimming in well-trained swimmers. Indeed, swimmers show a highly efficient antioxidant system by stimulating the mobilization of nonenzymatic antioxidants.

Aqueous Extract of Agaricus blazei Murrill Prevents Age-Related Changes in the Myenteric Plexus of the Jejunum in Rats

This study evaluated the effects of the supplementation with aqueous extract of Agaricus blazei Murrill (ABM) on biometric and blood parameters and quantitative morphology of the myenteric plexus and jejunal wall in aging Wistar rats. The animals were euthanized at 7 (C7), 12 (C12 and CA12), and 23 months of age (C23 and CA23). The CA12 and CA23 groups received a daily dose of ABM extract (26 mg/animal) via gavage, beginning at 7 months of age. A reduction in food intake was observed with aging, with increases in the Lee index, retroperitoneal fat, intestinal length, and levels of total cholesterol and total proteins. Aging led to a reduction of the total wall thickness, mucosa tunic, villus height, crypt depth, and number of goblet cells. In the myenteric plexus, aging quantitatively decreased the population of HuC/D(+) neuronal and S100(+) glial cells, with maintenance of the nNOS(+) nitrergic subpopulation and increase in the cell body area of these populations. Supplementation with the ABM extract preserved the myenteric plexus in old animals, in which no differences were detected in the density and cell body profile of neurons and glial cells in the CA12 and CA23 groups, compared with C7 group. The supplementation with the aqueous extract of ABM efficiently maintained myenteric plexus homeostasis, which positively influenced the physiology and prevented the death of the neurons and glial cells.

Effects of CoQ10 Supplementation on Lipid Profiles and Glycemic Control in Patients with Type 2 Diabetes: a randomized, double blind, placebo-controlled trial

Background

Low grade inflammation and oxidative stress are the key factors in the pathogenesis and development of diabetes and its complications. Coenzyme Q10 (CoQ10) is known as an antioxidant and has a vital role in generation of cellular energy providing. This study was undertaken to evaluate the effects of CoQ10 supplementation on lipid profiles and glycemic controls in patients with diabetes.

Methods

Fifty patients with diabetes were randomly allocated into two groups to receive either 150 mg CoQ10 or placebo daily for 12 weeks. Before and after supplementation, fasting venous blood samples were collected and lipid profiles containing triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) and glycemic indices comprising of fasting plasma glucose (FPG), insulin and hemoglobin A₁C (HbA₁C) were measured. Insulin resistance was calculated using HOMA-IR index.

Results

Forty patients completed the study. After intervention FPG and HbA₁C were significantly lower in the CoQ10 group compared to the placebo group, but there were no significant differences in serum insulin and HOMA-IR between the two groups. Although total cholesterol did not change in the Q10 group after supplementation, triglyceride and HDL-C significantly decreased and LDL-C significantly increased in the CoQ10 group.

Conclusion

The present study showed that treatment with Q10 may improve glycemic control with no favorable effects on lipid profiles in type 2 patients with diabetes.

Trial registration

IRCT registry number: IRCT138806102394N1

Ubiquinol-10 supplementation activates mitochondria functions to decelerate senescence in senescence-accelerated mice

AIM

The present study was conducted to define the relationship between the anti-aging effect of ubiquinol-10 supplementation and mitochondrial activation in senescence-accelerated mouse prone 1 (SAMP1) mice.

RESULTS

Here, we report that dietary supplementation with ubiquinol-10 prevents age-related decreases in the expression of sirtuin gene family members, which results in the activation of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a major factor that controls mitochondrial biogenesis and respiration, as well as superoxide dismutase 2 (SOD2) and isocitrate dehydrogenase 2 (IDH2), which are major mitochondrial antioxidant enzymes. Ubiquinol-10 supplementation can also increase mitochondrial complex I activity and decrease levels of oxidative stress markers, including protein carbonyls, apurinic/apyrimidinic sites, malondialdehydes, and increase the reduced glutathione/oxidized glutathione ratio. Furthermore, ubiquinol-10 may activate Sirt1 and PGC-1α by increasing cyclic adenosine monophosphate (cAMP) levels that, in turn, activate cAMP response element-binding protein (CREB) and AMP-activated protein kinase (AMPK).

INNOVATION AND CONCLUSION

These results show that ubiquinol-10 may enhance mitochondrial activity by increasing levels of SIRT1, PGC-1α, and SIRT3 that slow the rate of age-related hearing loss and protect against the progression of aging and symptoms of age-related diseases.

Mitochondrial dysfunction in obesity: potential benefit and mechanism of Co-enzyme Q10 supplementation in metabolic syndrome

Co-enzyme Q10 (Co-Q10) is an essential component of the mitochondrial electron transport chain. Most cells are sensitive to co-enzyme Q10 (Co-Q10) deficiency. This deficiency has been implicated in several clinical disorders such as heart failure, hypertension, Parkinson's disease and obesity. The lipid lowering drug statin inhibits conversion of HMG-CoA to mevalonate and lowers plasma Co-Q10 concentrations. However, supplementation with Co-Q10 improves the pathophysiological condition of statin therapy. Recent evidence suggests that Co-Q10 supplementation may be useful for the treatment of obesity, oxidative stress and the inflammatory process in metabolic syndrome. The anti-inflammatory response and lipid metabolizing effect of Co-Q10 is probably mediated by transcriptional regulation of inflammation and lipid metabolism. This paper reviews the evidence showing beneficial role of Co-Q10 supplementation and its potential mechanism of action on contributing factors of metabolic and cardiovascular complications.

Doxorubicin-induced oxidative stress in rats is efficiently counteracted by dietary anthocyanin differently enriched strawberry (Fragaria × ananassa Duch.)

This study investigated the effects of two different strawberry cultivars, Adria and Sveva, against doxorubicin (DOX)-induced toxicity in rats. A controlled dietary intervention was conducted over 16 weeks with four groups: (i) normal diet; (ii) normal diet + DOX injection; (iii) Adria supplementation + DOX injection; and (iv) Sveva supplementation + DOX injection. Sveva presented higher total antioxidant capacity value and phenol and and vitamin C levels than Adria, which in turn presented higher anthocyanin contents. DOX drastically increased lymphocyte DNA damage, liver biomarkers of protein and lipid oxidation, and mitochondrial ROS content and markedly decreased plasma retinol level, liver antioxidant enzymes, and mitochondrial functionality. After 2 months of strawberry supplementation, rats presented a significant reduction of DNA damage and ROS concentration and a significant improvement of oxidative stress biomarkers, antioxidant enzyme activities, and mitochondrial performance. These results suggest that strawberry supplementation can counteract DOX toxicity, confirming the potential health benefit of strawberry in vivo against oxidative stress.

Coenzyme Q10 as a therapy for mitochondrial disease

Treatment of mitochondrial respiratory chain (MRC) disorders is extremely difficult, however, coenzyme Q10 (CoQ10) and its synthetic analogues are the only agents which have shown some therapeutic benefit to patients. CoQ10 serves as an electron carrier in the MRC as well as functioning as a potent lipid soluble antioxidant. CoQ10 supplementation is fundamental to the treatment of patients with primary defects in the CoQ10 biosynthetic pathway. The efficacy of CoQ10 and its analogues in the treatment of patients with MRC disorders not associated with a CoQ10 deficiency indicates their ability to restore electron flow in the MRC and/or increase mitochondrial antioxidant capacity may also be important contributory factors to their therapeutic potential.

Postprandial antioxidant gene expression is modified by Mediterranean diet supplemented with coenzyme Q(10) in elderly men and women

Postprandial oxidative stress is characterized by an increased susceptibility of the organism towards oxidative damage after consumption of a meal rich in lipids and/or carbohydrates. We have investigated whether the quality of dietary fat alters postprandial gene expression and protein levels involved in oxidative stress and whether the supplementation with coenzyme Q(10) (CoQ) improves this situation in an elderly population. Twenty participants were randomized to receive three isocaloric diets each for 4 weeks: Mediterranean diet supplemented with CoQ (Med + CoQ diet), Mediterranean diet (Med diet), saturated fatty acid-rich diet (SFA diet). After 12-h fast, volunteers consumed a breakfast with a fat composition similar to that consumed in each of the diets. Nrf2, p22(phox) and p47(phox), superoxide dismutase 1 and 2 (SOD1 and SOD2), glutathione peroxidase 1 (GPx1), thiorredoxin reductase (TrxR) gene expression and Kelch-like ECH associating protein 1 (Keap-1) and citoplasmic and nuclear Nrf2 protein levels were determined. Med and Med + CoQ diets induced lower Nrf2, p22(phox), p47(phox), SOD1, SOD2 and TrxR gene expression and higher cytoplasmic Nrf2 and Keap-1 protein levels compared to the SFA diet. Moreover, Med + CoQ diet produced lower postprandial Nrf2 gene expression and lower nuclear Nrf2 protein levels compared to the other diets and lower GPx1 gene expression than the SFA diet. Our results support the antioxidant effect of a Med diet and that exogenous CoQ supplementation has a protective effects against free radical overgeneration through the lowering of postprandial oxidative stress modifying the postprandial antioxidant protein levels and reducing the postprandial expression of antioxidant genes in peripheral blood mononuclear cells.

Postprandial antioxidant effect of the Mediterranean diet supplemented with coenzyme Q10 in elderly men and women

Postprandial oxidative stress is characterized by an increased susceptibility of the organism towards oxidative damage after consumption of a meal rich in lipids and/or carbohydrates. We have investigated whether the quality of dietary fat alters postprandial cellular oxidative stress and whether the supplementation with coenzyme Q(10) (CoQ) lowers postprandial oxidative stress in an elderly population. In this randomized crossover study, 20 participants were assigned to receive three isocaloric diets for periods of 4 week each: (1) Mediterranean diet supplemented with CoQ (Med+CoQ diet), (2) Mediterranean diet (Med diet), and (3) saturated fatty acid-rich diet (SFA diet). After a 12-h fast, the volunteers consumed a breakfast with a fat composition similar to that consumed in each of the diets. CoQ, lipid peroxides (LPO), oxidized low-density lipoprotein (oxLDL), protein carbonyl (PC), total nitrite, nitrotyrosine plasma levels, catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities and ischemic reactive hyperaemia (IRH) were determined. Med diet produced a lower postprandial GPx activity and a lower decrease in total nitrite level compared to the SFA diet. Med and Med+CoQ diets induced a higher postprandial increase in IRH and a lower postprandial LPO, oxLDL, and nitrotyrosine plasma levels than the SFA diet. Moreover, the Med+CoQ diet produced a lower postprandial decrease in total nitrite and a greater decrease in PC levels compared to the other two diets and lower SOD, CAT, and GPx activities than the SFA diet.In conclusion, Med diet reduces postprandial oxidative stress by reducing processes of cellular oxidation and increases the action of the antioxidant system in elderly persons and the administration of CoQ further improves this redox balance.

Mediterranean diet supplemented with coenzyme Q10 modifies the expression of proinflammatory and endoplasmic reticulum stress-related genes in elderly men and women

We have investigated whether the quality of dietary fat and supplementation with coenzyme Q(10) (CoQ) modifies expression of genes related with inflammatory response and endoplasmic reticulum stress in elderly persons. Twenty participants received three diets for 4 weeks each: Mediterranean diet + CoQ (Med + CoQ), Mediterranean diet (Med), and saturated fatty acid-rich diet (SFA). After 12-hour fast, volunteers consumed a breakfast with a fat composition similar to that consumed in each of the diets. Med and Med + CoQ diets produced a lower fasting calreticulin, IL-1b, and JNK-1 gene expression; a lower postprandial p65, IKK-b, MMP-9, IL-1b, JNK-1, sXBP-1, and BiP/Grp78 gene expression; and a higher postprandial IkB-a gene expression compared with the SFA diet. Med + CoQ diet produced a lower postprandial decrease p65 and IKK-b gene expression compared with the other diets. Our results support the anti-inflammatory effect of Med diet and that exogenous CoQ supplementation in synergy with a Med diet modulates the inflammatory response and endoplasmic reticulum stress.

Micronutrient special issue: coenzyme Q(10) requirements for DNA damage prevention

Coenzyme Q(10) (CoQ(10)) is an essential component for electron transport in the mitochondrial respiratory chain and serves as cofactor in several biological processes. The reduced form of CoQ(10) (ubiquinol, Q(10)H(2)) is an effective antioxidant in biological membranes. During the last years, particular interest has been grown on molecular effects of CoQ(10) supplementation on mechanisms related to DNA damage prevention. This review describes recent advances in our understanding about the impact of CoQ(10) on genomic stability in cells, animals and humans. With regard to several in vitro and in vivo studies, CoQ(10) provides protective effects on several markers of oxidative DNA damage and genomic stability. In comparison to the number of studies reporting preventive effects of CoQ(10) on oxidative stress biomarkers, CoQ(10) intervention studies in humans with a direct focus on markers of DNA damage are limited. Thus, more well-designed studies in healthy and disease populations with long-term follow up results are needed to substantiate the reported beneficial effects of CoQ(10) on prevention of DNA damage.

Effects of coenzyme Q10 and α-lipoic acid supplementation in fructose fed rats

This study was conducted to investigate the effects of α-lipoic acid and coenzyme Q10 on plasma levels of lipids, asymmetric dimethylarginine, oxidative stress in fructose fed rats which provide a model of dietary-induced insulin resistance and to evaluate vascular changes developing in these rats by histologically. Male Sprague Dawley rats were used in this study. The animals were divided into 4 groups. Group 1 did not receive any medication and served as a control. Group 2 received a regular diet and water ad libitum and fructose was administered as % 10 solution in drinking water. Group 3 received α-lipoic acid (100 mg/kg/day) i.p. for 5 weeks and Group 4 received coenzyme Q10 (10 mg/kg/day) i.p. for 5 weeks. For determination of plasma asymmetric dimethylarginine, glutathione and malondialdehyde levels, high-performance liquid chromatography system was used. Homeostatic model assessment as a measure of insulin resistance was calculated. Lipid profile measurements were determined using enzymatic assay on an Auto analyzer. The high fructose diet was significantly associated with an increase in levels of plasma LDL, VLDL and total cholesterol and decrease in level of HDL cholesterol. Plasma asymmetric dimethylarginine, malondialdehyde and glutathione levels were also increase in these rats. α-lipoic acid or coenzyme Q10 supplementation was found to have some positive effect on these parameters. These findings were also demonstrated by morphological observation of the aorta. We demonstrated that administration of α-lipoic acid and coenzyme Q10 notably suppresses oxidative and nitrative stress, hyperinsulinemia, insulin resistance developing in fructose fed rats, a model of metabolic syndrome (MS). These positive effects of α-lipoic acid or coenzyme Q10 can be attributed to its antioxidant activity.

Age-related changes in brain mitochondrial DNA deletion and oxidative stress are differentially modulated by dietary fat type and coenzyme Q₁₀

Mitochondria-related oxidative damage is a primary event in aging and age-related neurodegenerative disorders. Some dietary treatments, such as antioxidant supplementation or the enrichment of mitochondrial membranes with less oxidizable fatty acids, reduce lipid peroxidation and lengthen life span in rodents. This study compares life-long feeding on monounsaturated fatty acids (MUFAs), such as virgin olive oil, and n-6 polyunsaturated fatty acids, such as sunflower oil, with or without coenzyme Q₁₀ supplementation, with respect to age-related molecular changes in rat brain mitochondria. The MUFA diet led to diminished age-related phenotypic changes, with lipoxidation-derived protein markers being higher among the older animals, whereas protein carbonyl compounds were lower. It is noteworthy that the MUFA diet prevented the age-related increase in levels of mitochondrial DNA deletions in the brain mitochondria from aged animals. The findings of this study suggest that age-related oxidative stress is related, at the mitochondrial level, to other age-related features such as mitochondrial electron transport and mtDNA alterations, and it can be modulated by selecting an appropriate dietary fat type and/or by suitable supplementation with low levels of the antioxidant/electron carrier molecule coenzyme Q.

Effect of beer consumption on levels of complex I and complex IV liver and heart mitochondrial enzymes and coenzymes Q9 and Q10 in adriamycin-treated rats

BACKGROUND

There is increasing evidence indicating that the dietary intake of food with high antioxidant capacity may protect mitochondria from damage and exert positive effects on different pathogenic processes.

AIM OF THE STUDY

The present study was designed to evaluate the possible protective effect of alcohol-free beer intake on chain components dysfunction of liver and heart mitochondria, and to compare with the effect of alcohol beer intake.

METHODS

The study was carried out in rat heart and liver mitochondria by inducing with Adriamycin the dysfunction of the respiratory chain. Heart and liver mitochondria were isolated from rats and subjected to oxidative stress with two doses of Adriamycin (5 mg/Kg) 7 days from the beginning of consumption of both alcohol-free and alcohol beer during 31 days. Complexes I and IV and the levels of coenzymes Q(9) and Q(10) were evaluated and compared with a control group.

RESULTS

Liver and heart mitochondria isolated from rats treated with Adryamicin showed a decrease in levels of complex I and complex IV enzymatic activity and in levels of coenzymes Q(9) and Q(10). Beer intake for itself does not affect any of the studied parameters. Therefore, the consumption of both alcohol and alcohol-free beer by rats treated with Adriamycin prevents the inhibition of enzymatic activities of complexes I and IV and the oxidation of coenzymes Q(9) and Q(10) in rat heart and liver mitochondria.

CONCLUSIONS

These results indicate that alcohol-free beer prevents adriamycin-induced damage to mitochondrial chain components and, therefore, helps to prevent mitochondrial dysfunction.

Supplementation of coenzyme Q10 and alpha-tocopherol lowers glycated hemoglobin level and lipid peroxidation in pancreas of diabetic rats

The importance of nutritional supplementation in diabetes remains an unresolved issue. The present study was undertaken to examine the effects of alpha-tocopherol and CoQ(10), powerful antioxidants, on metabolic control and on the pancreatic mitochondria of GK rats, a model of type 2 diabetes. We also evaluated the efficacy of these nutrients in preventing the diabetic pancreatic lesions observed in GK rats. Rats were divided into 4 groups, a control group of diabetic GK rats and 3 groups of GK rats administered with alpha-tocopherol and CoQ(10) alone or both in association, during 8 weeks. Fasting blood glucose levels were not significantly different between the groups, nor were blood glucose levels at 2 hours after a glucose load. HbA1c level was significantly reduced in the group supplemented with both antioxidants. Diabetes induced a decrease in coenzyme Q plasma levels that prevailed after treatment with antioxidants. In addition, the plasma alpha-tocopherol levels were higher after treatment with the antioxidants. An increment in some components of the antioxidant defense system was observed in pancreatic mitochondria of treated GK rats. Moreover, the antioxidants tested either alone or in association failed to prevent the pancreatic lesions in this animal model of type 2 diabetes. In conclusion, our results indicate that CoQ(10) and alpha-tocopherol decrease glycated HbA1c and pancreatic lipid peroxidation. These antioxidants increase some components of the antioxidant defense system but do not prevent pancreatic lesions. Thus, we cannot rule out the potential benefit of antioxidant treatments in type 2 diabetes in the prevention of their complications.

Oxidative stress status in liver mitochondria and lymphocyte DNA damage of atherosclerotic rabbits supplemented with water soluble coenzyme Q10

The effects of the administration of water soluble coenzyme Q10 (25 mg/kg per day) over 30 days, after 50 days feeding on a high-fat diet (3% lard + 1.3% cholesterol), were investigated in the plasma and liver mitochondria of rabbits. Results showed that this atherogenic diet enhanced lipid levels both in plasma and liver mitochondria, reduced plasma and mitochondrial concentrations of retinol and coenzyme Q10, led to higher DNA damage in peripheral blood lymphocytes and reactive oxygen species concentration in liver mitochondria. The treatment of animals with coenzyme Q10 reduced (to the healthy group levels) lipid concentration in liver mitochondria with no effect on plasma lipids, increased mitochondrial levels of alpha-tocopherol, restored mitochondrial coenzyme Q10 and improved alpha-tocopherol levels in plasma. Moreover, coenzyme Q10 supplementation reduced mitochondrial reactive oxygen species levels and decreased DNA damage in peripheral blood lymphocytes. The findings suggest that antioxidant therapy with coenzyme Q10 may be used in the treatment of liver pathologies associated to the intake of high-fat, atherogenic, diets.

The evidence basis for coenzyme Q therapy in oxidative phosphorylation disease

The evidence supporting a treatment benefit for coenzyme Q10 (CoQ10) in primary mitochondrial disease (mitochondrial disease) whilst positive is limited. Mitochondrial disease in this context is defined as genetic disease causing an impairment in mitochondrial oxidative phosphorylation (OXPHOS). There are no treatment trials achieving the highest Level I evidence designation. Reasons for this include the relative rarity of mitochondrial disease, the heterogeneity of mitochondrial disease, the natural cofactor status and easy 'over the counter availability' of CoQ10 all of which make funding for the necessary large blinded clinical trials unlikely. At this time the best evidence for efficacy comes from controlled trials in common cardiovascular and neurodegenerative diseases with mitochondrial and OXPHOS dysfunction the etiology of which is most likely multifactorial with environmental factors playing on a background of genetic predisposition. There remain questions about dosing, bioavailability, tissue penetration and intracellular distribution of orally administered CoQ10, a compound which is endogenously produced within the mitochondria of all cells. In some mitochondrial diseases and other commoner disorders such as cardiac disease and Parkinson's disease low mitochondrial or tissue levels of CoQ10 have been demonstrated providing an obvious rationale for supplementation. This paper discusses the current state of the evidence supporting the use of CoQ10 in mitochondrial disease.