Coenzyme Q10: From bench to clinic in aging diseases, a translational review

Advancing coenzyme Q10 delivery with plant protein-based nanoparticle-mediated nanosuspensions

Coenzyme Q10 (CoQ10) possesses significant health-promoting potential, yet its oral delivery encounters obstacles stemming from its distinctive physicochemical characteristics, such as poor solubility, sensitivity to environmental factors and low bioaccessibility. To overcome these challenges, we developed high-payload CoQ10 nanosuspensions (CQ@SPNP, CQ@RPNP, and CQ@WPNP) using plant-based protein nanoparticles (NPs) derived from soybean (SPNP), rice (RPNP), and walnut (WPNP). The nanosuspensions include spherical particles, characterized by small particle size (<230 nm), low polydispersity (PDI < 0.15), and a high zeta potential (<-44 mV). CoQ10 loading capacity exceeded 70.3 %, with an encapsulation efficiency of over 77.4 %. CoQ10 interacted with plant protein-based NPs via hydrophobic effect without losing its crystal structure. Moreover, SPNP, RPNP, and WPNP significantly increased the stability of CoQ10 nanosuspensions against light, heat, long-term storage, and in vitro digestion. In particular, CQ@WPNP exhibited the highest stability and CoQ10 bioaccessibility post-digestion. The observed increases in stability and bioaccessibility were closely related to the specific NPs utilized. This study highlights the potential of plant protein-based NPs in addressing challenges of CoQ10 delivery, offering a promising approach to improve its efficacy.

Amelioration of Phytanic Acid-Induced Neurotoxicity by Nutraceuticals: Mechanistic Insights

Phytanic acid (PA) (3,7,11,15-tetramethylhexadecanoic acid) is a methyl-branched fatty acid that enters the body through food consumption, primarily through red meat, dairy products, and fatty marine foods. The metabolic byproduct of phytol is PA, which is then oxidized by the ruminal microbiota and some marine species. The first methyl group at the 3-position prevents the β-oxidation of branched-chain fatty acid (BCFA). Instead, α-oxidation of PA results in the production of pristanic acid (2,10,14-tetramethylpentadecanoic acid) with CO2. This fatty acid (FA) builds up in individuals with certain peroxisomal disorders and is historically linked to neurological impairment. It also causes oxidative stress in synaptosomes, as demonstrated by an increase in the production of reactive oxygen species (ROS), which is a sign of oxidative stress. This review concludes that the nutraceuticals (melatonin, piperine, quercetin, curcumin, resveratrol, epigallocatechin-3-gallate (EGCG), coenzyme Q10, ω-3 FA) can reduce oxidative stress and enhanced the activity of mitochondria. Furthermore, the use of nutraceuticals completely reversed the neurotoxic effects of PA on NO level and membrane potential. Additionally, the review further emphasizes the urgent need for more research into dairy-derived BCFAs and their impact on human health.

Location and interaction of idebenone and mitoquinone in a membrane similar to the inner mitochondrial membrane. Comparison with ubiquinone 10

Oxygen is essential for aerobic life on earth but it is also the origin of harmful reactive oxygen species (ROS). Ubiquinone is par excellence the endogenous cellular antioxidant, but a very hydrophobic one. Because of that, other molecules have been envisaged, such as idebenone (IDE) and mitoquinone (MTQ), molecules having the same redox active benzoquinone moiety but higher solubility. We have used molecular dynamics to determine the location and interaction of these molecules, both in their oxidized and reduced forms, with membrane lipids in a membrane similar to that of the mitochondria. Both IDE and reduced IDE (IDOL) are situated near the membrane interface, whereas both MTQ and reduced MTQ (MTQOL) locate in a position adjacent to the phospholipid hydrocarbon chains. The quinone moieties of both ubiquinone 10 (UQ10) and reduced UQ10 (UQOL10) in contraposition to the same moieties of IDE, IDOL, MTQ and MTQOL, located near the membrane interphase, whereas the isoprenoid chains remained at the middle of the hydrocarbon chains. These molecules do not aggregate and their functional quinone moieties are located in the membrane at different depths but near the hydrophobic phospholipid chains whereby protecting them from ROS harmful effects.

Safety and efficacy indicators of guarana and Brazil nut extract carried in nanoparticles of coenzyme Q10: Evidence from human blood cells and red earthworm experimental model

This study characterized a nanosupplement based on coenzyme Q10 containing guarana (Paullinia cupana) and Brazil nuts oil (Bertholetia excelsa) (G-Nut). Determined cytotoxic and oxi-immunomodulatory effects on human peripheral blood mononuclear cells (PBMCs) and its effect on mortality of red Californian earthworms (Eisenia fetida) and on the immune efficiency of its coelomocytes immune by in vitro exposure to yeast dead microorganism. The cytotoxic and immunomodulatory effects of G-Nut and the GN-Free extract (0.25-3 mg/mL) were determined in PBMC cultures. Apoptotic, oxidative, and inflammatory markers were determined using biochemical, immunological, and molecular protocols. The effects of G-Nut and GN-Free extracts on mortality and immune efficiency were investigated in earthworms. G-Nut and GN-Free did not induce cytotoxic events in PBMCs, triggering the decrease in apoptotic (caspases 3 and 8) gene expression, lipid and protein oxidation levels, or pro-inflammatory cytokine levels. G-Nut and GN-Free did not trigger earthworm mortality and improved coelomocyte immune efficiency by increasing Eisenia neutrophil extracellular DNA traps and brown body formation when exposed to dead yeasts. The G-Nut nanoformulation is safe and can be used as a new form of food supplement by oral or transdermal delivery.

Targeting Mitochondrial Dysfunction for the Prevention and Treatment of Metabolic Disease by Bioactive Food Components

Dysfunctional mitochondria have been linked to the pathogenesis of obesity-associated metabolic diseases. Excessive energy intake impairs mitochondrial biogenesis and function, decreasing adenosine-5'-triphosphate production and negatively impacting metabolically active tissues such as adipose tissue, skeletal muscle, and the liver. Compromised mitochondrial function disturbs lipid metabolism and increases reactive oxygen species production in these tissues, contributing to the development of insulin resistance, type 2 diabetes, and non-alcoholic fatty liver disease. Recent studies have demonstrated the therapeutic potential of bioactive food components, such as resveratrol, quercetin, coenzyme Q10, curcumin, and astaxanthin, by enhancing mitochondrial function. This review provides an overview of the current understanding of how these bioactive compounds ameliorate mitochondrial dysfunction to mitigate obesity-associated metabolic diseases.

Preparation and characterization of novel nanostructured lipid carriers (NLC) and solid lipid nanoparticles (SLN) containing coenzyme Q10 as potent antioxidants and antityrosinase agents

We developed novel and optimal Q10-NLC/SLN formulations as antioxidant and anti-tyrosinase agents. The formulations were analyzed for particle size, morphology, entrapment efficiency (EE %), and long-term stability. The in vitro drug release and in vivo skin penetration were evaluated using dialysis bag diffusion and Sprague Dawley (SD) rats, respectively. Cytotoxicity and protecting effects were assessed by AlamarBlue® assay, ROS level by DCFH-DA, and tyrosinase activity by l-DOPA assay, measuring the absorbance at 470 nm. The selected formulations had optimal surface characterizations, including Z-average size, PDI, and Zeta potential ranging from 125 to 207 nm, 0.09-0.22, and -7 to -24, respectively. They also exhibited physiochemical stability for up to 6 months and EE% above 80 %. The lipids ratio and co-Q10 amount as variable factors significantly affected particle size and zeta potential but were insignificant on PDI. The in vitro release diagram showed that Q10-NLC/SLN revealed a fast release during the first 8 h and prolonged release afterward. The in vivo skin permeation revealed a higher accumulative uptake of co-Q10 in the skin for Q10-NLC/SLN compared to Q10 emulsions. Both selected Q10-NLC and Q10-SLN could reduce intracellular ROS after exposure to H2O2. The Q10-NLC was found to be more potent for inhibiting the tyrosinase activity compared to O10-SLN. The results suggest that the new formulations are promising carriers for topical delivery of co-Q10 as an anti-aging and skin-whitening agent.

Coenzyme Q10 for Enhancing Physical Activity and Extending the Human Life Cycle

BACKGROUND

Coenzyme Q (CoQ) is an enzyme family that plays a crucial role in maintaining the electron transport chain and antioxidant defense. CoQ10 is the most common form of CoQ in humans. A deficiency of CoQ10 occurs naturally with aging and may contribute to the development or progression of many diseases. Besides, certain drugs, in particular, statins and bisphosphonates, interfere with the enzymes responsible for CoQ10 biosynthesis and, thus, lead to CoQ10 deficiency.

OBJECTIVES

This article aims to evaluate the cumulative studies and insights on the topic of CoQ10 functions in human health, focusing on a potential role in maintaining physical activity and extending the life cycle.

RESULTS

Although supplementation with CoQ10 offers many benefits to patients with cardiovascular disease, it appears to add little value to patients suffering from statin-associated muscular symptoms. This may be attributed to substantial heterogeneity in doses and treatment regimens used.

CONCLUSION

Therefore, there is a need for further studies involving a greater number of patients to clarify the benefits of adjuvant therapy with CoQ10 in a range of health conditions and diseases.

Ferroptosis in Parkinson's disease: Molecular mechanisms and therapeutic potential

Parkinson's Disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN), leading to motor and non-motor symptoms. While the exact mechanisms remain complex and multifaceted, several molecular pathways have been implicated in PD pathology, including accumulation of misfolded proteins, impaired mitochondrial function, oxidative stress, inflammation, elevated iron levels, etc. Overall, PD's molecular mechanisms involve a complex interplay between genetic, environmental, and cellular factors that disrupt cellular homeostasis, and ultimately lead to the degeneration of dopaminergic neurons. Recently, emerging evidence highlights ferroptosis, an iron-dependent non-apoptotic cell death process, as a pivotal player in the advancement of PD. Notably, oligomeric α-synuclein (α-syn) generates reactive oxygen species (ROS) and lipid peroxides within cellular membranes, potentially triggering ferroptosis. The loss of dopamine, a hallmark of PD, could predispose neurons to ferroptotic vulnerability. This unique form of cell demise unveils fresh insights into PD pathogenesis, necessitating an exploration of the molecular intricacies connecting ferroptosis and PD progression. In this review, the molecular and regulatory mechanisms of ferroptosis and their connection with the pathological processes of PD have been systematically summarized. Furthermore, the features of ferroptosis in PD animal models and clinical trials targeting ferroptosis as a therapeutic approach in PD patients' management are scrutinized.

Non-alcoholic fatty liver disease: Dietary and nutraceutical approaches

Non-alcoholic fatty liver disease (NAFLD), defined as the presence of fat accumulation in imaging or histology in more than 5% of hepatocytes and exclusion of other causes for secondary hepatic fat accumulation, is one of the major causes of chronic liver disease worldwide. Metabolic syndrome is associated with an increased risk of progression from NAFLD to non-alcoholic steatohepatitis (NASH), fibrosis, and forthcoming liver failure. Also, genetic predisposition contributes to the risk of NAFLD development. This review explores the role of diets and nutraceuticals in delaying the development and the evolution of NAFLD to chronic liver disease. The Mediterranean diet, high-protein diet, low-carbohydrate/high-fat diet, high-carbohydrate/low-fat diet, and intermittent fasting are the dietary approaches investigated given the presence of relevant literature data. Moreover, this review focused on nutraceuticals with proven efficacy in ameliorating NAFLD and grouped them into four different categories: plant-based nutraceuticals (Ascophyllum nodosum and Fucus vesiculosus, Silymarin, Berberine, Curcumin, Resveratrol, Nigella sativa, Quercetin), vitamin-like substances (vitamin E, vitamin D, vitamin C, coenzyme Q10, inositol), fatty acids (omega-3), and microbiota-management tools (probiotics).

New Insights on the Uptake and Trafficking of Coenzyme Q

Coenzyme Q (CoQ) is an essential lipid with many cellular functions, such as electron transport for cellular respiration, antioxidant protection, redox homeostasis, and ferroptosis suppression. Deficiencies in CoQ due to aging, genetic disease, or medication can be ameliorated by high-dose supplementation. As such, an understanding of the uptake and transport of CoQ may inform methods of clinical use and identify how to better treat deficiency. Here, we review what is known about the cellular uptake and intracellular distribution of CoQ from yeast, mammalian cell culture, and rodent models, as well as its absorption at the organism level. We discuss the use of these model organisms to probe the mechanisms of uptake and distribution. The literature indicates that CoQ uptake and distribution are multifaceted processes likely to have redundancies in its transport, utilizing the endomembrane system and newly identified proteins that function as lipid transporters. Impairment of the trafficking of either endogenous or exogenous CoQ exerts profound effects on metabolism and stress response. This review also highlights significant gaps in our knowledge of how CoQ is distributed within the cell and suggests future directions of research to better understand this process.

Effects of dietary coenzyme Q10 supplementation during gestation on the embryonic survival and reproductive performance of high-parity sows

BACKGROUND

Fertility declines in high-parity sows. This study investigated whether parity-dependent declines in embryonic survival and reproductive performance could be restored by dietary coenzyme Q10 (CoQ10) supplementation.

METHODS

Two experiments were performed. In Exp. 1, 30 young sows that had completed their 2^nd parity and 30 high-parity sows that had completed their 10^th parity, were fed either a control diet (CON) or a CON diet supplemented with 1 g/kg CoQ10 (+ CoQ10) from mating until slaughter at day 28 of gestation. In Exp. 2, a total of 314 post-weaning sows with two to nine parities were fed the CON or + CoQ10 diets from mating throughout gestation.

RESULTS

In Exp. 1, both young and high-parity sows had a similar number of corpora lutea, but high-parity sows had lower plasma CoQ10 concentrations, down-regulated genes involved with de novo CoQ10 synthesis in the endometrium tissues, and greater levels of oxidative stress markers in plasma and endometrium tissues. High-parity sows had fewer total embryos and alive embryos, lower embryonic survival, and greater embryo mortality than young sows. Dietary CoQ10 supplementation increased the number of live embryos and the embryonic survival rate to levels similar to those of young sows, as well as lowering the levels of oxidative stress markers. In Exp. 2, sows showed a parity-dependent decline in plasma CoQ10 levels, and sows with more than four parities showed a progressive decline in the number of total births, live births, and piglets born effective. Dietary supplementation with CoQ10 increased the number of total births, live births, and born effective, and decreased the intra-litter covariation coefficients and the percentage of sows requiring farrowing assistance during parturition.

CONCLUSIONS

Dietary CoQ10 supplementation can improve the embryonic survival and reproductive performance of gestating sows with high parity, probably by improving the development of uterine function.

Increased SIRT1 Concentration Following Four Years of Selenium and Q10 Intervention Associated with Reduced Cardiovascular Mortality at 10-Year Follow-Up-Sub-Study of a Previous Prospective Double-Blind Placebo-Controlled Randomized Clinical Trial

Background: Selenium and coenzyme Q₁₀ (SeQ₁₀) possess antioxidant and anti-inflammatory properties, potentially mediated via Sirtuin1 (SIRT1). We aimed to investigate the influence of a SeQ₁₀ intervention on SIRT1 concentration, with potential interactions with microRNAs. Methods: In this sub-study of a prospective double-blind placebo-controlled clinical trial, healthy subjects (mean age 76 years) were randomized to receive an active treatment (n = 165, combined 200 µg/day of Se and 200 mg/day of Q₁₀) or a placebo (n = 161). SIRT1 concentration and microRNAs were measured with ELISA and PCR, respectively. Results: After four years, SIRT1 concentration was increased in the active treatment group, with mean (SD) ng/mL of 469 (436) vs. 252 (162), p < 0.001, and decreased in the placebo group, 190 (186) vs. 269 (172), p = 0.002, and the differences between the groups were significant (p = 0.006, adjusted). Those who suffered CV death during a 10-year follow-up (n = 25 and n = 52 in the active treatment and placebo groups, respectively) had significantly lower baseline SIRT1 concentrations compared to the survivors (p < 0.001). MiR-130a-3p was significantly downregulated during the intervention and correlated inversely with SIRT1 at baseline (r = -0.466, p = 0.007). Conclusion: The increased SIRT1 concentration after the SeQ₁₀ intervention associated with reduced CV mortality, partly mediated via miR-1303a-3p, suggests that SIRT1 is an additional mediator of the intervention, preventing vascular ageing.

Novel druggable mechanism of Parkinson's disease: Potential therapeutics and underlying pathogenesis based on ferroptosis

Genetics, age, environmental factors, and oxidative stress have all been implicated in the development of Parkinson's disease (PD); however, a complete understanding of its pathology remains elusive. At present, there is no cure for PD, and currently available therapeutics are insufficient to meet patient needs. Ferroptosis, a distinctive iron-dependent cell death mode characterized by lipid peroxidation and oxidative stress, has pathophysiological features similar to those of PD, including iron accumulation, reactive oxygen species-induced oxidative damage, and mitochondrial dysfunction. Ferroptosis has been identified as a specific pathway of neuronal death and is closely related to the pathogenesis of PD. Despite the similarities in the biological targets involved in PD pathogenesis and ferroptosis, the relationship between novel targets in PD and ferroptosis has been neglected in the literature. In this review, the mechanism of ferroptosis is discussed, and the potential therapeutic targets implicated in both PD and ferroptosis are compared. Furthermore, the anti-PD effects of several ferroptosis inhibitors, as well as clinical studies thereof, and the identification of novel lead compounds for the treatment of PD and the inhibition of ferroptosis are reviewed. It is hoped that this review can promote research to further elucidate the relationship between ferroptosis and PD and provide new strategies for the development of novel ferroptosis-targeting PD therapy.

Potential Synergistic Supplementation of NAD+ Promoting Compounds as a Strategy for Increasing Healthspan

Disrupted biological function, manifesting through the hallmarks of aging, poses one of the largest threats to healthspan and risk of disease development, such as metabolic disorders, cardiovascular ailments, and neurodegeneration. In recent years, numerous geroprotectors, senolytics, and other nutraceuticals have emerged as potential disruptors of aging and may be viable interventions in the immediate state of human longevity science. In this review, we focus on the decrease in nicotinamide adenine dinucleotide (NAD+) with age and the supplementation of NAD+ precursors, such as nicotinamide mononucleotide (NMN) or nicotinamide riboside (NR), in combination with other geroprotective compounds, to restore NAD+ levels present in youth. Furthermore, these geroprotectors may enhance the efficacy of NMN supplementation while concurrently providing their own numerous health benefits. By analyzing the prevention of NAD+ degradation through the inhibition of CD38 or supporting protective downstream agents of SIRT1, we provide a potential framework of the CD38/NAD+/SIRT1 axis through which geroprotectors may enhance the efficacy of NAD+ precursor supplementation and reduce the risk of age-related diseases, thereby potentiating healthspan in humans.

Mitoquinone shifts energy metabolism to reduce ROS-induced oxeiptosis in female granulosa cells and mouse oocytes

The female reproductive system is quite sensitive to regulation, and external environmental stimuli may cause oxidative stress which in turn may lead to accelerated aging and programmed cell death in female reproductive cells. The aim of this study was to investigate whether or not mitoquinone (MitoQ) could resist ROS-induced apoptosis in human granulosa cells and mouse oocytes. We found that the MitoQ treatment significantly reduced production of reactive oxygen species (ROS) and imbalance in mitochondrial membrane potential. The MitoQ treatment prevented an excessive mitochondrial fragmentation by upregulating Drp1 S637 and decreasing Drp1 S637 phosphorylation. More importantly, MitoQ maintained aerobic respiration and reduced anaerobic respiration by regulating reprogramming of intracellular energy metabolism, which enhanced cellular ATP production. MitoQ effectively reduced the expressions of AIFM1 and PGAM5, key molecules whose expressions were reversed not only in granulosa cells but also in mouse oocytes. Our findings suggest that MitoQ can ameliorate the mitochondrial deterioration caused by ROS and reprogram cellular energy metabolism, providing protection to cells against apoptosis. The presence of MitoQ may help in protecting human germ cells under in vitro culture conditions.

Modulatory effect of exogenous Coenzyme Q10 on redox and inflammatory biomarkers during aging in rats

An impaired redox homeostasis is an important hallmark of biological aging. Coenzyme Q₁₀ is an endogenous lipophilic antioxidant that decreases with age and has been linked to oxidative stress. The purpose of this study was to evaluate the effect of CoQ₁₀ supplementation on redox homeostasis and levels of inflammatory cytokines in young and old rats. Male Wistar rats (young and old) were randomly divided into four groups (n = 6). Group I: young control, Group II: young rats treated with CoQ₁₀, Group III: old control, Group IV: old rats treated with CoQ₁₀. CoQ₁₀ (20 mg/kg) was administered daily to Group II and IV via oral gavage. After 28 days of treatment, rats were sacrificed and biomarkers of oxidative stress and inflammatory cytokines were evaluated. Results demonstrated a significant (p ≤ 0.05) increase in malondialdehyde, protein carbonyl oxidation, advanced oxidation protein products, inflammatory cytokines: CRP, IL-6, TNF-α, and a decline in levels of superoxide dismutase, catalase, reduced glutathione, ferric reducing antioxidant potential in plasma and plasma membrane redox system in old rats when compared to young rats. After treatment with CoQ₁₀ significant decrease in the level of MDA, PCO, AOPP, CRP, IL-6, and TNF-α was observed. Also, significant up-regulation of SOD, CAT, GSH, FRAP, and PMRS was observed. The results show that supplementing rats with CoQ₁₀ aids in the maintenance of redox equilibrium with replenishment of antioxidant reserves and down-regulation of inflammatory biomarkers. Thus CoQ₁₀ supplementation could be a potential anti-aging therapy.

Molecular mechanisms underlying the renal protective effects of coenzyme Q10 in acute kidney injury

Coenzyme Q10 (CoQ10), an endogenous antioxidant, has been reported frequently to exert an outstanding protective effect on multiple organ injury, including acute kidney injury (AKI). In this study, we aim to summarize all the current evidence of the protective action of CoQ10 against AKI as there are presently no relevant reviews in the literature. After a systematic search, 20 eligible studies, either clinical trials or experimental studies, were included and further reviewed. CoQ10 treatment exhibited a potent renal protective effect on various types of AKI, such as AKI induced by drugs (e.g., ochratoxin A, cisplatin, gentamicin, L-NAME, and nonsteroidal anti-inflammatory drug), extracorporeal shock wave lithotripsy (ESWL), sepsis, contrast media, and ischemia–reperfusion injury. The renal protective role of CoQ10 against AKI might be mediated by the antiperoxidative, anti-apoptotic, and anti-inflammatory potential of CoQ10. The molecular mechanisms for the protective effects of CoQ10 might be attributed to the regulation of multiple essential genes (e.g., caspase-3, p53, and PON1) and signaling cascades (e.g., Nrf2/HO-1 pathway). This review highlights that CoQ10 may be a potential strategy in the treatment of AKI.

Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration

Stem cell transplantation has been proved a promising therapeutic instrument in intervertebral disc degeneration (IVDD). However, the elevation of oxidative stress in the degenerated region impairs the efficiency of mesenchymal stem cells (BMSCs) transplantation treatment via exaggeration of mitochondrial ROS and promotion of BMSCs apoptosis. Herein, we applied an emulsion-confined assembly method to encapsulate Coenzyme Q10 (Co-Q10), a promising hydrophobic antioxidant which targets mitochondria ROS, into the lecithin micelles, which renders the insoluble Co-Q10 dispersible in water as stable colloids. These micelles are injectable, which displayed efficient ability to facilitate Co-Q10 to get into BMSCs in vitro, and exhibited prolonged release of Co-Q10 in intervertebral disc tissue of animal models. Compared to mere use of Co-Q10, the Co-Q10 loaded micelle possessed better bioactivities, which elevated the viability, restored mitochondrial structure as well as function, and enhanced production of ECM components in rat BMSCs. Moreover, it is demonstrated that the injection of this micelle with BMSCs retained disc height and alleviated IVDD in a rat needle puncture model. Therefore, these Co-Q10 loaded micelles play a protective role in cell survival and differentiation through antagonizing mitochondrial ROS, and might be a potential therapeutic agent for IVDD.

Effect of Treating Eggs with Coenzyme Q10 (CoQ10) on Growth Variables, Histomorphometry, and Antioxidant Capacity in Red Tilapia (Oreochromis aureus × Oreochromis mossambicus) Larvae

Red tilapia eggs one day post fertilization (dpf) were exposed to coenzyme Q10 (CoQ10) at rates of 0, 5, and 10 mg/L for control, treatment 2 (C5), and treatment 3 (C10), respectively, without exchanging water and until the larval mouth-opening stage. Fertilized eggs of red tilapia exposed to different concentrations of CoQ10 were hatched at rates (p > 0.05) between 38 to 54.67%. The yolk-sac diameter at the 2nd day post hatching (dph), ranged from 1.85 to 1.87 mm in depth and 1.63 to 1.88 mm in width and was not altered by the CoQ10 treatments. Similarly, red tilapia survival (p > 0.05) ranged from 22.67 to 32%. On 6 dph, a slight percentage (2.08%) of survived fishes exposed to high CoQ10 dose (C10) exhibited larval deformation in the form of an axial curvature of the spine in the abdominal and caudal region. Larvae displayed a normal structure of the esophagus folds in all fish groups, and larvae in the C5 group displayed the longest folds and widest muscularis layer, followed by fishes in the C10 group and the control. Red tilapia fry on 30 dph treated with CoQ10 possessed higher antioxidant potentials in terms of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) compared to the control. In conclusion, treating Red tilapia fertile eggs with 5 mg/L CoQ10 improves the growth, gut structure, and antioxidant efficiency of the produced larvae.

Effects of Coenzyme Q10 Supplementation on Biomarkers of Oxidative Stress in Adults: A GRADE-Assessed Systematic Review and Updated Meta-Analysis of Randomized Controlled Trials

Evidence shows that exogenous CoQ10 supplementation may potentially attenuate oxidative stress status. However, its effective dose and evidence certainty require further evaluation in the general population via more updated randomized controlled trials (RCTs). Databases (PubMed, Embase and Cochrane Library) were searched up to 30 March 2022. Evidence certainty was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Thirty-four RCTs containing 2012 participants were included in this review. Pooled effects of significant increase in total antioxidant capacity (TAC) (standardized mean difference: 1.83, 95%CI: [1.07, 2.59], p < 0.001) and significant reduction in malondialdehyde (MDA) concentrations (−0.77, [−1.06, −0.47], p < 0.001) were shown after CoQ10 supplementation compared to placebo. However, we could not determine that there was a significant increase in circulating superoxide dismutase (SOD) levels yet (0.47, [0.00, 0.94], p = 0.05). Subgroup analyses implied that CoQ10 supplementation was more beneficial to people with coronary artery disease or type 2 diabetes. Additionally, taking 100−150 mg/day CoQ10 supplement had better benefits for the levels of TAC, MDA and SOD (all p < 0.01). These results to a statistically significant extent lent support to the efficacy and optimal dose of CoQ10 supplementation on attenuating oxidative stress status in adults.

Royal jelly plus coenzyme Q10 supplementation improves high-intensity interval exercise performance via changes in plasmatic and salivary biomarkers of oxidative stress and muscle damage in swimmers: a randomized, double-blind, placebo-controlled pilot trial

Background

Excessive production of free radicals caused by many types of exercise results in oxidative stress, which leads to muscle damage, fatigue, and impaired performance. Supplementation with royal jelly (RJ) or coenzyme Q10 (CoQ10) has been shown to attenuate exercise-induced oxidant stress in damaged muscle and improve various aspects of exercise performance in many but not all studies. Nevertheless, the effects of treatments based on RJ plus CoQ10 supplementation, which may be potentially beneficial for reducing oxidative stress and enhancing athletic performance, remain unexplored. This study aimed to examine whether oral RJ and CoQ10 co-supplementation could improve high-intensity interval exercise (HIIE) performance in swimmers, inhibiting exercise-induced oxidative stress and muscle damage.

Methods

Twenty high-level swimmers were randomly allocated to receive either 400 mg of RJ and 60 mg of CoQ10 (RJQ) or matching placebo (PLA) once daily for 10 days. Exercise performance was evaluated at baseline, and then reassessed at day 10 of intervention, using a HIIE protocol. Diene conjugates (DC), Schiff bases (SB), and creatine kinase (CK) were also measured in blood plasma and saliva before and immediately after HIIE in both groups.

Results

HIIE performance expressed as number of points according to a single assessment system developed and approved by the International Swimming Federation (FINA points) significantly improved in RJQ group (p = 0.013) compared to PLA group. Exercise-induced increase in DC, SB, and CK levels in plasma and saliva significantly diminished only in RJQ group (p < 0.05). Regression analysis showed that oral RJQ administration for 10 days was significantly associated with reductions in HIIE-induced increases in plasmatic and salivary DC, SB, and CK levels compared to PLA. Principal component analysis revealed that swimmers treated with RJQ are grouped by both plasmatic and salivary principal components (PC) into a separate cluster compared to PLA. Strong negative correlation between the number of FINA points and plasmatic and salivary PC1 values was observed in both intervention groups.

Conclusion

The improvements in swimmers’ HIIE performance were due in significant part to RJQ-induced reducing in lipid peroxidation and muscle damage in response to exercise. These findings suggest that RJQ supplementation for 10 days is potentially effective for enhancing HIIE performance and alleviating oxidant stress.

Abbreviations

RJ, royal jelly; CoQ10, coenzyme Q10; HIIE, high-intensity interval exercise; DC, diene conjugates; SB, Schiff bases; CK, creatine kinase; RJQ, royal jelly plus coenzyme Q10; PLA, placebo; FINA points, points according to a single assessment system developed and approved by the International Swimming Federation; ROS, reactive oxygen species; 10H2DA, 10-hydroxy-2-decenoic acid; AMPK, 5′-AMP-activated protein kinase; FoxO3, forkhead box O3; MnSOD, manganese-superoxide dismutase; CAT, catalase; E, optical densities; PCA, principal component analysis; PC, principal component; MCFAs, medium-chain fatty acids; CaMKKβ, Ca²⁺/calmodulin-dependent protein kinase β; TBARS, thiobarbituric acid reactive substances; MDA, malondialdehyde.

HBM4EU Chromates Study: Urinary Metabolomics Study of Workers Exposed to Hexavalent Chromium

Exposure to hexavalent chromium Cr(VI) may occur in several occupational activities, placing workers in many industries at risk for potential related health outcomes. Untargeted metabolomics was applied to investigate changes in metabolic pathways in response to Cr(VI) exposure. We obtained our data from a study population of 220 male workers with exposure to Cr(VI) and 102 male controls from Belgium, Finland, Poland, Portugal and the Netherlands within the HBM4EU Chromates Study. Urinary metabolite profiles were determined using liquid chromatography mass spectrometry, and differences between post-shift exposed workers and controls were analyzed using principal component analysis. Based on the first two principal components, we observed clustering by industrial chromate application, such as welding, chrome plating, and surface treatment, distinct from controls and not explained by smoking status or alcohol use. The changes in the abundancy of excreted metabolites observed in workers reflect fatty acid and monoamine neurotransmitter metabolism, oxidative modifications of amino acid residues, the excessive formation of abnormal amino acid metabolites and changes in steroid and thyrotropin-releasing hormones. The observed responses could also have resulted from work-related factors other than Cr(VI). Further targeted metabolomics studies are needed to better understand the observed modifications and further explore the suitability of urinary metabolites as early indicators of adverse effects associated with exposure to Cr(VI).

Decreased Concentration of Fibroblast Growth Factor 23 (FGF-23) as a Result of Supplementation with Selenium and Coenzyme Q10 in an Elderly Swedish Population: A Sub-Analysis

There is a reduced intake of selenium in many countries due to low levels of selenium in the soil. This results in an increased cardiovascular risk. Fibroblast growth factor 23 (FGF-23) is active mainly in the metabolism of vitamin D and phosphorus. However, there are indications that FGF-23 may also provide information both on cardiovascular function and prognosis. The aim of the study was to evaluate the effect of supplementation with selenium and coenzyme Q₁₀ on the FGF-23 concentration in an elderly population with low concentrations of both selenium and coenzyme Q₁₀ and in which the supplementation improved cardiac function and mortality. In a randomised double-blind placebo-controlled trial, FGF-23 was measured in 219 individuals at the start and after 48 months. Selenium yeast (200 µg/day) and coenzyme Q₁₀ (200 mg/day) (n = 118) or placebo (n = 101) were given as a dietary supplement. The intervention time was 48 months. t-Tests, repeated measures of variance, and ANCOVA analyses were used to evaluate the differences in FGF-23 concentration. Following supplementation with selenium and coenzyme Q₁₀, a significantly lower level of FGF-23 could be seen (p = 0.01). Applying 10 years of follow-up, those who later died a cardiovascular death had a significantly higher FGF-23 concentration after 48 months compared with those who survived (p = 0.036), and a significantly lower FGF-23 concentration could be seen in those with a normal renal function compared to those with an impaired renal function (p = 0.027). Supplementation with selenium and coenzyme Q₁₀ to an elderly community-living population low in both substances prevented an increase of FGF-23 and also provided a reduced cardiovascular risk.

Potential Protective Effect of Coenzyme Q10 on Doxorubicin-Induced Neurotoxicity and Behavioral Disturbances in Rats

The aim of this study was to investigate the potential neuroprotective efficacy of coenzyme Q10 (CoQ10) against doxorubicin (DOX) -induced behavioral disturbances in rats. Female rats were randomly assigned into 4 groups as control, CoQ10, DOX, and DOX plus CoQ10. The CoQ10 groups received CoQ10 (200 mg kg^-1) for 21 days, and the DOX groups received DOX (4 mg kg^-1) on days 7 and 14 of the study. The open field (OF) and elevated plus maze (EPM) tests were performed to assess locomotor activity and anxiety levels. Additionally, malondialdehyde (MDA), and protein carbonyl (PC) levels and acetylcholinesterase (AChE), and glutathione peroxidase (GPx) activities and total antioxidant capacity (TAC) were quantified in brain tissue. DOX administration caused alterations in locomotor activity, and anxiety-like behaviors. Moreover, DOX produced significant elevation in AChE activity . PC level and GPx activity tended to alter with DOX administration. Co-treatment with CoQ10 significantly attenuated DOX-induced behavioral alterations via improving AChE activity in the brain tissue of rats. CoQ10 treatment may be potential for the alleviation of DOX-induced behavioral disturbances. This improvement might be due to the inhibition of AChE activity.

Coenzyme Q nanodisks counteract the effect of statins on C2C12 myotubes

Depletion of coenzyme Q (CoQ) is associated with disease, ranging from myopathy to heart failure. To induce a CoQ deficit, C2C12 myotubes were incubated with high dose simvastatin. This resulted in a concentration-dependent inhibition of cell viability. Simvastatin-induced effects were prevented by co-incubation with mevalonic acid. When myotubes were incubated with 60 μM simvastatin, mitochondrial CoQ content decreased while co-incubation with CoQ nanodisks (ND) increased mitochondrial CoQ levels and improved cell viability. Incubation of myotubes with simvastatin also led to a reduction in oxygen consumption rate (OCR). When myotubes were co-incubated with simvastatin and CoQ ND, the decline in OCR was ameliorated. The data indicate that CoQ ND represent a water soluble vehicle capable of delivering CoQ to cultured myotubes. Thus, these biocompatible nanoparticles have the potential to bypass poor CoQ oral bioavailability as a treatment option for individuals with severe CoQ deficiency syndromes and/or aging-related CoQ depletion.

Regulation of hepatic coenzyme Q biosynthesis by dietary omega-3 polyunsaturated fatty acids

Dietary fats are important for human health, yet it is not fully understood how different fats affect various health problems. Although polyunsaturated fatty acids (PUFAs) are generally considered as highly oxidizable, those of the n-3 series can ameliorate the risk of many age-related disorders. Coenzyme Q (CoQ) is both an essential component of the mitochondrial electron transport chain and the only lipid-soluble antioxidant that animal cells can synthesize. Previous work has documented the protective antioxidant properties of CoQ against the autoxidation products of PUFAs. Here, we have explored in vitro and in vivo models to better understand the regulation of CoQ biosynthesis by dietary fats. In mouse liver, PUFAs increased CoQ content, and PUFAs of the n-3 series increased preferentially CoQ₁₀. This response was recapitulated in hepatic cells cultured in the presence of lipid emulsions, where we additionally demonstrated a role for n-3 PUFAs as regulators of CoQ biosynthesis via the upregulation of several COQ proteins and farnesyl pyrophosphate levels. In both models, n-3 PUFAs altered the mitochondrial network without changing the overall mitochondrial mass. Furthermore, in cellular systems, n-3 PUFAs favored the synthesis of CoQ₁₀ over CoQ₉, thus altering the ratio between CoQ isoforms through a mechanism that involved downregulation of farnesyl diphosphate synthase activity. This effect was recapitulated by both siRNA silencing and by pharmacological inhibition of farnesyl diphosphate synthase with zoledronic acid. We highlight here the ability of n-3 PUFAs to regulate CoQ biosynthesis, CoQ content, and the ratio between its isoforms, which might be relevant to better understand the health benefits associated with this type of fat. Additionally, we identify for the first time zoledronic acid as a drug that inhibits CoQ biosynthesis, which must be also considered with respect to its biological effects on patients.

Coenzyme Q Biosynthesis: An Update on the Origins of the Benzenoid Ring and Discovery of New Ring Precursors

Coenzyme Q (ubiquinone or CoQ) is a conserved polyprenylated lipid essential for mitochondrial respiration. CoQ is composed of a redox-active benzoquinone ring and a long polyisoprenyl tail that serves as a membrane anchor. A classic pathway leading to CoQ biosynthesis employs 4-hydroxybenzoic acid (4HB). Recent studies with stable isotopes in E. coli, yeast, and plant and animal cells have identified CoQ intermediates and new metabolic pathways that produce 4HB. Stable isotope labeling has identified para-aminobenzoic acid as an alternate ring precursor of yeast CoQ biosynthesis, as well as other natural products, such as kaempferol, that provide ring precursors for CoQ biosynthesis in plants and mammals. In this review, we highlight how stable isotopes can be used to delineate the biosynthetic pathways leading to CoQ.

Coenzyme Q10 supplementation - In ageing and disease

Coenzyme Q₁₀ (CoQ₁₀) is an essential component of the mitochondrial electron transport chain. It is also an antioxidant in cellular membranes and lipoproteins. All cells produce CoQ₁₀ by a specialized cytoplasmatic-mitochondrial pathway. CoQ₁₀ deficiency can result from genetic failure or ageing. Some drugs including statins, widely used by inter alia elderly, may inhibit endogenous CoQ₁₀ synthesis. There are also chronic diseases with lower levels of CoQ₁₀ in tissues and organs. High doses of CoQ₁₀ may increase both circulating and intracellular levels, but there are conflicting results regarding bioavailability. Here, we review the current knowledge of CoQ₁₀ biosynthesis and primary and acquired CoQ₁₀ deficiency, and results from clinical trials based on CoQ₁₀ supplementation. There are indications that supplementation positively affects mitochondrial deficiency syndrome and some of the symptoms of ageing. Cardiovascular disease and inflammation appear to be alleviated by the antioxidant effect of CoQ₁₀. There is a need for further studies and well-designed clinical trials, with CoQ₁₀ in a formulation of proven bioavailability, involving a greater number of participants undergoing longer treatments in order to assess the benefits of CoQ₁₀ treatment in neurodegenerative disorders, as well as in metabolic syndrome and its complications.

Coenzyme Q10 Phytosome Formulation Improves CoQ10 Bioavailability and Mitochondrial Functionality in Cultured Cells

Coenzyme Q10 (CoQ10) is a lipid-soluble molecule with a dual role: it transfers electrons in the mitochondrial transport chain by promoting the transmembrane potential exploited by the ATPase to synthesize ATP and, in its reduced form, is a membrane antioxidant. Since the high CoQ10 hydrophobicity hinders its bioavailability, several formulations have been developed to facilitate its cellular uptake. In this work, we studied the bioenergetic and antioxidant effects in I407 and H9c2 cells of a CoQ10 phytosome formulation (UBIQSOME^®, UBQ). We investigated the cellular and mitochondrial content of CoQ10 and its redox state after incubation with UBQ. We studied different bioenergetic parameters, such as oxygen consumption, ATP content and mitochondrial potential. Moreover, we evaluated the effects of CoQ10 incubation on oxidative stress, membrane lipid peroxidation and ferroptosis and highlighted the connection between the intracellular concentration of CoQ10 and its antioxidant potency. Finally, we focused on the cellular mechanism that regulates UBQ internalization. We showed that the cell lines used in this work share the same uptake mechanism for UBQ, although the intestinal cell line was less efficient. Given the limitations of an in vitro model, the latter result supports that intestinal absorption is a critical step for the oral administration of Coenzyme Q10 formulations.

Coenzyme Q10 and Cardiovascular Diseases

Coenzyme Q₁₀ (CoQ₁₀), which plays a key role in the electron transport chain by providing an adequate, efficient supply of energy, has another relevant function as an antioxidant, acting in mitochondria, other cell compartments, and plasma lipoproteins. CoQ₁₀ deficiency is present in chronic and age-related diseases. In particular, in cardiovascular diseases (CVDs), there is a reduced bioavailability of CoQ₁₀ since statins, one of the most common lipid-lowering drugs, inhibit the common pathway shared by CoQ₁₀ endogenous biosynthesis and cholesterol biosynthesis. Different clinical trials have analyzed the effect of CoQ₁₀ supplementation as a treatment to ameliorate these deficiencies in the context of CVDs. In this review, we focus on recent advances in CoQ₁₀ supplementation and the clinical implications in the reduction of cardiovascular risk factors (such as lipid and lipoprotein levels, blood pressure, or endothelial function) as well as in a therapeutic approach for the reduction of the clinical complications of CVD.

Coenzyme Q10: Clinical Applications beyond Cardiovascular Diseases

Coenzyme Q10 (CoQ10) is an essential cofactor in oxidative phosphorylation (OXPHOS), present in mitochondria and cell membranes in reduced and oxidized forms. Acting as an energy transfer molecule, it occurs in particularly high levels in the liver, heart, and kidneys. CoQ10 is also an anti-inflammatory and antioxidant agent able to prevent the damage induced by free radicals and the activation of inflammatory signaling pathways. In this context, several studies have shown the possible inverse correlation between the blood levels of CoQ10 and some disease conditions. Interestingly, beyond cardiovascular diseases, CoQ10 is involved also in neuronal and muscular degenerative diseases, in migraine and in cancer; therefore, the supplementation with CoQ10 could represent a viable option to prevent these and in some cases might be used as an adjuvant to conventional treatments. This review is aimed to summarize the clinical applications regarding the use of CoQ10 in migraine, neurodegenerative diseases (including Parkinson and Alzheimer diseases), cancer, or degenerative muscle disorders (such as multiple sclerosis and chronic fatigue syndrome), analyzing its effect on patients' health and quality of life.

Dietary Supplementation with Selenium and Coenzyme Q10 Prevents Increase in Plasma D-Dimer While Lowering Cardiovascular Mortality in an Elderly Swedish Population

A low intake of selenium is associated with increased cardiovascular mortality. This could be reduced by supplementation with selenium and coenzyme Q₁₀. D-dimer, a fragment of fibrin mirroring fibrinolysis, is a biomarker of thromboembolism, increased inflammation, endothelial dysfunction and is associated with cardiovascular mortality in ischemic heart disease. The objective was to examine the impact of selenium and coenzyme Q₁₀ on the level of D-dimer, and its relationship to cardiovascular mortality. D-dimer was measured in 213 individuals at the start and after 48 months of a randomised double-blind placebo-controlled trial with selenium yeast (200 µg/day) and coenzyme Q₁₀ (200 mg/day) (n = 106) or placebo (n = 107). The follow-up time was 4.9 years. All included individuals were low in selenium (mean 67 μg/L, SD 16.8). The differences in D-dimer concentration were evaluated by the use of T-tests, repeated measures of variance and ANCOVA analyses. At the end, a significantly lower D-dimer concentration was observed in the active treatment group in comparison with those on placebo (p = 0.006). Although D-dimer values at baseline were weakly associated with high-sensitive CRP, while being more strongly associated with soluble tumour necrosis factor receptor 1 and sP-selectin, controlling for these in the analysis there was an independent effect on D-dimer. In participants with a D-dimer level above median at baseline, the supplementation resulted in significantly lower cardiovascular mortality compared to those on placebo (p = 0.014). All results were validated with a persisting significant difference between the two groups. Therefore, supplementation with selenium and coenzyme Q₁₀ in a group of elderly low in selenium and coenzyme Q₁₀ prevented an increase in D-dimer and reduced the risk of cardiovascular mortality in comparison with the placebo group. The obtained results also illustrate important associations between inflammation, endothelial function and cardiovascular risk.

A randomized controlled trial on the coloprotective effect of coenzyme Q10 on immune-inflammatory cytokines, oxidative status, antimicrobial peptides, and microRNA-146a expression in patients with mild-to-moderate ulcerative colitis

PURPOSE

Coenzyme Q10 (CoQ10), having potent antioxidant and anti-inflammatory pharmacological properties, has recently been shown to be a safe and promising agent in maintaining remission of ulcerative colitis (UC). This trial was, therefore, designed to determine CoQ10 efficacy on inflammation and antioxidant status, antimicrobial peptides, and microRNA-146a expression in UC patients.

METHODS

In this randomized double-blind controlled trial, 88 mild-to-moderate UC patients were randomly allocated to receive CoQ10 (200 mg/day) or placebo (rice flour) for 2 months. At the baseline and at an 8-week follow-up, serum levels of Nrf2, cathelicidin LL-37, β-defensin 2, IL-10, IL-17, NF-κB p65 activity in peripheral blood mononuclear cells (PBMCs), simple clinical colitis activity index questionnaire (SCCAIQ), and quality of life (IBDQ-32 score), as well as an expression rate of microRNA-146a were measured.

RESULTS

A significant reduction was detected in the serum IL-17 level, activity of NF-κB p65 in PBMCs, and also SCCAI score in the CoQ10 group compared to the placebo group, whereas IL-10 serum concentrations and IBDQ-32 score of the CoQ10 group considerably increased versus the control group; the changes of these variables were also significantly different within and between groups at the end of the study. Furthermore, CoQ10 remarkably increased serum levels of cathelicidin LL-37. A significant change in serum cathelicidin LL-37 levels was also observed between the two groups. No statistical difference, however, was seen between the two groups in terms of the serum levels of Nrf2 and β-defensin 2 and the relative expression of microRNA-146a.

CONCLUSIONS

Our results indicate that CoQ10 supplementation, along with drug therapy, appears to be an efficient reducer of inflammation in patients with mild-to-moderate UC at a remission phase.

TRIAL REGISTRATION

The research has also been registered at the Iranian Registry of Clinical Trials (IRCT): IRCT20090822002365N17.

Coenzyme Q10 for heart failure

BACKGROUND

Coenzyme Q10, or ubiquinone, is a non-prescription nutritional supplement. It is a fat-soluble molecule that acts as an electron carrier in mitochondria, and as a coenzyme for mitochondrial enzymes. Coenzyme Q10 deficiency may be associated with a multitude of diseases, including heart failure. The severity of heart failure correlates with the severity of coenzyme Q10 deficiency. Emerging data suggest that the harmful effects of reactive oxygen species are increased in people with heart failure, and coenzyme Q10 may help to reduce these toxic effects because of its antioxidant activity. Coenzyme Q10 may also have a role in stabilising myocardial calcium-dependent ion channels, and in preventing the consumption of metabolites essential for adenosine-5'-triphosphate (ATP) synthesis. Coenzyme Q10, although not a primary recommended treatment, could be beneficial to people with heart failure. Several randomised controlled trials have compared coenzyme Q10 to other therapeutic modalities, but no systematic review of existing randomised trials was conducted prior to the original version of this Cochrane Review, in 2014.

OBJECTIVES

To review the safety and efficacy of coenzyme Q10 in heart failure.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Web of Science, CINAHL Plus, and AMED on 16 October 2020; ClinicalTrials.gov on 16 July 2020, and the ISRCTN Registry on 11 November 2019. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials of either parallel or cross-over design that assessed the beneficial and harmful effects of coenzyme Q10 in people with heart failure. When we identified cross-over studies, we considered data only from the first phase.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods, assessed study risk of bias using the Cochrane 'Risk of bias' tool, and GRADE methods to assess the quality of the evidence. For dichotomous data, we calculated the risk ratio (RR); for continuous data, the mean difference (MD), both with 95% confidence intervals (CI). Where appropriate data were available, we conducted meta-analysis. When meta-analysis was not possible, we wrote a narrative synthesis. We provided a PRISMA flow chart to show the flow of study selection.

MAIN RESULTS

We included eleven studies, with 1573 participants, comparing coenzyme Q10 to placebo or conventional therapy (control). In the majority of the studies, sample size was relatively small. There were important differences among studies in daily coenzyme Q10 dose, follow-up period, and the measures of treatment effect. All studies had unclear, or high risk of bias, or both, in one or more bias domains. We were only able to conduct meta-analysis for some of the outcomes. None of the included trials considered quality of life, measured on a validated scale, exercise variables (exercise haemodynamics), or cost-effectiveness. Coenzyme Q10 probably reduces the risk of all-cause mortality more than control (RR 0.58, 95% CI 0.35 to 0.95; 1 study, 420 participants; number needed to treat for an additional beneficial outcome (NNTB) 13.3; moderate-quality evidence). There was low-quality evidence of inconclusive results between the coenzyme Q10 and control groups for the risk of myocardial infarction (RR 1.62, 95% CI 0.27 to 9.59; 1 study, 420 participants), and stroke (RR 0.18, 95% CI 0.02 to 1.48; 1 study, 420 participants). Coenzyme Q10 probably reduces hospitalisation related to heart failure (RR 0.62, 95% CI 0.49 to 0.78; 2 studies, 1061 participants; NNTB 9.7; moderate-quality evidence). Very low-quality evidence suggests that coenzyme Q10 may improve the left ventricular ejection fraction (MD 1.77, 95% CI 0.09 to 3.44; 7 studies, 650 participants), but the results are inconclusive for exercise capacity (MD 48.23, 95% CI -24.75 to 121.20; 3 studies, 91 participants); and the risk of developing adverse events (RR 0.70, 95% CI 0.45 to 1.10; 2 studies, 568 participants). We downgraded the quality of the evidence mainly due to high risk of bias and imprecision.

AUTHORS' CONCLUSIONS

The included studies provide moderate-quality evidence that coenzyme Q10 probably reduces all-cause mortality and hospitalisation for heart failure. There is low-quality evidence of inconclusive results as to whether coenzyme Q10 has an effect on the risk of myocardial infarction, or stroke. Because of very low-quality evidence, it is very uncertain whether coenzyme Q10 has an effect on either left ventricular ejection fraction or exercise capacity. There is low-quality evidence that coenzyme Q10 may increase the risk of adverse effects, or have little to no difference. There is currently no convincing evidence to support or refute the use of coenzyme Q10 for heart failure. Future trials are needed to confirm our findings.

Coenzyme Q10 Supplementation for the Reduction of Oxidative Stress: Clinical Implications in the Treatment of Chronic Diseases

Apart from its main function in the mitochondria as a key element in electron transport, Coenzyme Q₁₀ (CoQ₁₀) has been described as having multiple functions, such as oxidant action in the generation of signals and the control of membrane structure and phospholipid and cellular redox status. Among these, the most relevant and most frequently studied function is the potent antioxidant capability of its coexistent redox forms. Different clinical trials have investigated the effect of CoQ₁₀ supplementation and its ability to reduce oxidative stress. In this review, we focused on recent advances in CoQ₁₀ supplementation, its role as an antioxidant, and the clinical implications that this entails in the treatment of chronic diseases, in particular cardiovascular diseases, kidney disease, chronic obstructive pulmonary disease, non-alcoholic fatty liver disease, and neurodegenerative diseases. As an antioxidant, CoQ₁₀ has proved to be of potential use as a treatment in diseases in which oxidative stress is a hallmark, and beneficial effects of CoQ₁₀ have been reported in the treatment of chronic diseases. However, it is crucial to reach a consensus on the optimal dose and the use of different formulations, which vary from ubiquinol or ubiquinone Ubisol-Q₁₀ or Qter^®, to new analogues such as MitoQ, before we can draw a clear conclusion about its clinical use. In addition, a major effort must be made to demonstrate its beneficial effects in clinical trials, with a view to making the implementation of CoQ₁₀ possible in clinical practice.

Health-promoting role of dietary bioactive compounds through epigenetic modulations: a novel prophylactic and therapeutic approach

The epigenome is an overall epigenetic state of an organism, which is as important as that of the genome for normal development and functioning of an individual. Epigenetics involves heritable but reversible changes in gene expression through alterations in DNA methylation, histone modifications and regulation of non-coding RNAs in cells, without any change in the DNA sequence. Epigenetic changes are owned by various environmental factors including pollution, microbiota and diet, which have profound effects on epigenetic modifiers. The bioactive compounds present in the diet mainly include curcumin, resveratrol, catechins, quercetin, genistein, sulforaphane, epigallocatechin-3-gallate, alkaloids, vitamins, and peptides. Bioactive compounds released during fermentation by the action of microbes also have a significant effect on the host epigenome. Besides, recent studies have explored the new insights in vitamin's functions through epigenetic regulation. These bioactive compounds exert synergistic, preventive and therapeutic effects when combined as well as when used with chemotherapeutic agents. Therefore, these compounds have potential of therapeutic agents that could be used as "Epidrug" to treat many inflammatory diseases and various cancers where chemotherapy results have many side effects. In this review, the effect of diet derived bioactive compounds through epigenetic modulations on in vitro and in vivo models is discussed.

Aging-Related Disorders and Mitochondrial Dysfunction: A Critical Review for Prospect Mitoprotective Strategies Based on Mitochondrial Nutrient Mixtures

A number of aging-related disorders (ARD) have been related to oxidative stress (OS) and mitochondrial dysfunction (MDF) in a well-established body of literature. Most studies focused on cardiovascular disorders (CVD), type 2 diabetes (T2D), and neurodegenerative disorders. Counteracting OS and MDF has been envisaged to improve the clinical management of ARD, and major roles have been assigned to three mitochondrial cofactors, also termed mitochondrial nutrients (MNs), i.e., α-lipoic acid (ALA), Coenzyme Q10 (CoQ10), and carnitine (CARN). These cofactors exert essential–and distinct—roles in mitochondrial machineries, along with strong antioxidant properties. Clinical trials have mostly relied on the use of only one MN to ARD-affected patients as, e.g., in the case of CoQ10 in CVD, or of ALA in T2D, possibly with the addition of other antioxidants. Only a few clinical and pre-clinical studies reported on the administration of two MNs, with beneficial outcomes, while no available studies reported on the combined administration of three MNs. Based on the literature also from pre-clinical studies, the present review is to recommend the design of clinical trials based on combinations of the three MNs.

Disorders of Human Coenzyme Q10 Metabolism: An Overview

Coenzyme Q10 (CoQ10) has a number of vital functions in all cells, both mitochondrial and extramitochondrial. In addition to its key role in mitochondrial oxidative phosphorylation, CoQ10 serves as a lipid soluble antioxidant, plays an important role in fatty acid, pyrimidine and lysosomal metabolism, as well as directly mediating the expression of a number of genes, including those involved in inflammation. In view of the central role of CoQ10 in cellular metabolism, it is unsurprising that a CoQ10 deficiency is linked to the pathogenesis of a range of disorders. CoQ10 deficiency is broadly classified into primary or secondary deficiencies. Primary deficiencies result from genetic defects in the multi-step biochemical pathway of CoQ10 synthesis, whereas secondary deficiencies can occur as result of other diseases or certain pharmacotherapies. In this article we have reviewed the clinical consequences of primary and secondary CoQ10 deficiencies, as well as providing some examples of the successful use of CoQ10 supplementation in the treatment of disease.

The role of nutraceuticals as a complementary therapy against various neurodegenerative diseases: A mini-review

In recent times, many scientists have given great attention to nutraceuticals (complementary medicine) as it widely used for promoting health status. In particular for the prevention and treatment of various neurological diseases or disorders without or less adverse effects. The current mini-review was intended to compile all popular (major) nutraceuticals against various neurodegenerative diseases (NDDs) including Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD) with special reference to clinical trials. Preliminary reviews indicated that nutraceuticals like curcumin, resveratrol, Epigallocatechin-3-gallate (EGCG), Coenzyme Q10, ω-3 FA (DHA/EPA/ALA), showed better neuroprotective activity against various NDDs in human setting (clinical trial). Hence this contribution will focus only on those popular nutraceuticals with proposed brief mechanisms (antioxidant, anti-inflammatory, mitochondrial homeostasis, autophagy regulation, promote neurogenesis) and its recommendation. This mini-review would aid common people to choose better nutraceuticals to combat various NDDs along with standard neuroprotective agents and modified lifestyle pattern.

Dendrimer-like glucan nanoparticulate system improves the solubility and cellular antioxidant activity of coenzyme Q10

Aqueous coenzyme Q10 (CoQ10) dispersions were prepared using sugary maize dendrimer-like glucan (SMDG) with solid-dispersion treatment. After measuring solubility, recovery rate and loading rate, the initial weight ratio of CoQ10:SMDG was optimized to be 1:27, with the solubility markedly increasing up 188.8-folds compared to pure CoQ10 solution. The structural characterizations of CoQ10-SMDG formulation showed crystal CoQ10 was entrapped in SMDG matrix for amorphous state, associated with the strong interactions with glucan chains. The antioxidant activity of CoQ10-SMDG was assessed via DPPH and FRAP assay. DPPH scavenging activity and FRAP value of it were as high as 95.1% and 0.87 mM, respectively. The cellular uptake of CoQ10 in CoQ10-SMDG group was significantly higher than that of natural CoQ10. CoQ10-SMDG also exhibited significant protective effects against cellular damage in H₂O₂-induced HaCaT cell model. The results indicated that dendrimer-like glucan is an excellent platform to encapsulate and improve biological activity of hydropholic compounds.

Genes and lipids that impact uptake and assimilation of exogenous coenzyme Q in Saccharomyces cerevisiae

Coenzyme Q (CoQ) is an essential player in the respiratory electron transport chain and is the only lipid-soluble antioxidant synthesized endogenously in mammalian and yeast cells. In humans, genetic mutations, pathologies, certain medical treatments, and aging, result in CoQ deficiencies, which are linked to mitochondrial, cardiovascular, and neurodegenerative diseases. The only strategy available for these patients is CoQ supplementation. CoQ supplements benefit a small subset of patients, but the poor solubility of CoQ greatly limits treatment efficacy. Consequently, the efficient delivery of CoQ to the mitochondria and restoration of respiratory function remains a major challenge. A better understanding of CoQ uptake and mitochondrial delivery is crucial to make this molecule a more efficient and effective therapeutic tool. In this study, we investigated the mechanism of CoQ uptake and distribution using the yeast Saccharomyces cerevisiae as a model organism. The addition of exogenous CoQ was tested for the ability to restore growth on non-fermentable medium in several strains that lack CoQ synthesis (coq mutants). Surprisingly, we discovered that the presence of CoQ biosynthetic intermediates impairs assimilation of CoQ into a functional respiratory chain in yeast cells. Moreover, a screen of 40 gene deletions considered to be candidates to prevent exogenous CoQ from rescuing growth of the CoQ-less coq2Δ mutant, identified six novel genes (CDC10, RTS1, RVS161, RVS167, VPS1, and NAT3) as necessary for efficient trafficking of CoQ to mitochondria. The proteins encoded by these genes represent essential steps in the pathways responsible for transport of exogenously supplied CoQ to its functional sites in the cell, and definitively associate CoQ distribution with endocytosis and intracellular vesicular trafficking pathways conserved from yeast to human cells.

Metabolism of the Flavonol Kaempferol in Kidney Cells Liberates the B-ring to Enter Coenzyme Q Biosynthesis

Coenzyme Q (CoQ) is an essential component of the mitochondrial electron transport chain and an important antioxidant present in all cellular membranes. CoQ deficiencies are frequent in aging and in age-related diseases, and current treatments are limited to CoQ supplementation. Strategies that rely on CoQ supplementation suffer from poor uptake and trafficking of this very hydrophobic molecule. In a previous study, the dietary flavonol kaempferol was reported to serve as a CoQ ring precursor and to increase the CoQ content in kidney cells, but neither the part of the molecule entering CoQ biosynthesis nor the mechanism were described. In this study, kaempferol labeled specifically in the B-ring was isolated from Arabidopsis plants. Kidney cells treated with this compound incorporated the B-ring of kaempferol into newly synthesized CoQ, suggesting that the B-ring is metabolized via a mechanism described in plant cells. Kaempferol is a natural flavonoid present in fruits and vegetables and possesses antioxidant, anticancer, and anti-inflammatory therapeutic properties. A better understanding of the role of kaempferol as a CoQ ring precursor makes this bioactive compound a potential candidate for the design of interventions aiming to increase endogenous CoQ biosynthesis and may improve CoQ deficient phenotypes in aging and disease.

A New Food-grade Coenzyme Q10 Formulation Improves Bioavailability: Single and Repeated Pharmacokinetic Studies in Healthy Volunteers

BACKGROUND

Coenzyme Q10 is a fundamental endogenous factor involved in cell energy production that shows protective properties in oxidative stress, mainly in skeletal and heart muscle. Coenzyme Q10 supplementation appears to benefit athletes in strenuous training and in the elderly, demonstrating ant-inflammatory properties by reducing inflammatory cytokines. Improved absorption of coenzyme Q10 via a new delivery system would represent an important step forward in the use of coenzyme Q10 as a dietary supplement.

OBJECTIVE

The aim of the study was to evaluate the solubility and oral absorption in human healthy volunteers of a new food grade coenzyme Q10 phytosome formulation.

METHODS

Solubility studies were performed in vitro in simulated gastrointestinal fluids; human studies were conducted in healthy volunteers to evaluate oral absorption in a Single dose study, in comparison with the coenzyme Q10 capsules, and in a repeated study at two increasing doses.

RESULTS

The highest solubility shown by coenzyme Q10 phytosome in simulated intestinal fluids results in an improvement in oral absorption of coenzyme Q10 in healthy volunteers, three times more than the coenzyme Q10 according to AUC (area under the time/concentration curve) values. When two increasing doses (one and two capsules) were administered to healthy volunteers within a two-week schedule, the plasmatic levels of coenzyme Q10 resulted in 0.864±0.200 μg/ml (Mean±S.D.+41%) and 1.321±0.400 μg/ml (+116%), respectively versus baseline (0.614±0.120 μg/ml one capsule, 0.614±0.160 μg/ml two capsules). This detected dose-related bioavailability of coenzyme Q10 phytosome was even observed with no alterations in vital signs, neither in the physical examination nor in ECG, and no changes of clinical and biochemical parameters were observed.

CONCLUSION

These findings, taken together, support the safety profile and significantly improved coenzyme Q10 oral absorption in humans with this new phytosome delivery formulation.

Bioavailability of Coenzyme Q10: An Overview of the Absorption Process and Subsequent Metabolism

A lack of understanding of the processes determining the absorption and subsequent metabolism of coenzyme Q₁₀ (CoQ₁₀) has resulted in some manufacturers’ making incorrect claims regarding the bioavailability of their CoQ₁₀ supplements, with potential consequences for the use of such products in clinical trials. The purpose of the present review article is, therefore, to describe the various stages of exogenous CoQ₁₀ metabolism, from its first ingestion, stomach transit, absorption from the small intestine into the lymphatic system, transport in blood, and access into cells. In particular, the importance of CoQ₁₀ crystal dispersion in the initial formulation is emphasised, the absence of which reduces bioavailability by 75%. In addition, evidence comparing the relative bioavailability and efficacy of ubiquinone and ubiquinol forms of CoQ₁₀ has been reviewed.

Coenzyme Q10 Supplementation Improves Adipokine Levels and Alleviates Inflammation and Lipid Peroxidation in Conditions of Metabolic Syndrome: A Meta-Analysis of Randomized Controlled Trials

Evidence from randomized controlled trials (RCTs) suggests that coenzyme Q₁₀ (CoQ₁₀) can regulate adipokine levels to impact inflammation and oxidative stress in conditions of metabolic syndrome. Here, prominent electronic databases such as MEDLINE, Cochrane Library, and EMBASE were searched for eligible RCTs reporting on any correlation between adipokine levels and modulation of inflammation and oxidative stress in individuals with metabolic syndrome taking CoQ₁₀. The risk of bias was assessed using the modified Black and Downs checklist, while the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool was used to evaluate the quality of evidence. Results from the current meta-analysis, involving 318 participants, showed that CoQ₁₀ supplementation in individuals with metabolic syndrome increased adiponectin levels when compared to those on placebo (SMD: 1.44 [95% CI: -0.13, 3.00]; I² = 96%, p < 0.00001). Moreover, CoQ₁₀ supplementation significantly lowered inflammation markers in individuals with metabolic syndrome in comparison to those on placebo (SMD: -0.31 [95% CI: -0.54, -0.08]; I² = 51%, p = 0.07). Such benefits with CoQ₁₀ supplementation were related to its ameliorative effects on lipid peroxidation by reducing malondialdehyde levels, concomitant to improving glucose control and liver function. The overall findings suggest that optimal regulation of adipokine function is crucial for the beneficial effects of CoQ₁₀ in improving metabolic health.

Coenzyme Q10: Clinical Applications in Cardiovascular Diseases

Coenzyme Q₁₀ (CoQ₁₀) is a ubiquitous factor present in cell membranes and mitochondria, both in its reduced (ubiquinol) and oxidized (ubiquinone) forms. Its levels are high in organs with high metabolism such as the heart, kidneys, and liver because it acts as an energy transfer molecule but could be reduced by aging, genetic factors, drugs (e.g., statins), cardiovascular (CV) diseases, degenerative muscle disorders, and neurodegenerative diseases. As CoQ₁₀ is endowed with significant antioxidant and anti-inflammatory features, useful to prevent free radical-induced damage and inflammatory signaling pathway activation, its depletion results in exacerbation of inflammatory processes. Therefore, exogenous CoQ₁₀ supplementation might be useful as an adjuvant in the treatment of cardiovascular diseases such as heart failure, atrial fibrillation, and myocardial infarction and in associated risk factors such as hypertension, insulin resistance, dyslipidemias, and obesity. This review aims to summarize the current evidences on the use of CoQ₁₀ supplementation as a therapeutic approach in cardiovascular diseases through the analysis of its clinical impact on patients' health and quality of life. A substantial reduction of inflammatory and oxidative stress markers has been observed in several randomized clinical trials (RCTs) focused on several of the abovementioned diseases, even if more RCTs, involving a larger number of patients, will be necessary to strengthen these interesting findings.

Effects of NtSPS1 Overexpression on Solanesol Content, Plant Growth, Photosynthesis, and Metabolome of Nicotiana tabacum

Nicotiana tabacum solanesyl diphosphate synthase 1 (NtSPS1) is the key enzyme in solanesol biosynthesis. However, changes in the solanesol content, plant growth, photosynthesis, and metabolome of tobacco plants after NtSPS1 overexpression (OE) have not been previously reported. In the present study, these parameters, as well as photosynthetic gas exchange, chlorophyll content, and chlorophyll fluorescence parameters, were compared between NtSPS1 OE and wild type (WT) lines of tobacco. As expected, NtSPS1 OE significantly increased solanesol content in tobacco leaves. Although NtSPS1 OE significantly increased leaf growth, photosynthesis, and chlorophyll content, the chlorophyll fluorescence parameters in the leaves of the NtSPS1 OE lines were only slightly higher than those in the WT leaves. Furthermore, NtSPS1 OE resulted in 64 differential metabolites, including 30 up-regulated and 34 down-regulated metabolites, between the OE and WT leaves. Pathway enrichment analysis of these differential metabolites identified differentially enriched pathways between the OE and WT leaves, e.g., carbon fixation in photosynthetic organisms. The maximum carboxylation rate of RuBisCO and the maximum rate of RuBP regeneration were also elevated in the NtSPS1 OE line. To our knowledge, this is the first study to confirm the role of NtSPS1 in solanesol biosynthesis and its possible functional mechanisms in tobacco.

Atherosclerosis and Coenzyme Q10

Atherosclerosis is the most common cause of cardiac deaths worldwide. Classically, atherosclerosis has been explained as a simple arterial lipid deposition with concomitant loss of vascular elasticity. Eventually, this condition can lead to consequent blood flow reduction through the affected vessel. However, numerous studies have demonstrated that more factors than lipid accumulation are involved in arterial damage at the cellular level, such as inflammation, autophagy impairment, mitochondrial dysfunction, and/or free-radical overproduction. In order to consider the correction of all of these pathological changes, new approaches in atherosclerosis treatment are necessary. Ubiquinone or coenzyme Q₁₀ is a multifunctional molecule that could theoretically revert most of the cellular alterations found in atherosclerosis, such as cholesterol biosynthesis dysregulation, impaired autophagy flux and mitochondrial dysfunction thanks to its redox and signaling properties. In this review, we will show the latest advances in the knowledge of the relationships between coenzyme Q₁₀ and atherosclerosis. In addition, as atherosclerosis phenotype is closely related to aging, it is reasonable to believe that coenzyme Q₁₀ supplementation could be beneficial for both conditions.

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.