Coenzyme Q10 – A new player in the treatment of heart failure?

Improving the Bioavailability and Efficacy of Coenzyme Q10 on Alzheimer's Disease Through the Arginine Based Proniosomes

Coenzyme Q10 (CoQ10) is a fat-soluble vitamin-with a benzoquinone-like structure. CoQ10 plays a role in membrane stability, energy conversion, and ATP production. It is also one of the important antioxidants in the body. The bioavailability of exogenous CoQ10 is extremely low due to its poor aqueous solubility and large molecular mass. In this study, mixed proniosomal drug delivery systems have been used to increase solubility and bioavailability of CoQ10. Arginine (semi-essential amino acid) was incorporated in the formulation composition to achieve higher efficacy by boosting nitric oxide presence, endothelial dysfunction, and cellular uptake. Proniosomes were investigated in terms of particle size, polydispersity index, zeta potential, encapsulation efficiency, and process yield, and optimization studies were carried on by utilizing STATISTICA 8.0 software considering dependent factors (carrier amount, drug amount, and surfactant ratio). Optimum proniosome formulation (particle size 187.5 ± 16.35 nm, zeta potential: -44.7 ± 12.8 mV, encapsulation efficiency 99.05±0.30%, and product yield: 90.55%) was evaluated for thermal analysis, in-vitro drug release using microcentrifuge method. In-vitro cytotoxicity studies of proniosomes were performed on intestinal Epithelial Cells (Cellartis®, ChiPSC18) and no cytotoxic effects was seen during the 72 h. Besides, anti Alzheimer effect was investigated on APPSL-GFP lentivirus-infected human neural cells (APPSL-GFP-l-HNC) and Alzheimer biomarkers (p-tau181 and p-tau217). While CoQ10's relative bioavailability was statistically increased by proniosome compared to CoQ10 suspension (p<0.01, Grubb test). PK parameters of proniosome formulation, obtained with non-compartmental modeling, were fitting to the data (R2=0.956±0.026). The study results proved that proniosomal formulation has a high potential drug delivery system for both increasing bioavailability and anti-Alzheimer effect of CoQ10.

Role of Coenzyme Q10 in Health and Disease: An Update on the Last 10 Years (2010-2020)

The present review focuses on preclinical and clinical studies conducted in the last decade that contribute to increasing knowledge on Coenzyme Q₁₀'s role in health and disease. Classical antioxidant and bioenergetic functions of the coenzyme have been taken into consideration, as well as novel mechanisms of action involving the redox-regulated activation of molecular pathways associated with anti-inflammatory activities. Cardiovascular research and fertility remain major fields of application of Coenzyme Q₁₀, although novel applications, in particular in relation to topical application, are gaining considerable interest. In this respect, bioavailability represents a major challenge and the innovation in formulation aspects is gaining critical importance.

Randomized, double-blinded, controlled trial of the effects of coenzyme Q10 supplementation on plasma coenzyme Q10 concentration in dogs with myxomatous mitral valve disease

OBJECTIVE

To determine the dose of coenzyme Q₁₀ (CoQ₁₀) needed to achieve at least a 3-fold increase in plasma CoQ₁₀ concentration in dogs with myxomatous mitral valve disease (MMVD) and congestive heart failure (CHF).

ANIMALS

18 dogs with CHF due to MMVD and 12 healthy dogs.

PROCEDURES

In a randomized, double-blinded, controlled trial, dogs with MMVD were given 50 or 100 mg of water-soluble CoQ₁₀ (ubiquinone; total daily dose, 100 mg [n = 5] or 200 mg [6]) or a placebo (7), PO, twice a day for 2 weeks in addition to regular cardiac treatment. Plasma CoQ₁₀ concentration was measured in dogs with MMVD before (baseline) and at various time points after supplementation began and in healthy dogs once. Concentrations were compared among and within groups.

RESULTS

No significant difference in median baseline plasma CoQ₁₀ concentration was detected between healthy dogs and dogs with MMVD. Fold increases in plasma CoQ₁₀ concentrations ranged from 1.7 to 4.7 and 3.2 to 6.8 for individual dogs in the 100-mg and 200-mg groups, respectively. The change in plasma CoQ₁₀ concentration after supplementation began was significantly higher than in the placebo group at 4 hours and 1 and 2 weeks for dogs in the 200-mg group and at 1 and 2 weeks for dogs in the 100-mg group.

CONCLUSIONS AND CLINICAL RELEVANCE

A daily CoQ₁₀ dose of 200 mg was sufficient to achieve at least a 3-fold increase in plasma CoQ₁₀ concentration and may be used in CoQ₁₀ supplementation studies involving dogs with CHF due to MMVD.

A systematic review for the efficacy of coenzyme Q10 in patients with chronic kidney disease

BACKGROUND

The effects of coenzyme Q10 (CoQ10) supplementation in chronic kidney disease (CKD) patients remain controversial.

OBJECTIVE

A systematic review of current evidence was performed to systematically and comprehensively summarize the effects of CoQ10 on cardiovascular outcomes, oxidative stress, inflammation, lipid profiles, and glucose metabolism.

METHODS

MEDLINE, EMBASE, and the Cochrane Library database (Cochrane Central Register of Controlled Trials) were searched to identify eligible studies investigating the effects of CoQ10 supplementation on patients with CKD.

RESULTS

Twelve independent studies (including seventeen publications) were included in this systematic review. For CKD patients, six studies reported variable cardiovascular outcomes, which yielded inconsistent results. Regarding oxidative stress and inflammation, pooled analysis showed that CoQ10 supplementation significantly reduced malonaldehyde (WMD: - 1.15 95% CI - 1.48 to - 0.81) and high-sensitivity C reactive protein levels (WMD: - 1.18 95% CI - 2.21 to - 0.15). Regarding glucose metabolism, we found that CoQ10 supplementation resulted in significant improvements in HbA1c (WMD: - 0.80; 95% CI: - 1.35 to - 0.24) and QUICKI (WMD: 0.02; 95% CI: 0.01 to 0.03). The pooled results indicated that CoQ10 supplementation had no effects on total cholesterol, or LDL-cholesterol, or on HDL-cholesterol, and triglycerides.

CONCLUSIONS

Our systematic review demonstrated that CoQ10 supplementation might have promising effects on oxidative stress. This work provided some clues that CoQ10 supplementation might have the potential to improve inflammation levels, glucose metabolism, cardiac structure, and cardiac biomarkers. However, the effects of CoQ10 supplementation should be confirmed in larger high-quality studies.

Stability of Reduced and Oxidized Coenzyme Q10 in Finished Products

The efficiency of coenzyme Q10 (CoQ10) supplements is closely associated with its content and stability in finished products. This study aimed to provide evidence-based information on the quality and stability of CoQ10 in dietary supplements and medicines. Therefore, ubiquinol, ubiquinone, and total CoQ10 contents were determined by a validated HPLC-UV method in 11 commercial products with defined or undefined CoQ10 form. Both forms were detected in almost all tested products, resulting in a total of CoQ10 content between 82% and 166% of the declared. Ubiquinol, ubiquinone, and total CoQ10 stability in these products were evaluated within three months of accelerated stability testing. Ubiquinol, which is recognized as the less stable form, was properly stabilized. Contrarily, ubiquinone degradation and/or reduction were observed during storage in almost all tested products. These reactions were also detected at ambient temperature within the products’ shelf-lives and confirmed in ubiquinone standard solutions. Ubiquinol, generated by ubiquinone reduction with vitamin C during soft-shell capsules’ storage, may lead to higher bioavailability and health outcomes. However, such conversion and inappropriate content in products, which specify ubiquinone, are unacceptable in terms of regulation. Therefore, proper CoQ10 stabilization through final formulations regardless of the used CoQ10 form is needed.

Coenzyme Q10: Novel Formulations and Medical Trends

The aim of this review is to shed light over the most recent advances in Coenzyme Q10 (CoQ10) applications as well as to provide detailed information about the functions of this versatile molecule, which have proven to be of great interest in the medical field. Traditionally, CoQ10 clinical use was based on its antioxidant properties; however, a wide range of highly interesting alternative functions have recently been discovered. In this line, CoQ10 has shown pain-alleviating properties in fibromyalgia patients, a membrane-stabilizing function, immune system enhancing ability, or a fundamental role for insulin sensitivity, apart from potentially beneficial properties for familial hypercholesterolemia patients. In brief, it shows a remarkable amount of functions in addition to those yet to be discovered. Despite its multiple therapeutic applications, CoQ10 is not commonly prescribed as a drug because of its low oral bioavailability, which compromises its efficacy. Hence, several formulations have been developed to face such inconvenience. These were initially designed as lipid nanoparticles for CoQ10 encapsulation and distribution through biological membranes and eventually evolved towards chemical modifications of the molecule to decrease its hydrophobicity. Some of the most promising formulations will also be discussed in this review.

Prolonged oral coenzyme Q10-β-cyclodextrin supplementation increases skeletal muscle complex I+III activity in young Thoroughbreds

Coenzyme Q10 (CoQ10) is an essential component of the mitochondrial electron transport chain (ETC). Decreased skeletal muscle CoQ10 content may result in decreased ETC activity and energy production. This study tested the hypotheses that supplementation with oral CoQ10 will increase plasma CoQ10 concentrations and that prolonged supplementation will increase skeletal muscle CoQ10 content in young, healthy untrained Thoroughbreds. Nineteen Thoroughbreds (27.5±9.7 months old; 11 males, eight females) from one farm and maintained on a grass pasture with one grain meal per day were supplemented daily with 1.5 mg/kg body weight of an oral CoQ10-β-cyclodextrin inclusion complex. Whole-blood and skeletal muscle biopsies were collected before (T0) and after (T1) nine weeks of supplementation. Plasma CoQ10 concentrations were determined via high-performance liquid chromatography. Skeletal muscle mitochondrial ETC combined complex I+III enzyme activity (indirect measurement of CoQ10 content) was assessed spectrophotometrically and normalised to mitochondrial abundance. Horses accepted supplementation with no adverse effects. Plasma CoQ10 concentration increased in all horses following supplementation, with mean plasma CoQ10 concentration significantly increasing from T0 to T1 (0.13±0.02 vs 0.25±0.03 μg/ml; mean difference 0.12±0.03; P=0.004). However, variability in absorbance resulted in a 58% response rate (i.e. doubling of T1 above T0 values). The mean skeletal muscle complex I+III activity significantly increased from T0 to T1 (0.36±0.04 vs 0.59±0.05 pmol/min/mg of muscle, mean difference 0.23±0.05; P=0.0004), although T1 values for three out of 19 horses decreased on average by 23% below T0 values. In conclusion, oral supplementation with CoQ10 in the diet of young, healthy untrained Thoroughbreds increased mean plasma CoQ10 concentration by 99% with prolonged daily supplementation increasing mean skeletal muscle complex I+III activity by 65%. Additional research is warranted investigating training and exercise effects on skeletal muscle CoQ10 content in CoQ10 supplemented and un-supplemented Thoroughbreds.

The effect of coenzyme Q10 supplementation on oxidative stress: A systematic review and meta-analysis of randomized controlled clinical trials

Some evidence exists in supporting the beneficial effects of coenzyme Q10 (CoQ10) on oxidative stress. Since the findings of studies over the impact of CoQ10 supplementation on oxidative stress are contradictory, this study was conducted. The aim was to evaluate CoQ10 supplementation effect on total antioxidant capacity (TAC), malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) levels using data collected from randomized controlled trials (RCTs). Several databases including PubMed, Web of Science, Google Scholar, and Scopus were comprehensively searched up to 23 January 2019 to identify RCTs. A random-effects model, standardized mean difference (SMD), and 95% confidence interval (CI) were applied for data analysis. According to the meta-analysis results on 19 eligible studies, CoQ10 increased the levels of TAC (SMD = 1.29; 95% CI = 0.35-2.23; p = .007), GPX (SMD = 0.45; 95% CI = 0.17-0.74; p = .002), SOD (SMD = 0.63; 95% CI = 0.29-0.97; p < .0001), and CAT (SMD = 1.67; 95% CI = 0.29-3.10; p = .018) significantly. This supplementation also caused a significant reduction in MDA levels (SMD = -1.12; 95% CI = -1.58 to -0.65; p < .0001). However, the results of SOD and CAT should be stated carefully due to the publication bias. In conclusion, this research indicated that CoQ10 supplementation had beneficial effects on oxidative stress markers. However, further studies are needed to confirm these findings.

Oxidative stress and inflammation in the evolution of heart failure: From pathophysiology to therapeutic strategies

Both oxidative stress and inflammation are enhanced in chronic heart failure. Dysfunction of cardiac mitochondria is a hallmark of heart failure and a leading cause of oxidative stress, which in turn exerts detrimental effects on cellular components, including mitochondria themselves, thus generating a vicious circle. Oxidative stress also causes myocardial tissue damage and inflammation, contributing to heart failure progression. Furthermore, a subclinical inflammatory state may be caused by heart failure comorbidities such as obesity, diabetes mellitus or sleep apnoeas. Some markers of both oxidative stress and inflammation are enhanced in chronic heart failure and hold prognostic significance. For all these reasons, antioxidants or anti-inflammatory drugs may represent interesting additional therapies for subjects either at high risk or with established heart failure. Nonetheless, only a few clinical trials on antioxidants have been carried out so far, with several disappointing results except for vitamin C, elamipretide and coenzyme Q10. With regard to anti-inflammatory drugs, only preliminary data on the interleukin-1 antagonist anakinra are currently available. Therefore, a comprehensive, deep understanding of our current knowledge on oxidative stress and inflammation in chronic heart failure is key to providing some suggestions for future research on this topic.

Effects of Coenzyme Q10 Supplementation on Serum Adiponectin Levels: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background:

Adiponectin, a well-known adipokine plays a number of regulatory actions in human body metabolism. Decreased levels of adiponectin have been reported in type 2 diabetes mellitus, cardiovascular diseases, metabolic syndrome and hypertension. Coenzyme Q10 (Co Q10) is a fat-soluble antioxidant substance which has been reported to be effective in several metabolic disturbances such as insulin resistance and inflammation.

Objective:

Present systematic review and meta-analysis were performed to assess the effects of CoQ10 supplementation on adiponectin serum level.

Methods:

A comprehensive search was performed in electronic databases including EMBASE, Google scholar, and PubMed up to January 2018. A meta-analysis of eligible studies was performed using random effects model to estimate pooled effect size of CoQ10 supplementation on adiponectin.

Results:

A total of 209 subjects were recruited from 5 eligible studies. Meta-analysis did not suggest any significant effect of CoQ10 supplementation on adiponectin serum level (0.240 mg/dl, 95%CI: -0.216, 0.696, P= 0.303), without significant heterogeneity between included studies (I2= 40.9%, p= 0.149).

Conclusion:

Although present meta-analysis did not indicate any significant effects of CoQ10 supplementation on serum adiponectin levels but future long-term dose-response trials are needed before any firm conclusion.

Green Formulation of Triglyceride/Phospholipid-Based Nanocarriers as a Novel Vehicle for Oral Coenzyme Q10 Delivery

This study was aimed to develop a novel nanocarrier for coenzyme Q10 (CoQ10) by a green process that prevented the use of surfactants and organic solvents. Triglyceride/phospholipid-based nanocarriers were developed through high-pressure homogenization (an industrial feasible process), and a 2^5-1 fractional factorial design was adopted to assess the influences of formulation variables on the considered responses, including vesicle size, entrapment efficiency, loading capacity, and solubility of the vehicles in simulated gastrointestinal fluids. The optimized formulation was further in-depth characterized in terms of morphology, release behavior, biocompatibility (Caco-2 cell cytotoxicity and histological examination), thermal behavior, and Fourier transform infrared analysis. Optimal nanocarriers were found to have mean particle size of 75 nm, narrow particle distribution, and CoQ10 entrapment of 95%. The optimized formulation was stable upon incubation in simulated gastrointestinal fluids without considerable leakage of cargo, which was in agreement with their sustained release behavior. Microscopic observations also confirmed nanosized nature of the vesicles and revealed their spherical shape. Moreover, toxicity evaluations at the cellular and tissue levels revealed their nontoxic nature. In conclusion, triglyceride/phospholipid-based nanocarriers proved to be a green safe vehicle for delivery of CoQ10 with industrial-scale production capability and could provide a new horizon for delivery of hydrophobic nutraceuticals. PRACTICAL APPLICATION: Green nanostructure formulation approaches have recently gained tremendous attraction for their safe profile especially when it comes to supplements, which are generally recommended for daily use. However, their sufficient association with cargoes and industrial-scale production have remained considerable challenges. This study focuses on the development of lipid-based nanocarriers for CoQ10 by an industrial feasible process that prevents the use of any surfactants or organic solvents.

Efficacy of coenzyme Q10 in patients with chronic kidney disease: protocol for a systematic review

INTRODUCTION

Coenzyme Q10 (CoQ10) is a fat-soluble vitamin-like quinone that exerts antioxidative functions and is also an important factor in mitochondrial metabolism. Plasma concentrations of CoQ10 are depressed in patients with chronic kidney disease (CKD). CoQ10 supplement can reduce adverse cardiovascular events, improve mitochondrial function and decrease oxidative stress in patients with non-dialysis CKD and dialysis CKD. We performed this study as a systematic review to comprehensively assess the effect of CoQ10 supplement on patients with CKD.

METHODS AND ANALYSIS

The present systematic review protocol is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols guidelines. The MEDLINE, EMBASE and Cochrane library databases will be searched without language restrictions in December 2018. Two reviewers will independently screen the references in two stages: screening of the title/abstract and then of the full-text, to identify references meeting the inclusion criteria. A descriptive overview and tabular and/or graphical summaries will be generated, and directed content analysis will be carried out on the extracted data.

ETHICS AND DISSEMINATION

This systematic review will evaluate the efficacy and safety of CoQ10 in patients with CKD. Ethical approval is not required for this study. The results of this systematic review will be presented in relevant conferences and published in a peer-review journal.

PROSPERO REGISTRATION NUMBER

CRD42019120201.

Ubiquinone Plasma Levels are Correlated with Brain Natriuretic Peptide Plasma Levels in Patients with Chronic Heart Failure: The Potential of Coenzyme Q10 Combined Therapy

Despite the association of a worse HF-related clinical status with lower CoQ10 levels, the prognostic use of CoQ10 is controversial. The aim of this study is to optimize pharmacotherapy for patients with ischaemic CHF, based on the clinical and functional parameters of the heart and brain natriuretic peptide (BNP) plasma levels, which are correlated with the CoQ10 plasma levels, and to assess patient prognosis after receiving CoQ10 therapy. This prospective clinical study included 75 patients aged 56 to 63 years old with coronary heart disease (CHD) classified as class I–III according to the NYHA classification. After assessment of the clinical-instrumental characteristics of the CVD course (complaints, medical history, physical examination, a 6-minute walk test, echocardiography, and test for reactive hyperaemia), we determined the BNP level and CoQ10 plasma levels. At the same time, we assessed the efficacy of CoQ10 treatment (at a dose of 60 mg/per day) and tolerability in CVD-combined therapy during a follow-up of 12 weeks. CoQ10 supplementation in HF patients induced improvements in their functional cardiac parameters, such as the ejection fraction. Our results suggest that supplemental CoQ10 may be a useful option for effective management of heart failure and warrant future adequately powered randomized controlled trials of CoQ10 supplementation in patients with HF.

Endogenous non-enzymatic antioxidants in the human body

The exposure of cells, tissues and extracellular matrix to harmful reactive species causes a cascade of reactions and induces activation of multiple internal defence mechanisms (enzymatic or non-enzymatic) that provide removal of reactive species and their derivatives. The non-enzymatic antioxidants are represented by molecules characterized by the ability to rapidly inactivate radicals and oxidants. This paper focuses on the major intrinsic non-enzymatic antioxidants, including metal binding proteins (MBPs), glutathione (GSH), uric acid (UA), melatonin (MEL), bilirubin (BIL) and polyamines (PAs).

Cellular factories for coenzyme Q10 production

Coenzyme Q₁₀ (CoQ₁₀), a benzoquinone present in most organisms, plays an important role in the electron-transport chain, and its deficiency is associated with various neuropathies and muscular disorders. CoQ₁₀ is the only lipid-soluble antioxidant found in humans, and for this, it is gaining popularity in the cosmetic and healthcare industries. To meet the growing demand for CoQ₁₀, there has been considerable interest in ways to enhance its production, the most effective of which remains microbial fermentation. Previous attempts to increase CoQ₁₀ production to an industrial scale have thus far conformed to the strategies used in typical metabolic engineering endeavors. However, the emergence of new tools in the expanding field of synthetic biology has provided a suite of possibilities that extend beyond the traditional modes of metabolic engineering. In this review, we cover the various strategies currently undertaken to upscale CoQ₁₀ production, and discuss some of the potential novel areas for future research.

Effects of coenzyme Q10 supplementation on inflammatory markers: A systematic review and meta-analysis of randomized controlled trials

The aims of this meta-analysis were to evaluate the effects of coenzyme Q10 (CoQ10) supplementation on inflammatory mediators including C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) by analyzing published randomized controlled trials (RCTs). A systematic search in PubMed, Cochrane Library and Clinicaltrials.gov was performed to identify eligible RCTs. Data synthesis was performed using a random- or a fixed-effects model depending on the results of heterogeneity tests, and pooled data were displayed as weighed mean difference (WMD) and 95% confidence interval (CI). Seventeen RCTs were selected for the meta-analysis. CoQ10 supplementation significantly reduced the levels of circulating CRP (WMD: -0.35mg/L, 95% CI: -0.64 to -0.05, P=0.022), IL-6 (WMD: -1.61pg/mL, 95% CI: -2.64 to -0.58, P=0.002) and TNF-α (WMD: -0.49pg/mL, 95% CI: -0.93 to -0.06, P=0.027). The results of meta-regression showed that the changes of CRP were independent of baseline CRP, treatment duration, dosage, and patients characteristics. In the meta-regression analyses, a higher baseline IL-6 level was significantly associated with greater effects of CoQ10 on IL-6 levels (P for interaction=0.006). In conclusion, this meta-analysis of RCTs suggests significant lowering effects of CoQ10 on CRP, IL-6 and TNF-α. However, results should be interpreted with caution because of the evidence of heterogeneity and limited number of studies.