Functional connections and pathways of coenzyme Q10-inducible genes: an in-silico study

L-shaped association between dietary coenzyme Q10 intake and high-sensitivity C-reactive protein in Chinese adults: a national cross-sectional study

Background: Chronic inflammation contributes to the occurrence and progression of many diseases. Most previous clinical studies have explored the effect of high-dose CoQ10 supplements on inflammation. Food is another important source of CoQ10, but the relationship between the intake of CoQ10 from dietary sources and inflammation was unknown. We aimed to explore the dose-response association between the intake of dietary-derived CoQ10 and inflammation-related biomarkers. Methods: Seven thousand nine hundred and fifty-three Chinese adults from the China Health and Nutrition Survey (CHNS) were the subjects of this cross-sectional investigation. Dietary CoQ10 intake was assessed using dietary information from three days. High-sensitivity C-reactive protein (hsCRP) and white blood cell count (WBC) were assessed using fasting venous blood. Results: In an adjusted linear regression model, CoQ10 consumption from dietary sources was inversely associated with hsCRP, with effect sizes in each group: Q2 (β = -0.85 mg L-1, 95% CI: -1.43 to -0.28 mg L-1, P = 0.004), Q3 (β = -0.70 mg L-1, 95% CI: -1.28 to -0.12 mg L-1, P = 0.017), and Q4 (β = -0.79 mg L-1, 95% CI: -1.39 to -0.19 mg L-1, P = 0.010). Moreover, restricted cubic splines (RCS) revealed a non-linear L-shaped association between dietary-derived CoQ10 consumption and hsCRP (Pnonlinear < 0.001). According to subgroup analyses, these relationships were more significant in males, or >45 years old (Ptrend < 0.05). Nevertheless, no significant relationship was found between dietary-derived CoQ10 intake and WBC. Conclusions: These findings suggested a significant negative association between dietary-derived CoQ10 and hsCRP levels.

Systematic Review on Protocols of Coenzyme Q10 Supplementation in Non-Surgical Periodontitis Therapy

This systematic review focuses on the different study protocols on CoQ10 as an adjunct in non-surgical periodontitis therapy. The study protocol was developed following PRISMA guidelines and was registered in PROSPERO (CRD42021156887). A sensitive search up to January 2022 considered MEDLINE via PubMed and Web of Science, Embase, Web of Science Core Collection via Web of Science, Google Scholar, Cochrane CENTRAL, WHO (ICTRP), ClinicalTrials.gov, and grey literature. Randomized controlled (SRP with/without placebo) clinical trials (RCTs) on all types of CoQ10 administration were included. The primary outcome was probing pocket depth (PPD). Secondary outcomes were bleeding on probing, clinical attachment loss, and gingival and plaque indices. Twelve RCTs with local and five with systemic CoQ10 administration were included. The study protocols were heterogeneous. Local CoQ10 administration was performed once or several times in a period up to 15 days. Systemic CoQ10 was applied twice or three times daily for six weeks up to four months. The reporting quality was low, including missing information about CoQ10 doses. Risk of bias was high or unclear. About half of the studies reported significant group differences for PPD. Until now, no statement on the effectiveness of CoQ10 in non-surgical periodontitis therapy is possible. Further high-quality RCTs are necessary and should consider the protocol recommendations of this review.

Coenzyme Q10 and Its Therapeutic Potencies Against COVID-19 and Other Similar Infections: A Molecular Review

Purpose: New lethal coronavirus disease 2019 (COVID-19), currently, has been converted to a disastrous pandemic worldwide. As there has been found no definitive treatment for the infection in this review we focused on molecular aspects of coenzyme Q10 (CoQ10) and possible therapeutic potencies of CoQ10 against COVID-19 and similar infections. Methods: This is a narrative review in which we used some authentic resources including PubMed, ISI, Scopus, Science Direct, Cochrane, and some preprint databases, the molecular aspects of CoQ10 effects, regarding to the COVID-19 pathogenesis, have been analyzed and discussed. Results: CoQ10 is an essential cofactor in the electron transport chain of the phosphorylative oxidation system. It is a powerful lipophilic antioxidant, anti-apoptotic, immunomodulatory and anti-inflammatory supplement which has been tested for the management and prevention of a variety of diseases particularly diseases with inflammatory pathogenesis. CoQ10 is a strong anti-inflammatory agent which can reduce tumor necrosis factor-α (TNF-α), interleukin (IL)- 6, C-reactive protein (CRP), and other inflammatory cytokines. The cardio-protective role of CoQ10 in improving viral myocarditis and drug induced cardiotoxicity has been determined in different studies. CoQ10 could also improve the interference in the RAS system caused by COVID-19 through exerting anti-Angiotensin II effects and decreasing oxidative stress. CoQ10 passes easily through blood-brain barrier (BBB). As a neuroprotective agent CoQ10 can reduce oxidative stress and modulate the immunologic reactions. These properties may help to reduce CNS inflammation and prevent BBB damage and neuronal apoptosis in COVID-19 patients. Conclusion: CoQ10 supplementation may prevent the COVID-19-induced morbidities with a potential protective role against the deleterious consequences of the disease, further clinical evaluations are encouraged.

Coenzyme Q10 prevented Trypanosoma brucei rhodesiense-mediated breach of the blood brain barrier, inflammation and organ damage in late stage of Human African Trypanosomiasis

During the late stage of Human African Trypanosomiasis (HAT), there is severe cytokine-driven inflammation, oxidative stress and organ damage. Controlling inflammation and oxidative damage presents unique therapeutic opportunities to improve treatment outcome. The current study sought to determine the putative impact of Coenzyme-Q10 (Co-Q10), a potent antioxidant and anti-inflammatory, on adverse inflammatory and oxidative events during Trypanosoma brucei rhodesiense (T.b.r) infection. Group one constituted the control; the second group was infected with T.b.r; the third group was orally administered with 200 mg/kg Co-Q10 for two weeks; thereafter, Co-Q10 administration continued after infection with T.b.r. Co-Q10 improved the survival rate of infected mice and prevented full blown parasite driven splenomegaly and hepatomegaly. Co-Q10 prevented characteristic T.b.r-driven breach of the blood brain barrier and improved neurological integrity among T.b.r infected mice. Co-Q10 protected from T.b.r-induced microcytic hypochromic anaemia and thrombocytopenia. T.b.r-induced oxidative stress in the vital organs was assuaged following exposure to Co-Q10. Co-Q10 blocked T.b.r-induced derangement of high density lipoprotein and triglyceride levels. Co-Q10 significantly abrogated T.b.r-driven elevation of serum TNF-α and IFN-γ levels. Moreover, T.b.r-induced kidney and liver damage was assuaged by Co-Q10 administration. Co-Q10 administration downregulated T.b.r-induced elevation of uric acid and C-reactive protein. Likewise, T.b.r infected mice receiving Co-Q10 exhibited normal brain architecture. In conclusion, treatment with Co-Q10 may be useful in protecting against T.b.r-mediated organ injury, lethal inflammation and oxidative stress commonly present in severe late stage HAT; and presents unique opportunities for an adjunct therapy for late stage HAT.

Plasma CoQ10 Status in Patients with Propionic Acidaemia and Possible Benefit of Treatment with Ubiquinol

Propionic acidaemia (PA) is an innate error of metabolism involving a deficiency in the enzyme propionyl-CoA carboxylase. Better control of acute decompensation episodes together with better treatment and monitoring have improved the prognosis of patients with this problem. However, long-term complications can arise in those in whom good metabolic control is achieved, the result of mitochondrial dysfunction caused by deficient anaplerosis, increased oxidative stress, and reduced antioxidative capacity. Coenzyme Q10 (CoQ10) is a nutritional supplement that has a notable antioxidative effect and has been shown to improve mitochondrial function. The present prospective, interventional study examines the plasma concentration of CoQ10 in patients with PA, their tolerance of such supplementation with ubiquinol, and its benefits. Seven patients with PA (aged 2.5 to 20 years, 4 males) received supplements of CoQ10 in the form of ubiquinol (10 mg/kg/day for 6 months). A total of 6/7 patients showed reduced plasma CoQ10 concentrations that normalized after supplementation with ubiquinol (p-value < 0.001), which was well tolerated. Urinary citrate levels markedly increased during the study (p-value: 0.001), together with elevation of citrate/methlycitrate ratio (p-value: 0.03). No other significant changes were seen in plasma or urine biomarkers of PA. PA patients showed a deficiency of plasma CoQ10, which supplementation with ubiquinol corrected. The urinary excretion of Krebs cycle intermediate citrate and the citrate/methylcitrate ratio significantly increased compared to the baseline, suggesting improvement in anaplerosis. This treatment was well tolerated and should be further investigated as a means of preventing the chronic complications associated with likely multifactorial mitochondrial dysfunction in PA.

Molecular mechanisms underlying the promotion of wound repair by coenzyme Q10: PI3K/Akt signal activation via alterations to cell membrane domains

Coenzyme Q10 (CoQ10) promotes wound healing in vitro and in vivo. However, the molecular mechanisms underlying the promoting effects of CoQ10 on wound repair remain unknown. In the present study, we investigated the molecular mechanisms through which CoQ10 induces wound repair using a cellular wound-healing model. CoQ10 promoted wound closure in a dose-dependent manner and wound-mediated cell polarization after wounding in HaCaT cells. A comparison with other CoQ homologs, benzoquinone derivatives, and polyisoprenyl compounds suggested that the whole structure of CoQ10 is required for potent wound repair. The phosphorylation of Akt after wounding and the plasma membrane translocation of Akt were elevated in CoQ10-treated cells. The promoting effect of CoQ10 on wound repair was abrogated by co-treatment with a phosphatidylinositol 3-kinase (PI3K) inhibitor. Immuno­histochemical and biochemical analyses showed that CoQ10 increased the localization of caveolin-1 (Cav-1) to the apical membrane domains of the cells and the Cav-1 content in the membrane-rich fractions. Depletion of Cav-1 suppressed CoQ10-mediated wound repair and PI3K/Akt signaling activation in HaCaT cells. These results indicated that CoQ10 increases the translocation of Cav-1 to the plasma membranes, activating the downstream PI3K/Akt signaling pathway, and resulting in wound closure in HaCaT cells.

Coenzyme Q10 effects in neurological diseases

Coenzyme Q10 (CoQ10), a lipophilic substituted benzoquinone, is present in animal and plant cells. It is endogenously synthetized in every cell and involved in a variety of cellular processes. CoQ10 is an obligatory component of the respiratory chain in inner mitochondrial membrane. In addition, the presence of CoQ10 in all cellular membranes and in blood. It is the only endogenous lipid antioxidant. Moreover, it is an essential factor for uncoupling protein and controls the permeability transition pore in mitochondria. It also participates in extramitochondrial electron transport and controls membrane physicochemical properties. CoQ10 effects on gene expression might affect the overall metabolism. Primary changes in the energetic and antioxidant functions can explain its remedial effects. CoQ10 supplementation is safe and well-tolerated, even at high doses. CoQ10 does not cause any serious adverse effects in humans or experimental animals. New preparations of CoQ10 that are less hydrophobic and structural derivatives, like idebenone and MitoQ, are being developed to increase absorption and tissue distribution. The review aims to summarize clinical and experimental effects of CoQ10 supplementations in some neurological diseases such as migraine, Parkinson´s disease, Huntington´s disease, Alzheimer´s disease, amyotrophic lateral sclerosis, Friedreich´s ataxia or multiple sclerosis. Cardiovascular hypertension was included because of its central mechanisms controlling blood pressure in the brainstem rostral ventrolateral medulla and hypothalamic paraventricular nucleus. In conclusion, it seems reasonable to recommend CoQ10 as adjunct to conventional therapy in some cases. However, sometimes CoQ10 supplementations are more efficient in animal models of diseases than in human patients (e.g. Parkinson´s disease) or rather vague (e.g. Friedreich´s ataxia or amyotrophic lateral sclerosis).

The Roles of Coenzyme Q in Disease: Direct and Indirect Involvement in Cellular Functions

Coenzyme Q (CoQ) is a key component of the respiratory chain of all eukaryotic cells. Its function is closely related to mitochondrial respiration, where it acts as an electron transporter. However, the cellular functions of coenzyme Q are multiple: it is present in all cell membranes, limiting the toxic effect of free radicals, it is a component of LDL, it is involved in the aging process, and its deficiency is linked to several diseases. Recently, it has been proposed that coenzyme Q contributes to suppressing ferroptosis, a type of iron-dependent programmed cell death characterized by lipid peroxidation. In this review, we report the latest hypotheses and theories analyzing the multiple functions of coenzyme Q. The complete knowledge of the various cellular CoQ functions is essential to provide a rational basis for its possible therapeutic use, not only in diseases characterized by primary CoQ deficiency, but also in large number of diseases in which its secondary deficiency has been found.

Coenzyme Q homeostasis in aging: Response to non-genetic interventions

Coenzyme Q (CoQ) is a key component for many essential metabolic and antioxidant activities in cells in mitochondria and cell membranes. Mitochondrial dysfunction is one of the hallmarks of aging and age-related diseases. Deprivation of CoQ during aging can be the cause or the consequence of this mitochondrial dysfunction. In any case, it seems clear that aging-associated CoQ deprivation accelerates mitochondrial dysfunction in these diseases. Non-genetic prolongevity interventions, including CoQ dietary supplementation, can increase CoQ levels in mitochondria and cell membranes improving mitochondrial activity and delaying cell and tissue deterioration by oxidative damage. In this review, we discuss the importance of CoQ deprivation in aging and age-related diseases and the effect of prolongevity interventions on CoQ levels and synthesis and CoQ-dependent antioxidant activities.

Coenzyme Q10 in COPD: An Unexplored Opportunity?

COPD represents a major cause of mortality and morbidity worldwide, is linked to systemic inflammation and tends to coexist with a variety of comorbidities. Inflammation, oxidative stress and protease-antiprotease imbalance represent the pathogenic triad of COPD. Even though oxidative stress and mitochondrial dysfunction is a well-studied phenomenon in COPD and there is a variety of studies that aim to counteract its effect, there is limited data available on the use of coenzyme Q10 in COPD. The aim of the current review is to analyze the current data on the use of coenzyme Q10 in the management of COPD and frequently encountered comorbidities.

Coenzyme Q biosynthesis inhibition induces HIF-1α stabilization and metabolic switch toward glycolysis

Coenzyme Q₁₀ (CoQ, ubiquinone) is a redox-active lipid endogenously synthesized by the cells. The final stage of CoQ biosynthesis is performed at the mitochondrial level by the 'complex Q', where coq2 is responsible for the prenylation of the benzoquinone ring of the molecule. We report that the competitive coq2 inhibitor 4-nitrobenzoate (4-NB) decreased the cellular CoQ content and caused severe impairment of mitochondrial function in the T67 human glioma cell line. In parallel with the reduction in CoQ biosynthesis, the cholesterol level increased, leading to significant perturbation of the plasma membrane physicochemical properties. We show that 4-NB treatment did not significantly affect the cell viability, because of an adaptive metabolic rewiring toward glycolysis. Hypoxia-inducible factor 1α (HIF-1α) stabilization was detected in 4-NB-treated cells, possibly due to the contribution of both reduction in intracellular oxygen tension and ROS overproduction. Exogenous CoQ supplementation partially recovered cholesterol content, HIF-1α degradation, and ROS production, whereas only weakly improved the bioenergetic impairment induced by the CoQ depletion. Our data provide new insights on the effect of CoQ depletion and contribute to shed light on the pathogenic mechanisms of ubiquinone deficiency syndrome.

SmPPT, a 4-hydroxybenzoate polyprenyl diphosphate transferase gene involved in ubiquinone biosynthesis, confers salt tolerance in Salvia miltiorrhiza

SmPPT, which encodes 4-hydroxybenzoate polyprenyl diphosphate transferase involved in ubiquinone biosynthesis, confers salt tolerance to S. miltiorrhiza through enhancing the activities of POD and CAT to scavenge ROS. Ubiquinone (UQ), also known as coenzyme Q (CoQ), is a key electron transporter in the mitochondrial respiratory system. UQ is composed of a benzene quinone ring and a polyisoprenoid side chain. Attachment of polyisoprenoid side chain to the benzene quinone ring is a rate-limiting step catalyzed by 4-hydroxybenzoate polyprenyl diphosphate transferase (PPT). So far, only a few plant PPT-encoding genes have been functionally analyzed. Through genome-wide analysis and subsequent molecular cloning, a PPT-encoding gene, termed SmPPT, was identified from an economically and academically important medicinal model plant, Salvia miltiorrhiza. SmPPT contained many putative cis-elements associated with abiotic stresses in the promoter region and were responsive to PEG-6000 and methyl jasmonate treatments. The deduced SmPPT protein contains the PT_UbiA conserved domain of polyprenyl diphosphate transferase and an N-terminal mitochondria transit peptide. Transient expression assay of SmPPT-GFP fusion protein showed that SmPPT was mainly localized in the mitochondria. SmPPT could functionally complement coq2 mutation and catalyzed UQ6 production in yeast cells. Overexpression of SmPPT increased UQ production and enhanced salt tolerance in S. miltiorrhiza. Under salinity stress conditions, transgenic plants accumulated less H₂O₂ and malondialdehyde and exhibited higher peroxidase (POD) and catalase (CAT) activities compared with wild-type plants. It indicates that SmPPT confers salt tolerance to S. miltiorrhiza at least partially through enhancing the activities of POD and CAT to scavenge ROS.

Age-Dependent Loss of Mitochondrial Function in Epithelial Tissue Can Be Reversed by Coenzyme Q10

The process of aging is characterized by the increase of age-associated disorders as well as severe diseases. Due to their role in the oxidative phosphorylation and thus the production of ATP which is crucial for many cellular processes, one reason for this could be found in the mitochondria. The accumulation of reactive oxygen species damaged mitochondrial DNA and proteins can induce mitochondrial dysfunction within the electron transport chain. According to the “mitochondrial theory of aging,” understanding the impact of harmful external influences on mitochondrial function is therefore essential for a better view on aging in general, but the measurement of mitochondrial respiration in skin cells from cell cultures cannot completely reflect the real situation in skin. Here, we describe a new method to measure the mitochondrial respiratory parameters in epithelial tissue derived from human skin biopsies using a XF24 extracellular flux analyzer to evaluate the effect of coenzyme Q10. We observed a decrease in mitochondrial respiration and ATP production with donor age corresponding to the “mitochondrial theory of aging.” For the first time ex vivo in human epidermis, we could show also a regeneration of mitochondrial respiratory parameters if the reduced form of coenzyme Q10, ubiquinol, was administered. In conclusion, an age-related decrease in mitochondrial respiration and ATP production was confirmed. Likewise, an increase in the respiratory parameters by the addition of coenzyme Q10 could also be shown. The fact that there is a significant effect of administered coenzyme Q10 on the respiratory parameters leads to the assumption that this is mainly caused by an increase in the electron transport chain. This method offers the possibility of testing age-dependent effects of various substances and their influence on the mitochondrial respiration parameters in human epithelial tissue.

Integration of heterologous 4-hydroxybenzoic acid transport proteins in Rhodobacter sphaeroides for enhancement of coenzyme Q10production

This work provides a novel genetic engineering strategy that improves uptake of extracellular 4-hydroxybenzoic acid by heterologously expressing the membrane transport protein PcaK inR. sphaeroidesfor enhancement of CoQ₁₀production.

Molecular mechanisms of statin intolerance

Statins reduce cardiovascular morbidity and mortality in primary and secondary prevention. Despite their efficacy, many persons are unable to tolerate statins due to adverse events such as hepatotoxicity and myalgia/myopathy. In the case of most patients, it seems that mild-to-moderate abnormalities in liver and muscle enzymes are not serious adverse effects and do not outweigh the benefits of coronary heart disease risk reduction. The risk for mortality or permanent organ damage ascribed to statin use is very small and limited to cases of myopathy and rhabdomyolysis. Statin-induced muscle-related adverse events comprise a highly heterogeneous clinical disorder with numerous, complex etiologies and a variety of genetic backgrounds. Every patient who presents with statin-related side effects cannot undergo the type of exhaustive molecular characterization that would include all of these mechanisms. Frequently the only solution is to either discontinue statin therapy/reduce the dose or attempt intermittent dosing strategies at a low dose.

Accelerated Regeneration of ATP Level after Irradiation in Human Skin Fibroblasts by Coenzyme Q10

Human skin is exposed to a number of harmful agents of which the ultraviolet (UV) component of solar radiation is most important. UV-induced damages include direct DNA lesions as well as oxidative damage in DNA, proteins and lipids caused by reactive oxygen species (ROS). Being the main site of ROS generation in the cell, mitochondria are particularly affected by photostress. The resulting mitochondrial dysfunction may have negative effects on many essential cellular processes. To counteract these effects, coenzyme Q10 (CoQ10 ) is used as a potent therapeutic in a number of diseases. We analyzed the mitochondrial respiration profile, the mitochondrial membrane potential and cellular ATP level in skin fibroblasts after irradiation. We observed an accelerated regeneration of cellular ATP level, a decrease in mitochondrial dysfunction as well as a preservation of the mitochondrial membrane potential after irradiation in human skin fibroblasts by treatment with CoQ10 . We conclude that the faster regeneration of the ATP level was achieved by a preservation of mitochondrial function by the addition of CoQ10 and that the protective effect of CoQ10 is primarily mediated via its antioxidative function. We suggest also that it might be further dependent on a stimulation of DNA repair enzymes by CoQ10 .

Coenzyme Q and Its Role in the Dietary Therapy against Aging

Coenzyme Q (CoQ) is a naturally occurring molecule located in the hydrophobic domain of the phospholipid bilayer of all biological membranes. Shortly after being discovered, it was recognized as an essential electron transport chain component in mitochondria where it is particularly abundant. Since then, more additional roles in cell physiology have been reported, including antioxidant, signaling, death prevention, and others. It is known that all cells are able to synthesize functionally sufficient amounts of CoQ under normal physiological conditions. However, CoQ is a molecule found in different dietary sources, which can be taken up and incorporated into biological membranes. It is known that mitochondria have a close relationship with the aging process. Additionally, delaying the aging process through diet has aroused the interest of scientists for many years. These observations have stimulated investigation of the anti-aging potential of CoQ and its possible use in dietary therapies to alleviate the effects of aging. In this context, the present review focus on the current knowledge and evidence the roles of CoQ cells, its relationship with aging, and possible implications of dietary CoQ in relation to aging, lifespan or age-related diseases.

Nutraceuticals in Migraine: A Summary of Existing Guidelines for Use

BACKGROUND

The use of nutraceuticals or food/herbal products for health benefits is expanding in adults with migraine as they seek relief from pain in an effective and tolerable manner not always afforded by current conventional pharmacologic therapies. Guidelines from the American Academy of Neurology/American Headache Society, Canadian Headache Society, and European Federation of Neurological Societies have discussed nutraceuticals in varying degrees of detail with at times conflicting recommendations.

CONCLUSION

This review serves to provide a summary of existing guidelines for the use of certain nutraceuticals including riboflavin, coenzyme Q10, magnesium, butterbur, feverfew, and omega-3 polyunsaturated fatty acids. The review will also discuss the regulation of nutraceuticals in North America and the current controversy regarding butterbur and its safety.

Plastoquinone and Ubiquinone in Plants: Biosynthesis, Physiological Function and Metabolic Engineering

Plastoquinone (PQ) and ubiquinone (UQ) are two important prenylquinones, functioning as electron transporters in the electron transport chain of oxygenic photosynthesis and the aerobic respiratory chain, respectively, and play indispensable roles in plant growth and development through participating in the biosynthesis and metabolism of important chemical compounds, acting as antioxidants, being involved in plant response to stress, and regulating gene expression and cell signal transduction. UQ, particularly UQ₁₀, has also been widely used in people's life. It is effective in treating cardiovascular diseases, chronic gingivitis and periodontitis, and shows favorable impact on cancer treatment and human reproductive health. PQ and UQ are made up of an active benzoquinone ring attached to a polyisoprenoid side chain. Biosynthesis of PQ and UQ is very complicated with more than thirty five enzymes involved. Their synthetic pathways can be generally divided into two stages. The first stage leads to the biosynthesis of precursors of benzene quinone ring and prenyl side chain. The benzene quinone ring for UQ is synthesized from tyrosine or phenylalanine, whereas the ring for PQ is derived from tyrosine. The prenyl side chains of PQ and UQ are derived from glyceraldehyde 3-phosphate and pyruvate through the 2-C-methyl-D-erythritol 4-phosphate pathway and/or acetyl-CoA and acetoacetyl-CoA through the mevalonate pathway. The second stage includes the condensation of ring and side chain and subsequent modification. Homogentisate solanesyltransferase, 4-hydroxybenzoate polyprenyl diphosphate transferase and a series of benzene quinone ring modification enzymes are involved in this stage. PQ exists in plants, while UQ widely presents in plants, animals and microbes. Many enzymes and their encoding genes involved in PQ and UQ biosynthesis have been intensively studied recently. Metabolic engineering of UQ₁₀ in plants, such as rice and tobacco, has also been tested. In this review, we summarize and discuss recent research progresses in the biosynthetic pathways of PQ and UQ and enzymes and their encoding genes involved in side chain elongation and in the second stage of PQ and UQ biosynthesis. Physiological functions of PQ and UQ played in plants as well as the practical application and metabolic engineering of PQ and UQ are also included.

Coenzyme Q regulates the expression of essential genes of the pathogen- and xenobiotic-associated defense pathway in C. elegans

Coenzyme Q (CoQ) is necessary for mitochondrial energy production and modulates the expression of genes that are important for inflammatory processes, growth and detoxification reactions. A cellular surveillance-activated detoxification and defenses (cSADDs) pathway has been recently identified in C. elegans. The down-regulation of the components of the cSADDs pathway initiates an aversion behavior of the nematode. Here we hypothesized that CoQ regulates genes of the cSADDs pathway. To verify this we generated CoQ-deficient worms ("CoQ-free") and performed whole-genome expression profiling. We found about 30% (120 genes) of the cSADDs pathway genes were differentially regulated under CoQ-deficient condition. Remarkably, 83% of these genes were down-regulated. The majority of the CoQ-sensitive cSADDs pathway genes encode for proteins involved in larval development (enrichment score (ES) = 38.0, p = 5.0E(-37)), aminoacyl-tRNA biosynthesis, proteasome function (ES 8.2, p = 5.9E(-31)) and mitochondria function (ES 3.4, p = 1.7E(-5)). 67% (80 genes) of these genes are categorized as lethal. Thus it is shown for the first time that CoQ regulates a substantial number of essential genes that function in the evolutionary conserved cellular surveillance-activated detoxification and defenses pathway in C. elegans.

Effects of coenzyme Q10 on statin-induced myopathy: a meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the efficacy of coenzyme Q10 (CoQ10) supplementation on statin-induced myopathy.

PARTICIPANTS AND METHODS

We searched the MEDLINE, Cochrane Library, Scopus, and EMBASE databases (November 1, 1987, to May 1, 2014) to identify randomized controlled trials investigating the impact of CoQ10 on muscle pain and plasma creatine kinase (CK) activity as 2 measures of statin-induced myalgia. Two independent reviewers extracted data on study characteristics, methods, and outcomes.

RESULTS

We included 6 studies with 302 patients receiving statin therapy: 5 studies with 226 participants evaluated the effect of CoQ10 supplementation on plasma CK activity, and 5 studies (4 used in the CK analysis and 1 other study) with 253 participants were included to assess the effect of CoQ10 supplementation on muscle pain. Compared with the control group, plasma CK activity was increased after CoQ10 supplementation, but this change was not significant (mean difference, 11.69 U/L [to convert to μkat/L, multiply by 0.0167]; 95% CI, -14.25 to 37.63 U/L; P=.38). Likewise, CoQ10 supplementation had no significant effect on muscle pain despite a trend toward a decrease (standardized mean difference, -0.53; 95% CI, -1.33 to 0.28; P=.20). No dose-effect association between changes in plasma CK activity (slope, -0.001; 95% CI, -0.004 to 0.001; P=.33) or in the indices of muscle pain (slope, 0.002; 95% CI, -0.005 to 0.010; P=.67) and administered doses of CoQ10 were observed.

CONCLUSION

The results of this meta-analysis of available randomized controlled trials do not suggest any significant benefit of CoQ10 supplementation in improving statin-induced myopathy. Larger, well-designed trials are necessary to confirm the findings from this meta-analysis.

Coenzyme Q10 depletion in medical and neuropsychiatric disorders: potential repercussions and therapeutic implications

Coenzyme Q10 (CoQ10) is an antioxidant, a membrane stabilizer, and a vital cofactor in the mitochondrial electron transport chain, enabling the generation of adenosine triphosphate. It additionally regulates gene expression and apoptosis; is an essential cofactor of uncoupling proteins; and has anti-inflammatory, redox modulatory, and neuroprotective effects. This paper reviews the known physiological role of CoQ10 in cellular metabolism, cell death, differentiation and gene regulation, and examines the potential repercussions of CoQ10 depletion including its role in illnesses such as Parkinson's disease, depression, myalgic encephalomyelitis/chronic fatigue syndrome, and fibromyalgia. CoQ10 depletion may play a role in the pathophysiology of these disorders by modulating cellular processes including hydrogen peroxide formation, gene regulation, cytoprotection, bioenegetic performance, and regulation of cellular metabolism. CoQ10 treatment improves quality of life in patients with Parkinson's disease and may play a role in delaying the progression of that disorder. Administration of CoQ10 has antidepressive effects. CoQ10 treatment significantly reduces fatigue and improves ergonomic performance during exercise and thus may have potential in alleviating the exercise intolerance and exhaustion displayed by people with myalgic encepholamyletis/chronic fatigue syndrome. Administration of CoQ10 improves hyperalgesia and quality of life in patients with fibromyalgia. The evidence base for the effectiveness of treatment with CoQ10 may be explained via its ability to ameliorate oxidative stress and protect mitochondria.

Protective effects of coenzyme Q10 against angiotensin II-induced oxidative stress in human umbilical vein endothelial cells

Angiotensin II is the major effector in the renin-angiotensin system, and angiotensin II-induced oxidative stress and endothelial dysfunction are profoundly implicated in the pathogenesis of hypertension and cardiovascular disease. In the present study, we investigated the effect of an antioxidant reagent, coenzyme Q10, on angiotensin II-induced oxidative stress in human umbilical vein endothelial cells (HUVEC) to assess its potential usefulness for antioxidant therapy. Treatment of HUVEC with coenzyme Q10 (1-10μM) increased its intracellular levels in a concentration-dependent manner. Coenzyme Q10 (10μM) prevented the actions of angiotensin II (100nM): overproduction of reactive oxygen species, increases in expression of p22(phox) and Nox2 subunits of NADPH oxidase, and inhibition of insulin-induced nitric oxide production. In addition, coenzyme Q10 prevented angiotensin II-induced upregulation of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in HUVEC, and inhibited their adhesion to U937 monocytic cells. Moreover, treatment of HUVEC with coenzyme Q10 effectively ameliorated angiotensin II-induced increases in expression of Nox2 subunit of NADPH oxidase, ICAM-1, and VCAM-1. These results provide the first in vitro evidence that coenzyme Q10 is an efficient antioxidant reagent to improve angiotensin II-induced oxidative stress and endothelial dysfunction, possibly relevant to the causes of cardiovascular disease.

Effect of coenzyme Q10 on proteomic profile of blood plasma and cytosolic and microsomal fractions of rat hepatocytes during ontogeny

The proteomic features of blood plasma and subcellular fractions of rat hepatocytes were studied during long-term dietary consumption of coenzyme Q10 as the endogenous mediator of antioxidant and energy homeostasis in the cell. Long-term coenzyme Q10 consumption was followed by the formation of specific nutriproteomes of the microsomal and cytosolic fractions of rat hepatocytes.

Ubiquinol decreases monocytic expression and DNA methylation of the pro-inflammatory chemokine ligand 2 gene in humans

BACKGROUND

Coenzyme Q₁₀ is an essential cofactor in the respiratory chain and serves in its reduced form, ubiquinol, as a potent antioxidant. Studies in vitro and in vivo provide evidence that ubiquinol reduces inflammatory processes via gene expression. Here we investigate the putative link between expression and DNA methylation of ubiquinol sensitive genes in monocytes obtained from human volunteers supplemented with 150 mg/ day ubiquinol for 14 days.

FINDINGS

Ubiquinol decreases the expression of the pro-inflammatory chemokine (C-X-C motif) ligand 2 gene (CXCL2) more than 10-fold. Bisulfite-/ MALDI-TOF-based analysis of regulatory regions of the CXCL2 gene identified six adjacent CpG islands which showed a 3.4-fold decrease of methylation status after ubiquinol supplementation. This effect seems to be rather gene specific, because ubiquinol reduced the expression of two other pro-inflammatory genes (PMAIP1, MMD) without changing the methylation pattern of the respective gene.

CONCLUSION

In conclusion, ubiquinol decreases monocytic expression and DNA methylation of the pro-inflammatory CXCL2 gene in humans. Current Controlled Trials ISRCTN26780329.

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

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

Influence of liver-X-receptor on tissue cholesterol, coenzyme Q and dolichol content

The organ content of the mevalonate pathway lipids was investigated in liver-X-receptor (LXR) α, β and double knock-out mice. An extensive or moderate increase of total cholesterol in the double KO mice was found in all organs elicited by the increase of the esterified form. In LXRα and double KO mice, coenzyme Q (CoQ) was decreased in liver and increased in spleen, thymus and lung, while dolichol was increased in all organs investigated. This effect was confirmed using LXR- agonist GW 3965. Analysis of CoQ distribution in organelles showed that the modifications are present in all cellular compartments and that the increase of the lipid in mitochondria was the result of a net increase of CoQ without changing the number of mitochondria. It appears that LXR influences not only cellular cholesterol homeostasis but also the metabolism of CoQ and dolichol, in an indirect manner.

The production of coenzyme Q10 in microorganisms

Coenzyme Q10 has emerged as a valuable molecule for pharmaceutical and cosmetic applications. Therefore, research into producing and optimizing coenzyme Q10 via microbial fermentation is ongoing. There are two major paths being explored for maximizing production of this molecule to commercially advantageous levels. The first entails using microbes that naturally produce coenzyme Q10 as fermentation biocatalysts and optimizing the fermentation parameters in order to reach industrial levels of production. However, the natural coenzyme Q10-producing microbes tend to be intractable for industrial fermentation settings. The second path to coenzyme Q10 production being explored is to engineer Escherichia coli with the ability to biosynthesize this molecule in order to take advantage of its more favourable fermentation characteristics and the well-understood array of genetic tools available for this bacteria. Although many studies have attempted to over-produce coenzyme Q10 in E. coli through genetic engineering, production titres still remain below those of the natural coenzyme Q10-producing microorganisms. Current research is providing the knowledge needed to alleviate the bottlenecks involved in producing coenzyme Q10 from an E. coli strain platform and the fermentation parameters that could dramatically increase production titres from natural microbial producers. Synthesizing the lessons learned from both approaches may be the key towards a more cost-effective coenzyme Q10 industry.

Effects of coenzyme Q10 on vascular endothelial function in humans: a meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study was to quantify the effect of coenzyme Q10 on arterial endothelial function in patients with and without established cardiovascular disease.

BACKGROUND

Endothelial dysfunction has been implicated in the pathogenesis of atherosclerosis.

METHODS AND RESULTS

The search included MEDLINE, Cochrane Library, Scopus, and EMBASE to identify studies up to 1 July 2011. Eligible studies were randomized controlled trials on the effects of coenzyme Q10 compared with placebo on endothelial function. Two reviewers extracted data on study characteristics, methods, and outcomes. Five eligible trials enrolled a total of 194 patients. Meta-analysis using random-effects model showed treatment with coenzyme Q10 significantly improvement in endothelial function assessed peripherally by flow-mediated dilatation (SMD 1.70, 95% CI: 1.00-2.4, p<0.0001). However, the endothelial function assessed peripherally by nitrate-mediated arterial dilatation was not significantly improved by using fix-effects model (SMD -0.19, 95% CI: -1.75 to 1.38, p = 0.81).

CONCLUSION

Coenzyme Q10 supplementation is associated with significant improvement in endothelial function. The current study supports a role for CoQ10 supplementation in patients with endothelial dysfunction.

Nutraceuticals and headache: the biological basis

Nutrition must affect the structure and functioning of the brain. Since the brain has very high metabolic activity, what we consume throughout the day is likely to dramatically influence both its structure and moment to moment function. It follows that nutritional approaches to all neurological disorders are being researched and entering medical practice, while nutraceutical use is a mainstay of public habits. This review discusses the biological basis for non-conventional or non-mainstream approaches to the treatment of migraine. This requires at least limited discussion of current migraine pathophysiologic theory. How nutrients and other chemicals and approaches are mechanistically involved within migraine pathways is the focus of this article. The nutraceuticals reviewed in detail are: magnesium, riboflavin, coenzyme Q10, petasites, and feverfew with additional comments on marijuana and oxygen/hyperbaric oxygen. This article reviews the science when known related to the potential genetic susceptibility and sensitivity to these treatments. As we know, the basic science in this field is very preliminary, so whether to combine approaches and presumably mechanisms or use them alone or with or without conventional therapies is far from clear. Nonetheless, as more patients and providers participate in patient-centered approaches to care, knowledge of the science underpinning nutritional, nutraceutical, and complementary approaches to treatment for migraine will certainly benefit this interaction.

Prolonged coenzyme Q10 treatment in Down syndrome patients: effect on DNA oxidation

Oxidative stress is known to play a relevant role in Down syndrome (DS) and its effects are documented from embryonic life. Oxidative DNA damage has been shown to be significantly elevated in Down syndrome patients, and this has been indicated as an early event promoting neurodegeneration and Alzheimer type dementia. The aim of this study was to investigate the efficacy of coenzyme Q(10) (CoQ(10)) in delaying the effect of oxidative damage in these patients. In our previous study we demonstrated a mild protective effect of CoQ(10) on DNA, although the treatment was unable to modify the overall extent of oxidative damage at the patient level. Possible limitations of the previous study were: time of treatment (6 months) or spectrum of DNA lesions detected. In order to overcome these limitations we planned a continuation of the trial aimed at evaluating the effects of CoQ(10) following a prolonged treatment. Our results highlight an age-specific reduction in the percentage of cells showing the highest amount of oxidized bases, indicating a potential role of CoQ(10) in modulating DNA repair mechanisms.

Coenzyme Q plays opposing roles on bacteria/fungi and viruses in Drosophila innate immunity

Coenzyme Q (CoQ or ubiquinone) is a lipid-soluble component of virtually all types of cell membranes and has been shown to play multiple metabolic functions. Several clinical diseases including encephalomyopathy, cerebellar ataxia and isolated myopathy were shown to be associated with CoQ deficiency. However, the role of CoQ in immunity has not been defined. In the present study, we showed that flies defective in CoQ biosynthetic gene coq2 were more susceptible to bacterial and fungal infections, while were more resistant to viruses. We found that Drosophila contained both CoQ9 and CoQ10, and food supplement of CoQ10 could partially rescue the impaired immune functions of coq2 mutants. Surprisingly, wild-type flies fed CoQ10 became more susceptible to viral infection, which suggested that extra caution should be taken when using CoQ10 as a food supplement. We further showed that CoQ was essential for normal induction of anti-microbial peptides and amplification of viruses. Our work determined CoQ content in Drosophila and described its function in immunity for the first time.

Effects of ubiquinol-10 on microRNA-146a expression in vitro and in vivo

MicroRNAs (miRs) are involved in key biological processes via suppression of gene expression at posttranscriptional levels. According to their superior functions, subtle modulation of miR expression by certain compounds or nutrients is desirable under particular conditions. Bacterial lipopolysaccharide (LPS) induces a reactive oxygen species-/NF-kappaB-dependent pathway which increases the expression of the anti-inflammatory miR-146a. We hypothesized that this induction could be modulated by the antioxidant ubiquinol-10. Preincubation of human monocytic THP-1 cells with ubiquinol-10 reduced the LPS-induced expression level of miR-146a to 78.9 +/- 13.22%. In liver samples of mice injected with LPS, supplementation with ubiquinol-10 leads to a reduction of LPS-induced miR-146a expression to 78.12 +/- 21.25%. From these consistent in vitro and in vivo data, we conclude that ubiquinol-10 may fine-tune the inflammatory response via moderate reduction of miR-146a expression.

Ubichromanol: a prodrug to support mitochondrial ubiquinone functions?

Ubichromanol-9 (UCa9), with a side chain consisting of nine isoprene units) is a reductive cyclization product of ubiquinone-10 (UQ10). It acts as a radical scavenging antioxidant and is about half as effective as alpha-tocopherol. Already decades ago its one-electron oxidation product, the ubichromanoxyl radical had been identified. However, nothing was known so far about the two-electron oxidation product of this antioxidant and its bioactivity. This study proves that ubichromanol can be oxidized to a ubiquinone-like compound with a hydroxyl-substituted side chain (UQ10OH), a metabolite that is naturally present in bovine liver mitochondria. The bioactivity of this ubiquinone derivative in its reduced form as substrate for mitochondrial complex III (cytochrome bc1 complex) was slightly below that of native ubiquinol, but significantly higher than that of reduced alpha-tocopheryl quinone. Since ubiquinone-like molecules (UQ10OH, UQ10) were identified as oxidation products of UCa9 during lipid peroxidation, this ubiquinone derivative could provide a possibility to combine antioxidant properties of chromanols and bioenergetic benefits of UQ10.

Antiangiogenic and hypolipidemic activity of coenzyme Q10 supplementation to breast cancer patients undergoing Tamoxifen therapy

Tamoxifen, a non-steroidal anti-estrogen is now widely used and has led to an increase in both disease-free and overall survival of women after primary surgery. Tamoxifen therapy is found to cause hypertriglyceridemia by reducing activity of lipolytic enzymes on triglycerides, and thereby increasing the risk of cardiovascular disease. Angiogenesis promotes local tumour progression and invasion and enables tumour cell dissemination and metastasis formation. Our study has found that co-administration of Coenzyme Q10 (100 mg) along with tamoxifen (10 mg, twice a day) to breast cancer patients reduced the level of angiogenesis markers and lipid levels.

Functions of coenzyme Q10 in inflammation and gene expression

Clinical studies demonstrated the efficacy of Coenzyme Q10 (CoQ10) as an adjuvant therapeutic in cardiovascular diseases, mitochondrial myopathies and neurodegenerative diseases. More recently, expression profiling revealed that Coenzyme Q10 (CoQ10) influences the expression of several hundred genes. To unravel the functional connections of these genes, we performed a text mining approach using the Genomatix BiblioSphere. We identified signalling pathways of G-protein coupled receptors, JAK/STAT, and Integrin which contain a number of CoQ10 sensitive genes. Further analysis suggested that IL5, thrombin, vitronectin, vitronectin receptor, and C-reactive protein are regulated by CoQ10 via the transcription factor NFkappaB1. To test this hypothesis, we studied the effect of CoQ10 on the NFkappaB1-dependent pro-inflammatory cytokine TNF-alpha. As a model, we utilized the murine macrophage cell lines RAW264.7 transfected with human apolipoprotein E3 (apoE3, control) or pro-inflammatory apoE4. In the presence of 2.5 microM or 75 microM CoQ10 the LPS-induced TNF-alpha response was significantly reduced to 73.3 +/- 2.8% and 74.7 +/- 8.9% in apoE3 or apoE4 cells, respectively. Therefore, the in silico analysis as well as the cell culture experiments suggested that CoQ10 exerts anti-inflammatory properties via NFkappaB1-dependent gene expression.

Influence of Coenzyme Q_{10} on release of pro-inflammatory chemokines in the human monocytic cell line THP-1

Coenzyme Q_{10} (CoQ_{10}) is an obligatory element in the mitochondrial electron transport system and functions as a potent antioxidant of lipid membranes. In-vivo and in-vitro studies indicate an involvement of CoQ_{10} in inflammatory pathways. Here we studied in the human monocytic cell-line THP-1 the influence of CoQ_{10} on LPS-induced secretion of the pro-inflammatory chemokines Macrophage inflammatory protein-1 alpha (MIP-1alpha), Regulated upon activation, normal T cell expressed and secreted (RANTES) and Monocyte chemoattractant protein-1 (MCP-1). In comparison to unstimulated cells, LPS leads to 22-, 3- and 4.5-fold higher levels of MIP-1alpha, RANTES and MCP-1 in the cell culture medium, respectively. Pre-incubation of cells with 10 microM CoQ_{10} resulted in a significant decrease of LPS-induced MIP-1alpha and RANTES secretion to 55.04% (p = 0.02) and 76.84% (p = 0.04), respectively. In conclusion, CoQ_{10} reduces the LPS-induced secretion levels of the pro-inflammatory chemokines MIP-1alpha and RANTES in the human monocytic cell line THP-1. These data suggest that CoQ_{10} possesses anti-inflammatory properties.

Effects of Coenzyme Q10 on TNF-alpha secretion in human and murine monocytic cell lines

Studies in humans and cell culture as well as bioinformatics suggested that Coenzyme Q(10) (CoQ10) functions as an anti-inflammatory molecule. Here we studied the influence of CoQ10 (Kaneka Q10) on secretion of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) by using the human and murine monocytic cell lines THP-1 and RAW264.7 expressing human apolipoprotein E3 (apoE3) or pro-inflammatory apoE4. Incubation of cells with physiological (0.1-10 microM) and supra-physiological (> 10 to < 100 microM) concentrations of CoQ10 led to an intracellular accumulation of its reduced form without any cytotoxic effects. Stimulation of cell models with lipopolysaccharide (LPS) resulted in a substantially release of TNF-alpha. When THP-1 cells were pre-incubated with 10 microM CoQ10, the LPS-induced TNF-alpha release was significantly decreased to 72 +/- 32%. This effect is similar to those obtained by 10 microM N-Acetyl-Cysteine, a well known reference antioxidant. In RAW264.7-apoE3 and -apoE4 cells, significant reductions of LPS-induced TNF-alpha secretion to 73.3 +/- 2.8% and 74.7 +/- 8.9% were found with 2.5 microM and 75 microM CoQ10, respectively. In conclusion, CoQ10 has moderate anti-inflammatory effects in two monocytic cell lines which could be mediated by its antioxidant activity.