Ubiquinol

BACKGROUND/OBJECTIVES: Oxidized low-density lipoprotein (oxLDL) has emerged as a promising biomarker of oxidative burden and cardiovascular risk. This study is aimed at evaluating the effect of ubiquinol supplementation, a potent lipophilic antioxidant, on oxLDL levels in prediabetic patients. METHODS: This was a prospective, randomized, double-blinded, placebo-controlled pilot study of 20 adults with impaired fasting plasma glucose (FPG). Participants were randomized to receive either ubiquinol (100 mg/day) or placebo for 12 weeks. Plasma oxLDL levels were measured at baseline and Week 12. RESULTS: After 12 weeks, the ubiquinol group demonstrated a significant within-group reduction in plasma oxLDL compared with baseline (p = 0.049), whereas no significant change was observed in the placebo group (p = 0.237). No adverse events were reported. CONCLUSIONS: Daily ubiquinol (100 mg/day) for 12 weeks was associated with a significant within-group decrease in plasma oxLDL among prediabetic participants; however, the between-group difference versus placebo was not significant. TRIAL REGISTRATION: Thai Clinical Trials Registry: TCTR20250512008.

Coenzyme Q10 (CoQ10) is a naturally occurring biochemical cofactor found in all human cell membranes in two interconvertible forms: oxidized ubiquinone and reduced ubiquinol. Clinical studies indicate that different CoQ10 formulations have different absorption rates, highlighting research comparing their systemic bioavailability. This study compared the oral bioavailability of cocrystal formulation soft gels (test product), a novel ubiquinol formulation, and ubiquinone formulation (reference product) in a randomized, double-blind, two-period crossover study with 12 healthy subjects under fasting conditions. The secondary objective of this study was to evaluate the safety and tolerability of the ubiquinol formulation. The pharmacokinetic analyses indicated that the test ubiquinol formulation demonstrated substantially higher relative systemic bioavailability compared with the ubiquinone reference. The geometric mean ratios (test/reference) for baseline-corrected peak plasma concentration (Cmax) and area under the curve from zero to last quantifiable time (AUC0-t) were 2.20 and 2.01, respectively, with 90% confidence intervals of 1.59-3.04 and 1.51-2.70. The geometric mean ratio for AUC from time zero to infinity (AUC0-∞) was 3.43 (90% CI: 1.47-8.00). No adverse events were reported in this small pilot study for either of the formulations. These findings demonstrate that ubiquinol has a better systemic bioavailability than ubiquinone, supporting the novel formulation's potential as a promising alternative to traditional CoQ10 supplements. © 2026 Credevo Pte. Ltd. Cocrystal Health Industry Co., Ltd and The Author(s). Clinical Pharmacology in Drug Development published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.

INTRODUCTION: About 20-30% of cases of infertility are attributed to male factor and males are also contributing to infertility in a further 20%. Idiopathic male subfertility is the commonest cause in most cases. D-aspartic acid (D-Asp) is an endogenous amino acid occurring in several tissues and cells of both invertebrates and vertebrates. The current study is one of the first to evaluate the in vivo supplementation of D-aspartic acid in idiopathic male infertility. Thus, we aimed in the current study to evaluate the in vivo effect of D-aspartic acid, zinc and co-enzyme Q 10 supplementation on different semen parameters and serum testosterone level in idiopathic male infertility. METHODS: A total of 75 infertile patients were recruited from the outpatient andrology clinic from March 2023 to June 2024. The current study was registered at the UMIN clinical registry trials prior to initiating the study (UMIN000050023). Group (A) included 24 infertile patients who received 2660 mg d-aspartic acid plus 200 mg of ubiquinol plus 10 mg zinc once daily for 3 months. Group (B) included 24 infertile patients who received placebo (starch granules) daily for 3 months. RESULTS: Interestingly, patients in group (A) who received 2660 mg d-aspartic acid plus 200 mg of ubiquinol plus 10 mg zinc once daily for 3 months showed significant improvement in progressive sperm motility after 3 months (10.63 ± 8.64 vs 15.21 ± 12.11, p=0.047). Also, they showed highly significant increase in total testosterone level (5.06 ± 1.74 vs 5.89 ± 1.62, p=0.009). CONCLUSIONS: D-aspartic acid plus ubiquinol plus zinc are promising ingredients that showed good results when administrated once daily to infertile males.

The effect of diminished ovarian reserves after undergoing hysterectomies with bilateral salpingectomies is one of the health concerns among reproductive-age women with benign gynecological diseases. Coenzyme Q10 (CoQ10), an antioxidant, is crucial in mitochondrial energy production, improving oocyte quality and quantity. This study compares the benefit of a 14-d preoperative (CoQ10) v. placebo on ovarian reserve by measuring anti-Müllerian hormone (AMH) in women undergoing hysterectomy with bilateral salpingectomy. A double-blinded, randomised, placebo-controlled trial was conducted. Forty-four women with benign gynecological diseases were randomised to receive either oral CoQ10 300 mg per d or placebo for 14 d before undergoing hysterectomy with bilateral salpingectomy. Serum AMH levels were collected for analysis before taking CoQ10 and 6 weeks postoperatively in each group. The baseline demographic, clinical characteristics and baseline AMH levels were comparable between the groups (1·47 (0·45, 2·49) v. 1·29 (0·47, 2·11), P = 0·763). The serum AMH levels after the surgery were significantly decreased from preoperative levels (median 0·99 (0·37, 1·63) v. 1·34 (0·57, 2·30)), P = 0·001. However, there was no significant difference in the AMH change between the CoQ10 group and the placebo group (AMH per cent change -28·2 % (64·09, -4·81) v. -20·07 % (-61·51, -2·92)), P = 0·99, respectively. Age, gynecological disease, operative time and blood loss were not significantly associated with the AMH change. There were no significant side effects or adverse operative outcomes among CoQ10 users. In conclusion, hysterectomy with bilateral salpingectomy led to a significantly decreased AMH level. However, pretreatment with CoQ10 for 2 weeks was ineffective in protecting an ovarian reserve.

BACKGROUND: High-altitude exposure changes the electrical conduction of the heart. However, reports on electrocardiogram (ECG) characteristics and potent prophylactic agents during high-altitude acclimatization and de-acclimatization are inadequate. This study aimed to investigate the effects of ubiquinol on electrophysiology after high-altitude hypoxia and reoxygenation. METHODS: The study was a prospective, randomized, double-blind, placebo-controlled trial. Forty-one participants were randomly divided into two groups receiving ubiquinol 200 mg daily or placebo orally 14 days before flying to high altitude (3900 m) until the end of the study. Cardiopulmonary exercise testing was performed at baseline (300 m), on the third day after reaching high altitude, and on the seventh day after returning to baseline. RESULTS: Acute high-altitude exposure prolonged resting ventricular repolarization, represented by increased corrected QT interval (455.9 ± 23.4 vs. 427.1 ± 19.1 ms, P < 0.001) and corrected Tpeak-Tend interval (155.5 ± 27.4 vs. 125.3 ± 21.1 ms, P < 0.001), which recovered after returning to low altitude. Ubiquinol supplementation shortened the hypoxia-induced extended Tpeak-Tend interval (-7.7 ms, [95% confidence interval (CI), -13.8 to -1.6], P = 0.014), Tpeak-Tend /QT interval (-0.014 [95% CI, -0.027 to -0.002], P = 0.028), and reserved maximal heart rate (11.9 bpm [95% CI, 3.2 to 20.6], P = 0.013) during exercise at high altitude. Furthermore, the decreased resting amplitude of the ST-segment in the V3 lead was correlated with decreased peak oxygen pulse (R = 0.713, P < 0.001) and maximum oxygen consumption (R = 0.595, P < 0.001). CONCLUSIONS: Our results illustrated the electrophysiology changes during high-altitude acclimatization and de-acclimatization. Similarly, ubiquinol supplementation shortened the prolonged Tpeak-Tend interval and reserved maximal heart rate during exercise at high altitude. REGISTRATION: URL: www.chictr.org.cn; Unique identifier: ChiCTR2200059900.

Mitochondria-derived oxidative stress has been implicated in vascular and skeletal muscle abnormalities in chronic kidney disease (CKD). The purpose of this study was to investigate the effects of a mitochondria-targeted ubiquinol (MitoQ) on vascular function and exercise capacity in CKD. In this randomized controlled trial, 18 patients with CKD (means ± SE, age: 62 ± 3 yr and estimated glomerular filtration rate: 45 ± 3 mL/min/1.73 m2) received 4 wk of 20 mg/day MitoQ (MTQ group) or placebo (PLB). Outcomes assessed at baseline and follow-up included macrovascular function measured by flow-mediated dilation, microvascular function assessed by laser-Doppler flowmetry combined with intradermal microdialysis, aortic hemodynamics assessed by oscillometry, and exercise capacity assessed by cardiopulmonary exercise testing. Compared with PLB, MitoQ improved flow-mediated dilation (baseline vs. follow-up: MTQ, 2.4 ± 0.3% vs. 4.0 ± 0.9%, and PLB, 4.2 ± 1.0% vs. 2.5 ± 1.0%, P = 0.04). MitoQ improved microvascular function (change in cutaneous vascular conductance: MTQ 4.50 ± 2.57% vs. PLB -2.22 ± 2.67%, P = 0.053). Central aortic systolic and pulse pressures were unchanged; however, MitoQ prevented increases in augmentation pressures that were observed in the PLB group (P = 0.026). MitoQ did not affect exercise capacity. In conclusion, this study demonstrates the potential for a MitoQ to improve vascular function in CKD. The findings hold promise for future investigations of mitochondria-targeted therapies in CKD.NEW & NOTEWORTHY In this randomized controlled pilot study, we investigated the effects of a mitochondria-targeted ubiquinol (MitoQ) on vascular function and exercise capacity in chronic kidney disease. Our novel findings showed that 4-wk supplementation of MitoQ was well tolerated and improved macrovascular endothelial function, arterial hemodynamics, and microvascular function in patients with stage 3-4 chronic kidney disease. Our mechanistic findings also suggest that MitoQ improved microvascular function in part by reducing the NADPH oxidase contribution to vascular dysfunction.

BACKGROUND: Oral lichen planus (OLP) is a chronic mucocutaneous immunologically mediated condition that has a great adverse effect on oral functions. Corticosteroids are still the first drugs of choice used in the treatment of OLP; however, they have extensive medical side effects. The present study was carried out to assess the clinical therapeutic effect of the topical use of coenzyme Q10 (coQ10 or ubiquinol) versus topical corticosteroids in the management of symptomatic OLP and to determine whether the effect, if any, was due to the powerful antioxidant activity of coQ10. SUBJECTS AND METHODS: We performed a randomized, double blinded controlled trial at the Faculty of Dentistry, Cairo University, Egypt. The study was conducted on 34 patients suffering from symptomatic OLP. Patients were randomly divided into two groups: intervention group (I),who received topical CoQ10 in the form of mucoadhesive tablets (40% CoQ10) 3 times daily for one month and control group (II),who received topical corticosteroid (kenacort in Orabase: triamcinolone acetonide 0.1% 5-g adhesive paste - dermapharm), 4 times daily for one month. Patients were evaluated at one-week intervals using the clinical parameters (score) of pain (VAS) and lesion size. Additionally, salivary levels of malondialdehyde (MDA) were detected in both groups before and after treatment using ELISA. All recorded data were analysed using independent t test, ANOVA followed by Bonferroni post hoc test for lesion size and salivary level of MDA data and Mann-Whitney U test and Friedman test for VAS data. RESULTS: Both groups showed a significant reduction in pain and the size of the lesions (p ≤ 0.05) with no statistically significant difference between them (p > 0.05), and this clinical improvement was associated with a reduction in the salivary levels of MDA in both groups. CONCLUSIONS: The topical use of CoQ10 mucoadhesive tablets was as effective as the topical use of triamcinolone acetonide, and its clinical effect was associated with a reduction in the salivary level of MDA. TRIAL REGISTRATION: The study protocol was registered at www. CLINICALTRIAL: gov (NCT04091698) and registration date: 17/9/2019. © 202

Patients with heart failure with preserved ejection fraction (HFpEF) have few pharmacologic therapies, and it is not known if supplementing with ubiquinol and/or d-ribose could improve outcomes. The overall objective of this study was to determine if ubiquinol and/or d-ribose would reduce the symptoms and improve cardiac performance in patients with HFpEF. This was a phase 2 randomized, double-blind, placebo-controlled trial of 216 patients with HFpEF who were ≥ 50 years old with a left ventricular ejection fraction (EF) ≥ 50%. A total of 4 study groups received various supplements over 12 weeks: Group 1 received placebo ubiquinol capsules and d-ribose powder, Group 2 received ubiquinol capsules (600 mg/d) and placebo d-ribose powder, Group 3 received placebo ubiquinol capsules with d-ribose powder (15 g/d), and Group 4 received ubiquinol capsules and d-ribose powder. There were 7 outcome measures for this study: Kansas City Cardiomyopathy Questionnaire (KCCQ) clinical summary score, level of vigor using a subscale from the Profile of Mood States, EF, the ratio of mitral peak velocity of early filling to early diastolic mitral annular velocity (septal E/e' ratio), B-type natriuretic peptides, lactate/adenosine triphosphate ratio, and the 6-minute walk test. Treatment with ubiquinol and/or d-ribose significantly improved the KCCQ clinical summary score (17.30 to 25.82 points), vigor score (7.65 to 8.15 points), and EF (7.08% to 8.03%) and reduced B-type natriuretic peptides (-72.02 to -47.51) and lactate/adenosine triphosphate ratio (-4.32 to -3.35 × 10-4). There were no significant increases in the septal E/e' or the 6-minute walk test. In conclusion, ubiquinol and d-ribose reduced the symptoms of HFpEF and increased the EF. These findings support the use of these supplements in addition to standard therapeutic treatments for patients with HFpEF.

BACKGROUND: Metformin, which is known to produce profound changes in gut microbiota, is being increasingly used in gestational diabetes mellitus (GDM). The aim of this study was to elucidate the differences in gut microbiota composition and function in women with GDM treated with metformin compared to those treated with insulin. METHODS: From May to December 2018, 58 women with GDM were randomized to receive insulin (INS; n = 28) or metformin (MET; n = 30) at the University Hospital Virgen de la Victoria, Málaga, Spain. Basal visits, with at least 1 follow-up visit and prepartum visit, were performed. At the basal and prepartum visits, blood and stool samples were collected. The gut microbiota profile was determined through 16S rRNA analysis. RESULTS: Compared to INS, women on MET presented a lower mean postprandial glycemia and a lower increase in weight and body mass index (BMI). Firmicutes and Peptostreptococcaceae abundance declined, while Proteobacteria and Enterobacteriaceae abundance increased in the MET group. We found inverse correlations between changes in the abundance of Proteobacteria and mean postprandial glycemia (p = 0.023), as well as between Enterobacteriaceae and a rise in BMI and weight gain (p = 0.031 and p = 0.036, respectively). Regarding the metabolic profile of gut microbiota, predicted metabolic pathways related to propionate degradation and ubiquinol biosynthesis predominated in the MET group. CONCLUSION: Metformin in GDM affects the composition and metabolic profile of gut microbiota. These changes could mediate, at least in part, its clinical effects. Studies designed to assess how these changes influence metabolic control during and after pregnancy are necessary.

BACKGROUND: Attention Deficit Hyperactivity Disorder is a common child neurobehavioral disorder whose pathogenesis is not completely understood. However, some evidence indicates a crucial link between this disorder and the degree of oxidative stress. Coenzyme Q10 (ubiquinol) is an antioxidant that may play a significant role in the treatment of Attention Deficit Hyperactivity Disorder. OBJECTIVE: To assess the safety and efficacy of coenzyme Q10 as an add-on drug treatment for attention deficit hyperactivity disorder. METHODS: Sixty children, aged 6-16 years, with attention deficit hyperactivity disorder, non-responders to atomoxetine treatment for 6 months, were included in this double-blind, randomized, and controlled study. Group 1 received atomoxetine plus coenzyme Q10, and group 2 received atomoxetine plus placebo for 6 months. Follow-up by CONNERS parent rating scale questionnaire (CPRS-48) was performed before and after 1, 3, and 6 months of treatment, and any drug-related side effects were reported. RESULTS: The addition of coenzyme Q10 to atomoxetine in group 1 improved symptoms in a shorter time with minimal adverse effects. Group 1 showed improvement of about 33.87% in CPRS-48 total score versus 18.24% in group 2. There was a statistically significant decrease in CPRS-48 total score and its three subscales (learning problems, impulsive hyperactive subscale, and 10-items hyperactivity index) in group 1 versus group 2 after six months of treatment (p-value <0.001). CONCLUSION: Coenzyme Q10 has an important role as an add-on drug treatment for attention deficit hyperactivity disorder by improving symptoms, particularly hyperactivity, and in minimizing atomoxetine adverse effects.

Ubiquinone (UQ) is essential for the electron transport chain in Plasmodium falciparum, the causative agent of severe malaria. Its biosynthesis begins with the condensation of 4-hydroxybenzoate (4-HB) and an isoprenoid chain, catalyzed by 4-HB polyprenyltransferase (4-HPT; COQ2 gene). Atovaquone (AV) inhibits the mitochondrial bc1 complex by competing with ubiquinol (UQH2), but resistance to the synergic combination AV/proguanil therapy has emerged. Here, we show that 4-nitrobenzoate (4-NB) inhibits Pf4-HPT, enhances AV efficacy and selectivity, while preserving proguanil synergy. In Saccharomyces cerevisiae expressing PfCOQ2, 4-NB inhibited UQ biosynthesis. In vivo, 4-NB improved AV efficacy in Plasmodium berghei-infected mice. Structure-activity studies with 4-HB analogs further defined chemical features for potentiation. These findings support PfCOQ2 as a target to boost AV-based antimalarial therapy. Impact statement This study identifies a molecular rationale for enhancing atovaquone efficacy through targeted inhibition of ubiquinone biosynthesis. By validating PfCOQ2 as a druggable target and demonstrating in vivo potentiation, our findings offer strategic advance toward rational antimalarial combination therapies, moving beyond empirical approaches and addressing current resistance. © 2025 The Author(s). FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

Plasmodium falciparum is an apicomplexan parasite that causes the most severe malaria in humans. Due to a lack of effective vaccines and emerging of drug resistance parasites, development of drugs with novel mechanisms of action and few side effects are imperative. To this end, ideal drug targets are those essential to parasite viability as well as absent in their mammalian hosts. The mitochondrial electron transport chain (ETC) of P. falciparum is one source of such potential targets because enzymes, such as L-malate:quinone oxidoreductase (PfMQO), in this pathway are absent humans. PfMQO catalyzes the oxidation of L-malate to oxaloacetate and the simultaneous reduction of ubiquinone to ubiquinol. It is a membrane protein, involved in three pathways (ETC, the tricarboxylic acid cycle and the fumarate cycle) and has been shown to be essential for parasite survival, at least, in the intra-erythrocytic asexual stage. These findings indicate that PfMQO would be a valuable drug target for development of antimalarial with novel mechanism of action. Up to this point in time, difficulty in producing active recombinant mitochondrial MQO has hampered biochemical characterization and targeted drug discovery with MQO. Here we report for the first time recombinant PfMQO overexpressed in bacterial membrane and the first biochemical study. Furthermore, about 113 compounds, consisting of ubiquinone binding site inhibitors and antiparasitic agents, were screened resulting in the discovery of ferulenol as a potent PfMQO inhibitor. Finally, ferulenol was shown to inhibit parasite growth and showed strong synergism in combination with atovaquone, a well-described anti-malarial and bc1 complex inhibitor.

Measurements of aroxyl radical (ArO(•))-scavenging rate constants (ks(AOH)) of antioxidants (AOHs) (α-tocopherol (α-TocH), ubiquinol-10 (UQ10H2), and sodium ascorbate (Na(+)AsH(-))) were performed in 2-propanol/water (2-PrOH/H2O, 5/1, v/v) solution using stopped-flow spectrophotometry. ks(AOH) values were measured not only for each AOH but also for the mixtures of two AOHs ((i) α-TocH and UQ10H2 and (ii) α-TocH and Na(+)AsH(-)). A notable synergistic effect that the ks(AOH) values increase 1.6, 2.5, and 6.8 times for α-TocH, UQ10H2, and Na(+)AsH(-), respectively, was observed for the solutions including two kinds of AOHs. Furthermore, measurements of the regeneration rates of α-tocopheroxyl radical (α-Toc(•)) to α-TocH by UQ10H2 and Na(+)AsH(-) were performed in 2-PrOH/H2O using double-mixing stopped-flow spectrophotometry. Second-order rate constants (kr) obtained for UQ10H2 and Na(+)AsH(-) were 2.01 × 10(5) and 1.19 × 10(6) M(-1) s(-1), respectively. In fact, UV-vis absorption of α-Toc(•) (λmax = 428 nm), which had been produced by reaction of α-TocH with ArO(•), disappeared under the existence of UQ10H2 or Na(+)AsH(-) due to the above fast regeneration reaction. The result indicates that the prooxidant effect of α-Toc(•) is suppressed by the coexistence of UQ10H2 or Na(+)AsH(-). As α-TocH, UQ10H2, and ascorbate monoanion (AsH(-)) coexist in relatively high concentrations in plasma, blood, and various tissues, the above synergistic effect, that is, the increase of the free-radical-scavenging rate and suppression of the prooxidant reaction, may function in biological systems. [Effects of combined addition of atovaquone and lithium on the in vitro cell growth of the pathogenic yeast Candida albicans]. [Article in Japanese] Minagawa N(1), Uehara M, Seki S, Nitta A, Kogawara K. Author information: (1)Department of Biochemistry, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan. [email protected] Atovaquone, an analog of ubiquinone, binds tightly to the ubiquinol oxidation site (Qo site) of parasite cytochrome bc(1) complex to inhibit electron transport at concentrations far lower than those at which the mammalian system is affected.

14. Yakugaku Zasshi. 2010 Feb;130(2):247-51. doi: 10.1248/yakushi.130.247. [Effects of combined addition of atovaquone and lithium on the in vitro cell growth of the pathogenic yeast Candida albicans]. [Article in Japanese] Minagawa N(1), Uehara M, Seki S, Nitta A, Kogawara K. Author informatio

Coenzyme Q10 (CoQ10) is a promising agent for neuroprotection in neurodegenerative diseases. We tested the effects of various doses of two formulations of CoQ10 in food and found that administration in the diet resulted in significant protection against loss of dopamine (DA), which was accompanied by a marked increase in plasma concentrations of CoQ10. We further investigated the neuroprotective effects of CoQ10, reduced CoQ10 (ubiquinol), and CoQ10 emulsions in the (MPTP) model of Parkinson's disease (PD). We found neuroprotection against MPTP induced loss of DA using both CoQ10, and reduced CoQ10, which produced the largest increases in plasma concentrations. Lastly, we administered CoQ10 in the diet to test its effects in a chronic MPTP model induced by administration of MPTP by Alzet pump for 1 month. We found neuroprotective effects against DA depletion, loss of tyrosine hydroxylase neurons and induction of alpha-synuclein inclusions in the substantia nigra pars compacta. The finding that CoQ10 is effective in a chronic dosing model of MPTP toxicity, is of particular interest, as this may be more relevant to PD. These results provide further evidence that administration of CoQ10 is a promising therapeutic strategy for the treatment of PD.

We examined antioxidant activity of cabergoline, a dopamine agonist, during the aerobic oxidation of phosphatidylcholine liposomes at 37 degrees C. Cabergoline retarded the oxidation initiated with a lipid-soluble initiator significantly better than that with a water-soluble initiator, suggesting that cabergoline locates in the lipid layer of liposomal membranes. Cabergoline inhibited the oxidation of liposomal membranes synergistically with endogenous antioxidants such as ascorbic acid, ubiquinol-10 and vitamin E, and vitamin E was the most efficient synergist. These results suggest that cabergoline may have a neuroprotective effect on the substantia nigra of Parkinsonian patients because of its synergistic antioxidant activity with vitamin E as well as its action on dopamine receptor. Copyright 2004 W.S. Maney and Son Ltd

It has been claimed that coenzyme Q10 (Q10) would be an effective plasma antioxidant since it can regenerate plasma vitamin E. To test separate effects and interaction between Q10 and vitamin E in the change of plasma concentrations and in the antioxidative efficiency, we carried out a double-masked, double-blind clinical trial in 40 subjects with mild hypercholesterolemia undergoing statin treatment. Subjects were randomly allocated to parallel groups to receive either Q10 (200 mg daily), d-alpha-tocopherol (700 mg daily), both antioxidants or placebo for 3 months. In addition we investigated the pharmacokinetics of Q10 in a separate one-week substudy. In the group that received both antioxidants, the increase in plasma Q10 concentration was attenuated. Only vitamin E supplementation increased significantly the oxidation resistance of isolated LDL. Simultaneous Q10 supplementation did not increase this antioxidative effect of vitamin E. Q10 supplementation increased and vitamin E decreased significantly the proportion of ubiquinol of total Q10, an indication of plasma redox status in vivo. The supplementations used did not affect the redox status of plasma ascorbic acid. In conclusion, only vitamin E has antioxidative efficiency at high radical flux ex vivo. Attenuation of the proportion of plasma ubiquinol of total Q10 in the vitamin E group may represent in vivo evidence of the Q10-based regeneration of the tocopheryl radicals. In addition, Q10 might attenuate plasma lipid peroxidation in vivo, since there was an increased proportion of plasma ubiquinol of total Q10.

The effects of vitamin E on lipid peroxidation, intracellular free Ca2+ concentration ([Ca2+]i), and cell death were investigated in the postischemic immature cerebellum. Deprivation of oxygen and glucose for 10-min in a suspension of freshly dissociated granule cells from the cerebellum of 9-day-old male rat pups resulted in a recovery-induced consumption of cell nonenzymatic antioxidants (ascorbic acid, glutathione, and alpha-tocopherol) and development of membrane lipid peroxidation as measured by the thiobarbituric acid method. The rate of lipid peroxidation of the postischemic cells was stimulated, not reduced, by treatment of the cells with vitamin E (5-30 microM alpha-tocopherol phosphate). In flow-cytometric studies a 10-min period of ischemia resulted in a small increase in intracellular calcium concentration, lipid peroxidation products and cell death, but in the presence of alpha-tocopherol the same treatment caused a dramatic increase in cell death, accompanied by a large increase in [Ca2+]i and lipid peroxidation products. Pretreatment of the cells with a mixture of three antioxidants (vitamin C/rutin/ubiquinol-10, 10/5/1) or nickel (Ni2+) reduced the alpha-tocopherol-induced increases in [Ca2+]i, and cell death. Hydrogen peroxide (1 mM) and the water-soluble analogue of vitamin E, trolox (50 microM), mimicked the effect of vitamin E on lipid peroxidation in the postischemic cells. Pretreatment of the cells with the intracellular Ca2+ chelator BAPTA-AM, reduced both the alpha-tocopherol-induced increase in [Ca2+]i and cell death. The effect of vitamin E on [Ca2+]i was age dependent and decreased abruptly during maturation of the cerebellum between the first and second weeks of life. Results of in vitro treatment of the immature cerebellar cells with the water-soluble form of vitamin E (alpha-tocopherol phosphate) suggest that, after consumption of cellular co-antioxidants, vitamin E may be converted to an alpha-tocopheroxyl radical, which act as a toxic prooxidant as cellular bioenergetics deteriorate.

The mechanisms and dynamics of antioxidant action of ubiquinol have been studied. Ubiquinol scavenges peroxyl radical faster than alpha-tocopherol. However, it is autooxidized rapidly to give hydroperoxyl radical and/or superoxide and hence its antioxidant potency is smaller than that of alpha-tocopherol. The side chain of ubiquinol reduces the mobility between the membranes. It was concluded that ubiquinol acts as a potent antioxidant in combination with alpha-tocopherol.

Activated neutrophils produce both hydrogen peroxide (H2O2) and hypochlorous acid (HOCl). Previous work has shown that HOCl depletes antioxidants, modifies proteins, and forms fatty acid chlorohydrins but does not cause significant lipid peroxidation in human plasma. Because activated phagocytes have been claimed to stimulate lipid peroxidation in plasma, we examined the effects of H2O2 and HOCl alone and in combination on plasma constituents. Hydrogen peroxide at concentrations below 0.5 mmol/L had little effect, but 1 to 2 mmol/L H2O2 caused loss of ascorbic acid and protein thiol groups, an effect potentiated by preincubation of the plasma with sodium azide to inhibit catalase. H2O2 caused no detectable lipid peroxidation or loss of alpha-tocopherol in plasma, but some depletion of ubiquinol occurred. The combination of HOCl and H2O2 caused more lipid peroxidation than either agent alone. Peroxidation was not inhibited by the metal chelators ethylenediaminetetraacetic acid and deferoxamine or by the singlet O2/hydroxyl radical scavenger histidine. We hypothesize that the phagocyte-derived H2O2 and HOCl could interact in the microenvironment of the activated leukocyte to induce lipid peroxidation of plasma lipoproteins or cell membranes (or both).

Alterations in mitochondrial respiration contribute to the development and progression of cancer via abnormal biogenesis, including generation of reactive oxygen species. Ubiquinol-cytochrome c reductase hinge protein (UQCRH) consists of the cytochrome bc1 complex serving respiration in mitochondria. In the present study, we analyzed UQCRH abnormalities in hepatocellular carcinoma (HCC) and its association with clinical outcomes of patients. UQCRH expression in HCC was determined via semiquantitative and quantitative real-time reverse transcriptase polymerase chain reaction of 96 surgically resected HCC tissues positive for hepatitis B virus surface antigen. UQCRH was frequently overexpressed in HCC tissues (46.8%, based on 2.1-fold cutoff). UQCRH overexpression was observed in HCCs with larger tumor size, poorer differentiation, or vascular invasion. Kaplan-Meier analysis revealed significantly shorter overall (P = 0.005) and recurrence-free survival (P = 0.027) in patients with tumors overexpressing UQCRH. The prognostic impact of UQCRH was significant in subgroups of patients divided according to the α-fetoprotein (AFP) level. The patient subgroup with higher AFP levels (≥20 ng/mL) exhibited significant differences in 5-year overall (18.5% vs. 67.9%) and recurrence-free survival rates (11.1% vs. 46.4%) between groups with and without UQCRH overexpression. In contrast, no marked survival differences were observed between subgroups with lower AFP levels (<20 ng/mL). Multivariate analysis defined UQCRH as an independent poor prognostic factor. Conclusively, our results indicate that UQCRH overexpression is correlated with poor outcomes of HCC patients. Furthermore, in patients grouped as high risk based on elevated AFP, lack of UQCRH overexpression could be a useful indicator for clinical treatment. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Aim: We aim to analyze past literature to evaluate the efficacy of coenzyme Q10 (CoQ-10) in the population with heart failure (HF). Methods: A systematic literature search was conducted through MEDLINE (via PubMed) and Cochrane Library. The outcomes analyzed were a reduction in HF-related mortality, an improvement in exercise capacity, and the left ventricular ejection fraction (LVEF). Results: Among 16 studies, CoQ-10 significantly reduced HF-related mortality by 40% and improved exercise capacity in patients with HF, but demonstrated no significant difference in LVEF however, the potential of its efficacy on LVEF could not be ruled out. Conclusion: CoQ-10 significantly enhances exercise capacity and reduces HF-related mortality; however, its impact on patients with reduced LVEF requires further investigation. Plain Language Summary: [Box: see text].

Autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting 1 in 36 children and is associated with physiological abnormalities, most notably mitochondrial dysfunction, at least in a subset of individuals. This systematic review and meta-analysis discovered 204 relevant articles which evaluated biomarkers of mitochondrial dysfunction in ASD individuals. Significant elevations (all p < 0.01) in the prevalence of lactate (17%), pyruvate (41%), alanine (15%) and creatine kinase (9%) were found in ASD. Individuals with ASD had significant differences (all p < 0.01) with moderate to large effect sizes (Cohen's d' ≥ 0.6) compared to controls in mean pyruvate, lactate-to-pyruvate ratio, ATP, and creatine kinase. Some studies found abnormal TCA cycle metabolites associated with ASD. Thirteen controlled studies reported mitochondrial DNA (mtDNA) deletions or variations in the ASD group in blood, peripheral blood mononuclear cells, lymphocytes, leucocytes, granulocytes, and brain. Meta-analyses discovered significant differences (p < 0.01) in copy number of mtDNA overall and in ND1, ND4 and CytB genes. Four studies linked specific mtDNA haplogroups to ASD. A series of studies found a subgroup of ASD with elevated mitochondrial respiration which was associated with increased sensitivity of the mitochondria to physiological stressors and neurodevelopmental regression. Lactate, pyruvate, lactate-to-pyruvate ratio, carnitine, and acyl-carnitines were associated with clinical features such as delays in language, social interaction, cognition, motor skills, and with repetitive behaviors and gastrointestinal symptoms, although not all studies found an association. Lactate, carnitine, acyl-carnitines, ATP, CoQ10, as well as mtDNA variants, heteroplasmy, haplogroups and copy number were associated with ASD severity. Variability was found across biomarker studies primarily due to differences in collection and processing techniques as well as the intrinsic heterogeneity of the ASD population. Several studies reported alterations in mitochondrial metabolism in mothers of children with ASD and in neonates who develop ASD. Treatments targeting mitochondria, particularly c

Evidence exists to suggest that ROS induce muscular injury with a subsequent decrease in physical performance. Supplementation with certain antioxidants is important for physically active individuals to hasten recovery from fatigue and to prevent exercise damage. The use of nutritional supplements associated with exercise, with the aim of improving health, optimizing training or improving sports performance, is a scientific concern that not only drives many research projects but also generates great expectations in the field of their application in pathology. Since its discovery in the 1970s, coenzyme Q10 (CoQ10) has been one of the most controversial molecules. The interest in determining its true value as a bioenergetic supplement in muscle contraction, antioxidant or in the inflammatory process as a muscle protector in relation to exercise has been studied at different population levels of age, level of physical fitness or sporting aptitude, using different methodologies of effort and with the contribution of data corresponding to very diverse variables. Overall, in the papers reviewed, although the data are inconclusive, they suggest that CoQ10 supplementation may be an interesting molecule in health or disease in individuals without a pathological deficiency and when used for optimising exercise performance. Considering the results observed in the literature, and as a conclusion of this systematic review, we could say that it is an interesting molecule in sports performance. However, clear approaches should be considered when conducting future research.

BACKGROUND: Monoallelic variants in the KIF1A gene are associated with a large set of clinical phenotypes including neurodevelopmental and neurodegenerative disorders, underpinned by a broad spectrum of central and peripheral nervous system involvement. METHODS: In a multicenter study conducted in patients presenting spastic gait or complex neurodevelopmental disorders, we analyzed the clinical, genetic and neuroradiological features of 28 index cases harboring heterozygous variants in KIF1A. We conducted a literature systematic review with the aim to comparing our findings with previously reported KIF1A-related phenotypes. RESULTS: Among 28 patients, we identified nine novel monoallelic variants, and one a copy number variation encompassing KIF1A. Mutations arose de novo in most patients and were prevalently located in the motor domain. Most patients presented features of a continuum ataxia-spasticity spectrum with only five cases showing a prevalently pure spastic phenotype and six presenting congenital ataxias. Seventeen mutations occurred in the motor domain of the Kinesin-1A protein, but location of mutation did not correlate with neurological and imaging presentations. When tested in 15 patients, muscle biopsy showed oxidative metabolism alterations (6 cases), impaired respiratory chain complexes II + III activity (3/6) and low CoQ10 levels (6/9). Ubiquinol supplementation (1gr/die) was used in 6 patients with subjective benefit. CONCLUSIONS: This study broadened our clinical, genetic, and neuroimaging knowledge of KIF1A-related disorders. Although highly heterogeneous, it seems that manifestations of ataxia-spasticity spectrum disorders seem to occur in most patients. Some patients also present secondary impairment of oxidative metabolism; in this subset, ubiquinol supplementation therapy might be appropriate. © 2021. Springer-Verlag GmbH Germany, part of Springer Nature.

Coenzyme Q10 (CoQ10) is a lipid-soluble antioxidant that could have beneficial effects in patients undergoing cardiac surgery with cardiopulmonary bypass. There is no clear evidence about its clinical effects or a systematic review published yet. We aimed to conduct a systematic review and meta-analysis of the literature to elucidate the role of coenzyme Q10 in preventing complications in patients undergoing cardiac surgery with cardiopulmonary bypass. We searched the PubMed Database using the following keywords: Coenzyme Q10, ubiquinone, ubiquinol, CoQ10, Heart Surgery, Cardiac surgery. Articles were systematically retrieved, selected, assessed and summarized for this review. We performed separate meta-analyses for different outcomes (inotropic drug requirements after surgery, incidence of ventricular arrhythmias and atrial fibrillation, cardiac index 24 h after surgery and hospital stay), estimating pooled odds ratios (ORs) or mean differences of the association of CoQ10 administration with the risk of these outcomes. Eight clinical trials met our inclusion criteria. Patients with CoQ10 treatment were significantly less likely to require inotropic drugs after surgery {OR [95% confidence interval (CI) 0.47 (0.27-0.81)]}, and to develop ventricular arrhythmias after surgery [OR (95% CI) 0.05 (0.01-0.31)]. However, CoQ10 treatment was not associated with Cardiac index 24 h after surgery [mean difference (95% CI) 0.06 (-0.30 to 0.43)], hospital stay (days) [mean difference (95% CI) -0.61 (-4.61 to 3.39)] and incidence of atrial fibrillation [OR (95% CI) 1.06 (0.19-6.04)]. Since none of the clinical trials included in this review report any adverse effects associated to CoQ10 administration, and coenzyme Q10 has been demonstrated to be safe even at much higher doses in other studies, we conclude that CoQ10 should be considered as a prophylactic treatment for preventing complications in patients undergoing cardiac surgery with cardiopulmonary bypass. However, better quality randomized, controlled trials are needed to clarify the role of CoQ10 in patients undergoing cardiac surgery with cardiopulmonary bypass. © The Author 2014. Published by Oxford University Press