Stability of ubiquinol-10 (reduced form of coenzyme Q10 ) in human blood.

The ratio of ubiquinol-10 in total coenzyme Q10 (TQ10 ) in human plasma has been proposed as a useful biomarker of oxidative stress. Since ubiquinol-10 is easily oxidized in air, it is necessary to perform suitable processing at medical institutions prior to analysis. To establish stable storage conditions for blood to determine the ubiquinol-10/TQ10 ratios properly, the effects of temperature conditions on the stability of ubiquinol-10 were studied. Blood samples were collected from nine male Japanese volunteers. Changes in ubiquinol-10/TQ10 ratios in blood samples were evaluated under three temperature conditions (room temperature, refrigerated and ice-cooled). Plasma levels of ubiquinol-10 and ubiquinone-10 were determined by an HPLC system with electrochemical detection and the ubiquinol-10/TQ10 ratios were calculated. We found that the ubiquinol-10/TQ10 ratio was stable up to 8 or 4 h when blood samples were stored in refrigerator or ice-cold container, respectively, and its decreases during these periods were <1.0%. We conclude that, in order to evaluate ubiquinol-10/TQ10 ratios, blood samples should be stored in a refrigerator or an ice-cold container, and processed for plasma separation within 4 h.

Oral repeated-dose toxicity studies of coenzyme Q10 in beagle dogs.

To support phase III testing of coenzyme Q10 (CoQ10) in humans, we conducted pharmacokinetic and toxicology studies in beagle dogs. Following single gavage administration of CoQ10 at 600, 1200, 1800, or 2400 mg/kg per d no obvious dose response was observed in maximum concentration (C(max)) or area under the curve (AUC) versus time curve at the 3 highest dosages. In a repeated-dose study of CoQ10 at 600, 1200, 1800, or 2400 mg/kg per d for 4 weeks, CoQ10 reached steady state in plasma by 2 weeks at all dosages. Both C (max) and AUC increased with increasing dosage of CoQ10. The highest plasma levels were recorded at 1800 mg/kg per d. In a 39-week chronic toxicity study of CoQ10 at 1200 and 1800 mg/kg per d or placebo, CoQ10 reached steady state in plasma by 13 weeks. Behaviors, blood chemistries, and detailed histopathology were normal. No deaths occurred. These results support the use of a 2400 mg/d dosage of CoQ10 in human clinical trials.

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.

Safety assessment of coenzyme Q10 (CoQ10).

Coenzyme Q10 (CoQ10) is a naturally occurring component present in living cells. Its physiological function is to act as an essential cofactor for ATP production, and to perform important antioxidant activities in the body. In most countries, CoQ10 has been widely used as a dietary supplement for more than 20 years. Recently, the use of CoQ10 as a dietary supplement has grown with a corresponding increase in daily dosage. The present review describes the safety profile of CoQ10 on the basis of animal and human data. The published reports concerning safety studies indicate that CoQ10 has low toxicity and does not induce serious adverse effects in humans. The acceptable daily intake (ADI) is 12mg/kg/day, calculated from the no-observed-adverse-effect level (NOAEL) of 1200 mg/kg/day derived from a 52-week chronic toxicity study in rats, i.e., 720 mg/day for a person weighing 60 kg. Risk assessment for CoQ10 based on various clinical trial data indicates that the observed safety level (OSL) for CoQ10 is 1200 mg/day/person. Evidence from pharmacokinetic studies suggest that exogenous CoQ10 does not influence the biosynthesis of endogenous CoQ9/CoQ10 nor does it accumulate into plasma or tissues after cessation of supplementation. Overall, these data from preclinical and clinical studies indicate that CoQ10 is highly safe for use as a dietary supplement. Additionally, analysis of CoQ10 bioavailability or its pharmacokinetics provides the pertinent safety evaluation for CoQ10.

Effects of Pediococcus acidilactici R037 on Serum Triglyceride Levels in Mice and Rats after Oral Administration.

The biological effects of heat-killed Pediococcus acidilactici R037 (R037) were evaluated when orally administered in mice and rats. Oral R037 administration at a daily dose of 10 and 100 mg/kg for 3 wk dose-dependently reduced fasting and non-fasting serum triglyceride concentrations in KK-Ay/TaJcl mice, a model of type II diabetes, obesity, hypercholesterolemia, and hypertriglyceridemia. Serum levels of free fatty acids in the 100 mg/kg group tended to decrease (not statistically significant), and total cholesterol levels remained unchanged. Treatment with R037 resulted in a significant decrease in blood glucose (at 100 mg/kg) and liver weight (at 10 and 100 mg/kg), and a small body weight gain (at 100 mg/kg) as compared to those in control mice. In addition, oral R037 administration at 100, 200, and 400 mg/kg/d for 1 wk dose-dependently suppressed the increase in serum triglyceride levels in Wistar rats after oral fat loading. Moreover, intraduodenal injection of 120 mg of R037 in Wistar rats suppressed gastric vagal nerve activity (GVNA) indicating suppression of intestinal digestion and absorption of food, and suppression of appetite. The R037 injection potentiated epididymal white adipose tissue sympathetic nerve activity (WAT-SNA) and tended to potentiate pancreatic sympathetic nerve activity (PSNA), suggesting that R037 activated lipolysis. Taken together, these findings indicate that R037 lowers serum triglycerides, possibly through suppressing intestinal absorption and potentiating lipolytic pathways. R037 may be useful for primary prevention of coronary artery diseases in subjects with mild or borderline dyslipidemia in combination with lifestyle changes.

Coenzyme Q10 Prevents Senescence and Dysfunction Caused by Oxidative Stress in Vascular Endothelial Cells.

Oxidative damage in endothelial cells is proposed to play an important role in endothelial dysfunction and atherogenesis. We previously reported that the reduced form of coenzyme Q10 (CoQ10H2) effectively inhibits oxidative stress and decelerates senescence in senescence-accelerated mice. Here, we treated human umbilical vein endothelial cells (HUVECs) with H2O2 and investigated the protective effect of CoQ10H2 against senescence, oxidative damage, and reduction in cellular functions. We found that CoQ10H2 markedly reduced the number of senescence-associated ß-galactosidase-positive cells and suppressed the expression of senescence-associated secretory phenotype-associated genes in H2O2-treated HUVECs. Furthermore, CoQ10H2 suppressed the generation of intracellular reactive oxygen species (ROS) but promoted NO production that was accompanied by increased eNOS expression. CoQ10H2 prevented apoptosis and reductions in mitochondrial function and reduced migration and tube formation activity of H2O2-treated cells. The present study indicated that CoQ10H2 protects endothelial cells against senescence by promoting mitochondrial function and thus could delay vascular aging.

Absorption of dietary licorice isoflavan glabridin to blood circulation in rats.

Bioavailability of glabridin was elucidated to show that this compound is one of the active components in the traditional medicine licorice. Using a model of intestinal absorption, Caco-2 cell monolayer, incorporation of glabridin was examined. Glabridin was easily incorporated into the cells and released to the basolateral side at a permeability coefficient of 1.70+/-0.16 cm/s x 10(5). The released glabridin was the aglycone form and not a conjugated form. Then, 10 mg (30 micromol)/kg body weight of standard chemical glabridin and licorice flavonoid oil (LFO) containing 10 mg/kg body weight of glabridin were administered orally to rats, and the blood concentrations of glabridin was determined. Glabridin showed a maximum concentration 1 h after the dose, of 87 nmol/L for standard glabridin and 145 nmol/L for LFO glabridin, and decreased gradually over 24 h after the dose. The level of incorporation into the liver was about 0.43% of the dosed amount 2 h after the dose. These detected glabridins were in the aglycone form and not conjugated forms. The bioavailability was calculated to be AUC(inf) of 0.825 and 1.30 microM.h and elimination T(1/2 )of 8.2 and 8.5 h for standard glabridin and LFO, respectively. Adipocytokine levels were determined in the rats. The secreted amount of monocyte chemoattractant protein-1 was significantly lower in the glabridin group compared to control vehicle group. Thus, dietary glabridin was at least partly incorporated into the body in an unchanged form, though most dietary flavonoids are converted to non-active conjugate forms during intestinal absorption.

Coenzyme Q10 Improves Lipid Metabolism and Ameliorates Obesity by Regulating CaMKII-Mediated PDE4 Inhibition.

Our recent studies revealed that supplementation with the reduced form of coenzyme Q10 (CoQ10H2) inhibits oxidative stress and slows the process of aging in senescence-accelerated mice. CoQ10H2 inhibits adipocyte differentiation and regulates lipid metabolism. In the present study, we show that dietary supplementation with CoQ10H2 significantly reduced white adipose tissue content and improved the function of brown adipose tissue by regulating expression of lipid metabolism-related factors in KKAy mice, a model of obesity and type 2 diabetes. In the liver, CoQ10H2 reduced cytoplasmic Ca2+ levels and consequently inhibited the phosphorylation of CaMKII. CoQ10H2 also regulated the activity of the transcription factor C-FOS and inhibited gene expression of PDE4, a cAMP-degrading enzyme, via the CaMKII-MEK1/2-ERK1/2 signaling pathway, thereby increasing intracellular cAMP. This increased cAMP activated AMPK, enhanced oxidative decomposition of lipids, and inhibited de novo synthesis of fatty acids, inhibiting the development and progression of obesity and type 2 diabetes. These results suggest that CoQ10H2 supplementation may be useful as a treatment for metabolic disorders associated with obesity.

Reduced coenzyme Q10 supplementation decelerates senescence in SAMP1 mice.

The SAMP1 strain is a mouse model for accelerated senescence and severe senile amyloidosis. We determined whether supplementation with coenzyme Q10 (CoQ10) could decelerate aging in SAMP1 mice and its potential role in aging. Plasma concentrations of CoQ10 and CoQ9 decreased with age in SAMP1 but not in SAMR1 mice. Supplementation with reduced CoQ10 (CoQH2, 250 mg/kg/day) for one week increased plasma CoQ10 concentrations, with an accompanying decrease in plasma CoQ9 concentrations. In two series of experiments, lifelong supplementation with CoQH2 decreased the senescence grading scores from 10 to 14 months, 7 to 15 months, and at 17 months of age. The body weight of female mice increased from 2 to 10 months of age versus controls in the second series of experiments. Lifelong CoQH2 supplementation did not prolong or shorten the lifespan, nor did it alter the murine senile amyloid (AApoAII) deposition rate or cancer incidence. In the second series of experiments, urinary levels of 8-hydroxydeoxyguanosine did not change with age or long-term supplementation with CoQH2. Urinary levels of acrolein (ACR)-lysine adduct increased significantly with age in SAMP1 mice; however, CoQH2 had no effect. Thus, lifelong dietary supplementation with CoQH2 decreased the degree of senescence in middle-aged SAMP1 mice.

Enhancement of Fat Oxidation by Licorice Flavonoid Oil in Healthy Humans during Light Exercise.

Licorice flavonoid oil (LFO) is a new functional food ingredient consisting of hydrophobic licorice polyphenols in medium-chain triglycerides. Recent studies reported that LFO prevented and ameliorated diet-induced obesity via the regulation of lipid metabolism-related gene expression in the livers of mice and rats, while it reduced body weight in overweight human subjects by reducing total body fat. However, the direct effects of LFO on energy metabolism have not been studied in human subjects. Therefore, we investigated the effects of ingestion of LFO on energy metabolism, including fat oxidation, by measuring body surface temperature under resting conditions and respiratory gas analysis under exercise conditions in healthy humans. We showed that ingestion of a single 600 mg dose of LFO elevated body trunk skin temperature when measured in a slightly cooled air-conditioned room, and increased oxygen consumption and decreased the respiratory exchange ratio as measured by respiratory gas analysis during 40% Vo2max exercise with a cycle ergometer. Furthermore, repeated ingestion of 300 mg of LFO for 8 d decreased respiratory exchange during the recovery period following 40 min of 30% Vo2max exercise on a treadmill. These results suggest that LFO enhances fat oxidation in humans during light exercise.

Screening of dioxin-like toxicity equivalents for various matrices with wildtype and recombinant rat hepatoma H4IIE cells.

Determination of dioxin-like compounds utilizing in vitro bioassays such as ethoxyresorufin-O-deethylase (EROD) or chemical-activated luciferase expression (DR-CALUX) is an important tool to evaluate their Ah receptor-mediated toxic effects. The aim of this study is to describe advantages and limitations of these bioassays using rat hepatoma (H4IIE) wildtype and recombinant H4IIE cells in a 96 well microtiter plate format. We are using these bioassays for the evaluation of relative responses (REP) from several congeners of dioxins (e.g., 2,3,4,7,8-PCDF) or dioxin-like compounds (PCB-126, 2,3,4,7,8-PBDF) to 2,3,7,8-TCDD. In addition, total toxic equivalency factors (TEFs) of mixtures of these dioxin-like compounds from several kinds of matrices such as feed, sediment, or thermal waste residues are measured by both bioassays and additional chemical analysis. These samples were measured in a cross-validation study between two laboratories using the DR-CALUX technology in comparison to the H4IIE-EROD assay and chemical analysis. Improvement of the quality criteria of the newly developed DR-CALUX bioassays in comparison to the EROD bioassay was demonstrated (higher coefficient of determination r(2); better repeatability of TCDD and samples), while induction factor, limit of detection, and limit of quantification have been similar. The tested samples showed positive responses in both bioassays using different kinetics (EROD: 72 h; DR-CALUX: 24 h). Ratio of measured toxicity equivalent (TEQ) values varied around mean values of 0.89 (comparing both DR-CALUX laboratories, ranging from 0.68-3.1), 2.0 (comparing EROD and DR-CALUX, ranging from 0.57-8.1), and 1.6-2.5 (comparing EROD-TEQ and I-TEQ, mean 1.6, ranging from 1.0-3.9; for DR-CALUX/I-TEQ, 2.5; 0.61-8.3), respectively. This demonstrates that these bioassays can be used as alternative screening technology for monitoring I-TEQ values in various standards and matrices.

Brominated dioxin-like compounds: in vitro assessment in comparison to classical dioxin-like compounds and other polyaromatic compounds.

Recently, several countries agreed to adopt the Stockholm convention on persistent organic pollutants (POPs). One future obligation will be to add other POPs as new evidence becomes available. In vitro cell-based bioassays offer a rapid, sensitive, and relatively inexpensive solution to screen possible POP candidates. In the present study, we investigated the aryl hydrocarbon (Ah)-receptor activity of several dioxin-like POPs by using the Micro-EROD (Ethoxy-Resorufin-O-Deethylase) and DR-CALUX (Dioxin-Responsive-Chemical Activated Luciferase gene eXpression) bioassays, which are two state-of-the-art methods. The Micro-EROD system used in our study utilizes a wild-type rat liver cell line (rat liver H4IIEC3/T cells), while the DR-CALUX bioassay consists of a genetically modified rat hepatoma H4IIE cell line that incorporates the firefly luciferase gene coupled to dioxin-responsive elements (DREs) as a reporter gene. In the case of the DR-CALUX bioassay, we used an exposure time of 24 h, whereas we used a 72-h exposure time in the Micro-EROD bioassay. The aim of this study was to compare conventional dioxin-like POPs (such as polychlorinated dibenzodioxins and -furans, PCDD/Fs and coplanar polychlorinated biphenyls, PCBs) with several other classes of possible candidates to be added to the current toxicity equivalent factor (TEF) model in the future. Therefore, this study compares in vitro CYP1A1 (Micro-EROD bioassay) and firefly luciferase induction (DR-CALUX bioassay) in several mixed polyhalogenated dibenzodioxins and -furans (PXDD/Fs; X=Br, Cl, or F), alkyl-substituted polyhalogenated dibenzodioxins and -furans (PMCDD/Fs; M=methyl), polyhalogenated biphenyls (PXBs, X=Br, Cl ), polybrominated diphenyl ethers (PBDEs), pentabromophenols (PBPs), and tetrabromobisphenol-A (TBBP-A). We also evaluate congener-specific relative potencies (REPs) and efficacies (% of TCDD(max)) and discuss the dose-response curves of these compounds, as well as the dioxin-like potency of several other Ah-receptor agonists, such as those of the polyaromatic hydrocarbons (PAHs) and polychlorinated naphthalenes (PCNs). The highest REP values were found for several PXDD/F congeners, followed by some coplanar PXBs, trichlorinated PCDD/Fs, PAHs, PBDE-126, 1-6-HxCN, and some brominated flame retardants (TBBP-A). These in vitro investigations indicate that further research is necessary to evaluate more Ah-receptor agonists for dioxin-like potency.

Intra- and interlaboratory calibration of the DR CALUX bioassay for the analysis of dioxins and dioxin-like chemicals in sediments.

In the Fourth National Policy Document on Water Management in The Netherlands, it is defined that in 2003, in addition to the assessment of chemical substances, special guidelines for the assessment of dredged material should be recorded. The assessment of dredged material is based on integrated chemical and biological effect measurements. Among others, the DR CALUX (dioxin responsive-chemically activated luciferase expression) bioassay has tentatively been recommended for inclusion in the dredged material assessment. To ensure the reliability of this bioassay, an intra- and interlaboratory validation study, or ring test, was performed, organized by the Dutch National Institute for Coastal and Marine Management (RIKZ) in cooperation with BioDetection Systems BV (BDS). The intralaboratory repeatability and reproducibility and the limit of detection (LOD) and quantification (LOQ) of the DR CALUX bioassay were determined by analyzing sediment extracts and dimethyl sulfoxide (DMSO) blanks. The highest observed repeatability was found to be 24.1%, whereas the highest observed reproducibility was calculated to be 19.9%. Based on the obtained results, the LOD and LOQ to be applied for the bioassay are 0.3 and 1.0 pM, respectively. The interlaboratory calibration study was divided into three phases, starting with analyzing pure chemicals. During the second phase, sediment extracts were analyzed, whereas in the third phase, whole sediments had to be extracted, cleaned, and analyzed. The average interlaboratory repeatability increased from 14.6% for the analysis of pure compound to 26.1% for the analysis of whole matrix. A similar increase in reproducibility with increasing complexity of handlings was observed with the interlaboratory reproducibility of 6.5% for pure compound and 27.9% for whole matrix. The results of this study are intended as a starting point for implementing the integrated chemical-biological assessment strategy and for systematic monitoring of dredged materials and related materials in the coming years.

Melting and incineration plants of municipal waste. Chemical and biochemical diagnosis of thermal processing samples (emission, residues).

Control of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in emissions and thermal residues from incinerators has been a cause of public concern for more than one decade. Recently, several studies showed that other persistent organic pollutants (POPs) such as coplanar polychlorinated biphenyls (co-PCBs) also have dioxin-like activity and are released from incinerators. Therefore, the present study was aimed at making a risk assessment about dioxin-like activity in extracts of thermal waste residues (e.g. combustion gas; fly ash, slag) from incineration and melting processes in Germany and Japan. For this purpose, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), coplanar polychlorinated biphenyls (co-PCBs), polychlorinated naphthalenes (PCNs) and polyaromatic hydrocarbons (PAHs) were analyzed by chemical analysis. Additionally, 2, 3, 7, 8-TCDD equivalents (EROD-TEQs) were determined by in vitro Micro-EROD bioassay using rat H4IIE hepatoma cells. EROD-TEQs could be correlated to I-TEQ values (from PCDD/Fs/co-PCBs) analyzed by chemical analysis resulting in a maximal sixfold higher estimate. Our study indicates minor influences of co-PCBs, PAHs and PCNs to the sum of dioxin-like toxicity in the extracts of thermal waste residues as determined here. Furthermore, we showed that the levels of dioxins and co-PCBs contained in slag from melting processes and bottom ashes from incineration processes were lower by 1-2 orders of magnitude than that in fly ash.

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

AIM: The present study was conducted to define the relationship between the anti-aging effect of ubiquinol-10 supplementation and mitochondrial activation in senescence-accelerated mouse prone 1 (SAMP1) mice. RESULTS: Here, we report that dietary supplementation with ubiquinol-10 prevents age-related decreases in the expression of sirtuin gene family members, which results in the activation of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a major factor that controls mitochondrial biogenesis and respiration, as well as superoxide dismutase 2 (SOD2) and isocitrate dehydrogenase 2 (IDH2), which are major mitochondrial antioxidant enzymes. Ubiquinol-10 supplementation can also increase mitochondrial complex I activity and decrease levels of oxidative stress markers, including protein carbonyls, apurinic/apyrimidinic sites, malondialdehydes, and increase the reduced glutathione/oxidized glutathione ratio. Furthermore, ubiquinol-10 may activate Sirt1 and PGC-1α by increasing cyclic adenosine monophosphate (cAMP) levels that, in turn, activate cAMP response element-binding protein (CREB) and AMP-activated protein kinase (AMPK). INNOVATION AND CONCLUSION: These results show that ubiquinol-10 may enhance mitochondrial activity by increasing levels of SIRT1, PGC-1α, and SIRT3 that slow the rate of age-related hearing loss and protect against the progression of aging and symptoms of age-related diseases.

Ubiquinol affects the expression of genes involved in PPARα signalling and lipid metabolism without changes in methylation of CpG promoter islands in the liver of mice.

Coenzyme Q(10) is an essential cofactor in the respiratory chain and serves as a potent antioxidant in biological membranes. Recent studies in vitro and in vivo provide evidence that Coenzyme Q(10) is involved in inflammatory processes and lipid metabolism via gene expression. To study these effects at the epigenomic level, C57BL6J mice were supplemented for one week with reduced Coenzyme Q(10) (ubiquinol). Afterwards, gene expression signatures and DNA promoter methylation patterns of selected genes were analysed. Genome-wide transcript profiling in the liver identified 1112 up-regulated and 571 down-regulated transcripts as differentially regulated between ubiquinol-treated and control animals. Text mining and GeneOntology analysis revealed that the "top 20" ubiquinol-regulated genes play a role in lipid metabolism and are functionally connected by the PPARα signalling pathway. With regard to the ubiquinol-induced changes in gene expression of about +3.14-fold (p≤0.05), +2.18-fold (p≤0.01), and -2.13-fold (p≤0.05) for ABCA1, ACYP1, and ACSL1 genes, respectively, hepatic DNA methylation analysis of 282 (sense orientation) and 271 (antisense) CpG units in the respective promoter islands revealed no significant effect of ubiquinol. In conclusion, ubiquinol affects the expression of genes involved in PPARα signalling and lipid metabolism without changing the promoter DNA methylation status in the liver of mice.

Inhibition by licorice flavonoid oil of glutathione S-transferase-positive foci in the medium-term rat hepatocarcinogenesis bioassay.

Licorice flavonoid oil (LFO) is a new functional food ingredient consisting of hydrophobic licorice polyphenols in medium-chain triglycerides. Recently, it was reported that licorice and its derivatives have anticarcinogenic activity in some types of tumors. However, the anticarcinogenic activity has not been identified in the liver, which is a major target organ for carcinogenesis in human. Therefore, we hypothesized that LFO has antihepatocarcinogenic activity, and we tested this hypothesis using the rat medium-term liver bioassay for carcinogens. Six-week-old male F344 rats (15 animals/group) received N-diethylnitrosamine (200 mg/kg by intraperitoneal injection) to initiate carcinogenesis. From the second week after initiation, animals received a 6-week regimen of either LFO concentrate solution (0, 150, 300, or 600 mg/kg) intragastrically or phenobarbital sodium salt in the diet (500 ppm) as a positive control. During the third week after initiation, animals were subjected to a two-thirds partial hepatectomy. During the eighth week of the treatment period, liver samples were taken from animals and examined immunohistochemically for expression of glutathione S-transferase placental form. No increase in the number of glutathione S-transferase placental form-positive liver foci was observed in all LFO groups compared with the negative control (solvent) group, and the number of foci in the 600 mg/kg LFO group was significantly lower than that in the negative control group. These results indicate that LFO concentrate solution has a significant inhibitory effect on liver carcinogenesis at 600 mg/kg.

Supplementation with the reduced form of Coenzyme Q10 decelerates phenotypic characteristics of senescence and induces a peroxisome proliferator-activated receptor-alpha gene expression signature in SAMP1 mice.

Our present study reveals significant decelerating effects on senescence processes in middle-aged SAMP1 mice supplemented for 6 or 14 months with the reduced form (Q(10)H(2), 500 mg/kg BW/day) of coenzyme Q(10) (CoQ(10)). To unravel molecular mechanisms of these CoQ(10) effects, a genome-wide transcript profiling in liver, heart, brain and kidney of SAMP1 mice supplemented with the reduced (Q(10)H(2)) or oxidized form of CoQ(10) (Q(10)) was performed. Liver seems to be the main target tissue of CoQ(10) intervention, followed by kidney, heart and brain. Stringent evaluation of the resulting data revealed that Q(10)H(2) has a stronger impact on gene expression than Q(10), primarily due to differences in the bioavailability. Indeed, Q(10)H(2) supplementation was more effective than Q(10) to increase levels of CoQ(10) in the liver of SAMP1 mice. To identify functional and regulatory connections of the "top 50" (p<0.05) Q(10)H(2)-sensitive transcripts in liver, text mining analysis was used. Hereby, we identified Q(10)H(2)-sensitive genes which are regulated by peroxisome proliferator-activated receptor-alpha and are primarily involved in cholesterol synthesis (e.g. HMGCS1, HMGCL and HMGCR), fat assimilation (FABP5), lipoprotein metabolism (PLTP) and inflammation (STAT-1). These data may explain, at least in part, the decelerating effects on degenerative processes observed in Q(10)H(2)-supplemented SAMP1 mice.

Subchronic oral toxicity of ubiquinol in rats and dogs.

Ubiquinol is the two-electron reduction product of ubiquinone (coenzyme Q(10) or CoQ(10)) and functions as an antioxidant in both mitochondria and lipid membranes. In humans and most mammals, including dogs, the predominant form of coenzyme Q is coenzyme Q(10), whereas the primary form in rodents is coenzyme Q(9) (CoQ(9)). Therefore, the subchronic toxicity of ubiquinol was evaluated and compared in Sprague-Dawley rats and beagle dogs. In the initial rat study, males and females were given ubiquinol at doses of 0, 300, 600, or 1200 mg/kg or ubiquinone at 1200 mg/kg by gavage for 13 weeks. This was followed by the second study, where females were given with doses of 75, 150, 200, or 300 mg/kg/day in order to determine a no observed adverse effect level (NOAEL). In the dog study, the test material was administered to males and females at dose levels of 150, 300, and 600 mg/kg, and ubiquinone was included at 600 mg/kg. Clinical observations, mortality, body weights, food and water consumption, ophthalmoscopy, urinalysis, hematology, blood biochemistry, gross findings, organ weights, and histopathological findings were examined. In both species, determination of plasma and liver ubiquinol concentrations, measured as total coenzyme Q(10), were performed. There were no deaths or test article-related effects in body weight, food consumption, ophthalmology, urinalysis, or hematology in rats. Histopathological examinations revealed test article-related effects on the liver, spleen, and mesenteric lymph node in female rats but not in male rats. In the liver, fine vacuolation of hepatocytes was observed in the ubiquinol groups at 200 mg/kg and above. These changes were judged to be of no toxicological significance because they were not considered to induce cytotoxic changes. Microgranuloma and focal necrosis with accumulation of macrophages were observed in the ubiquinol groups at 300 mg/kg and above. These findings were accompanied by slight increases in blood chemistry enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and lactate dehydrogenase [LDH]), which was suggestive of either potential hepatotoxicity or a normal physiological response to ubiguinol loading. Microgranuloma, and focal necrosis were judged to be only adverse effects induced by test article based on their incidence and pathological characteristics. These changes observed in liver were thought due to uptake of the administered ubiquinol by the liver as an adaptive response to xenobiotics, and the microgranulomas and focal necrosis were considered the results of excessive uptake of ubiquinol, which exceeded the capacity for adaptive response. Based on these findings the NOAEL in rats was conservatively estimated to be 600 mg/kg/day for males and 200 mg/kg/day for females. In dogs, there were no deaths or ubiquinol-related toxicity findings during the administration period. No test article-related effects were observed in body weight, food consumption, ophthalmology, electrocardiogram, urinalysis, hematology, or blood chemistry. Histopathological examination revealed no effects attributable to administration of ubiquinol or ubiquinone in any organs examined. Based on these findings, a NOAEL for ubiquinol in male and female dogs was estimated to be more than 600 mg/kg/day under the conditions of this study.

Study on safety and bioavailability of ubiquinol (Kaneka QH) after single and 4-week multiple oral administration to healthy volunteers.

The safety and bioavailability of ubiquinol (the reduced form of coenzyme Q(10)), a naturally occurring lipid-soluble nutrient, were evaluated for the first time in single-blind, placebo-controlled studies with healthy subjects after administration of a single oral dose of 150 or 300 mg and after oral administration of 90, 150, or 300 mg for 4 weeks. No clinically relevant changes in results of standard laboratory tests, physical examination, vital signs, or ECG induced by ubiquinol were observed in any dosage groups. The C(max) and AUC(0-48 h) derived from the mean plasma ubiquinol concentration-time curves increased non-linearly with dose from 1.88 to 3.19 micro g/ml and from 74.61 to 91.76 micro g h/ml, respectively, after single administration. Trough concentrations had nearly plateaued at levels of 2.61 micro g/ml for 90 mg, 3.66 micro g/ml for 150 mg, and 6.53 micro g/ml for 300 mg at day 14, and increased non-linearly with dose in the 4-week study. In conclusion, following single or multiple-doses of ubiquinol in healthy volunteers, significant absorption of ubiquinol from the gastrointestinal tract was observed, and no safety concerns were noted on standard laboratory tests for safety or on assessment of adverse events for doses of up to 300 mg for up to 2 weeks after treatment completion.