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

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

Coenzyme Q10 prevents RANKL-induced osteoclastogenesis by promoting autophagy via inactivation of the PI3K/AKT/mTOR and MAPK pathways.

Coenzyme Q10 (CoQ10) is a potent antioxidant that is implicated in the inhibition of osteoclastogenesis, but the underlying mechanism has not been determined. We explored the underlying molecular mechanisms involved in this process. RAW264.7 cells received receptor activator of NF-κB ligand (RANKL) and CoQ10, after which the differentiation and viability of osteoclasts were assessed. After the cells were treated with CoQ10 and/or H2O2 and RANKL, the levels of reactive oxygen species (ROS) and proteins involved in the PI3K/AKT/mTOR and MAPK pathways and autophagy were tested. Moreover, after the cells were pretreated with or without inhibitors of the two pathways or with the mitophagy agonist, the levels of autophagy-related proteins and osteoclast markers were measured. CoQ10 significantly decreased the number of TRAP-positive cells and the level of ROS but had no significant impact on cell viability. The relative phosphorylation levels of PI3K, AKT, mTOR, ERK, and p38 were significantly reduced, but the levels of FOXO3/LC3/Beclin1 were significantly augmented. Moreover, the levels of FOXO3/LC3/Beclin1 were significantly increased by the inhibitors and mitophagy agonist, while the levels of osteoclast markers showed the opposite results. Our data showed that CoQ10 prevented RANKL-induced osteoclastogenesis by promoting autophagy via inactivation of the PI3K/AKT/mTOR and MAPK pathways in RAW264.7 cells.

Protective effect of coenzyme Q10 in cyclophosphamide-induced kidney damage in rats.

OBJECTIVE: We aimed to investigate the effect of coenzyme q10 on cyclophosphamide-induced kidney damage in rats. METHODS: A total of 30 female Wistar-Albino rats were utilized to form three groups. In group 1 (control group) (n=10), no drugs were given. In group 2 (cyclophosphamide group) (n=10), 30 mg/kg intraperitoneal cyclophosphamide was administered for 7 days. In group 3 (cyclophosphamide+coenzyme q10 group) (n=10), 30 mg/kg cyclophosphamide and 10 mg/kg coenzyme q10 were given for 7 days via intraperitoneal route. Right kidneys were removed in all groups. Blood malondialdehyde levels and activities of catalase and superoxide dismutase were measured. Histopathological damage was evaluated by examining the slides prepared from kidney tissue using a light microscope. RESULTS: Tissue damage was significantly higher in the cyclophosphamide group than in the cyclophosphamide+coenzyme q10 group (p<0.05). The malondialdehyde levels were significantly higher and the activities of superoxide dismutase and catalase were lower in the cyclophosphamide group than in the cyclophosphamide+coenzyme q10 group (p<0.05). CONCLUSION: Coenzyme q10 may be a good option to prevent cyclophosphamide-induced kidney damage.

The effect of coenzyme Q10 on cryotolerance of in vivo-derived mouse embryos.

OBJECTIVE: Cryopreservation has some adverse effects on embryos including cell metabolism reduction, mitochondria and plasma membrane damage, excess production of 'Reactive Oxygen Species' and damage to DNA. In the present study. In this study we assessed the effect of coenzyme Q10 as an exogenous antioxidant on mouse embryos following cryopreservation. METHODS: We collected mice embryos at the morula stage from uterine horns on the third day of gestation. The morulae were divided into 9 groups (1 control, 2 vehicles and 6 experimental), then vitrified. The culture and/or vitrification media of the experimental groups were supplemented by 10 or 30 µM of CoQ10. After one week, the embryos were warmed and then cultured. After 48 hours of embryo culture, the blastocyst rate, total cell number, viability; and after 72 hours of embryo culture, we assessed the hatching rate. RESULTS: Blastocyst rate and hatching rate were significantly reduced in the groups containing 30 µM CoQ10 supplemented culture media compared to other groups (p<0.05). The hatching rate in the groups containing 10 µM CoQ10 supplemented in both culture and vitrification media was significantly higher than in the other groups (p<0.05). In groups containing 10 µM CoQ10 supplemented culture media, the viability was higher than that in the other groups (p<0.05). CONCLUSIONS: It seems that CoQ10 in a dose-dependent manner is able to improve hatching rate and viability following cryopreservation through its antioxidant and anti-apoptotic properties, and through the production of ATP.

Novel approach over template molecule elimination in molecularly imprinted polymers by using heat activated persulfate.

This study proposes a new alternative for template removal from molecularly imprinted polymers by heat activated persulfate. It is known that trace amounts of template molecule remains in the polymer network after extraction by current methodologies leading to bleeding and incomplete removal of template which could compromise final determination of target analytes especially in trace analysis. A previously developed molecularly imprinted polymer specially designed for Coenzyme Q10 (CoQ10) extraction was employed as a model to test this template elimination approach. This polymer is based on methacrylic acid and ethylene glycol dimethylacrylate as monomers and Coenzyme Q0 as template. This coenzyme has the same quinone group as the CoQ10. Selectivity was analyzed comparing the recovery of CoQ10 and ubichromenol, a CoQ10 related substance. Chemical degradation using heat-activated persulfate allows the elimination of the template molecule with a high level of efficiency, being a simple and ecological methodology, yielding a polymer that exhibits comparable selectivity and imprinting effect with respect to traditional extraction methods.

LEDT and Idebenone treatment modulate autophagy and improve regenerative capacity in the dystrophic muscle through an AMPK-pathway.

PURPOSE: Considering the difficulties and challenges in Duchenne muscular dystrophy (DMD) treatment, such as the adverse effects of glucocorticoids, which are the main medical prescription used by dystrophic patients, new treatment concepts for dystrophic therapy are very necessary. Thus, in this study, we explore the effects of photobiomodulation (PBM; a non-invasive therapy) and Idebenone (IDE) treatment (a potent antioxidant), applied alone or in association, in dystrophic muscle cells and the quadriceps muscle, with special focus on autophagy and regenerative pathways. METHODS: For the in vitro studies, the dystrophic primary muscle cells received 0.5J LEDT and 0.06µM IDE; and for the in vivo studies, the dystrophic quadriceps muscle received 3J LEDT and the mdx mice were treated with 200mg/kg IDE. RESULTS: LEDT and IDE treatment modulate autophagy by increasing autophagy markers (SQSTM1/p62, Beclin and Parkin) and signaling pathways (AMPK and TGF-ß). Concomitantly, the treatments prevented muscle degeneration by reducing the number of IgG-positive fibers and the fibers with a central nucleus; decreasing the fibrotic area; up-regulating the myogenin and MCH-slow levels; and down-regulating the MyoD and MHC-fast levels. CONCLUSION: These results suggest that LEDT and IDE treatments enhance autophagy and prevented muscle degeneration in the dystrophic muscle of the experimental model. These findings illustrate the potential efficacy of LEDT and IDE treatment as an alternative therapy focused on muscle recovery in the dystrophic patient.

Effect of genistein and coenzyme Q10 in oxidative damage and mitochondrial membrane potential in an attenuated type II mucopolysaccharidosis cellular model.

Mucopolysaccharidosis type II (MPS II) is an inborn error of the metabolism resulting from several possible mutations in the gene coding for iduronate-2-sulfatase (IDS), which leads to a great clinical heterogeneity presented by these patients. Many studies demonstrate the involvement of oxidative stress in the pathogenesis of inborn errors of metabolism, and mitochondrial dysfunction and oxidative stress can be related since most of reactive oxygen species come from mitochondria. Cellular models have been used to study different diseases and are useful in biochemical research to investigate them in a new promising way. The aim of this study is to develop a heterozygous cellular model for MPS II and analyze parameters of oxidative stress and mitochondrial dysfunction and investigate the in vitro effect of genistein and coenzyme Q10 on these parameters for a better understanding of the pathophysiology of this disease. The HP18 cells (heterozygous c.261_266del6/c.259_261del3) showed almost null results in the activity of the IDS enzyme and presented accumulation of glycosaminoglycans (GAGs), allowing the characterization of this knockout cellular model by MPS II gene editing. An increase in the production of reactive species was demonstrated (p < .05 compared with WT vehicle group) and genistein at concentrations of 25 and 50 µm decreased in vitro its production (p < .05 compared with HP18 vehicle group), but there was no effect of coenzyme Q10 in this parameter. There was a tendency for lysosomal pH change in HP18 cells in comparison to WT group and none of the antioxidants tested demonstrated any effect on this parameter. There was no increase in the activity of the antioxidant enzymes superoxide dismutase and catalase and oxidative damage to DNA in HP18 cells in comparison to WT group and neither genistein nor coenzyme q10 had any effect on these parameters. Regarding mitochondrial membrane potential, genistein induced mitochondrial depolarization in both concentrations tested (p < .05 compared with HP18 vehicle group and compared with WT vehicle group) and incubation with coenzyme Q10 demonstrated no effect on this parameter. In conclusion, it is hypothesized that our cellular model could be compared with a milder MPS II phenotype, given that the accumulation of GAGs in lysosomes is not as expressive as another cellular model for MPS II presented in the literature. Therefore, it is reasonable to expect that there is no mitochondrial depolarization and no DNA damage, since there is less lysosomal impairment, as well as less redox imbalance.

Coenzyme Q in Thraustochytrium sp. RT2316-16: Effect of the Medium Composition.

Coenzyme Q (CoQ; ubiquinone) is an essential component of the respiratory chain. It is also a potent antioxidant that prevents oxidative damage to DNA, biological membranes, and lipoproteins. CoQ comprises a six-carbon ring with polar substituents that interact with electron acceptors and donors, and a hydrophobic polyisoprenoid chain that allows for its localization in cellular membranes. Human CoQ has 10 isoprenoid units (CoQ10) within the polyisoprenoid chain. Few microorganisms produce CoQ10. This work shows that Thraustochytrium sp. RT2316-16 produces CoQ10 and CoQ9. The CoQ10 content in RT2316-16 depended strongly on the composition of the growth medium and the age of the culture, whereas the CoQ9 content was less variable probably because it served a different function in the cell. Adding p-hydroxybenzoic acid to the culture media positively influenced the CoQ10 content of the cell. The absence of some B vitamins and p-aminobenzoic acid in the culture medium negatively affected the growth of RT2316-16, but reduced the decline in CoQ10 that otherwise occurred during growth. The highest content of CoQ9 and CoQ10 in the biomass were 855 µg g-1 and 10 mg g-1, respectively. The results presented here suggest that the thraustochytrid RT2316-16 can be a potential vehicle for producing CoQ10. Metabolic signals that trigger the synthesis of CoQ10 in RT2316-16 need to be determined for optimizing culture conditions.

Lipid nanoparticles containing coenzyme Q10 for topical applications: An overview of their characterization.

The coenzyme Q10 is a compound widely used in pharmaceutical and cosmetic formulations because it is a potent eliminator of free radicals, giving it antioxidant and anti-aging properties. It is naturally synthesized by the human body, but its production wanes with age, leading to the formation of wrinkles. The efficacy of topical application of the coenzyme to counteract this process is subject to several difficulties, due to its instability in the presence of light, low solubility in water and high lipophilicity. Because of these drawbacks, many studies have been conducted of release systems. Lipid nanoparticles stand out in this sense due to the advantages of skin compatibility, protection of the active ingredient against degradation in the external medium, capacity to increase penetration of that ingredient in the skin, and its controlled and prolonged release. In this context, this article presents a review of the main studies of the coenzyme Q10 encapsulated in lipid nanoparticles for topical use, focusing on the analytic methods used to characterize the systems regarding morphology, zeta potential, release profile, Q10 content, encapsulation efficiency, crystalline organization and structure of the lipid matrix, rheology, antioxidant activity, skin penetration and efficacy, among other aspects. We also describe the main results of the different studies and discuss the critical aspects - the simplest, most reproducible, best, and most relevant - that characterize lipid nanoparticles with encapsulated Q10 for topical use.

Effect of Quinolinic Acid on Behavior, Morphology, and Expression of Inflammatory/oxidative Status in Rats' Striatum: Is Coenzyme Q10 a Good Protector?

Quinolinic acid (QUIN) is a toxic compound with pro-oxidant, pro-inflammatory, and pro-apoptotic actions found at high levels in the central nervous system (CNS) in several pathological conditions. Due to the toxicity of QUIN, it is important to evaluate strategies to protect against the damage caused by this metabolite in the brain. In this context, coenzyme Q10 (CoQ10) is a provitamin present in the mitochondria with a protective role in cells through several mechanisms of action. Based on these, the present study was aimed at evaluating the possible neuroprotective role of CoQ10 against damage caused by QUIN in the striatum of young Wistar rats. Twenty-one-day-old rats underwent a 10-day pretreatment with CoQ10 or saline (control) intraperitoneal injections and on the 30th day of life received QUIN intrastriatal or saline (control) administration. The animals were submitted to behavior tests or euthanized, and the striatum was dissected to neurochemical studies. Results showed that CoQ10 was able to prevent behavioral changes (the open field, object recognition, and pole test tasks) and neurochemical parameters (alteration in the gene expression of IL-1ß, IL-6, SOD, and GPx, as well as in the immunocontent of cytoplasmic Nrf2 and nuclear p-Nf-κß) caused by QUIN. These findings demonstrate the promising therapeutic effects of CoQ10 against QUIN toxicity.

Characterization and bioavailability of a novel coenzyme Q10 nanoemulsion used as an infant formula supplement.

Supplementation with Coenzyme Q10 (CoQ10), in patients with its deficiency, has greater odds of success if the treatment is carried out early with an appropriate formulation. For neonatal CoQ10 deficiency, infant formula supplementation could be an attractive option. However, solid CoQ10 cannot be solubilized or dispersed in milk matrix leading to an inefficient CoQ10 dosage and poor intestinal absorption. We developed and characterized a high-dose CoQ10 oil-in-water (O/W) nanoemulsion suitable to supplement infant formula without modifying its organoleptic characteristics. CoQ10 powder and soy lecithin were solubilized in an oil phase consisted of Labrasol® and LabrafacTM. The aqueous phase was Tween 80, TPGS, methylparaben and propylparaben. O/W nanoemulsion was prepared by adding dropwise the oil phase to the aqueous phase under stirring to a final concentration of CoQ10 9.5 % w/w followed by ultrasonic homogenization. Pharmacotechnical parameters were determined. This formulation resulted to be easily to be dispersed in milk matrix, stable for at least 90 days, with no cytotoxicity in in vitro assays, and higher bioavailability than CoQ10 powder. CoQ10 nanoemulsion supplementation in the infant formula facilitates the individualized administration for the child with accurate dosage, overcome swallowing difficulties and in turn could increase the treatment adherence and efficacy.

Genomic and physiological characterization of Novosphingobium terrae sp. nov., an alphaproteobacterium isolated from Cerrado soil containing a mega-sized chromid.

A novel bacterial strain, designated GeG2T, was isolated from soils of the native Cerrado, a highly biodiverse savanna-like Brazilian biome. 16S rRNA gene analysis of GeG2T revealed high sequence identity (100%) to the alphaproteobacterium Novosphingobium rosa; however, comparisons with N. rosa DSM 7285T showed several distinctive features, prompting a full characterization of the new strain in terms of physiology, morphology, and, ultimately, its genome. GeG2T cells were Gram-stain-negative bacilli, facultatively anaerobic, motile, positive for catalase and oxidase activities, and starch hydrolysis. Strain GeG2T presented planktonic-sessile dimorphism and cell aggregates surrounded by extracellular matrix and nanometric spherical structures were observed, suggesting the production of exopolysaccharides (EPS) and outer membrane vesicles (OMVs). Despite high 16S rDNA identity, strain GeG2T showed 90.38% average nucleotide identity and 42.60% digital DNA-DNA hybridization identity with N. rosa, below species threshold. Whole-genome assembly revealed four circular replicons: a 4.1 Mb chromosome, a 2.7 Mb extrachromosomal megareplicon, and two plasmids (212.7 and 68.6 kb). The megareplicon contains a few core genes and plasmid-type replication/maintenance systems, consistent with its classification as a chromid. Genome annotation shows a vast repertoire of carbohydrate-active enzymes and genes involved in the degradation of aromatic compounds, highlighting the biotechnological potential of the new isolate. Chemotaxonomic features, including polar lipid and fatty acid profiles, as well as physiological, molecular, and whole-genome comparisons showed significant differences between strain GeG2T and N. rosa, indicating that it represents a novel species, for which the name Novosphingobium terrae is proposed. The type strain is GeG2T (= CBMAI 2313T = CBAS 753 T).

Coenzyme Q10 for Diabetes and Cardiovascular Disease: Useful or Useless?

INTRODUCTION: Diabetes mellitus (T2DM) and cardiovascular diseases (CVDs) have become some of the most urgent and prevalent health problems in recent decades, side by side with the growing obesity crisis. The close relationship between T2DM and CVD has become clear: endothelial dysfunction caused by oxidative stress and inflammation resulting from hyperglycaemia are the key factors in the development of vascular complications of T2DM, leading to CVD. Coenzyme Q10 (CoQ10) is a great candidate for the treatment of these diseases, acting precisely at the intersection between T2DM and CVD that is oxidative stress, due to its strong antioxidant activity and fundamental physiological role in mitochondrial bioenergetics. CoQ10 is a biologically active liposoluble compound comprising a quinone group and a side chain of 10 isoprenoid units, which is synthesized endogenously in the body from tyrosine and mevalonic acid. The main biochemical action of CoQ10 is as a cofactor in the electron transport chain that synthesizes adenosine triphosphate (ATP). As most cellular functions depend on an adequate supply of ATP, CoQ10 is essential for the health of virtually all human tissues and organs. CoQ10 supplementation has been used as an intensifier of mitochondrial function and an antioxidant with the aim of palliating or reducing oxidative damage that can worsen the physiological outcome of a wide range of diseases including T2DM and CVDs. CONCLUSION: Although there is not enough evidence to conclude it is effective for different therapeutic indications, CoQ10 supplementation is probably safe and well-tolerated, with few drug interactions and minor side effects. Many valuable advances have been made in the use of CoQ10 in clinical practice for patients with T2DM and a high risk of CVD. However, further research is needed to assess the real safety and benefit to indicate CoQ10 supplementation in patients with T2DM.

Antioxidant Effect of Coenzyme Q10 in the Prevention of Oxidative Stress in Arsenic-Treated CHO-K1 Cells and Possible Participation of Zinc as a Pro-Oxidant Agent.

Oxidative stress is an imbalance between levels of reactive oxygen species (ROS) and antioxidant enzymes. Compounds with antioxidant properties, such as coenzyme Q10 (CoQ10), can reduce cellular imbalance caused by an increase in ROS. CoQ10 participates in modulating redox homeostasis due to its antioxidant activity and its preserving mitochondrial functions. Thus, the present study demonstrated the protective effects of CoQ10 against oxidative stress and cytotoxicity induced by arsenic (As). Antioxidant capacity, formation of hydroperoxides, generation of ROS, and the effect on cellular viability of CoQ10, were investigated to determine the protective effect of CoQ10 against As and pro-oxidant compounds, such as zinc. Cell viability assays showed that CoQ10 is cytoprotective under cellular stress conditions, with potent antioxidant activity, regardless of the concentration tested. Zn, when used at higher concentrations, can increase ROS and show a pro-oxidant effect causing cell damage. The cytotoxic effect observed for As, Zn, or the combination of both could be prevented by CoQ10, without any decrease in its activity at cellular levels when combined with Zn.

Recycling amino acids ensures meiosis and seed development.

Nitrogen (N) nutrition and meiosis demand large amounts of energy and widely affect crop yield. Recently, Yang and colleagues connected both processes by demonstrating that meiosis initiation depends on the electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase (ETF/ETFQO) system, whereas meiotic defects of the etfß mutant can be rescued using N supplementation.

Genome-based reclassification of Azospirillum brasilense Az39 as the type strain of Azospirillum argentinense sp. nov.

Strain Az39T of Azospirillum is a diazotrophic plant growth-promoting bacterium isolated in 1982 from the roots of wheat plants growing in Marcos Juárez, Córdoba, Argentina. It produces indole-3-acetic acid in the presence of l-tryptophan as a precursor, grows at 20-38 °C (optimal 38 °C), and the cells are curved or spiral-shaped, with diameters ranging from 0.5-0.9 to 1.8-2.2 µm. They contain C16 : 0, C18 : 0 and C18 : 1 ω7c/ω6c as the main fatty acids. Phylogenetic analysis of its 16S rRNA gene sequence confirmed that this strain belongs to the genus Azospirillum, showing a close relationship with Azospirillum baldaniorum Sp245T, Azospirillum brasilense Sp7T and Azospirillum formosense CC-Nfb-7T. Housekeeping gene analysis revealed that Az39T, together with five strains of the genus (Az19, REC3, BR 11975, MTCC4035 and MTCC4036), form a cluster apart from A. baldaniorum Sp245T, A. brasilense Sp7T and A. formosense CC-Nfb-7T. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between Az39T and the aforementioned type strains revealed values below 96 %, the circumscription limit for the species delineation (ANI: 95.3, 94.1 and 94.0 %; dDDH: 62.9, 56.3 and 55.6 %). Furthermore, a phylogeny evaluation of the core proteome, including 809 common shared proteins, showed an independent grouping of Az39T, Az19, REC3, BR 11975, MTCC4035 and MTCC4036. The G+C content in the genomic DNA of these six strains varied from 68.3 to 68.5 %. Based on the combined phylogenetic, genomic and phenotypic characterization presented here, we consider that strain Az39T, along with strains Az19, REC3, BR 11975, MTCC4035 and MTCC4036, are members of a new Azospirillum species, for which the name Azospirillum argentinense sp. nov. is proposed. The type strain is Az39T (=LBPCV39T=BR 148428T=CCCT 22.01T).

Coenzyme Q10 and melatonin protect cryopreserved equine sperm against lipoperoxidation.

The objective of the experiment was to evaluate the effect of the addition of different concentrations of the antioxidants Coenzyme Q10 (CoQ10) and melatonin to equine semen freezing diluent, alone or in combination, during the cryopreservation process. Twenty ejaculates (n = 5 stallions) were divided in groups: Control (C, without the addition of antioxidants), melatonin 0.75 mM (MEL1), melatonin 1.5 mM (MEL2), CoQ10 40 µg/mL (Q1), CoQ10 200 µg/mL (Q2), and CoQ10 40 µg/mL+ 0.75 mM melatonin (Q1 +MEL1). Q1 and Q2 groups demonstrated intact plasma membrane and high mitochondrial membrane potential after 30 (M-30) and 60 (M-60) min of incubation compared with the control group (Q1: 64.8 % ± 9.9 %, Q2: 65.2 % ± 10.5 %, C: 55.1 % ± 10.0 %; M-30 and Q1: 63.3 % ± 10.4 %, Q2: 64.6 % ± 10.8 %, C: 53.1 ± 10.6 %; M-60; P < 0.05). Melatonin conferred greater membrane stability at all evaluated times compared with the control group (MEL1: 42.1 % ± 6.0 %; MEL2: 44.0 % ± 6.7 %, C: 35.9 % ± 5.9 %; M-0; MEL1: 40.8 % ± 5.6 %; MEL2: 42.6 % ± 7.2 %, C: 33.1 % ± 6.6 %; M-30 and MEL1: 37.5 % ± 7.4 %; MEL2: 39.1 % ± 7.2 %; C: 31.3 % ± 6.5 %; M-60; P < 0.05). The use of antioxidants alone or in combination resulted in lower levels of lipoperoxidation at all times evaluated compared with in the control group (P < 0.05). In conclusion, CoQ10 and melatonin were effective in the cryopreservation of equine semen by decreasing lipoperoxidation and promoting a higher percentage of spermatozoa with a high mitochondrial potential, total and progressive motility, and prevention of membrane lipid disorder.

Reprint of: Production of Superoxide Radicals and Hydrogen Peroxide by NADH- Ubiquinone Reductase and Ubiquinol-Cytochrome c Reductase from Beef-Heart Mitochondria.

Complex I (NADH-ubiquinone reductase) and Complex III (ubiquinol-cytochrome c reductase) supplemented with NADH generated O2-at maximum rates of 9.8 and 6.5 nmol/min/mg of protein, respectively, while, in the presence of superoxide dismutase, the same systems generated H2O2 at maximum rates of 5.1 and 4.2 nmol/min/mg of protein, respectively. H2O2 was essentially produced by disproportionation of O2-, which constitutes the precursor of H2O2. The effectiveness of the generation of oxygen intermediates by Complex I in the absence of other specific electron acceptors was 0.95 mol of O2- and 0.63 mol of H2O2/mol of NADH. A reduced form of ubiquinone appeared to be responsible for the reduction of O2 to O2-, since (a) ubiquinone constituted the sole common major component of Complexes I and III, (b) H202 generation by Complex I was inhibited by rotenone, and (c) supplementation of Complex I with exogenous ubiquinones increased the rate of H2O2 generation. The efficiency of added quinones as peroxide generators decreased in the order Q1 > Q0 > Q2 > Q6 = Q10, in agreement with the quinone capacity of acting as electron acceptor for Complex I. In the supplemented systems, the exogenous quinone was reduced by Complex I and oxidized nonenzymati- cally by molecular oxygen. Additional evidence for the role of ubiquinone as peroxide generator is provided by the generation of O2- and H2O2 during autoxidation of quinols. In oxygenated buffers, ubiquinol (Q0H2), benzoquinol, duroquinol and menadiol generated O2-with k3 values of 0.1 to 1.4 M-1 s-1 and H2O2 with k4 values of 0.009 to 4.3 m-1·s-1.

Quinolinic Acid Impairs Redox Homeostasis, Bioenergetic, and Cell Signaling in Rat Striatum Slices: Prevention by Coenzyme Q10.

Quinolinic acid (QUIN) is an important agonist of NMDA receptors that are found at high levels in cases of brain injury and neuroinflammation. Therefore, it is necessary to investigate neuroprotection strategies capable of neutralizing the effects of the QUIN on the brain. Coenzyme Q10 (CoQ10) is a provitamin that has an important antioxidant and anti-inflammatory action. This work aims to evaluate the possible neuroprotective effect of CoQ10 against the toxicity caused by QUIN. Striatal slices from 30-day-old Wistar rats were preincubated with CoQ10 25-100 µM for 15 min; then, QUIN 100 µM was added to the incubation medium for 30 min. A dose-response curve was used to select the CoQ10 concentration to be used in the study. Results showed that QUIN caused changes in the production of ROS, nitrite levels, activities of antioxidant enzymes, glutathione content, and damage to proteins and lipids. CoQ10 was able to prevent the effects caused by QUIN, totally or partially, except for damage to proteins. QUIN also altered the activities of electron transport chain complexes and ATP levels, and CoQ10 prevented totally and partially these effects, respectively. CoQ10 prevented the increase in acetylcholinesterase activity, but not the decrease in the activity of Na+,K+-ATPase caused by QUIN. We also observed that QUIN caused changes in the total ERK and phospho-Akt content, and these effects were partially prevented by CoQ10. These findings suggest that CoQ10 may be a promising therapeutic alternative for neuroprotection against QUIN neurotoxicity.