Quasi-vitamins: Ubiquinones Domina Petric, MD
Chemical nature The ubiquinones are a group of tetra-substituted 1,4-benzoquinone derivatives with isoprenoid side chains of variable length. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Ubiquinone (Coenzyme Q10, CoQ10) Cyberlipid.org 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Metabolic functions 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Mitochondrial respiratory chain component The ubiquinones function as electron acceptors for complexes I and II of mitochondrial electron transport chains. They pass electrons from flavoproteins (NADH or succinic dehydrogenases) to the cytochromes via cytochrome b5. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Mitochondrial respiratory chain component Ubiquinones perform this function by undergoing reversible reduction/oxidation to cycle between the 1,4-quinone (oxidized) and 1,4-dihydroxybenzene (reduced) species. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Antioxidant CoQ10 functions beyond the nonelectron transport chain as a membrane bound antioxidant that protects and spares α-tocopherol in subcellular membranes. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Antioxidant Along with α-tocopherol, β-carotene and selenium, CoQ10 has been shown to provide significant protection from lipid peroxidation in animal models. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Antioxidant Administration of CoQ10 has been found to protect against myocardial damage mediated by free-radical mechanisms (ischemia, drug toxicities) in animal models. It has been proposed that CoQ10 plays a major role in the determination of membrane potentials of subcellular membrane systems. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Biosynthesis 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Coenzyme Q10 is synthesized in most tissues. Biosynthesis Coenzyme Q10 is synthesized in most tissues. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Biosynthesis The biosynthetic process derives the isoprenyl side chain from mevalonate, the ring system from tyrosine, the hydroxyl groups from molecular oxygen and the methyl groups from S-adenosylmethionine to produce a 50-carbon polyisoprene chain (containing 10 isoprene units). 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Biosynthesis Biosynthetic rate may decline with age. Because endogenous tissue biosynthesis appears sufficient to support membrane saturation levels, supplementation increases tissue levels above normal in only liver and spleen. Biosynthetic rate may decline with age. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Dietary sources The most important food sources are probably tissues of high cellularity and those rich in mitochrondria such as heart and muscle. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Tissue distribution Coenzyme Q10 is distributed in all membranes in the cell. Relatively great concentrations of CoQ10 are found in the liver, heart, spleen, kidney, pancreas and adrenals. The total CoQ10 pool size in the human adult is estimated to be 0.5–1.5 g. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Tissue ubiquinone levels: Tissue distribution Tissue ubiquinone levels: Increase under the influence of oxidative stress, cold acclimation and thyroid hormone treatment. Decrease with cardiomyopathy, other muscle diseases and aging. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Clinical trials with humans have indicated benefits of supplemental CoQ10 of several types. Health effects 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Neurologic conditions Modest improvements in symptoms were reported from a small, randomized, controlled trial with Parkinson’s disease patients. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
A small, open-label trial reported CoQ10 to reduce headache frequency. Migraine A small, open-label trial reported CoQ10 to reduce headache frequency. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Congestive heart failure A meta-analysis of randomized, controlled trials showed CoQ10 supplements to reduce dyspnea, edema and the frequency of hospitalization. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Hypertension A systematic review of eight randomized, controlled trials suggested that CoQ10 supplementation to decrease systolic pressure by an average of 16 mmHg, and diastolic pressure by an average of 10 mmHg. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Atherosclerosis A randomized, controlled trial found CoQ10 supplementation after myocardial infarction to reduce subsequent myocardial events and cardiac deaths. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Endothelial dysfunction A randomized, controlled trial found CoQ10 supplementation to improve endothelial function of peripheral arteries of dyslipidemic patients with type II diabetes. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Tolerance to cancer chemotherapy A systematic review of six randomized, controlled trials suggested that CoQ10 supplementation provided some protection against cardiac or hepatic toxicity. 13.11.2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.
Literature Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. 13.11.2018