Riboflavin compounds show NAD(P)H dependent quinone oxidoreductase-like quinone reducing activity.

NAD(P)H-dependent quinone oxidoreductase (NQO) is an essential enzyme in living organisms and cells protecting them from oxidative stress. NQO reduces coenzyme Q (CoQ) using NAD(P)H as an electron donor. In the present study, we searched for coenzyme Q10 reducing activity from fractions of gel filtration-fractionated rat liver homogenate.

Simultaneous detection of reduced and oxidized forms of coenzyme Q10 in human cerebral spinal fluid as a potential marker of oxidative stress.

The redox balance of coenzyme Q10 in human plasma is a good marker of oxidative stress because the reduced form of coenzyme Q10 (ubiquinol-10) is very sensitive to oxidation and is quantitatively converted to its oxidized form (ubiquinone-10). Here we describe an HPLC method for simultaneous detection of ubiquinol-10 and ubiquinone-10 in human cerebral spinal fluid to meet a recent demand for measuring local oxidative stress. Since the levels of coenzyme Q10 in human cerebral spinal fluid are less than 1/500 of those in human plasma, cerebral spinal fluid extracted with 2-propanol requires concentration for electrochemical detection.

Increased oxidative stress and renal injury in patients with sepsis.

Sepsis remains one of the leading causes of death in intensive care units. The early phase of sepsis is characterized by a massive formation of reactive oxygen and nitrogen species such as superoxide and nitric oxide. However, few comprehensive studies on plasma antioxidants have been reported.

Increased oxidative stress and coenzyme Q10 deficiency in centenarians.

Aging populations are expanding worldwide, and the increasing requirement for nursing care has become a serious problem. Furthermore, successful aging is one of the highest priorities for individuals and societies. Centenarians are an informative cohort to study and inflammation has been found to be a key factor in predicting cognition and physical capabilities.

Oxidative stress and abnormal cholesterol metabolism in patients with post-cardiac arrest syndrome.

Patients with post-cardiac arrest syndrome (PCAS) suffer from whole body ischemia/reperfusion injury similar to that experienced by newborn babies. Increased oxidative stress was confirmed in PCAS patients ( = 40) at the time of hospitalization by a significant increase in the percentage of the oxidized form of coenzyme Q10 in total coenzyme Q10 compared to age-matched healthy controls ( = 55). Tissue oxidative damage in patients was suggested by the significant increase in plasma levels of free fatty acids (FFA) and the significant decrease in polyunsaturated fatty acid contents in total FFA.

Increased oxidative stress in patients with amyotrophic lateral sclerosis and the effect of edaravone administration.

Objectives And Methods: Compared to age-matched healthy controls (n = 55), patients with amyotrophic lateral sclerosis (ALS) (n = 26) showed increased oxidative stress as indicated by a significantly increased percentage of oxidized coenzyme Q10 (%CoQ10) in total plasma coenzyme Q10, a significantly decreased level of plasma uric acid, and a significantly decreased percentage of polyunsaturated fatty acids in total plasma free fatty acids (FFA). Therefore, the efficacy of edaravone, a radical scavenger, in these ALS patients was examined.

Results And Discussion: Among 26 ALS patients, 17 received edaravone (30 mg/day, one to four times a week) for at least 3 months, and 13 continued for 6 months.

Randomized, double-blind, placebo-controlled pilot trial of reduced coenzyme Q10 for Parkinson's disease.

Introduction: Mitochondrial complex I deficiencies have been found in post-mortem brains of patients with Parkinson's disease (PD). Coenzyme Q10 (CoQ10) is the electron acceptor found in complexes I and II, and is a potent antioxidant. A recent trial of the oxidized form of CoQ10 for PD failed to show benefits; however, the reduced form of CoQ10 (ubiquinol-10) has shown better neuroprotective effects in animal models.