Possible Interaction: NADH and Ubiquinone

“This study aimed to examine whether oral coenzyme Q10 and NADH (reduced form of nicotinamide adenine dinucleotide) co-supplementation could improve perceived fatigue, unrefreshing sleep, and health-related quality of life in ME/CFS patients.”

“By improving the efficiency of shuttle mechanisms that transfer high-energy electrons from the cytoplasm to the mitochondrial respiratory chain, CoQ may decrease cytoplasmic NADH levels and thereby diminish the reductive power that drives superoxide synthesis in endothelium and vascular smooth muscle.”

“Extraction of coenzyme Q from the membrane decreases NADH dehydrogenase and NADH :oxygen oxidoreductase activity.”

“It conserves energy, from the reduction of ubiquinone by NADH , as a protonmotive force across the inner membrane, but the mechanism of energy transduction is not known.”

“The effect of the side chain structure of coenzyme Q suggests that NADH binding to the enzyme results in a conformational change, in the coenzyme Q binding site , which enables the site to accept coenzyme Q with a side chain significantly larger than one isoprenoid unit.”

“The possibility of enhancing the rate of NADH oxidation by CoQ therapy is hindered by the fact that the CoQ concentration in mitochondria appears to be regulated by its mixability with the membrane phospholipids.”

“We have also … experimental evidence that CoQ concentration may be rendered … rate-limiting for NADH oxidation either by a decrease of CoQ content (as in liver regeneration or under an acute oxidative …), or by a possible increase of the Km for CoQ, as in some mitochondrial diseases and ageing.”

“… NADH and DT-diaphorase to … homologs, including CoQ9 and CoQ10 , resulted in essentially complete reduction of the CoQ. Incorporation of either CoQ9H2 or CoQ10H2 and the lipophylic radical generator 2,… MLVs in the presence of DT-diaphorase and NADH maintained the reduced state of CoQ and inhibited lipid peroxidation.”

“The reduction of K3Fe(CN)6 by NADH or NADPH was unaffected, but a slow decrease in the rate of reduction of ubiquinone-1 by NADH was observed.”

“In intact mitochondria and ETP, CoQ 3 inhibits NADH oxidation while leaving succinate oxidation unaffected; the inhibition of NADH oxidation by CoQ 3 is not reversed by serum albumin but is reversed by CoQ 7 , particularly when the membrane has been previously “opened” with deoxycholate.”

“This suggestion is based primarily on the demonstration that partial removal, or incorporation, of UQ limits the activity of both NADH and succinate oxidase.”