ANTIOXIDATIVE EFFECT OF DIETARY COENZYME Q(10) IN HUMAN BLOOD-PLASMA

The effect of an oral dose of 90 mg/day coenzyme Q(10) on the antioxidative status in 22 healthy young subjects (9 men and 13 women) was investigated before and after induction of an oxidative stress by fish oil supplementation. The levels of oxidised and reduced coenzyme Q(10), alpha-tocopherol, ascorbate, TBARS and the fatty acid composition of phospholipids were determined in plasma. The total amount of plasma enzyme Q(10) increased significantly from 0.7+/-0.1 mu mol/l before supplementation to 1.7+/-0.3 mu mol/l before supplementation while the redox status (reduced CoQ(10)/total CoQ(10)) remained constant, even during a follow-up fish oil supplementation. The level of TBARS decreased during the first 2 weeks of CoQ(10) ingestion while the content of alpha tocopherol increased in the second week and ascorbate did not change. The decrease of TBARS and the presence of the majority of the orally supplemented CoQ(10) in the reduced form in plasma seem to indicate an antioxidative role of CoQ(10) in blood plasma.