The antioxidant effect of ubiquinone and combined therapy on mitochondrial function in blood cells in non-proliferative diabetic retinopathy: A randomized, double-blind, phase IIa, placebo-controlled study.

Objectives: To evaluate the effect of ubiquinone and combined antioxidant therapy on mitochondrial function in non-proliferative diabetic retinopathy (NPDR) in a randomized, double-blind, phase IIa, placebo-controlled, clinical trial. Three groups of 20 patients were formed: Group 1, ubiquinone; Group 2, combined therapy; and Group 3, placebo (one daily dose for 6 months).Methods: Fluidity of the submitochondrial membrane in platelets was determined by examining intensity of fluorescence between the monomer (Im) and excimer (Ie). Hydrolytic activity of the mitochondrial F0F1-ATPase was evaluated with the spectrophotometric method.Results: Normal, baseline submitochondrial membrane fluidity, 0.24 ± 0.01 Ie/Im, was significantly diminished in the three study groups vs. normal values (P < 0.0001); placebo, 0.14 ± 0.01 Ie/Im; ubiquinone, 0.14 ± 0.01 Ie/Im; and combined therapy, 0.13 ± 0.00 Ie/Im. Afterward, it increased significantly (P < 0.0001), the ubiquinone group 0.22 ± 0.01 Ie/Im, combined therapy group...