title: The effect of ubiquinone and combined antioxidant therapy on oxidative stress markers in non-proliferative diabetic retinopathy: A phase IIa, randomized, double-blind, and placebo-controlled study.
abstract: Objective To evaluate the effect of ubiquinone (Coenzyme Q10) and combined antioxidant therapy (CAT) on oxidative stress markers in non-proliferative diabetic retinopathy (NPDR) under clinical management. Study design In a randomized, double-blind, phase IIa, placebo-controlled, clinical trial, three study groups were formed and administered medications as follows: Group 1, Coenzyme Q10; Group 2, CAT; and Group 3, placebo. Methods Serum levels of the products of lipid peroxidation (LPO) and nitrites/nitrates, as markers of oxidative/nitrosative stress, were measured. As antioxidants, the total antioxidant capacity (TAC), catalase activity, and glutathione peroxidase (GPx) activity were measured. Results Baseline serum levels of LPO and nitrites/nitrates were significantly elevated in the three groups vs. healthy group (P < 0.0001), while final levels in the Coenzyme Q10 and CAT groups were decreased vs. normal levels (P < 0.0001). The baseline TAC was consumed in the three groups (P < 0.0001), while final results in the Coenzyme Q10 and CAT groups improved (P < 0.0001). Baseline catalase activity was increased in all groups vs. normal values (P < 0.001), while final levels in the Coenzyme Q10 (P < 0.001) and CAT groups (P < 0.0001) were decreased. GPx behaved similarly to catalase and improved in the final results (P < 0.0001). Discussion Adjunctive antioxidant treatment for 6 months was effective and safe for improving the oxidative stress in NPDR.
authors: a Department of Physiology , Clinical and Experimental Treatment Institute, University Health Sciences Centre, University of Guadalajara,  Mexico (Instituto de Terapéutica Experimental y Clínica, Departamento de Fisiología).
authors: Adolfo Daniel
authors: AD
authors: Rodríguez-Carrizalez
authors: b Department of Ophthalmology , Specialties Hospital of the National Occidental Medical Centre, Mexican Social Security Institute, Mexico (Hospital de Especialidades del Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social).
authors: José Alberto
authors: JA
authors: Castellanos-González
authors: b Department of Ophthalmology , Specialties Hospital of the National Occidental Medical Centre, Mexican Social Security Institute, Mexico (Hospital de Especialidades del Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social).
authors: Esaú César
authors: EC
authors: Martínez-Romero
authors: b Department of Ophthalmology , Specialties Hospital of the National Occidental Medical Centre, Mexican Social Security Institute, Mexico (Hospital de Especialidades del Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social).
authors: Guillermo
authors: G
authors: Miller-Arrevillaga
authors: c University Centre of Exact and Engineering Sciences, University of Guadalajara, Mexico (Centro Universitario de Ciencias Exactas e Ingeniería).
authors: Fermín Paul
authors: FP
authors: Pacheco-Moisés
authors: a Department of Physiology , Clinical and Experimental Treatment Institute, University Health Sciences Centre, University of Guadalajara,  Mexico (Instituto de Terapéutica Experimental y Clínica, Departamento de Fisiología).
authors: Luis Miguel
authors: LM
authors: Román-Pintos
authors: a Department of Physiology , Clinical and Experimental Treatment Institute, University Health Sciences Centre, University of Guadalajara,  Mexico (Instituto de Terapéutica Experimental y Clínica, Departamento de Fisiología).
authors: Alejandra Guillermina
authors: AG
authors: Miranda-Díaz
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D002374:Catalase / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000188:drug therapy* / Q000378:metabolism; D004311:Double-Blind Method; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D014451:Ubiquinone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D014451:Ubiquinone; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; C024989:coenzyme Q10
keywords: Antioxidants; Diabetes mellitus; Diabetic retinopathy; Nitrosative stress; Oxidative stress