Antioxidant Efficacy of Natural Ubiquinol Compared to Synthetic References – In Vitro Study

There are many studies dealing with the oxidized form (Ubiquinone) of coenzyme Q10, but only a little of its reduced form (Ubiquinol). Two yeast‐based Ubiquinols (UQH 2 _S, Sigma‐Aldrich; UQH 2 _K, Kaneka) were investigated for in vitro antioxidant efficacy compared to synthetic antioxidants. The antioxidant efficacy of UQH2_S and UQH2_K by the 2,2‐diphenyl‐1‐picrylhydrazyl’ (DPPH) assay as well as by the 2,2’‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic) acid’ (ABTS) assay was almost identical (IC50 DPPH/ABTS 0.387/0.226–0.219 mM, respectively). The values were higher (p<0.05) than that of α‐tocopherol, Gallic acid, Butylhydroxyanisole, Butylhydroxytoluene. Ferric Reducing Antioxidant Power’ values for Ubiquinols (0.05–0.3 mM) were higher (p<0.05) than for the other antioxidants, except Gallic acid. According to the Electron paramagnetic resonance assay, the antioxidant activity of α‐tocopherol/UQH 2 _S mixture was higher compared to the individual antioxidant only in specific combinations.