Application of ABTS method for assessment of radical-binding effect of Creatine monohydrate

Due to its antioxidant properties Creatine exhibits benefits on muscle, bone, and brain function, and can be of great importance for the prevention of the oxidative stress-related diseases. The aim of current study was the investigation of antiradical effect of Creatine monohydrate by the application of ABTS method. The radical-scavenging activity of Creatine monohydrate against methanol solution of ABTS radical was evaluated by measuring the decrease in the absorbance at λ = 744 nm. For the estimation of antiradical effect of the compound examined the following parameters were calculated: radical scavenging activity in [%], IC 50 value; antioxidant power 1/IC 50 , Trolox equivalent activity. Linear relationship between the enhanced radical scavenging activity and decrease of absorbances and of not-bound ABTS-radical with the increase of concentration of Trolox (0.002 mM ÷ 0.75 mM) and Creatine monohydrate (20 mM ÷ 200 mM) has been established. Linearity was characterized by coefficients of linear regression, which were proven to be higher than 0.97. From the experimental results it was observed that Creatine monohydrate (IC 50 = 100.98 mM) exerts antiradical effect, but is less active compared to Trolox (IC 50 = 0.2 mM) due to higher IC 50 value and lower antioxidant power (1/IC 50 , = 0.01) than Trolox (1/IC 50 = 5).