Effect of Diclofenac and Potassium Ions on Catalase Activity

The aim of this study was to investigate the type of inhibition of the anti - inflammatory drug diclofenac and potassium ions on the activity of the enzyme catalase in vitro. All experiments in this work were performed at a temperature of 37 °C, which corresponds to normal human body temperature, by the spectrophotometric method at a wavelength of 405 nm. The blank sample contained the substrate hydrogen peroxide (H2O2), catalase, ammonium molybdate and phosphate buffer, and the tested samples in addition to the listed components also contained diclofenac in various concentrations of 0,5065; 1,013; 1,5195; 2,026; 2,5325 and 3,039 mM, as well as a 4,5 mM KCl concentration. Based on the obtained results for the values of kinetic constants Vmax (maximum rate) and KM (Michaelis-Menten constant), obtained by the graphical method, we conclude that diclofenac, as well as potassium ions have a partially competitive type of inhibition on enzyme catalase.