Background: Catalase is a basic antioxidant enzyme that exits in human organs, mainly in the liver. The liver as a main tissue in the body that plays a substantial role in the catabolism and detoxification of drugs is a target of toxic and carcinogenic effects of many drugs. In the present study, the side effects of an anti-cancer compound of oxali-palladium on the function and structure of liver catalase were investigated.

Materials and Methods: In this experimental study, changes in the enzyme activity were studied by conversion in substrate (hydrogen peroxide) absorption at wavelength of 240 nm, using UV-visible spectroscopy in the absence and presence of different concentrations of oxali-palladium at room temperature. Furthermore, the effect of oxali-palladium on the tertiary structure of catalase was investigated using fluorescence spectroscopy via studying the changes in the intrinsic enzyme emission in the absence and presence of different concentrations of oxali-palladiumat at both room and physiologic temperatures.

Results: Kinetics data showed that the Km value of bovine liver catalase was 26.8 mM. Moreover, in the presence of different concentrations of oxali-palladium‚ the enzyme activity showed a gradual decrease in a dose-dependent manner (p<0.001). Fluorescence data presented changes in the tertiary structure of the enzyme by quenching fluorescence emission‚ that indicated alteration in protein chromophore environment.

Conclusion: It could be concluded that inhibition of catalase enzyme by anticancer drug of oxali-palladium increases the content of reactive oxygen species. Increase in reactive oxygen species values is one of the chief mechanisms of different anticancer drugs.