Effect of 5-aminoorotic acid and its gallium (III) complex on the antioxidant activity of rat blood serum

Abstract

Investigating pro-oxidant and antioxidant properties of a potential medication is a matter of importance, particularly in the field of oncology. Gallium(III) salts have anticancer activity. In this investigation, the impact of a new complex of Ga(III), GaAOA, with 5-aminoorotic acid (HAOA) and HAOA itself on the antioxidant activity of rat blood serum was estimated. Aqueous solutions of 10-6, 10-5 and 10-4 M HAOA and GaAOA were left in contact with rat blood serum containing 1 mg/ml proteins. The discoloration of 2,2-Diphenyl-1-picrylhydrazyl (DPPH•, characteristic wavelength of 515 nm) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical-cation (ABTS•+, characteristic wavelength 660 nm) caused by HAOA and GaAOA both in absence and in presence of blood serum was measured and compared with the corresponding discoloration in presence of the blood serum alone. In presence of HAOA and GaAOA the antioxidant activity of the rat blood serum via electron transfer and hydrogen donation increased, the effect being stronger with GaAOA compared to HAOA.