Abstract
BACKGROUND: Human serum albumin (HSA) is a valuable component of non-enzymatic and endogenous antioxidant mechanisms. The antioxidant activity of HSA can be modulated by ligands, including drugs. Although this is a central topic in the field of oxidation, there is still a lack of information about the protection against the effects of elevated free radical levels. METHODS: The aim of this study was to investigate the antioxidant activity of kanamycin (KAN) and neomycin (NEO) and their effect on the antioxidant potential of HSA using spectroscopic and microcalorimetric techniques. RESULTS: Despite the fact that kanamycin and neomycin interact with HSA, no changes in the secondary structure of the protein have been observed. The analysis of the aminoglycoside antibiotics showed their low antioxidant activity and a synergistic effect of the interaction, probably due to the influence of ligands (KAN, NEO) on the availability of HSA amino acid residues functional groups, such as the free thiol group (Cys-34). CONCLUSIONS: Based on the spectroscopic and microcalorimetric data, both KAN and NEO can be considered modulators of the HSA antioxidant activity.