Antioxidant properties of aspirin: characterization of the ability of aspirin to inhibit silica-induced lipid peroxidation, DNA damage, NF-KB activation, and TNF-alpha production.
Shi-X; Ding-M; Dong-Z; Chen-F; Ye-J; Wang-S; Leonard-SS; Castranova-V; Vallyathan-V
Mol Cell Biochem 1999 Sep; 199(1):93-102
Electron spin resonance (ESR) was used to investigate the reaction of aspirin toward reactive oxygen species, such as hydroxyl radicals (·OH), superoxide radicals ( O2 - ) and H2O2. The Fenton reaction (Fe(II) + H2O2 ---> FE(III) + -OH + OR) was used as a source of -OH radicals. The results show that aspirin is an efficient -OH radical scavenger with a reaction rate constant of k = 3.6 x 1010 M-1sec-1, which is faster than several well established antioxidants, such as ascorbate, glutathione and cysteine. However, aspirin is not a good scavenger for O2 - or H2O2. Through its antioxidant property, aspirin exhibited a protective effect against silica-induced lipid peroxidation and DNA strand breakage. Aspirin also inhibited the activation of nuclear transcription factor-b induced by silica, lipopolysaccharide or the transition metal, Fe(II), as demonstrated by electrophoretic mobility shift assay. The results show that aspirin functions as an antioxidant via its ability to scavenge -OH radicals. This antioxidant property may explain some of its various physiological and pharmacological actions.
Hydroxylation-reactions; Carcinogenesis; Carcinogenicity; Carcinogens; Silicates; DNA-damage; Antioxidants; Antioxidation; Peroxidases; Medicinal-chemicals; Cancer; Statistical-analysis; Free-radicals
Molecular and Cellular Biochemistry