Bilirubin as an Antioxidant: Kinetic Studies of the Reaction of Bilirubin with Peroxyl Radicals in Solution, Micelles, and Lipid Bilayers
journal contributionposted on 13.05.2004, 00:00 by Gillian L. Hatfield, L. Ross C. Barclay
Bilirubin (BR) showed very weak antioxidant activity in a nonpolar medium of styrene or cumene in chlorobenzene. In contrast, BR exhibited strong antioxidant activity in polar media such as aqueous lipid bilayers or SDS micelles/methyl linoleate (pH 7.4), where the rate with peroxyl radicals, kinh = 5.0 × 104 M-1 s-1, was comparable to that with vitamin E analogues, Trolox, or PMHC. An electron-transfer mechanism accounts for the effect of the medium on the antioxidant properties of BR.