Biliverdin is a porphyrin bile pigment and precursor in the biosynthesis of bilirubin .^1,2It is formedviaoxidative catabolism of heme by heme oxygenase-1 (HO-1) and further reduced to bilirubin by biliverdin reductase. Biliverdin has antioxidant activity in oxygen radical absorbance capacity (ORAC) and Trolox equivalent absorbance capacity (TEAC) assays when used at concentrations greater than 0.5 µM.³

1.Liu, Y., MoËnne-Loccoz, P., Loehr, T.M., et al.Heme oxygenase-1, intermediates in verdoheme formation and the requirement for reduction equivalentsJ. Biol. Chem.272(11)6909-6917(1997) 2.Maines, M.D.The heme oxygenase system: A regulator of second messenger gasesAnnu. Rev. Pharmacol. Toxicol.37517-554(1997) 3.MÖlzer, C., Huber, H., Steyrer, A., et al.In vitro antioxidant capacity and antigenotoxic properties of protoporphyrin and structurally related tetrapyrrolesFree Radic. Res.46(11)1369-1377(2012)