<unk>  is created by the activity of<unk> verdin reductase on<unk> verdin, a green tetrapyrrolic<unk> e pigment that is also a product of heme catabolism.<unk> , when oxidized, reverts to become<unk> verdin once again. This cycle, in addition to the demonstration of the potent antioxidant activity of<unk> , has led to the hypothesis that<unk> 's main physiologic role is as a cellular antioxidant. Consistent with this, animal studies suggest that eliminating<unk>  results in endogenous oxidative stress.<unk> 's antioxidant activity may be particularly important in the<unk> ain, where it prevents excitotoxicity and neuronal death by scavenging superoxide during N-methyl-D-aspartic acid neurotransmission.
Bilirubin
Lumirubin
Bile acid
Uric acid
Lipoprotein
Blood protein
Hemoglobin
Alanine transaminase