The bile pigment bilirubin is a known antioxidant and is associated with protection from cancer and cardiovascular disease (CVD) when present in too strong concentrations. Unconjugated bilirubin (UCB) might also possess anti-genotoxic potential by preventing oxidative damage to DNA.
Moderately elevated bilirubin levels are found in individuals with Gilbert syndrome and more severe in the hyperbilirubinemic Gunn rat model. This study was therefore aimed to assess the levels of oxidative damage to DNA in Gilbert syndrome subjects and Gunn rats compared tomatched controls.
Seventy-six individuals (age- and sex-matched) were allocated into Gilbert syndrome (UCB >= 17.1 mu mol/L; n - 38) or control groups (UCB = 25 kg/m(2) (1.70 +/- 0.67 vs. 1.38 +/- 0.43 nmol/mmol creatinine, P < 0.05), although this group showed lower UCB levels than normal weight subjects. This study suggests that the disease preventative effect of UCB is unrelated to DNA oxidation/strand breaks in human and animal models of hyperbilirubinaemia. (c)2013 AACR.