Bilirubin as a new antioxidant in melasma

Oxidative stress and its role in the pathogenesis of cutaneous diseases have been widely investigated. However, there are few studies that have solely assessed the contribution of intracellular antioxidants in the etiopathology of melasma. Furthermore, there are convincing reports about antioxidant properties of bilirubin (Bil) and uric acid (UA) in some skin disorders but not melasma.This study aimed to determine serum levels of two major extracellular antioxidants (Bil and UA) levels in patients with melasma and their correlation with the severity and extent of the disease.In this case-control study, the serum levels of bilirubin and uric acid of 50 melasma patients were compared with 50 healthy controls. Moreover, the correlation of serum concentrations of these antioxidants with the extent and severity of the disease were assessed.The serum concentration of Bil was significantly higher in the case group (p < 0.05). Furthermore, serum Bil level had a positive correlation with the extent of the melasma (correlation coefficient, +0.3; p < 0.05). No significant difference was found between the serum concentrations of UA between the study and control group. Neither Bil nor UA had a significant correlation with the severity of the disease.Oxidative stress may play a major role in the etiopathology of melasma and bilirubin, as an antioxidant, could be involved in the process of oxidative stress.