To date, the biological properties and toxicity of biliverdin, bilirubin and its photoisomers have been studied extensively for decades. However, the bioactive properties of bilirubin degradation products, resulting mainly from bilirubin oxidation, have been overlooked. This article discusses the importance of bilirubin oxidized products and their potential implications in hepatocellular function. Previously, biliverdin and bilirubin were the only considered end products of heme catabolism.

Nowadays, however, there is evidence for further degradation these end products to diverse bioactive products. Bilirubin oxidized products (BOX) arise upon oxidation with unknown implications for hepatocellular function and integrity. Clinical Evidence Several studies have investigated the impact of Z-BOX A and B on hepatic functions and explored their alterations in health and cholestatic…