is it just an inducer of heme oxygenase-1 expression?
Inflammatory reactions are often associated with hemolysis and consequently with the accumulation of free heme released from oxidized hemoglobin. This results in internalization of the free heme by vascular endothelial cells (ECs), where the iron in the core of the heme structure acts as a potent pro-oxidant to promote EC cytotoxicity.1 The only manner in which ECs can decrease the intracellular levels of free heme is to up-regulate the expression heme oxygenase-1 (HO-1), a stress-responsive enzyme that catalyzes the initial and rate-limiting steps in the oxidative degradation of heme into biliverdin, iron, and carbon monoxide (CO).
