Cytoprotective role of heme oxygenase-1 and heme degradation derived end products in liver injury

Figure 1 The heme oxygenase enzyme reaction. Heme is enzymatically degraded to yield carbon monoxide, iron and biliverdin (which is converted into bilirubin in a coupled reaction). CO: Carbon monoxide; NADP: Nicotinamide adenine dinucleotide phosphate; NADPH: β-Nicotinamide adenine dinucleotide 2'-phosphate reduced tetrasodium salt.

Figure 2 A variety of stimuli induce heme oxygenase-1 expression, a wide array of hepatotoxic chemicals and conditions conferring an adaptive cytoprotective response. HO-1: Heme oxygenase-1; UV: Ultraviolet.