Figure 4.

Heme oxygenase-1 antioxidant products derived from heme degradation. Heme oxyge-nase-1 (HO-1) catabolizes heme degradation into equimolar amounts of carbon monoxide (CO), Fe²⁺ and biliverdin. Biliverdin is converted to bilirubin by biliverdin reductase (BVR). All these products have shown antioxidant, anti-thrombotic and anti-inflammatory properties. In addition, HO-1 induces the production of ferritin, an iron storing protein—reducing the levels of Fe²⁺ which could derive into ROS via Fenton reaction.