Heme oxygenase-1: a fundamental guardian against oxidative tissue injuries in acute inflammation.

Free heme contributes as a major threat to the oxidative tissue injuries because it catalyzes the formation of reactive oxygen species. When free heme concentration is increased, it results in the induction of heme oxygenase-1 (HO-1), which then breaks free heme down. As such, HO-1 plays a pivotal role in the protection of tissues from oxidative injuries.