Heme oxygenases are enzymes that play a crucial role in breaking down heme, a component of hemoglobin found in red blood cells. They catalyze the conversion of heme into biliverdin, carbon monoxide, and free iron. This process is essential for recycling iron and regulating levels of heme in the body. There are two main types of heme oxygenases: HO-1 and HO-2. HO-1 is inducible and often activated in response to stress, while HO-2 is constitutively expressed in various tissues. Both types contribute to important physiological functions, including antioxidant defense and modulation of inflammation.