Antioxidants aid in the prevention of the development of chronic diseases. Common examples include compounds derived specifically from plants, e.g. curcumin from the root of a spice called turmeric, or carnosol, which is obtained from rosemary or sage.
Heme oxygenase 1, also known as HO-1, is an enzyme that catalyzes the degradation of heme and is crucial to the metabolism of hemoglobin – the oxygen-carrying molecule of the blood. HO-1 helps to reduce oxidative stress and therefore possesses anti-inflammatory effects. It is regulated by short DNA sequences known as antioxidant response elements, or ARE’s, which are activated during periods of oxidative stress.
However, other mechanisms of action exist that can also activate HO-1. One such example is polyphenol, a substance found in herbal products. Polyphenols and substances like it can up-regulate the expression of the HO-1 gene and therefore directly induce the desired anti-inflammatory effect.
In an in vitro study in psoriasis patients by Ford AR et al (1), it has been shown that carnosol and curcumin can inhibit the maturation of dendritic cells and suppress the release of proinflammatory cytokines, that is, substances that cause inflammation. In addition, the study showed that the activation of important white blood cells, T-cells in this case, was also inhibited.
Important pro-inflammatory cytokines, such as IL-17, IL-22, and interferon gamma, are inhibited by curcumin. Another publication demonstrating these effects can be found in the work of Campbell NK and colleagues (3).