Anthralin

Anthralin inhibits the proliferation of keratinocytes (epidermal skin cells), prevents the action of T-cells, and promotes cell differentiation, likely through mitochondrial dysfunction. In addition, the production of free radicals may contribute to its anti-psoriatic effect. In vitro studies demonstrate that anthralin prolongs the prophase component of mitosis for keratinocytes and leukocytes. Prophase is the first step of mitosis, the process separating the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. In vivo studies demonstrate that anthralin blocks DNA synthesis and can increase the release of reactive oxygen species.

Anthralin is believed to normalize the rate of epidermal cell proliferation and keratinization by reducing the mitotic activity of the epidermal hyperplasia in psoriasis.

Anti-proliferative and anti-inflammatory effects of anthralin have been demonstrated on both psoriatic and healthy skin. The anti-proliferative effects of anthralin are thought to be due to a combination of inhibition of DNA synthesis and its strong reducing properties. The effectiveness of anthralin as an anti-psoriatic agent is partly owed to its ability to promote lipid peroxidation and reduce the concentration of endothelial adhesion molecules, which are found to be elevated in psoriatic patients.

Recent studies suggest that its ability to prevent T-lymphocyte activation and normalize keratinocyte differentiation may occur by a direct effect on mitochondria.