Anthralin is a leukotriene biosynthesis inhibitor. It inhibits LTB4 omega-oxidation and disrupts mitochondria function. Anthralin is used in the treatment of psoriasis, as a fungicide, in the treatment of ringworm infections and in chronic dermatoses. It accumulates in mitochondria where it interferes with the supply of energy to the cell, probably by the oxidation of dithranol releasing free radicals. This impedes DNA replication and so slows the excessive cell division that occurs in psoriatic plaques. Numerous studies have demonstrated anti-proliferative and anti-inflammatory effects of anthralin on psoriatic and normal skin. It is also used as matrix substance for MALDI-MS (matrix-assisted laser desorption ionization MS).