title: The antipsoriatic drug, anthralin, inhibits protein kinase C--implications for its mechanism of action.
abstract: In psoriatic patients, anthralin is known to attenuate lesional inflammation, but often generates perilesional dermatitis. This phenomenon is well reflected by the contrasting action of anthralin on human leukocytes. The release of reactive oxygen species (ROS) is inhibited by anthralin in phorbol ester-activated leukocytes, whereas anthralin directly induces this cellular response in unstimulated cells. In order to elaborate further the underlying mechanisms, we compared the kinetics of anthralin and different well-characterized stimuli, including the phorbol ester, phorbol-12-myristate-13-acetate, in this test system. Compared with standard stimuli, anthralin only marginally induced the release of ROS from human leukocytes and displayed different kinetics. Protein kinase C (PKC), the major cellular phorbol ester receptor, is considered to be involved in the regulation of this cellular response. Furthermore, its involvement in the pathophysiology of psoriasis has been suggested. Therefore, we also investigated the effects of anthralin on purified PKC. Anthralin was found to inhibit the enzyme activity in a dose-dependent manner but not to display any stimulatory effects. The present results provide first evidence that the therapeutic activity of anthralin, at least in part, might be mediated by inhibition of PKC.
authors.affiliation: Department of Dermatology, University of Köln, Federal Republic of Germany.
authors.forename: L
authors.initials: L
authors.lastname: Hegemann
authors.forename: R
authors.initials: R
authors.lastname: Fruchtmann
authors.forename: L A
authors.initials: LA
authors.lastname: van Rooijen
authors.forename: R
authors.initials: R
authors.lastname: Müller-Peddinghaus
authors.forename: G
authors.initials: G
authors.lastname: Mahrle
mesh_terms: D000818:Animals; D000875:Anthralin / Q000494:pharmacology* / Q000627:therapeutic use; D066298:In Vitro Techniques; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D011565:Psoriasis / Q000188:drug therapy*; D051381:Rats; D011919:Rats, Inbred Strains; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D000875:Anthralin